Infrared pupillography in routine police traffic checks

Background

In order to evaluate the ability of traffic participants to drive, standardized and objective measurement methods are needed. In recent analyses it was shown that pupil function is a significant indicator of being under the influence of substances acting on the central nervous system.

Objective

The aim of this study was to answer the question whether it is possible to detect if a person is under the influence of drugs or medication based on pupil function.

Material and methods

In total 121 subjects were exposed to different light stimuli and an infrared pupillographic investigation of the eyes was carried out. The study cohort consisted of 41 healthy test subjects and 80 subjects under the influence of drugs or medication. Several neural network models with different network architectures were trained in a learning group, further analyzed in a verification sample and most importantly tested in an independent test sample. Specificity, sensitivity, negative and positive predictive values as well as the percentage of correctly predicted subjects were analyzed. A 95?% confidence interval (CI) was included for all performance measurements.

Results

A neural network model was found which performed with a specificity of 91?% (95% CI, 78–98?%), sensitivity 90?% (95% CI, 81–96?%), negative predictive value 85?% (95% CI, 72–94?%), positive predictive value 94?% (95% CI, 86–98?%) and a correct prediction was made for 90?% (95% CI, 83–95?%) of the subjects.

Conclusion

The results of this study clearly show that infrared pupillography provides excellent discrimination between healthy subjects and persons under the influence of drugs or medication in this specific setting.

     

How to improve femoral component rotational alignment in computer-assisted TKA

Purpose

Although several anatomical landmarks have been proposed to obtain adequate femoral component alignment in total knee arthroplasty (TKA), there is still no consensus regarding the best way to correctly position the prosthetic component on the horizontal plane. A previous computed tomography (CT)-based study has demonstrated anatomical transepicondylar axis (aTEA) to be externally rotated relative to surgical transepicondylar axis (sTEA) of approximately 4.5°. In this study, it is described a new methodological approach to femoral component rotational positioning through the use of previously reported CT scan information and navigation.

Methods

Eight consecutive patients scheduled for navigated TKA were selected. Rotational placement of the femoral component was performed using navigation system. The femoral component was implanted setting 4.5° of internal rotation relative to the aTEA. Within 1 week from surgery, all patients underwent a CT scan, and the posterior condylar angle (PCA) was measured. A PCA of 0.0°, meaning component placement parallel to sTEA, was set as femoral rotational alignment target. Clinical evaluation was performed at a mean 14.3 months of follow-up with KOOS questionnaire.

Results

The mean PCA measured on post-operative CT images was 0.4° (SD 1.3°), meaning that the femoral component was averagely implanted with 0.4° of internal rotation relative to the sTEA. Seven out of eight cases (87.5 %) resulted to have within 1° deviation from the rotational alignment target. All patients but one reported good clinical results.

Conclusions

Relevant finding of the present study was that the use of navigation and aTEA as a reference demonstrated to be accurate to set up femoral component rotational positioning on the horizontal plane in TKA. Further study should be performed to confirm this conclusion.

Level of evidence

III.     

Quality control of involved field radiotherapy in the HD 13 and HD 14 trials

Introduction

As part of the foundation of the German Hodgkin Study Group (GHSG) in 1978, a central radiotherapy (RT) reference centre was established to evaluate and to improve the quality of treatment. During the study generations, the quality assurance programs (QAP) were continued and adapted to the demands of each study. The purpose of this article is to demonstrate the results of the fifth study generation and to compare them to the previous findings.

Methods

With the start of the fourth GHSG study generation (HD10–12), a central prospective review of all diagnostic images was established to create an individual treatment plan for each early stage study patient. The quality of involved field RT was retrospectively evaluated by an expert panel of radiation oncologists. In the fifth study generation (HD13–15), the retrospective review of radiotherapy performed was refined and the results were compared with the findings of the fourth generation.

Results

The expert panel analyzed the RT planning and application of 1037 (28?%) patients (HD13 n = 465, HD14 n = 572). Simulation films were available in 85?% of cases and verification films in 87?%. RT was assessed as major violation in 46?% (HD13 = 38?%, HD14 = 52?%), minor violation in 9?% (HD13 = 9?%, HD14 = 9?%) and according to the protocol in 45?% (HD13 = 52?%, HD14 = 38?%).

Conclusion

The value for QAP of RT within the GHSG trials is well known. Still there were several protocol violations. In the future, the QAP program has to be adapted to the requirements of “modern RT” in malignant lymphoma.

     

Environmental Factors Predictive of No-Show Visits in Radiology: Observations of Three Million Outpatient Imaging Visits Over 16 Years

PurposeTo evaluate the impact of environmental and socioeconomic factors on outpatient cancellations and “no-show visits” (NSVs) in radiology.Materials and MethodsWe conducted a retrospective analysis by collecting environmental factor data related to outpatient radiology visits occurring between 2000 and 2015 at our multihospital academic institution. Appointment attendance records were joined with daily weather observations from the National Oceanic and Atmospheric Administration and estimated median income from the US Census American Community Survey. A multivariate logistic regression model was built to examine relationships between NSV rate and median income, commute distance, maximum daily temperature, and daily snowfall.ResultsThere were 270,574 (8.0%) cancellations and 87,407 (2.6%) NSVs among 3,379,947 scheduled outpatient radiology appointments and 575,206 unique patients from 2000 to 2015. Overall cancellation rates decreased from 14% to 8%, and NSV rates decreased from 6% to 1% as median income increased from $20,000 to $120,000 per year. In a multivariate model, the odds of NSV decreased 10.7% per $10,000 increase in median income (95% confidence interval [CI]: 10.3%-11.1%) and 2.0% per 10°F increase in maximum daily temperature (95% CI: 1.3%-1.6%). The odds of NSV increased 1.4% per 10-mile increase in commute distance (95% CI: 1.3%-1.6%) and 4.5% per 1-inch increase in daily snowfall (95% CI: 3.6%-5.3%). Commute distance was more strongly associated with NSV for those in the two lower tertiles of income than the highest tertile (P < .001).ConclusionEnvironmental factors are strongly associated with patients’ attendance at scheduled outpatient radiology examinations. Modeling of appointment failure risk based on environmental features can help increase the attendance of outpatient radiology appointments.     

The role of pharmacological stress testing in women

Pharmacological stress is an alternative method to dynamic exercise that combined with noninvasive imaging allows the detection of flow-limiting coronary artery disease (CAD). It represents the stress procedure of choice in patients who cannot exercise appropriately. In women, pharmacological stress combined with myocardial perfusion scintigraphy (MPS) has demonstrated to be highly accurate for the detection of obstructive CAD and a valuable tool that helps separate patients at low cardiac risk from those with an adverse prognosis. Pharmacological stress with positron emission tomographic (PET) imaging is increasingly used in the investigation of suspected obstructive CAD; available evidence shows that the diagnostic profile and prognostic value of stress PET imaging is similar to that of stress MPS in women.     

Intra-individual comparison of different contrast media concentrations (300 mg, 370 mg and 400 mg iodine) in MDCT

Objective  

To compare intra-individual contrast enhancement in multi-detector-row computed tomography (MDCT) using contrast media (CM) containing 300, 370 and 400 mg iodine per ml (mgI/ml).     

High-resolution myocardial perfusion imaging at 3 T: comparison to 1.5 T in healthy volunteers

The purpose of this study was to evaluate high-resolution (HR) myocardial first-pass perfusion in healthy volunteers at 3 T compared to a typical clinical imaging protocol at 1.5 T, with respect to overall image quality and the presence of subendocardial dark rim artifacts. Myocardial first-pass rest perfusion studies were performed at both field strengths using a T1-weighted saturation-recovery segmented k-space gradient-echo sequence combined with parallel imaging (Gd-DTPA 0.05 mmol/kg). Twenty-six healthy volunteers underwent (1) a HR perfusion scan at 3 T(pixel size 3.78 mm²) and (2) a standard perfusion approach at 1.5 T(pixel size 9.86 mm²). The contrast enhancement ratio (CER) and overall image quality (4-point grading scale: 4: excellent; 1: non-diagnostic) were assessed, and a semiquantitative analysis of dark rim artifacts was performed for all studies. CER was slightly higher (1.31 ± 0.32 vs. 1.14 ± 0.34; p<0.01), overall image quality was significantly improved (3.03 ± 0.43 vs. 2.37 ± 0.39; p<0.01), and the number of dark rim artifacts (139 ± 2.09 vs. 243 ± 2.33; p<0.01) was significantly reduced for HR perfusion imaging at 3 T compared to the standard approach at 1.5 T. HR myocardial rest perfusion at 3 T is superior to the typical clinical perfusion protocol performed at 1.5 T with respect to the overall image quality and presence of subendocardial dark rim artifacts.     

Cranial MRI in Behçet’s disease: 134 examinations of 98 patients

Two observers, blinded to the patients neurological status, reviewed 134 MRI studies of 98 consecutive patients with Behçets disease (BD), to define imaging patterns and to look for any relationship between the MRI findings and the timing of the examination in patients with differing courses of disease. There were 43 patients with overt parenchymal central nervous system (CNS) involvement, 22 with attacks and remissions, 15 with secondary progressive and six with primary progressive disease; 14 had raised intracranial pressure (RICP). Of the remaining 41 patients without specific neurological complaints, 16 had abnormalities on examination (silent CNS involvement) and 25 did not. During an acute CNS attack, the most common finding was a large lesion in the brain-stem or basal ganglia, extending to the diencephalon. On MRI performed after remission of an acute attack or during secondary progression, the same sites were affected, but the lesions were smaller or scattered, with less clearly defined margins. In primary progressive disease or silent CNS involvement, the cerebral white matter was most commonly involved, but almost half the MRI studies were normal. The brain parenchyma was abnormal in only one of the patients with RICP. MRI was normal in all but three patients without clinical CNS involvement, in whom it showed a few millimetric white-matter lesions. Brain-stem atrophy was seen in 15 patients examined >1 year after an initial parenchymal CNS episode, with secondary progressive cases predominating.Part of this work was presented at the Eighth International Conference on Behçets Disease, Reggio Emilia, October 1998 and at the Eighth Meeting of the European Neurological Society, Nice, June 1998     

Oxidative stress and glutathione S-transferase genetic polymorphisms in medical staff professionally exposed to ionizing radiation

Purpose: Ionizing radiation (IR) is considered as a diagnostic and therapeutic tool in medicine. However, chronic occupational exposure of medical staff to IR may affect the antioxidant status and, as a result, DNA damage and cancers as well. The objective of our study was to evaluate the oxidative stress profile caused by IR in 29 Tunisian medical staff from radiology and radiotherapy departments, and to find an association between the GSTM1 null, GSTT1 null, and GSTP1 Ile105Val polymorphisms and oxidative stress biomarkers.

Materials and methods: The oxidant biomarkers malondialdehyde (MDA) and advanced oxidation protein product (AOPP) and the activities of the antioxidant superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) enzymes were spectrophotometrically determined in erythrocytes hemolysates. The analysis of GSTT1 null, GSTM1 null, and GSTP1 Ile105Val polymorphisms was determined for each participant using PCR methods.

Results: A significant increase of white blood cell (WBC) numbers (p?<?.05) and a significant decrease by 11% of hemoglobin (Hb) (p?<?.01) were noted in the exposed subjects in our study. Moreover, we report a significant increase of MDA level and the activities of SOD and CAT enzymes of the IR-exposed group compared to controls (p?<?.001). Interestingly, a close association was noted between the genotypes GSTP1 low active, GSTT1 null, GSTM1 null, and both GSTT1/GSTM1 null and oxidative stress biomarkers, especially with MDA level, SOD, and CAT activities.

Conclusions: Our findings indicate that the medical staff exposed to low IR levels were under risk of significant oxidative stress that was enhanced by their glutathione S-transferase (GST) polymorphisms.     

Dosimetric predictors of radiation-induced pericardial effusion in esophageal cancer

Purpose

To evaluate the dose–volume parameters of the pericardium and heart in order to reduce the risk of radiation-induced pericardial effusion (PE) and symptomatic PE (SPE) in esophageal cancer patients treated with concurrent chemoradiotherapy.

Methods

In 86 of 303 esophageal cancer patients, follow-up CT was obtained at least 24 months after concurrent chemoradiotherapy. Correlations between clinical factors, including risk factors for cardiac disease, dosimetric factors, and the incidence of PE and SPE after radiotherapy were analyzed using Cox proportional hazard regression analysis. Significant dosimetric factors with the highest hazard ratios were investigated using zones separated according to their distance from esophagus.

Results

PE developed in 49 patients. Univariate analysis showed the mean heart dose, heart V₅–V₅₅, mean pericardium dose, and pericardium V₅–V₅₀ to all significantly affect the incidence of PE. Additionally, body surface area was correlated with the incidence of PE in multivariate analysis. Grade 3 and 4 SPE developed in 5 patients. The pericardium V₅₀ and pericardium D₁₀ significantly affected the incidence of SPE. The pericardium V₅₀ in patients with SPE ranged from 17.1 to 21.7%. Factors affecting the incidence of SPE were the V₅₀ of the pericardium zones within 3?cm and 4?cm of the esophagus.

Conclusion

A wide range of radiation doses to the heart and pericardium were related to the incidence of PE. A pericardium V₅₀ ≤ 17% is important to avoid symptomatic PE in esophageal cancer patients treated with concurrent chemoradiotherapy.

     

Unprotected carotid artery stenting: complications in 6 months follow-up

Introduction  

The most serious complications of carotid artery stenting (CAS) are related to the release of particles into the cerebral circulation. Although embolic protection devices may reduce the incidence of cerebral embolization, their use may be associated with additional complications including spasm or dissection. In this report, we present our experience with patients who underwent unprotected CAS.     

MRI of the ankle joint in healthy non-athletes and in marathon runners: image quality issues at 7.0 T compared to 1.5 T

Objective

To present imaging characteristics of the ankle at 7.0 T and to investigate the appearance and image quality of presumed pathologies of ankles without physical strain as well as of ankles after a marathon run in comparison to 1.5 T.

Materials and methods

Appearance of presumed pathologic findings and image quality of TSE (PD, T2, and STIR) and GRE sequences (MEDIC, DESS, and/or CISS) at 7.0 T and 1.5 T MRI were compared by two senior radiologists in consensus in two healthy controls without strain and in six marathon runners after a full-length marathon (eight males, mean age 49.1 years).

Results

Overall, 7.0 T MRI allowed for higher resolution images for most of the sequences while requiring comparable acquisition times and achieving high contrast images mainly in gradient echo sequences. Bursal or presumed peritendineal fluid and/or edematous tissue, which were found in seven of eight subjects, could be best appreciated with 7.0 T MEDIC. Other findings with sharper delineation at 7.0 T included cartilage defects (best: CISS), osseous avulsions, and osteophytes (best: DESS). Nevertheless, 1.5 T STIR imaging enabled assessment of a tibiotalar bone edema-like lesion in two runners, which was barely visible at 7.0 T using STIR, but not with any other sequence at 7.0 T including MEDIC (with frequency selective fat suppression). 7.0 T showed larger image quality variations with challenges especially in the TSE sequences.

Conclusion

Our initial results of ultra-high-field ankle joint imaging demonstrate the improved depiction of ankle anatomy, fluid depositions, and cartilage defects. However imaging of edema-like bone lesions remains challenging at ultra-high magnetic field strength, and TSE coverage in particular is limited by the specific absorption rate.     

Strahlenhygiene in der medizinischen Röntgenbildgebung, Teil 1

In this first part of a series of three articles on radiation hygiene in medical X-ray imaging the characteristics of X-rays, their interactions with matter and the components of X-ray equipment are described from a radiation protection point of view. The fundamental radiation protection measures like filtration and beam limitation are introduced as well as the various conventional and digital image receptor systems. Moreover the absorbed dose and other practical dose terms as well as metrological and theoretical methods for dose assessment are introduced. The aim of this paper is to explain the essential physical and technical basics of X-ray imaging and the assessment of the resulting radiation dose.     

Comparable outcomes after total knee arthroplasty in patients under 55 years than in older patients: a matched prospective study with minimum follow-up of 10 years

Purpose

To compare outcomes after TKA for osteoarthritis between patients younger than 55 years and older patients.

Methods

A cohort of 61 patients aged 55 years or younger was prospectively matched for gender, body mass index and knee function with patients with median age of 66 (range 60–70) years. Clinical evaluation was performed by the Knee Society scores (KSS), reduced Western Ontario and McMasters Universities (WOMAC) and Short-Form 12 (SF12) questionnaires. Radiological evaluation was also performed.

Results

The median follow-up was 12 (range 10–14) years. Survival at 14 years was 96.7% (95% CI 92–100%) in the younger group and 98.2% (95% CI 95–100%) in the older group (n.s.). There was no deep infection or loosening of femoral or patellar component in either group. In the younger group, 2 patients required revision (aseptic tibial loosening at 8 years, and polyethylene wear at 10 years). In the older group, there was 1 revision (aseptic tibial loosening). Revision rate was not significantly different (n.s.). Multivariate analysis showed no significant relationship between revision and age, gender or BMI. At 5-year follow-up, there were no significant differences between groups in KSS knee or function, WOMAC pain or function, or SF12 physical or mental, but in the last evaluation there were better results in younger patients for KSS-function (p = 0.018), WOMAC-function (p = 0.028), SF12-physical (p = 0.001) and SF12-mental (p = 0.035), although these differences were not clinically relevant. A significant decline was noted for KSS-function in either group from 5-year to at last follow-up.

Conclusions

The TKA survival in younger patients was comparable to older active patients, without increased complications or revisions at a minimum follow-up of 10 years. Primary hybrid TKA can provide successful pain relief, function and quality of life in younger patients than 55 years with osteoarthritis. TKA is a suitable option for these young patients with appropriate surgical indications.

Level of evidence

II.