Cumulative Radiation Dose in Patients With Hereditary Hemorrhagic Telangiectasia and Pulmonary Arteriovenous Malformations

Purpose

To determine the cumulative effective dose (CED) of radiation from medical imaging and intervention in patients with hereditary hemorrhagic telangiectasia (HHT) who have pulmonary arteriovenous malformations and to identify clinical factors associated with exposure to high levels of radiation.

Methods

All patients with at least 1 pulmonary arteriovenous malformation were identified from the dedicated patient database of a tertiary HHT referral centre. Computerized imaging and electronic patient records were systematically examined to identify all imaging studies performed from 1989-2010. The effective dose was determined for each study, and CED was calculated retrospectively.

Results

Among 246 patients (mean age, 53 years; 62.2% women) with a total of 2065 patient-years, 3309 procedures that involved ionizing radiation were performed. CED ranged from 0.2-307.6 mSv, with a mean of 51.7 mSv. CED exceeded 100 mSv in 26 patients (11%). Interventional procedures and computed tomography (CT) were the greatest contributors, which accounted for 51% and 46% of the total CED, respectively. Factors associated with high cumulative exposure were epistaxis (odds ratio 2.7 [95% confidence interval, 1.1-6.3]; P = .02), HHT-related gastrointestinal bleeding (odds ratio 2.0 [95% confidence interval, 1.0-3.8]; P = .04) and number of patient-years (P < .0001).

Conclusions

Patients with HHT are exposed to a significant cumulative radiation dose from diagnostic and therapeutic interventions. Identifiable subsets of patients are at increased risk. A proportion of patients receive doses at levels that are associated with harm. Imaging indications and doses should be optimized to reduce radiation exposure in this population.     

Informed Consent for Radiation in Interventional Radiology Procedures

Purpose

To explore the patient perception on radiation-related cancer risk from interventional radiology (IR) procedures and whether informed radiation consent is warranted.

Eye lens radiation exposure and repeated head CT scans: A problem to keep in mind

Objectives

The deterministic character of radiation-induced cataract is being called into question, raising the possibility of a risk in patients, especially children, exposed to ionizing radiation in case of repeated head CT-scans. This study aims to estimate the eye lens doses of a pediatric population exposed to repeated head CTs and to assess the feasibility of an epidemiological study.

Methods

Children treated for a cholesteatoma, who had had at least one CT-scan of the middle ear before their tenth birthday, were included. Radiation exposure has been assessed from medical records and telephone interviews.

Results

Out of the 39 subjects contacted, 32 accepted to participate. A total of 76 CT-scans were retrieved from medical records. At the time of the interview (mean age: 16 years), the mean number of CT per child was 3. Cumulative mean effective and eye lens doses were 1.7 mSv and 168 mGy, respectively.

Conclusion

A relatively high lens radiation dose was observed in children exposed to repeated CT-scans. Due to that exposure and despite the difficulties met when trying to reach patients’ families, a large scale epidemiological study should be performed in order to assess the risk of radiation-induced cataracts associated with repeated head CT.     

Mapping very low level occupational exposure in medical imaging: A useful tool in risk communication and decision making

Objectives

The use of ionising radiation in medical imaging is accompanied with occupational exposure which should be limited by optimised room design and safety instructions. These measures can however not prevent that workers are exposed to instantaneous dose rates, e.g. the residual exposure through shielding or the exposure of discharged nuclear medicine patients. The latter elements are often questioned by workers and detailed assessment should give more information about the impact on the individual radiation dose.

Methods

Cumulated radiation exposure was measured in a university hospital during a period of 6 months by means of thermoluminescent dosimeters. Radiation exposure was measured at background locations and at locations where enhanced exposure levels are expected but where the impact on the individual exposure is unclear.

Results

The results show a normal distribution of the cumulated background radiation level. No enhanced cumulated radiation exposure which significantly differs from this background level could be found during the operation of intra-oral apparatus, during ultrasonography procedures among nuclear medicine patients and at operator consoles of most CT-rooms.

Conclusions

This 6 months survey offers useful information about occupational low level exposure in medical imaging and the findings can be useful in both risk communication and decision making.     

Looking Back,Moving Forward: An Analysis of Complaints Submitted to a Canadian Tertiary Care Radiology Department and Lessons Learned

Purpose

We present an analysis of various types and strata of complaints received in a geographically isolated tertiary care center over a 2.5-year period.

Methods

Research ethics board approval was obtained. The institution described is a closed system with formalized procedures for submitting complaints. All complaints submitted between November 2010 and March 2013 were collected retrospectively. The following data were extracted: type of complainant, nature of the complaint, site or modality of concern, dates in question, and the response. The data were analysed in multiple subgroups and compared with patient and study volume data.

Results

The frequency of complaints equalled 0.01% (100/1,050,000). The largest group of those who submitted complaints were patients (69% [69/100]), followed by referring physicians (16%). Examination scheduling and interpersonal conflicts were equally of greatest frequency of concern (21% [21/100]), followed by issues with study reporting (16%). The average time interval between complaint submission and formal address was 15 days.

Conclusions

We present a low frequency of complaints, with the majority of these complaints submitted by patients; scheduling and personal interactions were most often involved. Effective communication, both with patients and referring physicians, was identified as a particular focus for improving satisfaction.     

Systematic review on physician's knowledge about radiation doses and radiation risks of computed tomography

Background

The frequent use of computed tomography is a major cause of the increasing medical radiation exposure of the general population. Consequently, dose reduction and radiation protection is a topic of scientific and public concern.

Aim

We evaluated the available literature on physicians’ knowledge regarding radiation dosages and risks due to computed tomography.

Methods

A systematic review in accordance with the Cochrane and PRISMA statements was performed using eight databases. 3091 references were found. Only primary studies assessing physicians’ knowledge about computed tomography were included.

Results

14 relevant articles were identified, all focussing on dose estimations for CT. Overall, the surveys showed moderate to low knowledge among physicians concerning radiation doses and the involved health risks. However, the surveys varied considerably in conduct and quality. For some countries, more than one survey was available. There was no general trend in knowledge in any country except a slight improvement of knowledge on health risks and radiation doses in two consecutive local German surveys.

Conclusions

Knowledge gaps concerning radiation doses and associated health risks among physicians are evident from published research. However, knowledge on radiation doses cannot be interpreted as reliable indicator for good medical practice.     

Complete written/oral information about dose exposure in CT: is it really useful to guarantee the patients’ awareness about radiation risks?

Aims and objectives

According to the European directive 2013/59/Euratom, starting from February 2018, the information relating to patient exposure will be part of computed tomography (CT) reports, but the impact of this information on patients has not been deeply evaluated. Aim of our study was to evaluate patients’ perception of radiation exposure related to routine CT and their understanding after communication of their dose exposure.

Materials and methods

A survey, investigating patient’s knowledge of radiation dose, was given to all adult patients (>?18 years) undergoing a CT examination both before and after CT scan. The first survey was the same for all patients. After CT scan, a second questionnaire was administered (after receiving the CT dose bill report and medical written and/or explanation about ionizing radiation risk). Results of the pre- and post-CT questionnaires responses were compared according to demographics characteristics and among the four post-CT groups.

Results

For some questions, statistically significant differences were found between the two centres. Seventy per cent of the patients answered that the presence of CT parameters in the report is considered useful. Even if not always statistically significant there was a slight increase in awareness of ionizing radiation risk comparing the pre- and post-CT surveys. The group that had both written and oral explanations had a better comprehension of CT dose bill (group III vs. I, p?=?0.002).

Conclusion

The way of communication of ionizing radiation risks did not affect the results of the post-CT survey. Indeed, the interest in the topic did not rise in the post-CT survey in any of the group. Adequate information about ionizing radiation risks provided together with dose exposure information may be useful. However, there is not a standardized better way of communicating information on ionizing radiation risks due to CT.

     

The role of advanced MRI techniques in differentiating typical,from atypical and malignant meningiomas

Background

Meningiomas are the commonest primary, non-glial intracranial tumors. The diagnosis is often correctly predicted from characteristic imaging appearances. Some meningiomas have atypical imaging appearance that may cause diagnostic confusion.

Aim

Is to evaluate the role of advanced MR imaging techniques in differentiating typical from atypical and malignant meningiomas before surgery.

Patient

Thirty patients were retrospectively included in this study. They were referred from Neurosurgery Department and all of them suspected to have intracranial meningioma according to the contrast enhanced CT.

Methods

All patients were subjected to conventional magnetic resonance imaging followed by advanced magnetic resonance imaging in the form of diffusion weighted imaging, perfusion weighted imaging and MR spectroscopy by single-voxel techniques.

Results

The overall results based on differentiation of typical from atypical and malignant meningiomas by advanced MRI techniques. Twenty four patients had typical meningioma and 6 patients had atypical and malignant Meningiomas by advanced MRI techniques.

Conclusion

Appearance of meningiomas on DWIs and the calculation of ADC values could be correlated with their histopathological grading. On MRS, alanine was not found to be increased in all meningiomas, so MRS cannot reliably differentiate typical intracranial meningomas from atypical meningiomas.     

Magnetic resonance spectroscopy in recurrent breast masses following conservative surgery and radiation therapy

Purpose

The purpose of our study was to assess the value of functional magnetic resonance spectroscopy (1H MRS) in evaluating patients with recurrent cancer breast after breast conservative therapy (BCT) and radiation therapy by the presence of the choline-containing compounds (Cho) as a marker of malignancy.

Patients and methods

Twenty-six patients were included in the study all the patients were subjected to previous BCT and associated radiation therapy. All of them were suspected to have tumor recurrence by clinical examinations, periodic mammographic examination and or ultrasonography. All the patients were submitted to dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) followed by magnetic resonance spectroscopy (MRS) at 1.5 T MRI machine.

Results

Local recurrence was confirmed by histopathology in 19 patients, MRS detected 18 patients with sensitivity of 94.7%, false positive was seen in one patient in whom histopathology revealed inflammatory mastitis (specificity 85.7%). One patient was false negative diagnosed by histopathology as ductal carcinoma in situ (DCIS) with negative predictive value of 85.7% and overall accuracy of 92.3%.

Conclusion

In our study breast MRS using choline (Cho) integral was accurate in evaluating patients with recurrent breast masses after BCT and radiation therapy. It reaches a high level of diagnostic performance.     

Impact of F-18 Fluorodeoxyglucose Positron Emission Tomography–Computed Tomography on Oncologic Patient Management: First 2 Years' Experience at a Single Canadian Cancer Center

Purpose

The purpose of this study was to assess the influence of positron emission tomography–computed tomography (PET-CT) results on patient management from a single Canadian oncology center during its first 2 years of operation.

Methods

A total of 3,779 consecutive patients, 18 years of age and older, who were referred for PET-CT imaging at the British Columbia Cancer Agency between July 1, 2005 and June 30, 2007, were included in this analysis. Results were tabulated from a standard questionnaire, which was given to referring physicians following completion of their patient's PET-CT study.

Results

From July 1, 2005 to June 30, 2007, 3,779 consecutive fluoro-2-deoxyglucose PET-CT examinations were performed in patients aged 18 years or older. A total of 3,429 referring-physician surveys (90.7%) were returned. The results of the PET-CT study resulted in a change in treatment decision in 49.8% of the studies and resulted in improved decision making in 83.2% of the studies.

Conclusion

This series demonstrated that the results from PET-CT studies performed at a single Canadian oncology center during the first 2 years of its operation altered patient management in 50% of cases and resulted in improved decision making in the majority of cases.     

Brain magnetic resonance imaging findings in cryptogenic stroke patients under 60 years with patent foramen ovale

Purpose

To compare magnetic resonance imaging (MRI) brain feature in cryptogenic stroke patients with patent foramen ovale (PFO), cryptogenic stroke patients without PFO and patients with cardioembolic stroke.

Materials and methods

The ethics committee required neither institutional review board approval nor informed patient consent for retrospective analyses of the patients’ medical records and imaging data. The patients’ medical files were retrospectively reviewed in accordance with human subject research protocols. Ninety-two patients under 60 years of age were included: 15 with cardioembolic stroke, 32 with cryptogenic stroke with PFO and 45 with cryptogenic stroke without PFO. Diffusion-weighted imaging of brain MRI was performed by a radiologist blinded to clinical data. Univariate, Fischer's exact test for qualitative data and non-parametric Wilcoxon test for quantitative data were used.

Results

There was no statistically significant difference found between MRI features of patients with PFO and those with cardioembolic stroke (p < .05). Patients without PFO present more corticosubcortical single lesions (p < .05) than patients with PFO. Patients with PFO have more often subcortical single lesions larger than 15 mm, involvement of posterior cerebral arterial territory and intracranial occlusion (p < .05) than patients with cryptogenic stroke without PFO.

Conclusion

Our study suggests a cardioembolic mechanism in ischemic stroke with PFO.     

Role of multi-slice CT angiography in the evaluation of pulmonary venous anomalies

Purpose and aim

To assess the role of MSCT angiography in evaluation of extra-cardiac vascular abnormalities in pulmonary venous anomalies and compare it with echocardiography.

Materials and methods

This study included 26 patients with an age range of 15 days–25 years. All of these patients underwent MSCT angiography and echocardiography. Only 10 patients underwent cardiac catheterization.

Results

Our initial experience showed that MSCT is capable of complementing echocardiography and replacing diagnostic cardiac catheterization for anatomical delineation if performed with an optimum technique.MSCT angiography proved to be a worthy primary investigation tool in patients whom ECHO has been able to clearly identify the intracardiac anatomy, but not the extra-cardiac vascular anatomy.

Conclusion

MDCT correctly depicted the TAPVR (Total anomalous pulmonary venous return) and PAPVR (Partial anomalous pulmonary venous return) types of pulmonary venous anomalies with sensitivity 100%, and specificity 100%. The specificity of echocardiography was 50% for both findings. Inspite of the risk of ionizing radiation and contrast medium injection the adoption of our minimal invasive, low radiation, non-ECG gated protocol greatly reduces the time, radiation dose, and contrast medium volume needed to perform an optimum CT angiographic technique. Thus, paving a clear road map for pre and post operative assessment of patients with pulmonary venous anomalies.     

Superior orbital fissure syndrome and its mimics: What the radiologist should know?

Aim of this study

The aim of this study was to assess the rule of imaging in the superior orbital fissure syndrome (SOFS) and to identify the rule of the radiologist in guidance of the management.

Material and methods

This study was conducted on 7 patients with clinical diagnosis of SOFS. Contrast enhanced MRI was used in examination of all patients. With exception of metastatic lesions, follow up MRI study was performed to all lesions. Final diagnosis was reached either by dramatic response to cortico-steroid therapy, tissue biopsy or by correlation with clinical and other imaging data.

Results

In all patients enhancing abnormal T1 and T2 intermediate intensities are seen localized to the anatomical site of the superior orbital fissure (SOF). Four patients presented with sheet like enhancement casting the SOF. Nodular enhancement is noted along the medial aspect of the SOF in one case. Two patients presented with sizable destructive space occupying lesions at SOF.

Conclusion

In management of SOFS, if there is a dramatic clinical and radiological response to corticosteroid therapy, we recommend MRI follow-up study after 6 week interval. As the symptoms were resolving, the potential risks associated with tissue biopsy from that area will be unacceptable.     

Contrast-enhanced ultrasound in the differentiation between phlegmon and abscess in Crohn's disease and other abdominal conditions

Aim

To evaluate the diagnostic accuracy of the contrast-enhanced ultrasound (CEUS) to differentiate between intra-abdominal phlegmon and abscess.

Methods

We retrospectively reviewed all contrast-enhanced ultrasound performed between June 2006 and May 2012 to identify patients with the terms “inflammatory mass”, “phlegmon” or “abscess” on the sonographic report. The initial CEUS report was used for the diagnosis of phlegmon or abscess.

Results

71 inflammatory masses in 50 patients were identified in CEUS examination. 57 masses, 21 phlegmons and 36 abscesses, were confirmed by other imaging techniques, percutaneous drainage or surgery. CEUS specificity for the diagnosis of abscess was 100%. Kappa coefficient between CEUS and other techniques in the diagnosis of phlegmon or abscess was excellent (kappa = 0.972). Only in one patient surgery detected a small abscess (<2 cm) within a phlegmon that not was detected by CEUS. Statistically significant differences were found between the size of the abscesses before and after contrast agent injection. The interobserver agreement in the diagnosis of phlegmon or abscess was excellent (kappa = 0.953).

Conclusions

CEUS is an accurate method for differentiating between intra-abdominal phlegmon and abscess in gastrointestinal conditions, especially in CD. Its use may help to better define the size of the collections and avoid other techniques that use ionizing radiation. CEUS should be used to confirm an inflammatory mass identified at US.     

Multidetector CT chest with bronchial and pulmonary angiography determining causes,site and vascular origin of bleeding in patients with hemoptysis

Objective

To assess the role of MDCT chest with bronchial and pulmonary angiography in determining the cause, site of bleeding, and its vascular origin in patients presenting with hemoptysis.

Materials and methods

Fifty patients suffering from hemoptysis were evaluated by MDCT with bronchial and pulmonary angiographic techniques.

Results

MDCT chest with angiography revealed the cause in 84% of cases, the site and vascular origin in 76% of cases presenting with hemoptysis.

Conclusion

MDCT of the chest with bronchial and pulmonary angiography is considered a primary noninvasive imaging modality in the evaluation of patients with hemoptysis. It also serves as a guide for other diagnostic or therapeutic procedures.     

Ossification variants of the femoral condyles are not associated with osteochondritis dissecans

Purpose

To determine if ossification variants of the femoral condyles involving the subchondral bone plate are associated with osteochondritis dissecans (OCD).

Materials and methods

The prevalence of ossification variants of the unaffected femoral condyle in 116 patients (aged 9–14 years) with unicondylar OCD on MRI (magnetic resonance imaging) of the knee was compared to a control group of 579 patients (aged 9–14 years) without OCD. The evolution of the ossification variants in both groups was studied by reviewing follow-up MR imaging side by side with the baseline study.

Results

The prevalence of ossification variants in the unaffected condyle in patients with OCD (12.9%) and in the control group of patients without OCD (12.6%) was similar (p = 0.88).Evolution of ossification variants to OCD was not seen on follow-up MRI examinations. All variants had decreased in size or were no longer visible.

Conclusion

Ossification variants of the femoral condyle that involve the subchondral bone plate are not associated with OCD.

Clinical relevance statement

Ossification variants are not associated with OCD, indicating that routine MRI follow-up in affected children is not mandatory.     

MR cartilage imaging in assessment of the regenerative power of autologous peripheral blood stem cell injection in knee osteoarthritis

Background

Osteoarthritis (OA) describes an age-related, heterogeneous group of disorders characterized pathologically by focal areas of loss of articular cartilage in synovial joints, associated with varying degrees of osteophyte formation, subchondral bone change, and synovitis. Currently, cartilage repair remains a major challenge for physicians, being avascular with limited regenerative capacity. Stem cell therapy opened new horizons for hyaline cartilage repair. Peripheral blood stem cells (PBSC) due to their multi-lineage potential, immunosuppressive activities, and limited immunogenicity, were tried as an intra articular injection.

Aim of study

To find out the regenerative effect of repeated intra articular injections of autologous PBSC in knee joints of OA patients using MR cartilage imaging.

Methods

10 patients (3 males and 7 females) diagnosed with bilateral knee joints OA were included in this study, they underwent history taking, clinical examination and MR cartilage imaging using the semi-quantitative whole joint assessment score of knee for OA (MOAKS). Three intra articular injections of 8 ml of autologous PBSC in each knee were administered. Clinical and MRI assessments were repeated after 1 year.

Results

A significant reduction was seen in all parameters post injection. MR images analysis showed increased cartilage thickness in 65 knee joint compartments out of 160 affected compartments.

Conclusion

Limited good level of evidence showed that repeated intra-articular injections of autologous PBSC resulted in an improvement of the quality of articular cartilage repair and physical function as observed by MRI and clinical assessment.     

Magnetic resonance perfusion and diffusion imaging characteristics of transient bone marrow edema,avascular necrosis and subchondral insufficiency fractures of the proximal femur

Purpose

To evaluate magnetic resonance (MR) perfusion and diffusion imaging characteristics in patients with transient bone marrow edema (TBME), avascular necrosis (AVN), or subchondral insufficiency fractures (SIF) of the proximal femur.

Materials and methods

29 patients with painful hip and bone marrow edema pattern of the proximal femur on non-contrast MR imaging were examined using diffusion-weighted and dynamic gadolinium-enhanced sequences. Apparent diffusion coefficients (ADCs) and perfusion parameters were calculated for different regions of the proximal femur. Regional distribution and differences in ADC values and perfusion parameters were evaluated.

Results

Seven patients presented with TBME, 15 with AVN and seven with SIF of the proximal femur. Perfusion imaging showed significant differences for maximum enhancement values (E_max), slope (E_slope) and time to peak (TTP) between the three patient groups (p < 0.05). In contrast, no significant differences for ADC values were calculated when comparing TBME, AVN, and SIF patients.

Conclusion

Diffusion weighted imaging of bone marrow of the proximal femur did not show significant differences between patients with TBME, AVN or SIF. In contrast, MR perfusion imaging demonstrated significant differences for the different patient groups and may as a complementary imaging technique add information to the understanding of the pathophysiology of diseases associated with bone marrow edema.