Femoral neck shaft angle width is associated with hip-fracture risk in males but not independently of femoral neck bone density

Objective:

To investigate the specificity of the neck shaft angle (NSA) to predict hip fracture in males.

Methods:

We consecutively studied 228 males without fracture and 38 with hip fracture. A further 49 males with spine fracture were studied to evaluate the specificity of NSA for hip-fracture prediction. Femoral neck (FN) bone mineral density (FN-BMD), NSA, hip axis length and FN diameter (FND) were measured in each subject by dual X-ray absorptiometry. Between-mean differences in the studied variables were tested by the unpaired t-test. The ability of NSA to predict hip fracture was tested by logistic regression.

Results:

Compared with controls, FN-BMD (p < 0.01) was significantly lower in both groups of males with fractures, whereas FND (p < 0.01) and NSA (p = 0.05) were higher only in the hip-fracture group. A significant inverse correlation (p < 0.01) was found between NSA and FN-BMD. By age-, height- and weight-corrected logistic regression, none of the tested geometric parameters, separately considered from FN-BMD, entered the best model to predict spine fracture, whereas NSA (p < 0.03) predicted hip fracture together with age (p < 0.001). When forced into the regression, FN-BMD (p < 0.001) became the only fracture predictor to enter the best model to predict both fracture types.

Conclusion:

NSA is associated with hip-fracture risk in males but is not independent of FN-BMD.

Advances in knowledge:

The lack of ability of NSA to predict hip fracture in males independent of FN-BMD should depend on its inverse correlation with FN-BMD by capturing, as the strongest fracture predictor, some of the effects of NSA on the hip fracture. Conversely, NSA in females does not correlate with FN-BMD but independently predicts hip fractures.Hip fracture is the worst osteoporotic fracture with regard to cost^1,2 and adverse consequences,^3,4 so its prevention by checking for the related fracture risk factors is an important goal. Although low bone mineral density (BMD) is generally recognized as the main risk factor for hip fracture,^5,6 there is growing evidence that other bone characteristics, such as proximal femur geometry (PFG) parameters, are implicated in determining the risk profile for hip fracture.^7,8 This evidence, however, mainly derives from studies carried out in females,^9–13 whereas contradictory results characterize studies carried out in males.^14–20 Authors'' opinions seem to vary widely about the ability of the neck shaft angle (NSA), one of the PFG factors, to predict osteoporotic hip fractures in males,^14–16,21 whereas its association with the risk of hip fracture in females^10,11,14,22 is generally accepted. Gender differences in the hip anatomy²³ have been put forward as a possible explanation for the different relationship of NSA with the hip-fracture risk between genders, whereas geographic and racial differences²⁴ among the examined male populations have been advocated as a possible cause of authors'' discrepancies on the relationship between NSA and the hip-fracture risk in males.This topic is therefore still under debate, and further studies are required to clarify the association of the NSA with hip-fracture risk in males. The authors of the current study contribute to this topic by studying the relationship between NSA and the hip fragility fracture in a sample of white Italian males.     

Hepatic radiofrequency ablation: in vivo and ex vivo comparisons of 15-gauge (G) and 17-G internally cooled electrodes

Objective:

To compare the performance of the 15-G internally cooled electrode with that of the conventional 17-G internally cooled electrode.

Methods:

A total of 40 (20 for each electrode) and 20 ablation zones (10 for each electrode) were made in extracted bovine livers and in in vivo porcine livers, respectively. Technical parameters, three dimensions [long-axis diameter (Dl), vertical-axis diameter (Dv) and short-axis diameter (Ds)], volume and the circularity (Ds/Dl) of the ablation zone were compared.

Results:

The total delivered energy was higher in the 15-G group than in the 17-G group in both ex vivo and in vivo studies (8.78 ± 1.06 vs 7.70 ± 0.98 kcal, p = 0.033; 11.20 ± 1.13 vs 8.49 ± 0.35 kcal, p = 0.001, respectively). The three dimensions of the ablation zone had a tendency to be larger in the 15-G group than in the 17-G group in both studies. The ablation volume was larger in the 15-G group than in the 17-G group in both ex vivo and in vivo studies (29.61 ± 7.10 vs 23.86 ± 3.82 cm³, p = 0.015; 10.26 ± 2.28 vs 7.79 ± 1.68 cm³, p = 0.028, respectively). The circularity of ablation zone was not significantly different in both the studies.

Conclusion:

The size of ablation zone was larger in the 15-G internally cooled electrode than in the 17-G electrode in both ex vivo and in vivo studies.

Advances in knowledge:

Radiofrequency ablation of hepatic tumours using 15-G electrode is useful to create larger ablation zones.Radiofrequency ablation (RFA) is the most widely used local ablation technique for the management of primary and metastatic liver tumours. However, previous studies have reported that RFA showed a relatively higher local tumour progression rate than did hepatic resection.^1,2 One of the most important factors affecting local tumour progression was insufficient tumour-free ablation margin of hepatic parenchyma around the tumour margin.^3–6Several strategies have been developed to obtain sufficient ablation margin. In the aspect of RFA techniques, overlapping technique and combined treatment with transcatheter arterial chemoembolization can be used.^7–9 Another strategy is to use switching monopolar, bipolar or multipolar modes to deliver radiofrequency (RF) energy more efficiently.^10,11 Sufficient ablation margin can also be achieved by more efficient electrodes: internally cooled electrode increases the size of ablation zone by preventing charring around the electrode tip.^12,13 Perfusion electrodes can also enlarge the ablation zone by increasing electrical conductance and thermal conductivity.^14–16The diameter of an electrode is also known to be associated with the size of the ablation zone. Theoretically, as the diameter of an electrode becomes larger, the contact surface of the electrode with the surrounding tissue becomes bigger, thereby increasing the active electric field.^17,18 As a result, an electrode with a larger diameter is likely to create a larger ablation zone. In a previous study, Goldberg et al¹⁷ reported that the extent of coagulation necrosis by RFA increases as the diameter of an electrode increases through an in vivo experimental study. However, this study was performed with an electrode without an internal cooling system. Recently, a clinical study comparing therapeutic efficacy and safety between 15-G and 17-G internally cooled electrodes of RFA for hepatocellular carcinoma was published.¹⁹ According to that study, the 15-G internally cooled electrode created a larger ablation volume than did the 17-G electrode. However, the study was limited by selection bias owing to the retrospective study design. In addition, the ablation protocol was not exactly the same between the two groups. Therefore, the issue whether an internally cooled electrode with a larger diameter creates a larger ablation volume should be verified with ex vivo and in vivo experimental studies.The purpose of this experimental study was to compare the performance of the 15-G internally cooled RF electrode with that of the conventional 17-G electrode in both ex vivo and in vivo studies.     

The challenge of segmental small bowel motility quantitation using MR enterography

Objective:

Analysis of “cine” MRI using segmental regions of interest (ROIs) has become increasingly popular for investigating bowel motility; however, variation in motility in healthy subjects both within and between scans remains poorly described.

Methods:

20 healthy individuals (mean age, 28 years; 14, males) underwent MR enterography to acquire dynamic motility scans in both breath hold (BH) and free breathing (FB) on 2 occasions. Motility data were quantitatively assessed by placing four ROIs per subject in different small bowel segments and applying two measures: (1) contractions per minute (CPM) and (2) Jacobian standard deviation (SD) motility score. Within-scan (between segment) variation was assessed using intraclass correlation (ICC), and repeatability was assessed using Bland–Altman limits of agreement (BA LoA).

Results:

Within-scan segmental variation: BH CPM and Jacobian SD metrics between the four segments demonstrated ICC R = 0.06, p = 0.100 and R = 0.20, p = 0.027 and in FB, the CPM and Jacobian SD metrics demonstrated ICC R = −0.26, p = 0.050 and R = 0.19, p = 0.030. Repeatability: BH CPM for matched segments ranged between 0 and 14 contractions with BA LoA of ±8.36 and Jacobian SD ranged between 0.09 and 0.51 with LoA of ±0.33. In FB data, CPM ranged between 0 and 10 contractions with BA LoA of ±7.25 and Jacobian SD ranged between 0.16 and 0.63 with LoA = ±0.28.

Conclusion:

The MRI-quantified small bowel motility in normal subjects demonstrates wide intersegmental variation and relatively poor repeatability over time.

Advances in knowledge:

This article presents baseline values for healthy individuals of within- and between-scan motility that are essential for understanding how this process changes in disease.Dynamic “cine” MRI acquired during MR enterography is increasingly utilized to assess bowel motility in a range of conditions, notably inflammatory bowel disease and enteric dysmotility syndromes.^1–4 Analysis of the data remains primarily subjective in clinical routine, but the ability to apply quantitative techniques makes this a potentially powerful methodology to explore gastrointestinal physiology in disease as well as an emerging application as a biomarker for drug efficacy.^5–7Despite the growing literature, a consensus has yet to be reached as to the best method of quantitatively analysing small bowel data and indeed a range of motility metrics are proposed.^2,3,8–12 The most commonly used metric is the change in luminal diameter at a fixed anatomical position through the time series. By tracking bowel diameter, a characteristic curve can be produced with the number of contractions expressed per minute (CPM) to give an intuitive and broadly accepted metric for small bowel motility (SBM).^{2–4,9,11,13–15} To date, several studies have reported a relationship between CPM and dysmotility in disease, either compared with a histopathological standard or “normal” reference bowel loops.^2–4,12 An array of additional metrics derived both from bowel diameter measures and more abstract processing techniques have further been implemented with varying degrees of effectiveness in disease and health.^{2,4,5,8,10,14,16}Although intuitively attractive, the robustness of assessing overall enteric motility using only an isolated loop of bowel has received relatively little attention to date irrespective of the precise metric applied. It is unclear how representative the selected bowel loops are of overall SBM and if normal motility intrinsically differs between bowel segments, for example, between the jejunum and ileum. Furthermore, the repeatability of single loop metrics, even in normal individuals, is not well described, knowledge of which is vital if segmental analysis is to be used to diagnose, guide treatment and monitor enteric pathology.The purpose of this study is to explore segmental variation in SBM in healthy volunteers measured using two commonly reported small bowel metrics [CPM and Jacobian standard deviation (SD)] looking at (1) within-scan motility variation between different segments and (2) between-scan variation (repeatability) across two time points.     

Medial temporal lobe atrophy in Alzheimer's disease/mild cognitive impairment with depression

Objective:

Depression is common in patients with Alzheimer''s disease (AD) and mild cognitive impairment (MCI). Patients with depression have an earlier onset and rapid progression of cognitive decline. Medial temporal lobe atrophy (MTA) is common in AD and MCI, and some degree of atrophy is found in almost all patients. In the present study, an attempt was made to know if MTA is more common in patients with AD/MCI with depression than those without it.

Methods:

Patients reporting to the outpatient department of a neurology centre of a tertiary care hospital were recruited for the present study. After initial general physical and neurological examination, they were evaluated using National Institute of Neurological and Communicative Disorders and Stroke and Related Disorders Association criteria for diagnosis of AD. Clinical Dementia rating scale was used for the diagnosis of MCI. Cornell scale for depression in dementia (CSDD) was used.

Results:

We found 20 cases with depression as per CSDD out of a sample of 37 patients (male:female = 30:7). There were 26 patients with AD and 11 with MCI. The mean age of all patients was 72.33 ± 6.45 years. The mean mini mental status examination score was 19.00 ± 6.73. The mean time since diagnosis was 4.19 ± 3.26 years. The mean Scheltens visual rating scale score for right MTA was 2.08 ± 0.95 and was 2.05 ± 0.94 for the left. Both scores did not differ statistically when analyzed using paired t-test (p > 0.05). However, difference in those with depression (2.36 ± 0.95) from those without depression (1.60 ± 0.74) was significant (p < 0.05).

Conclusion:

MTA scores were higher in those with AD/MCI with depression than those without it.Depression¹ is common in patients with Alzheimer''s disease (AD) and mild cognitive impairment (MCI). Relationship between depression and cognitive decline is a complex one, and depression is both an aetiological risk factor² and comorbidity for dementia.³ Incidence and prevalence of depressive symptoms in MCI range from 15% in population-based studies to 44% in hospital-based studies.⁴ Likewise, up to two-thirds of patients with AD have been reported to have depression.⁵ Because in many studies, depression has been seen to be an early manifestation of AD, it has been suggested that it may represent a continuum⁴ from depression to MCI to AD (late-life depression → MCI → AD). Two recent meta-analyses have found that a history of depression approximately doubles an individual''s risk for subsequent dementia in general and AD in particular.⁶ Depression is known to be neurotoxic to medial temporal lobe structures and can contribute to their atrophy.^7–9 Atrophy is more so, when depression is severe or recurrent⁷ and medial temporal lobe atrophy (MTA) has a temporal association with depression.⁹ Continued treatment of depression has been shown to protect the hippocampus from the ill effects of depression.¹⁰ Although volumetric method could be a preferred mode of measuring the hippocampal volume in AD, qualitative rating of MTA is a good alternative.¹¹ Visual rating of the hippocampal volume^12–14 can be carried out using Scheltens et al¹⁵ rating scale that is based on the width of the choroid fissure, the width of the temporal horn and the height of hippocampal formation and is a quantitative scale.     

Obscure gastrointestinal bleeding: diagnostic performance of 64-section multiphase CT enterography and CT angiography compared with capsule endoscopy

Objective:

To compare the diagnostic capabilities between capsule endoscopy (CE) and multislice CT (MSCT) enterography in combination with MSCT angiography for assessment of obscure gastrointestinal bleeding (OGIB).

Methods:

A total of 127 patients with OGIB were looked at in this study. 82 patients (aged 42.7 ± 19.1 years; 34 males) were assigned to receive MSCT diagnosis and 67 patients to (aged 53.9 ± 16.2 years; 28 males) receive CE diagnosis. Among them, 22 patients (aged 54.1 ± 19.1 years; 12 males) received both examinations. Oral isotonic mannitol and intramuscular injection of anisodamine were performed; non-ionic contrast (iopromide, 370 mg I ml⁻¹) was intravenously administered; and then multiphase scanning was conducted at arterial, small intestinal and portal venous phases in MSCT. The results were compared with findings of reference standards including double balloon enteroscopy, digital subtraction angiography, intraoperative pathological examination and/or clinical diagnosis.

Results:

Administration of anisodamine markedly increased the satisfaction rate of bowel filling (94.67% vs 28.57%; p < 0.001) but not the diagnostic yield (p = 0.293) of MSCT. Compared with MSCT, CE showed an improved overall diagnostic yield (68.66% vs 47.56%; p = 0.010), which was also observed in overt bleeding patients (i.e. patients with continued passage of visible blood) (76.19% vs 51.02%; p = 0.013) and in patients aged younger than 40 years of age (85% vs 51.28%; p = 0.024). However, CE had similar positive rates to MSCT (p > 0.05). Among the 22 cases in whom both examinations were conducted, CE showed no significantly different diagnostic capability compared with MSCT (p = 0.4597).

Conclusion:

Both CE and MSCT are safe and effective diagnostic methods for OGIB.

Advances in knowledge:

CE is preferred for overt bleeding or patients aged younger than 40 years. The combined use of CE and MSCT is recommended in OGIB diagnosis.Obscure gastrointestinal bleeding (OGIB), which accounts for approximately 5% of all gastrointestinal haemorrhage cases,¹ is defined as persistent or recurring gastrointestinal bleeding without an obvious aetiology after gastroduodenoscopy and colonoscopy.^2,3 Based on the presence or absence of clinically evident bleeding, OGIB could be divided into occult (no visible blood) and overt (continued passage of visible blood, such as haematemesis, melaena or haematochezia) bleeding.^3,4 OGIB frequently occurs in the small bowel and is caused by small bowel diseases such as intestinal erosions, ulcers, vascular anomaly, gastrointestinal tumours and inflammatory bowel and parasitic diseases.^5,6Multiple diagnostic techniques have been developed to elucidate the causes of OGIB. Among them, two non-invasive technologies, capsule endoscopy (CE) and multislice CT (MSCT) markedly improved the ability to determine the causes of OGIB by allowing the visualization of the gastrointestinal tract.^2,3,6 CE is able to obtain direct visualization of mucosal surface of the entire small intestine.^4,7,8 However, capsule retention remains a major risk of CE diagnosis.^4,9–11 In addition, the visual field restriction limits the value of CE in diagnosis of umbilicate or extraluminal lesions, since the small bowel is difficult to evaluate owing to its large length and tortuous course.^4,10 Conversely, MSCT, including MSCT angiography (MSCTA), MSCT enteroclysis and MSCT enterography (MSCTE), has full capacity to depict the extraintestinal lesions, owing to the combination of the advantages of enteral volume challenge with the ability of cross-sectional imaging.^4,12 Yet, substantial patient radiation exposure is one of the major disadvantages of MSCT diagnosis.^3,13 Careful preparation is also needed before examination.¹⁴ Considering that both CE and MSCT have advantages and disadvantages, a limited number of published data have compared the two diagnostic tools in patients with OGIB.^4,6,15–17 However, most of these studies did not refer to MSCTA, and apparently different results were obtained owing to the advancement of the two technologies. Thus, an updated and comprehensive comparison is required.Hence, we compared the diagnostic capability of MSCTE in combination with MSCTA with CE in patients suffering from OGIB. In this study, MSCTE and MSCTA technologies performed with a 64-slice spiral CT scanner were combined by non-contrast-enhanced scanning after oral administration of a neutral enteric contrast material (isotonic mannitol, 2.5%) and the intramuscular injection of anisodamine to restrain enterocinesia, and the following multiphase scanning at arterial, small intestinal and portal venous phases followed the intravenous infusion of non-ionic iodinated contrast material (iopromide, 370 mg I ml⁻¹). In addition, the influences of the clinical bleeding pattern and age on the diagnostic capability were also investigated.     

Biphasic and monophasic repair: comparative implications for biologically equivalent dose calculations in pulsed dose rate brachytherapy of cervical carcinoma

Objective:

To consider the implications of the use of biphasic rather than monophasic repair in calculations of biologically-equivalent doses for pulsed-dose-rate brachytherapy of cervix carcinoma.

Methods:

Calculations are presented of pulsed-dose-rate (PDR) doses equivalent to former low-dose-rate (LDR) doses, using biphasic vs monophasic repair kinetics, both for cervical carcinoma and for the organ at risk (OAR), namely the rectum. The linear-quadratic modelling calculations included effects due to varying the dose per PDR cycle, the dose reduction factor for the OAR compared with Point A, the repair kinetics and the source strength.

Results:

When using the recommended 1 Gy per hourly PDR cycle, different LDR-equivalent PDR rectal doses were calculated depending on the choice of monophasic or biphasic repair kinetics pertaining to the rodent central nervous and skin systems. These differences virtually disappeared when the dose per hourly cycle was increased to 1.7 Gy. This made the LDR-equivalent PDR doses more robust and independent of the choice of repair kinetics and α/β ratios as a consequence of the described concept of extended equivalence.

Conclusion:

The use of biphasic and monophasic repair kinetics for optimised modelling of the effects on the OAR in PDR brachytherapy suggests that an optimised PDR protocol with the dose per hourly cycle nearest to 1.7 Gy could be used. Hence, the durations of the new PDR treatments would be similar to those of the former LDR treatments and not longer as currently prescribed.

Advances in knowledge:

Modelling calculations indicate that equivalent PDR protocols can be developed which are less dependent on the different α/β ratios and monophasic/biphasic kinetics usually attributed to normal and tumour tissues for treatment of cervical carcinoma.The use of low-dose-rate (LDR) brachytherapy (BT) for cervical cancer is being phased out and replaced by either high-dose-rate (HDR) or pulsed-dose-rate (PDR) BT [1–4]. At the Christie Hospital in Manchester, UK, PDR has been implemented in place of LDR for the BT component of a combined external beam (EB) and BT treatment of cervical carcinoma [4]. The Groupe Europeen de Curietherapie–European Society for Radiotherapy & Oncology (GEC-ESTRO) recommendations [5] were used to calculate the equivalent prescribed doses of PDR BT compared with those of the formerly used LDR-BT protocol [6]. Those guidelines use generic values of linear-quadratic parameters and monophasic repair kinetics. For the organs at risk (OARs), biphasic repair has become a more accurate characterisation of the repair kinetics. This is based on clinical evidence of a slow repair component for skin telangiectasia [7], oral mucosa [8] and subcutaneous fibrosis [9]. There is also more detailed knowledge of the two fast and slow components for clonogenic cells in mouse kidney [10], rat spinal cord paralysis [11], mouse pneumonitis [12,13] and pig skin early reactions [14].PDR BT uses cycles (or pulses) of 0.5–1.0 Gy given usually at 1–1.5-h intervals, and dose distributions using PDR or LDR can be made virtually identical [15]. It was shown that 1 Gy cycles at intervals of 1–3 h (varied among animal studies) resulted in similar biological effects from the same total doses delivered continuously at 0.50–0.75 Gy per hour. Higher doses per cycle and different cycle intervals resulted in deviations from equivalence because of biphasic repair, in particular for late-reacting tissues [16,17]. The therapeutic ratio of PDR vs LDR depends on cycle dose size and interval and tissue repair characteristics [α/β ratios and repair half-times (T_1/2)]. In normal tissues with a T_1/2<0.5-h component, PDR may be more damaging than LDR [18], but the effect should be reduced if the dose per cycle is <1 Gy [16,19].The present study reports calculations of LDR-equivalent PDR doses using biphasic vs monophasic repair kinetics for both the tumour and for the OAR, and the consequent implications.     

Radiographers' professional knowledge regarding parameters and safety issues in plain radiography: a questionnaire survey

Objective:

To review the knowledge of radiographers and examine the possible sociodemographic and situational contributors to this knowledge.

Methods:

A questionnaire survey was devised and distributed to a cohort of 120 radiographers. Each questionnaire contained two sections. In the first section, background data, including sex, age, highest academic level, grade point average (GPA), length of time from graduation, work experience as a radiographer and the status of previous refresher course(s), were collected. The second section contained 17 multiple-choice questions concerning radiographic imaging parameters and safety issues.

Results:

The response rate was 63.8%. In univariate analytic model, higher academic degree (p < 0.001), higher GPA (r² = 0.11; p = 0.001), academic workplace (p = 0.04) and taking previous refresher course(s) (p = 0.01) were significantly associated with higher knowledge score. In multivariate analytic model, however, higher academic degree (B = 1.62; p = 0.01), higher GPA (B = 0.50; p = 0.01) and taking previous refresher course(s) (B = −1.26; p = 0.03) were independently associated with higher level of knowledge. Age, sex, length of time from graduation and work experience were not associated with the respondents'' knowledge score.

Conclusion:

Academic background is a robust indicator of a radiographer''s professional knowledge. Refresher courses and regular knowledge assessments are highly recommended.

Advances in knowledge:

This is the first study in the literature that examines professional knowledge of radiographers in terms of technical and safety issues in plain radiography. Academic degree, GPA and refresher courses are independent predictors of this knowledge. Regular radiographer professional knowledge checks may be recommended.The Joint Commission on Accreditation of Healthcare Organizations mandates “processes that are designed to ensure that the competency of all staff members is assessed, maintained, demonstrated and improved on an ongoing basis.” Tests with practical questions that reflect the knowledge required to perform daily examinations have been proposed as effective tools to attain this purpose. The results enable us to take on existing blemishes and improve the competency.¹Medical imaging, as a field with growing complexity and increasing impact on diagnosis, plans of management and patient health status,² is a good example of raised requirements for competency.^3–8Knowledge assessment may be useful for detecting possible weaknesses in an organization and spotlighting existing educational flaws and shortcomings.⁹ According to some reports, knowledge assessment takes priority over checking competency,^7,10 particularly in professions that are completely mediated by technology.¹¹In addition, although clinical education is the mainstay for developing skills, it has been shown that the combination of practical and theoretical education would lead to a significantly better outcome in the field of teaching. This integrated approach of using both knowledge and practice in education enables the trainee to work more competently and be prepared to take responsibility in his/her future career.¹²Although radiography using film for imaging the internal organs of the body has been introduced for over a century,¹³ it is still among the most widespread and useful imaging modalities all over the world. Radiographers are generally in charge of radiological equipment, imaging examination and frequently nursing care.^7,14,15Incompetent radiographers could render radiographic examinations suboptimal. A poor radiographic technique, in turn, may lead to unnecessary exposures to X-radiation, poor image quality, repeated views and examinations, patient discomfort or further injury because of poor positioning and the possibility of a missed diagnosis or misdiagnosis.¹⁶Furthermore, a rapid shift from conventional to fully digitized radiology departments, along with rapidly evolving changes in healthcare administration¹⁷ entails knowledgeable, up-to-date radiographers who utilize the technology.¹⁸Except for very limited number of studies that have described radiographers'' self-reported competency^7,16 and the level of awareness pertaining to the protection against radiation,^19,20 to the best of our knowledge, there is no study in the literature regarding radiographers'' level of knowledge with a dedicated focus on technical parameters and safety in plain radiography.This study sets out to examine knowledge amongst a cohort of radiographers and to investigate possible association of some sociodemographic and situational factors with the level of this knowledge.     

Whole-body CT-based imaging algorithm for multiple trauma patients: radiation dose and time to diagnosis

Objective:

To determine the number of imaging examinations, radiation dose and the time to complete trauma-related imaging in multiple trauma patients before and after introduction of whole-body CT (WBCT) into early trauma care.

Methods:

120 consecutive patients before and 120 patients after introduction of WBCT into the trauma algorithm of the University Hospital Zurich were compared regarding the number and type of CT, radiography, focused assessment with sonography for trauma (FAST), additional CT examinations (defined as CT of the same body regions after radiography and/or FAST) and the time to complete trauma-related imaging.

Results:

In the WBCT cohort, significantly more patients underwent CT of the head, neck, chest and abdomen (p < 0.001) than in the non-WBCT cohort, whereas the number of radiographic examinations of the cervical spine, chest and pelvis and of FAST examinations were significantly lower (p < 0.001). There were no significant differences between cohorts regarding the number of radiographic examinations of the upper (p = 0.56) and lower extremities (p = 0.30). We found significantly higher effective doses in the WBCT (29.5 mSv) than in the non-WBCT cohort (15.9 mSv; p < 0.001), but fewer additional CT examinations for completing the work-up were needed in the WBCT cohort (p < 0.001). The time to complete trauma-related imaging was significantly shorter in the WBCT (12 min) than in the non-WBCT cohort (75 min; p < 0.001).

Conclusion:

Including WBCT in the initial work-up of trauma patients results in higher radiation doses, but fewer additional CT examinations are needed, and the time for completing trauma-related imaging is shorter.

Advances in knowledge:

WBCT in trauma patients is associated with a high radiation dose of 29.5 mSv.CT represents an important imaging modality in the evaluation of trauma patients and traditionally was performed after an initial evaluation with conventional radiography and sonography. Owing to technical developments, whole-body CT (WBCT) became feasible, which led to its integration into the early work-up of patients.^1–5 A recent retrospective multicentre study suggested that the use of WBCT as the primary imaging modality would significantly increase the probability of survival in patients with multiple trauma compared with an imaging algorithm using radiography, sonography, eventually followed by CT of selected body regions.⁶ Thus, WBCT was recommended by various authors as the primary diagnostic method for trauma patients,^7,8 even when such patients are borderline haemodynamically unstable.^2,9–11However, the true benefit of WBCT remains a matter of debate. A recent systematic review demonstrated that it is still not determined whether the benefit in terms of decreased mortality is a true effect of WBCT or is mediated through changes in the management of trauma patients.¹² Another relevant issue is the associated radiation dose of CT, in particular when employing WBCT.¹² Interestingly, most previous studies did not determine radiation doses of WBCT but rather provided estimates or extrapolations,^6,13–15 and no study, to our knowledge, directly compared radiation doses of patients with multiple trauma undergoing radiography and selected CT with those undergoing WBCT, taking into account the additional CT imaging that was necessary for completing the trauma-related imaging work-up if radiography and sonography were not sufficient.Thus, the purpose of our study was to assess the number of radiological investigations and radiation doses in the initial imaging evaluation of patients with multiple trauma before and after the introduction of WBCT into early trauma care in our hospital. Furthermore, we determined the time from the patients'' admission to the completion of trauma-related diagnostic work-up.     

3-T diffusion tensor imaging (DTI) of normal uterus in young and middle-aged females during the menstrual cycle: evaluation of the cyclic changes of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values

Objective:

To evaluate cyclic changes of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of normal uterus in different age groups during the menstrual cycle, and the correlation with serum female hormone levels.

Methods:

29 normal volunteers accepted diffusion tensor imaging of the uterus on menstrual phase (MP), follicular phase (FP), ovulatory phase (OP) and luteal phase. FA and ADC values of different uterine layers on midsagittal images were measured. Differences between two age groups during the menstrual cycle were evaluated using liner mixed models and one-way analysis of variance. Pearson correlation analysis compared variation of FA and ADC values with serum female hormone levels measured in MP.

Results:

During menstrual cycle, endometrial FA values declined, whereas ADC values increased with significant differences (p < 0.05). Serum oestradiol (E) levels correlated moderately with variations of FA values between MP-FP (p = 0.045; r = 0.389) and MP-OP (p = 0.008; r = 0.511). FA and ADC values of junctional zones showed no significant difference (p > 0.05) as well as FA values of myometrium (p = 0.0961), while ADC values of myometrium showed significant increase from menstrual phase to luteal phase (p < 0.05). FA and ADC values of uterine three zonal structures showed significant differences (p < 0.05) at each phase during the menstrual cycle. No significant difference of FA and ADC values was found between age groups (p > 0.05).

Conclusion:

Dynamic changes of uterine FA and ADC values were observed during menstrual cycle. Variation of FA values between MP-FP, MP-OP correlated moderately with serum E levels.

Advances in knowledge:

No publications on the relationship between FA and ADC values and the female hormone levels were found; our study prospectively investigated the cyclic changes of FA and ADC values of the normal uterus and the correlation with the basic serum female hormone levels in MP.Diffusion tensor imaging (DTI) is a well-established technique, which has been widely used in variable neurological diseases^1–4 and other parts of the body, such as the musculoskeletal system,^5,6 prostate^7,8 and kidney.^9,10In recent years, limited publications of its application in the female pelvis have been emerging. Current published studies include ex vivo and in vivo studies.^11–16 In 2006, three-dimensional fibre architecture of the normal human uterus based on DTI has been ex vivo evaluated in five samples by Weiss et al.¹¹ Toba et al¹² ex vivo study showed that DTI might be a useful tool for the diagnosis of myometrial invasion of uterine endometrial cancer. However, fractional anisotropy (FA) value of a normal uterus has not been thoroughly investigated yet. What is more there is no known publication, to the best of our knowledge, found on the relationship between FA value and female menstrual cycle. It would be ambiguous to use this MR parameter to evaluate malignancy situations without knowing the possible differences in various uterine structures, including endometrium, myometrium and junctional zone. In 2012, Fiocchi et al¹³ investigated the feasibility of depicting fibre architecture of the human uterus in vivo using 3-T MR-DTI based on 30 volunteers in different menstrual phases (MPs). In 2013, Fujimoto et al¹⁴ compared the DTI parameters in the different uterine layers of nine subjects in vivo, but limited their study group to the luteal phase (LP) only. A more comprehensive study based on 11 normal young females was reported by Kido et al;¹⁵ however, only apparent diffusion coefficient (ADC) value changes were evaluated during three phases of menstrual cycle. To the best of our knowledge, there are no published data focused on the cyclic changes of FA value in a normal uterus during four phases of menstrual cycle with a larger study cohort. Moreover, as it has been learned from MRI studies, anatomical and physiological characteristics of uterine structures, such as the endometrium and junctional zone, are heavily related to female hormone levels.^17–22 Nevertheless, no publications on the relationships between FA or ADC values and the hormone level were found.So, the aim of our study was to prospectively investigate the cyclic changes of FA and ADC values of the normal uterus in a larger population divided into different age groups during the four phases of the menstrual cycle, and the correlation with the basic serum hormone levels in MP.     

Diffusion-weighted MRI in the follow-up of chronic periaortitis

Objective:

To evaluate the usefulness of diffusion-weighted MRI (DWI) for the assessment of the intraindividual follow-up in patients with chronic periaortitis (CP) under medication.

Methods:

MRI data of 21 consecutive patients with newly diagnosed untreated disease were retrospectively examined before and after medical therapy, with a median follow-up of 16 weeks. DWI parameters [b800 signal, apparent diffusion coefficient (ADC) values] of the CP and psoas muscle were analysed together with the extent and contrast enhancement. Pre- and post-treatment laboratory inflammation markers were acquired parallel to each MR examination.

Results:

Statistically significant lower b800 signal intensities (p ≤ 0.0001) and higher ADC values (p ≤ 0.0001) were observed after medical treatment within the fibrous periaortic tissue. Extent and contrast enhancement of the CP showed also a statistically significant decrease (p ≤ 0.0001) in the follow-up examinations, while the control parameters within the psoas muscle showed no differences.

Conclusion:

DWI seems to be a useful method for the evaluation of response to treatment without contrast agents. The technique may be helpful in the assessment of disease activity to guide further therapeutic strategies.

Advances in knowledge:

DWI detects significant differences in the intraindividual follow-up of CP under medical therapy.Chronic periaortitis (CP) is a proliferating fibroinflammatory disease of the perivascular retroperitoneal space and aortic wall.^1–4 Owing to adventitial inflammation, some recent theories consider CP as a large vessel vasculitis.⁵ Clinical manifestations of CP include idiopathic retroperitoneal fibrosis, inflammatory aortic aneurysm and perianeurysmal retroperitoneal fibrosis.^2,6,7 The three manifestations with very similar histopathological characteristics are distinguished by the diameter of the abdominal aorta and concomitant ureteral affection.^1,3,7Specific clinical symptoms are caused by extrinsic compression of the ureters or retroperitoneal veins, resulting in hydronephrosis, oliguria, lower extremity oedema and deep vein thrombosis.^1,8Under medical treatment with steroids, CP has a good prognosis.⁷ Today tamoxifen is suggested as a safe and effective therapeutic alternative, and immunosuppressive drugs can be considered in patients with suboptimal responses to these drugs or multiple relapses.^9–11CT and MRI are the modalities of first choice for diagnosis and follow-up of CP.^1,7,12 The fibrotic para-aortic tissue shows significant contrast uptake in gadolinium-enhanced MRI.^12–14 Dynamic contrast-enhanced MRI was suggested for the assessment of the disease activity.^15,16 However, in cases with impaired renal function (e.g. by ureteral compression), gadolinium-independent imaging methods should be preferred owing to the potential development of a nephrogenic systemic fibrosis.¹⁷Diffusion-weighted MRI (DWI) is a non-contrast MR modality that has been successfully applied for the assessment of retroperitoneal masses, inflammatory abdominal aortic aneurysms and for the differentiation between retroperitoneal fibrosis and malignant retroperitoneal neoplasms.^18–21DWI indicates restricted diffusion of water, for example caused by a high cellularity in malignant disease or active inflammation. The apparent diffusion coefficient (ADC) is a quantitative parameter for the level of restricted diffusion, which is calculated from the signals of different diffusion gradients (b-values).²²In the context of untreated CP diffusion-weighted MRI may detect restricted inflammation as a sign of high cellularity caused by active inflammation.There are no data for the evaluation of intraindividual follow-up and the response to treatment by DWI of CP so far. Therefore, the aim of the present study was to analyse differences in DWI signals during follow-up in patients with CP before and after treatment. In addition, we sought to elucidate the potential of DWI in the therapy monitoring of CP.     

Stage T3a renal cell carcinoma: staging accuracy of CT for sinus fat,perinephric fat or renal vein invasion

Objective:

To study the accuracy of CT for staging T3a (TNM 2009) renal cell carcinoma (RCC).

Methods:

Unenhanced and nephrographic phase CT studies of 117 patients (male:female = 82:35; age range, 21–86 years) with T1–T3a RCC were independently reviewed by 2 readers. The presence of sinus or perinephric fat, or renal vein invasion and tumour characteristics were noted.

Results:

Median (range) tumour size was 5.5 (0.9–19.0) cm; and 46 (39%), 16 (14%) and 55 (47%) tumours were pT1, pT2 and pT3a RCC, respectively. The sensitivity/specificity for sinus fat, perinephric fat and renal vein invasion were 71/79%, 83/76% and 59/93% (Reader 1) and 88/71%, 68/72% and 69/91% (Reader 2) with κ = 0.41, 0.43 and 0.61, respectively. Sinus fat invasion was seen in 47/55 (85%) cases with T3a RCC vs 16/55 (29%) and 33/55 (60%) for perinephric fat and renal vein invasion. Tumour necrosis, irregularity of tumour edge and direct tumour contact with perirenal fascia or sinus fat increased the odds of local invasion [odds ratio (OR), 2.5–3.7; p < 0.05; κ = 0.42–0.61]. Stage T3a tumours were centrally located (OR, 3.9; p = 0.0009).

Conclusion:

Stage T3a RCC was identified with a sensitivity of 59–88% and specificity of 71–93% (κ = 0.41–0.61). Sinus fat invasion was the most common invasive feature.

Advances in knowledge:

Centrally situated renal tumours with an irregular tumour edge, inseparable from sinus structures or the perirenal fascia and CT features of tumour necrosis should alert the reader to the possibility of Stage T3a RCC (OR, 2.5–3.9).Current guidelines¹ recommend nephron-sparing procedures (either partial nephrectomy or ablation) for Stage T1a (<4 cm) renal cell carcinomas (RCCs), but the indications for nephron-sparing procedures are widening.² Successful surgical series have been reported with Stage T1b (<4–7 cm) tumours and even Stage T2 RCCs.³ Central location is not necessarily a barrier to good clinical outcome after partial nephrectomy,³ but nephron-sparing procedures are contraindicated for stage ≥T3a renal cancers.¹ Thus, prior accurate recognition of T3a stage is important, especially with central renal masses, as any pre-operative suspicion of local invasion should contraindicate nephron-sparing surgery or ablation.In the most recent TNM iteration, Stage T1 and T2 tumours are defined by tumour diameter (T1a, ≤4 cm; T1b, 4–7 cm; T2a, 7–10 cm; and T2b, ≥10 cm) and the absence of any local invasion. Stage T3a RCC was redefined to include invasion of either renal sinus or perinephric fat.⁴ Renal vein invasion [main renal vein and/or segmental (muscle-containing) branch invasion], without caval involvement, was downgraded from Stage T3b to Stage T3a, whilst adrenal invasion was upgraded from Stage T3a to Stage T4. Size is not a governing factor with ≥T3a tumours, and some renal masses <7 cm in diameter will be locally advanced. Nearly half of all pT3a RCCs (n = 309/623) in one study were <7 cm in diameter.⁵ Other studies have confirmed the poor prognostic significance of sinus fat or venous invasion in masses <7 cm, with a 4–6 times increased risk of cancer-related death.^6,7 Centrally located masses are more likely to demonstrate local invasion with positive surgical resection margins after partial nephrectomy,^8,9 and unrecognized sinus invasion may explain the recurrence of cancer, and subsequent death from metastatic disease, in some cases of presumed T1 RCCs.⁸However, in previous studies, CT staging has been variably accurate^10–18 for RCCs, and staging inaccuracies, usually understaging, are said to be most common with Stage T3a disease.^12,17 For venous invasion, the specificity and sensitivity have ranged between 58–97% and 32–96%,^10,14–16 and for perinephric infiltration, the figures have been 32–96% and 85–93%,^14–16 respectively. The CT accuracy for sinus fat invasion has not been previously investigated. The primary aim of this study was to define the accuracy of contrast-enhanced CT for identifying any of the three defining features of Stage T3a RCC, that is, sinus or perinephric fat invasion, or renal vein invasion. Secondary study objectives were to identify any tumour characteristics that increase the odds of T3a disease and may be used as accessory CT signs to alert the reader to an increased likelihood of local invasion by RCC.     

Repeatability of quantitative metrics derived from MR diffusion tractography in paediatric patients with epilepsy

Objective:

To quantify the test–retest repeatability of mean diffusivity (MD) and fractional anisotropy (FA) derived from diffusion tensor imaging (DTI) tractography in a cohort of paediatric patients with localization-related epilepsy.

Methods:

30 patients underwent 2 DTI acquisitions [repetition time/echo time (ms), 7000/90; flip, 90°; b-value, 1000 s mm⁻²; voxel (mm), 2 × 2 × 2]. Two observers used Diffusion Toolkit and TrackVis (www.trackvis.org) to segment and analyse the following tracts: corpus callosum, corticospinal tracts, arcuate fasciculi, inferior longitudinal fasciculi and inferior fronto-occipital fasciculi. Mean MD and mean FA were calculated for each tract. Each observer independently analysed one of the DTI data sets for every patient.

Results:

Segmentation identified all tracts in all subjects, except the arcuate fasciculus. There was a highly consistent relationship between repeated observations of MD (r = 0.993; p < 0.0001) and FA (r = 0.990; p < 0.0001). For each tract, coefficients of variation ranged from 0.9% to 2.1% for MD and from 1.5% to 2.8% for FA. The 95% confidence limits (CLs) for change ranged from 2.8% to 6% for MD and from 4.3% to 8.6% for FA. For the arcuate fasciculus, Cohen''s κ for agreement between the observers (identifiable vs not identifiable) was 1.0.

Conclusion:

We quantified the repeatability of two commonly utilized scalar metrics derived from DTI tractography. For an individual patient, changes greater than the repeatability coefficient or 95% CLs for change are unlikely to be related to variability in their measurement.

Advances in knowledge:

Reproducibility of these metrics will aid in the design of future studies and might one day be used to guide management in patients with epilepsy.Epilepsy is a common neurological condition defined by recurrent unprovoked seizures that affects 1% of the population, including 1 in 200 children.^1,2 Unlike in adults, developmental lesions predominate as the source of seizures in children; in particular, focal cortical dysplasia is the most common anatomical substrate for intractable epilepsy in the paediatric population.³ A high proportion of epilepsies occurring in the setting of cortical malformations are pharmacoresistant,⁴ highlighting the importance of alternative management strategies. In appropriately selected patients who fail medical management, surgical resection of the dysplastic cortex can be curative. In such cases, pre-operative identification and complete resection of the structural lesion are important prognostic factors.^5,6 Decision making surrounding the pursuit of invasive alternatives is rarely straightforward, however, and in practice relies heavily on supplementary information provided by novel diagnostic techniques.Although surgical management is an attractive option for many patients with focal seizures, medical therapy continues to be adopted as the “safe” strategy in a significant portion of this population. However, there is good evidence to suggest that ongoing seizures and treatment with antiseizure medication might be associated with progressive alterations in white matter integrity.^7–9 Furthermore, these same ongoing processes can contribute to progressive functional decline.^10,11 As such, the ability to confidently identify progression of network alterations in an individual patient with epilepsy, whether on the basis of ongoing seizure activity, antiseizure medication or both, would be of great value to informed decision making surrounding potential surgical intervention.With the advent of diffusion-weighted imaging (DWI), the microstructural properties of a tissue of interest can be non-invasively probed at a spatial scale that is otherwise unattainable using even the most advanced structural MR techniques. Diffusion tensor imaging (DTI) is a variation on the theme of DWI, which quantifies water motion in three orthogonal dimensions and, therefore, is better able to capture the anisotropic tendencies of diffusion in highly organized tissues, such as cerebral white matter.¹² Numerous scalar metrics can be derived from the tensor; the most commonly referenced are mean diffusivity (MD) and fractional anisotropy (FA). MD provides a measure of overall incoherent motion within a voxel without regard for direction and reflects tissue organization at the cellular level.¹³ Increased MD is a common manifestation of white matter pathology of diverse aetiology.^14–16 By contrast, FA provides a measure of the degree to which a single direction of water motion dominates overall diffusivity in a voxel. As such, FA has been shown to be a relatively robust measure of white matter integrity.^17–21 Diffusion tractography is an extension of DTI in which the directional tendencies of water diffusion are used to create three-dimensional representations of white matter tracts based on their structural coherence.^22,23 In many instances, the functional role of the constructed pathways is at least in part known, which enables assessment of brain parenchymal abnormalities in terms of functional systems.^16,24DTI and diffusion tractography already occupy a prominent place in epilepsy research, and they are increasingly used to guide clinical management of epilepsy patients.^7,25–30 Although preliminary results are promising, a thorough understanding of the test–retest reproducibility of metrics derived from DTI will be crucial to the widespread application of this technique. Such knowledge would inform the design of both cross-sectional and longitudinal studies, including appropriate sample size selection. Furthermore, the clinical utility of such quantitative techniques will be predicated on an understanding of their intrinsic variability at the level of the individual. In particular, an understanding of what represents true difference at the individual level will be required to ascribe significance to changes in these metrics that occur in an individual patient. To date, however, the reproducibility of quantitative metrics derived from tractography has not been widely studied and, in particular, there are very few data from either the paediatric or epilepsy populations.³¹ The goal of this study, therefore, was to measure the repeatability of MD and FA derived from DTI tractography in a cohort of paediatric patients with localization-related epilepsy.     

Assessing and ensuring patient safety during breath-holding for radiotherapy

Objective:

While there is recent interest in using repeated deep inspiratory breath-holds, or prolonged single breath-holds, to improve radiotherapy delivery, breath-holding has risks. There are no published guidelines for monitoring patient safety, and there is little clinical awareness of the pronounced blood pressure rise and the potential for gradual asphyxia that occur during breath-holding. We describe the blood pressure rise during deep inspiratory breath-holding with air and test whether it can be abolished simply by pre-oxygenation and hypocapnia.

Methods:

We measured blood pressure, oxygen saturation (SpO₂) and heart rate in 12 healthy, untrained subjects performing breath-holds.

Results:

Even for deep inspiratory breath-holds with air, the blood pressure rose progressively (e.g. mean systolic pressure rose from 133 ± 5 to 175 ± 8 mmHg at breakpoint, p < 0.005, and in two subjects, it reached 200 mmHg). Pre-oxygenation and hypocapnia prolonged breath-hold duration and prevented the development of asphyxia but failed to abolish the pressure rise. The pressure rise was not a function of breath-hold duration and was not signalled by any fall in heart rate (remaining at resting levels of 72 ± 2 beats per minute).

Conclusion:

Colleagues should be aware of the progressive blood pressure rise during deep inspiratory breath-holding that so far is not easily prevented. In breast cancer patients scheduled for breath-holds, we recommend routine screening for heart, cardiovascular, renal and cerebrovascular disease, routine monitoring of patient blood pressure and SpO₂ during breath-holding and requesting patients to stop if systolic pressure rises consistently >180 mmHg and or SpO₂ falls <94%.

Advances in knowledge:

There is recent interest in using deep inspiratory breath-holds, or prolonged single breath-holding techniques, to improve radiotherapy delivery. But there appears to be no clinical awareness of the risks to patients from breath-holding. We demonstrate the progressive blood pressure rise during deep inspiratory breath-holds with air, which we show cannot be prevented by the simple expedient of pre-oxygenation and hypocapnia. We propose patient screening and safety guidelines for monitoring both blood pressure and SpO₂ during breath-holds and discuss their clinical implications.There is recent clinical interest in using both deep inspiratory breath-holds and techniques for prolonging breath-holding¹ for patients undergoing radiotherapy or imaging,² with up to four radiology articles per week mentioning breath-holding over the past 3 years. In particular, those with left breast cancer may undergo breath-holding to spare the heart from exposure to radiation. Sequentially repeated breath-holds with air of ca. 22 s are generally used,² but prolonged single breath-holds of 3–7 min^1,2 are now feasible.Blood pressure is not routinely reported in such clinical studies for radiotherapy or imaging,^2,3 and we are not aware of any consideration of its implications for patient safety. There appears to be no clinical awareness of the pronounced blood pressure rise (by 40 mmHg or more) that occurs during breath-holding.^1,4–10 In young, otherwise healthy patients, brief periods of such hypertension are well tolerated. Patients requiring radiotherapy and complex imaging are, however, typically from an older age group and frequently have significant coexisting disease. Patients with atheromatous coronary artery plaques, aortic disease or cerebrovascular disease are at particular risk from sudden rises in systemic arterial blood pressure. Myocardial infarction, aortic dissection/rupture and haemorrhagic stroke are all potentially lethal complications in these patients. A systolic blood pressure >180 mmHg is considered a “hypertensive crisis” in current medical practice and is associated with a significant risk of end organ damage.¹¹Whilst multiple breath-holds and prolonged single breath-holding techniques are not yet widely enough used to generate any literature or reporting of serious adverse effects in patients from breath-holding, it is now prudent to consider safety guidelines formally before adverse advents might occur.We therefore describe the blood pressure rise during the clinically used technique of breath-holding with air and have sought a simple, non-pharmacological and non-invasive method of preventing this rise. The conventional explanation is that the rise is caused by hypoxia and hypercapnia (i.e. asphyxia) of breath-holding stimulating systemic (peripheral) chemoreceptors.^12–14 If this is correct, then the rise should be preventable because breath-holding can be easily prolonged with hyperoxia and/or hypocapnia.¹⁵It might be expected that the pronounced blood pressure rise during breath-holding would be signalled, by a corresponding fall in heart rate (owing to baroreflex operation), which might be easier to measure non-invasively than blood pressure. We resolve the long-standing dispute over what happens to the heart rate during simple breath-holding at rest^{1,6–9,16–18} by using the latest techniques for instantaneous heart rate analysis to show that the blood pressure rise is not signalled by any corresponding fall in heart rate.     

Walking on thin ice! Identifying methamphetamine “drug mules” on digital plain radiography

Objective:

The purpose of this study was to retrospectively evaluate the sensitivity, specificity and accuracy of identifying methamphetamine (MA) internal payloads in “drug mules” by plain abdominal digital radiography (DR).

Methods:

The study consisted of 35 individuals suspected of internal MA drug containers. A total of 59 supine digital radiographs were collected. An overall calculation regarding the diagnostic accuracy for all “drug mules” and a specific evaluation concerning the radiological appearance of drug packs as well as the rate of clearance and complications in correlation with the reader''s experience were performed. The gold standard was the presence of secured drug packs in the faeces.

Results:

There were 16 true-positive “drug mules” identified. DR of all drug carriers for Group 1 (forensic imaging experienced readers, n = 2) exhibited a sensitivity of 100%, a mean specificity of 76.3%, positive predictive value (PPV) of 78.5%, negative predictive value (NPV) of 100% and a mean accuracy 87.2%. Group 2 (inexperienced readers, n = 3) showed a lower sensitivity (93.7%), a mean specificity of 86%, a PPV of 86.5%, an NPV of 94.1% and a mean accuracy of 89.5%. The interrater agreement within Group 1 was 0.72 and within Group 2 averaged to 0.79, indicating a fair to very good agreement.

Conclusion:

DR is a valuable screening tool in cases of MA body packers with huge internal payloads being associated with a high diagnostic insecurity. Diagnostic insecurity on plain films may be overcome by low-dose CT as a cross-sectional imaging modality and addressed by improved radiological education in reporting drug carriers on imaging.

Advances in knowledge:

Diagnostic signs (double-condom and halo signs) on digital plain radiography are specific in MA “drug mules”, although DR is associated with high diagnostic insecurity and underreports the total internal payload.For the past decade, significant worldwide manufacturing of amphetamine-type stimulants has been reported to the United Nations Office on Drugs and Crime, Vienna, Austria, with a predominance of methamphetamine (MA) and its derivatives, which are also known as “syabu” or “ice”, throughout East and South East Asia.¹ In this region, the use of this synthetic drug is more prevalent than that of cocaine or heroin, which are more common in relatively developed areas, such as Europe and the USA.² During the course of this development, an increase in the number of drug carriers being intercepted by law enforcement at the borders of Malaysia has been observed. Drug carriers or “drug mules” are generally referred to as a human harbouring internal illicit drug packet(s). Internal body concealment of illegal drugs is one of the methods used to smuggle this illicit drug across the border.^3,4 “Drug mules” are generally known as body packers.^5,6 However, for correct terminology, one should differentiate between the terms body packer, body pusher and body stuffer. A body packer swallows a large amount of specially prepared drug packets to smuggle the packets in their gastrointestinal tract across a national border.^5,6 A body pusher hides a few containers in easily accessible body cavities, such as the rectum or vagina. Body stuffers, including traffickers and users, ingest intentionally small amounts of loosely wrapped drug pellets (typically initially hidden in the mouth), usually immediately before an unexpected encounter with law enforcement.^5–10The generally accepted radiological examination is a plain abdominal radiograph in the supine projection.^4–6 This technique is widely available at a low cost and is a simple method of detecting drug-filled packets within the alimentary tract. Radiation exposure to the patient is relatively moderate. In the literature, the detection rate for drug-filled packets is highly variable, and sensitivities from 58.3% to 90% have been reported.^4,5,11 Hence, plain abdominal radiography is a flawed screening method for identifying “drug mules”. Examining the bowel for foreign bodies, such as drug containers with variable sizes and radiodensities, is problematic, even for an experienced radiologist because the drug-filled packets may have an appearance similar to that of stool and gas and may be superimposed. Specific appearances described in the literature, such as the “double-condom”, “halo” and “rosette” signs, may be diagnostic for drug packages but are not necessarily so.^{4–6,11–13} Other modalities employed worldwide for the identification of body packers include CT, ultrasound, MRI and low-dose linear slit digital radiography (LSDR or LODOX®; Lodox Systems, Johannesburg, South Africa).^4,5,14–18Recent research has mainly concentrated on cocaine and heroin drug trafficking, which occurs predominantly in Western countries.^{3,4,6,7,11,14,19} There is little research on the accuracy of plain abdominal radiography in MA drug carriers, although there has been a significant increase of MA in Asia, accompanied by draconian legal measures in cases of drug trafficking.^1,2 The purpose of this study was to retrospectively evaluate the sensitivity, specificity and accuracy of plain abdominal digital radiography (DRL) for identifying the internal payloads of MA in “drug mules”.     

Lung ischaemia–reperfusion injury in a canine model: dual-energy CT findings with pathophysiological correlation

Objective:

To evaluate dual-energy CT (DECT) findings of pulmonary ischaemic–reperfusion injury (PIRI) and its pathophysiological correlation in the canine model.

Methods:

A PIRI model was established in 11 canines, utilizing closed pectoral balloon occlusion. Two control canines were also included. For the PIRI model, the left pulmonary artery was occluded with a balloon, which was deflated and removed after 2 h. DECT was performed before, during occlusion and at 2, 3 and 4 h thereafter and was utilized to construct pulmonary perfusion maps. Immediately after the CT scan at the fourth hour post reperfusion, the canines were sacrificed, and lung specimens were harvested for pathological analysis. CT findings, pulmonary artery pressure and blood gas results were then analysed.

Results:

Data at every time point were available for 10 animals (experimental group, n = 8; control group, n = 2). Quantitative measurements from DECT pulmonary perfusion maps found iodine attenuation values of the left lung to be the lowest at 2 h post embolization and the highest at 1 h post reperfusion. In the contralateral lung, perfusion values also peaked at 1 h post reperfusion. Continuous hypoxia and acid–based disorders were observed during PIRI, and comprehensive analysis showed physiological changes to be worst at 3 h post reperfusion.

Conclusion:

DECT pulmonary perfusion mapping demonstrated pulmonary perfusion of the bilateral lungs to be the greatest at 1 h post reperfusion. These CT findings corresponded with pathophysiological changes.

Advances in knowledge:

DECT pulmonary perfusion mapping can be used to evaluate lung ischaemia–reperfusion injury.Ischaemia–reperfusion injury (IRI) occurs under a variety of clinical conditions, including lung and/or cardiac transplantation, cardiopulmonary bypass, pulmonary resection, re-expansion pulmonary oedema, shock, cardiopulmonary resuscitation and pulmonary embolism.^1–3 Pulmonary embolism is a common cause of pulmonary IRI (PIRI), and the incidence of pulmonary embolism is increasing^4,5 with a mortality rate of up to 30%.⁶ With timely identification and treatment of pulmonary embolism, mortality rates can be reduced to <10%.⁷ However, reperfusion after treatment for lung ischaemia can also cause serious complications, such as haemorrhage and pulmonary oedema.⁸ Therefore, it is important to understand both the pathophysiological and imaging appearances of pulmonary IRI. Lung transplantation is also a common cause for PIRI following pulmonary arterial occlusion. Currently, the incidence of PIRI following transplantation is estimated at up to 25%. Post transplantation, PIRI can lead to insufficiency of the primary lung graft, delayed graft function, acute or chronic rejection (e.g. pulmonary oedema and acute respiratory failure), and increased early post-operative mortality and graft failure.^9,10CT is currently the predominant modality for the imaging assessment of thoracic disorders, including PIRI. Dual-energy CT (DECT) allows simultaneous acquisition of dual-energy data sets, allowing for decomposition of the scanned entity based on differences in attenuation between air, soft tissue and iodine.¹¹ One application of this principle in pulmonary imaging is the ability to obtain iodine maps demonstrating the distribution of pulmonary perfusion. The use of CT perfusion mapping has been shown to be relatively sensitive and highly specific for the detection of pulmonary emboli.¹²Recent research into PIRI has focused on the pathological and molecular biological mechanisms.^13–16 To date, there are few reports on imaging and pathophysiological findings in PIRI.^17,18 CT perfusion findings in PIRI have also not yet been described. The aim of this study was to assess PIRI imaging and pathophysiological findings in a canine model.     

125I particle implantation combined with chemoradiotherapy to treat advanced pancreatic cancer

Objective:

To evaluate the therapy effects of ¹²⁵I implantation combined with chemoradiotherapy on pancreatic cancer patients.

Methods:

30 patients with Stage III or IV pancreatic cancer were equally divided into two groups (control and treatment group). The patients in the treatment group (nine males, six females) received chemotherapy in the first week and ¹²⁵I implantation in the third week, followed by combined chemoradiotherapy in the fifth week. The patients in the control group (10 males, 5 females) received the same treatment except ¹²⁵I implantation. The therapy in the control group and treatment group was repeated every 4 weeks.

Results:

The median conformal radiotherapy dose in the treatment group (30.62 Gy) was significantly lower than that in the control group (47.86 Gy). The total radiation dose was 88.71 ± 27.39 Gy, and the surface activity was 0.6 mCi in the treatment group. After treatment, the average tumour size decreased both in the treatment group [9.17 cm², 95% confidence interval (CI): 5.60–12.74, p < 0.001] and in the control group (4.54 cm², 95% CI: 2.74–6.35, p < 0.001). The median survival time in the treatment group was 14 months (95% CI: 12.215–14.785) and in the control group was 12 months (95% CI: 10.884–13.116). There was no statistical significance in survival rates between the two groups (χ² = 0.908, p = 0.341).

Conclusion:

¹²⁵I implanted into tumour combined with chemoradiotherapy has higher local control rate of advanced pancreatic cancer than chemoradiotherapy.

Advances in knowledge:

We combined chemoradiotherapy with ¹²⁵I implantation to treat advanced pancreatic cancer and obtained a higher local control rate and better quality of life than when using chemoradiatherapy alone.Pancreatic cancer is currently one of the most intractable cancers with high and continually rising mortality in China.¹ The main risk factors are smoking, age and some genetic disorders, although the primary causes are poorly understood.² Pancreatic cancer causes no early symptoms, so the majority of patients are diagnosed as having advanced cancer with rapid progression when they come to the hospital.³ Thus, patients miss the opportunity for tumour resection when first diagnosed. Even if the cancer is discovered early, only 20% of patients can undergo surgical excision, whereas the other 80% cannot.² For patients who have undergone radical excision, the 5-year survival rate is just 20–25%.^4–9Advanced pancreatic cancer, according to the TNM stage of pancreatic carcinoma by the American Joint Committee on Cancer (AJCC),¹⁰ includes Stages III and IV, and pancreatectomy is not well accepted.¹¹ It is reported that approximately 40% of pancreatic cancer patients present with locally advanced, non-metastatic disease.¹² Local lesions play a vital role in a patient''s survival.^13–16 The aim of advanced pancreatic cancer treatment is to enhance local lesion control and improve the quality of life (QOL).^17,18Gemcitabine is a type of pyrimidine analogue, which acts as a ribonucleoside reductase inhibitor and destroys cells and terminates the DNA chains. It has been approved by the US Food and Drug Administration as a gold standard agent in chemotherapy¹⁹ for the treatment of cancer, especially for advanced pancreatic cancer.²⁰ Currently, the major therapy is comprehensive treatment, namely chemoradiotherapy, which is superior to either radiotherapy²¹ or chemotherapy.²² But the overall survival time is not prolonged by chemoradiotherapy in advanced pancreatic cancer compared with single-agent gemcitabine.²³ The 5-year survival rate is still <5%.²⁴ However, interstitial implantation of radioactive seeds (brachytherapy) combined with conformal radiotherapy (external beam radiation therapy) has a good effect for local control of pancreatic cancer.^{25,26 125}I particles are reported to be the most commonly used for brachytherapy because of their long half-life and short radiation distance.²⁷ Therefore, we infer that ¹²⁵I implantation combined with chemoradiation may obtain better curative effects.In this study, we compared the local control rate, pain relief and survival rate of 30 patients with advanced pancreatic cancer who were treated with or without ¹²⁵I implantation combined with chemoradiotherapy in our hospital during October 2006 to January 2012. We expected that the implantation of ¹²⁵I particles could be an efficient therapy for patients with advanced pancreatic cancer.