Forensic imaging: New challenges for radiographers : B-588

Purpose: Cross-sectional imaging techniques have pioneered forensic medicine. The involvement of a radiographer and formation of "forensic radiographers" allows an improvement of the quality of radiological examinations and facilitates the implementation of techniques, such as sample collections, and the performance of post-mortem angiography. Methods and Materials: During a period of three months, five radiographers with clinical experience have undergone a special training in order to learn procedures dedicated to forensic imaging. These procedures involved: I). acquisition of MDCT data, II). sample collection for toxicological or histological analyses by performing CT-guided biopsies and liquid sampling, III). post-mortem angiography and IV). post-processing of all data acquired. To perform the post-mortem angiography, radiographers were in charge of the preparation of the perfusion device and the investigated body. Therefore, cannulas were inserted into the femoral vessels and connected to the machine. For angiography, the radiographers had to synchronize the perfusion with the CT-acquisitions. Results: All five radiographers have acquired new skills to become "forensic radiographers". They were able to perform post-mortem MDCT, sample collection, post-mortem angiography and post-processing of the acquired data all by themselves. Most problems have been observed concerning the preparation of the body for post-mortem angiography. Conclusion: Our experience shows that radiographers are able to perform high quality examinations after a short period of training. Their collaboration is well accepted by the forensic team and regarding the increase of radiological exams in forensic department, it would be nonsense to exclude radiographers from the forensic-radiological team.

Radiation risks : a way to inform patient : 3.10

Purpose: Diagnostic radiology involving ionizing radiation often leads to crucial information but also involves risk. Estimated cancer risks associated with CT range between 1 in 1000 to 1 in 10 000, depending on age and exposure settings. The aim of this contribution is to provide radiologists a way to inform a patient about these risks on a collective and individual base. Materials and methods: After a brief review of the effects of ionizing radiations, conversion from dose indicators into effective dose will be presented for radiography, fluoroscopy and CT. The Diagnostic Reference Level (DRL) concept will be then introduced to enable the reader to compare the level of exposure of various examinations. Finally, the limit of effective dose will be explained and risk projections after various radiological procedures for adults and children will be presented. Results: From an individual standpoint the benefit of a well justified and optimized CT examination clearly outweigh its risk of inducing a fatal cancer. The uncertainties associated with the effective dose concept should be kept in mind in order to avoid cancer risk projections after an examination on an individual basis. Conclusion: Risk factors or effective dose are not the simplest tools to communicate when dealing with radiological risks. Thus, a set of categories should be preferred as proposed in the ICRP (International Commission on Radiation Protection) report 99.

Budd-Chiari syndrome due to prothrombotic disorder: mid-term patency and efficacy of endovascular stents.

Our objective was to evaluate efficacy and patency of metallic stent placement for symptomatic Budd-Chiari syndrome (BCS) due to prothrombotic disorders. Eleven patients with proved BCS due to prothrombotic disorders were referred for endovascular treatment because of refractory ascites (n=9), abdominal pain (n=8), jaundice (n=6), and/or gastrointestinal bleeding (n=4). Stents were inserted for stenosed hepatic vein (n=7), inferior vena cava (n=2), or mesenterico-caval shunt (n=2). Clinical efficacy and stent patency was evaluated by clinical and Doppler follow-up. After a mean follow-up of 21 months, 6 patients had fully patent stents without reintervention (primary stent patency: 55%). Two patients with hepatic vein stenosis had stent thrombosis and died 4 months after procedure. Restenosis occurred in 3 cases (2 hepatic vein and 1 mesenterico-caval shunt stenosis) and were successfully treated by balloon angioplasty (n=2) and addition of new stents (n=1) leading to a 82% secondary stent patency. Of 9 patients with patent stent, 7 were asymptomatic (77%) at the end of the study. Stent placement is a safe and effective procedure to control of symptomatic BCS. Prothrombotic disorder does not seem to jeopardize patency in anticoagulated patients.

Hind limb ischemia in rabbit model: T2-prepared versus time-of-flight MR angiography at 3 T.

PURPOSE: To prospectively compare various parameters of vessels imaged at 3 T by using time-of-flight (TOF) and T2-prepared magnetic resonance (MR) angiography in a rabbit model of hind limb ischemia. MATERIALS AND METHODS: Experiments were approved by the institutional animal care and use committee. Endovascular occlusion of the left superficial femoral artery was induced in 14 New Zealand white rabbits. After 2 weeks, MR angiography and conventional (x-ray) angiography were performed. Vessel sharpness was evaluated visually in the ischemic and nonischemic limbs, and the presence of small collateral vessels was evaluated in the ischemic limbs. Vessel sharpness was also quantified by evaluating the magnitude of signal intensity change at the vessel borders. RESULTS: The sharpness of vessels in the nonischemic limbs was similar between the TOF and the T2-prepared images. In the ischemic limbs, however, T2-prepared imaging, as compared with TOF imaging, generated higher vessel sharpness in arteries with diminished blood flow (mean vessel sharpness: 44% vs 30% for popliteal arteries, 45% vs 28% for saphenous arteries; P < .001 for both comparisons) and enabled better detection of small collateral vessels (93% vs 36% of vessels, P < .001). CONCLUSION: T2-prepared imaging can facilitate high-spatial-resolution MR angiography of small vessels with low blood flow and thus has potential as a tool for noninvasive evaluation of arteriogenic therapies, without use of contrast material. Supplemental material: http://radiology.rsnajnls.org/cgi/content/full/2452062067/DC1.

Planning-Level Guidelines for Modern Roundabouts, 2008

This technical memorandum provides preliminary planning-level guidance to engineers, technicians, planners, and policymakers who may be considering a modern roundabout at an existing or proposed intersection in Iowa.

Review of CT features of saprophytic aspergillosis (Aspergilloma) and correlation with final diagnosis : P21

Purpose: 1. To review Ct features suggestive of saprophytic aspergillosis (aspergilloma) and to correlate them with the final pathological results. 2. To illustrate the wide range of differential diagnosis. Methods and materials: The electronic database of our department from 1995 to 2007 revealed CT reports of 48 patients that had been considered very suggestive of aspergilloma. Two radiologists with 6 and 12 years experience in thoracic radiology jointly reviewed the corresponding CT features including ancillary findings and the underlying lung diseases and correlated them with the final pathological diagnosis. Results: Forty patients could be included in the study (12 women, mean age 52), while in 8 patients there was no adequate clinical follow-up. In 17 patients the diagnosis "mycetoma" due to aspergillus fumigatus infection was confirmed, either by surgery, biopsy or bronchoscopy. In 23 patients, differential diagnoses were found, such as cavitating bronchial carcinoma (n = 7), bacterial abscess (n = 3), typical (n = 2) and atypical (n = 2) tuberculosis, as well as inflammatory changes due to mucoviscidosis (n = 1), Wegener's disease (n = 1) or chronic obstructive pulmonary disease (n = 3). Fibromyxoide hamartoma, lung infarction and bronchomucocele were responsible for the typical CT feature in one patient each. Conclusion: 1. The typical CT feature suggesting mycetoma is softtissue proliferation within a pre-existing wall-thickened lung cavity, oten even considered "pathognomonic". However, this diagnosis was finally confirmed by surgery or laboratory findings in less than 50% of patients only. 2. Since differential diagnoses are very large, not only including cavitating lung cancer and tuberculosis, the individual underlying lung disease needs strongly being taken into account often giving the best clue for the correct diagnosis.

Malignant gastroduodenal obstruction: palliation with self-expanding metallic stents.

PURPOSE: To evaluate the feasibility, efficacy, and tolerance of self-expanding metallic stent insertion under fluoroscopic guidance for palliation of symptoms related to malignant gastroduodenal obstruction. MATERIALS AND METHODS: Seventy-two patients (38 men, 34 women) aged 25-98 years (mean, 62 years) with duodenal (n = 43), antropyloric (n = 13), surgical gastrojejunostomy (n = 10), or pyloroduodenal (n = 6) malignant obstruction were referred for insertion of self-expanding metallic stents over a 6-year period. Stent insertion was performed with use of a peroral or transgastric approach when necessary (n = 11). RESULTS: Stents were successfully inserted in 70 of the 72 patients (97%) and provided symptom relief in 65 patients (90%). Inserted stents were mainly uncovered vascular (n = 55) or enteral (n = 10) Wallstents. One hundred eight stents were initially inserted: one, two, three, or four stents were indicated in 43, 17, nine, and one patient, respectively. Mean follow-up was 119 days (range, 4-513 days). Mean stent patency was 113 days (range, 4-513 days). Mean survival of patients was 120 days. During follow-up, stent obstruction occurred in seven patients as a result of tumoral overgrowth (n = 5) or ingrowth (n = 2). Complications occurred in 12 of the 72 patients (17%), including stent migration (n = 8), stent fracture (n = 1), duodenal perforation (n = 1), and death related to general anesthesia (n = 1). CONCLUSION: Despite a significant complication rate, self-expanding metallic stent insertion under fluoroscopic guidance appears to be a feasible and useful technique in the palliative management of malignant gastroduodenal obstruction.

Evaluation of peripheral arterial bypass grafts with multi-detector row CT angiography: comparison with duplex US and digital subtraction angiography.

PURPOSE: To assess the technical feasibility of multi-detector row computed tomographic (CT) angiography in the assessment of peripheral arterial bypass grafts and to evaluate its accuracy and reliability in the detection of graft-related complications, including graft stenosis, aneurysmal changes, and arteriovenous fistulas. MATERIALS AND METHODS: Four-channel multi-detector row CT angiography was performed in 65 consecutive patients with 85 peripheral arterial bypass grafts. Each bypass graft was divided into three segments (proximal anastomosis, course of the graft body, and distal anastomosis), resulting in 255 segments. Two readers evaluated all CT angiograms with regard to image quality and the presence of bypass graft-related abnormalities, including graft stenosis, aneurysmal changes, and arteriovenous fistulas. The results were compared with McNemar test with Bonferroni correction. CT attenuation values were recorded at five different locations from the inflow artery to the outflow artery of the bypass graft. These findings were compared with the findings at duplex ultrasonography (US) in 65 patients and the findings at conventional digital subtraction angiography (DSA) in 27. RESULTS: Image quality was rated as good or excellent in 250 (98%) and in 252 (99%) of 255 bypass segments, respectively. There was excellent agreement both between readers and between CT angiography and duplex US in the detection of graft stenosis, aneurysmal changes, and arteriovenous fistulas (kappa = 0.86-0.99). CT angiography and duplex US were compared with conventional DSA, and there was no statistically significant difference (P >.25) in sensitivity or specificity between CT angiography and duplex US for both readers for detection of hemodynamically significant bypass stenosis or occlusion, aneurysmal changes, or arteriovenous fistulas. Mean CT attenuation values ranged from 232 HU in the inflow artery to 281 HU in the outflow artery of the bypass graft. CONCLUSION: Multi-detector row CT angiography may be an accurate and reliable technique after duplex US in the assessment of peripheral arterial bypass grafts and detection of graft-related complications, including stenosis, aneurysmal changes, and arteriovenous fistulas.

The atypical faces of neuroblastoma : pictorial essay : P49

Purpose: Neuroblastoma represents 8 to 10% of all pediatric tumors and account for 15% of cancer deaths in children. Neuroblastoma may arise anywhere sympathetic tissue is present and its clinical presentation may be very variable. Therefore, a significant number of unusual tumor presentation and imaging findings are possible.The purpose of this pictorial essay is to review the unusual imaging findings of neuroblastoma. Methods and materials: We retrospectively revised the 25 cases f neuroblastoma detected and treated at our institution in the last 3 years and selected those cases with atypical imaging findings at the initial diagnosis and the follow-up studies. Results: A significant number of our studies showed atypical imaging findings concerning the site of origin, the initial characteristics and extension of the primary tumor or the site of metastasis. Conclusion: The variability of origin and the changing clinical evolution of neuroblastoma may originate a wide spectrum of unusual imaging findings, which should be recognized to allow a correct diagnosis.

Association of DNA repair inhibition and radiofrequency ablation in the treatment of xenografted colorectal cancer

Purpose: Most of the patients with advanced colorectal cancer will develop liver metastasis, even after primary tumor resection. Although surgical resection remains the gold standard treatment of hepatic metastases, only few patients are eligible to curative resection. Radiofrequency ablation (RFA) is the most common curative alternative. Dbait are new molecules that inhibit DNA double-strand breaks repair. In vitro, Dbait has shown to increase cell death after hyperthermia. Here, we have assessed the combination of Dbait and RFA in the treatment of human colorectal cancer model xenografted in nude mice.Materials: 98 mice were flank-grafted with HT29 (human colon adenocarcinoma). When tumor reached 500 mm3, mice were sham treated (n=19), treated by Dbait via local injections (n=20), treated by RFA using an incomplete ablation scheme (n=20) or treated by combination of Dbait and RFA (n=39 separated in two Dbait regimens). After RFA, 39 mice were sacrificed for blinded pathological study, and 59 others were followed for survival analysis.Results: Mice treated by RFA-Dbait had significantly longer survival as compared to RFA alone (median survival: 56 vs 39 days, p<0.05) while RFA improved survival as compared to controls (median survival: 39 vs 28 days, p<0.05). Pathological studies of tumor slice have demonstrated significant decrease of tumor area and cancer cell viability in the RFA-Dbait group.Conclusions: While the implication of DNA repair activity in heat sensitivity remains unclear, our results show that the addition of Dbait to RFA enhances the antitumor response in this model and provide an experimental basis for the use of Dbait as an additional therapy to RFA.

Skull base chordomas: presentation of six cases and review of the literature.

Chordomas are uncommon tumours occuring from remnants of the notochord. They are mainly localized in the sacrococcygium, the spine and the skull base. We focused our study on skull base chordomas and reviewed 531 published cases and 6 cases diagnosed in our institution. The six cases diagnosed at our hospital are described with a special mention of a unique case presenting with meningitis. Clinical features, radiology, histopathology and survival with different treatments are reviewed. Skull base chordomas can occur at any age and are slightly more frequent in males. Patients complain most often of diplopia and headaches. Abducens nerve palsy is the commonest neurological finding. Radiological examination should include both CT-scan which shows extensive osteolysis, calcifications and contrast enhancement and MRI for topographical definition. Metastases rarely occur. Treatment remains controversial but combined surgery and radiotherapy is the best treatment with a 5 year survival rate of 75%.

Mesenteric venous thrombosis : MDCT features according to the underlying etiology : P1

Purpose: To work out certain, well-defined aetiologies frequently associated with mesenteric venous thrombosis (MVT) in order to predict a typical population at risk, since MVT is nowadays often incidentally detected on cross-sectional imaging. To demonstrate the MDCT features, frequency and extent of associated bowel ischemia according to the underlying pathology. Methods and materials: Our electronic database revealed 71 patients (25 women, mean age 55) with thrombosis of the superior and/or inferior mesenteric vein detected by MDCT between 2000 and 2008. Two radiologists jointly reviewed the corresponding MDCT features including intraluminal extension, underlying aetiology and associated bowel ischemia, if present. Results: MVT was associated with carcinoma in 31 (43.7%) patients (pancreas 21.1%, liver 9.9%, others 12.7%). Concomitant inflammation was seen in 15 (21.1%) patients (pancreatitis 11.3%, diverticulitis 4.2%, others 5.6%), whereas coagulation/hematologic disorders were found in 7 (9.9%) patients, liver cirrhosis in 6 (8.5%), mixed/miscellaneous causes in 5 (7%) and still unknown aetiologies in 5 patients (7%). MVT resulted from recent operations in 2 (2.8%) patients. MDCT features of venous bowel ischemia were present in 15 patients (21.1%). 46.5% of MVT were (sub) acute, while 53.5% chronic. The luminal extension was complete in 52.1%, subtotal (>50% of lumen) in 22.5% and partial (<50% of lumen) in 25.4% of patients, consisting either of blood clots (76.1%) or tumoral tissue (23.9%), the latter mainly due to pancreas adenocarcinoma (76.4%). Conclusion: MDCT features of MVT are seen with a wide range of underlying diseases. Signs of intestinal ischemia are infrequently associated, mostly occurring with coagulation/hematologic disorders (40%).

Early detection of lung cancer: a statement from an expert panel of the Swiss university hospitals on lung cancer screening.

The discussion about setting up a program for lung cancer screening was launched with the publication of the results of the National Lung Screening Trial, which suggested reduced mortality in high-risk subjects undergoing CT screening. However, important questions about the benefit-harm balance and the details of a screening program and its cost-effectiveness remain unanswered. A panel of specialists in chest radiology, respiratory medicine, epidemiology, and thoracic surgery representing all Swiss university hospitals prepared this joint statement following several meetings. The panel argues that premature and uncontrolled introduction of a lung cancer screening program may cause substantial harm that may remain undetected without rigorous quality control. This position paper focuses on the requirements of running such a program with the objective of harmonizing efforts across the involved specialties and institutions and defining quality standards. The underlying statement includes information on current evidence for a reduction in mortality with lung cancer screening and the potential epidemiologic implications of such a program in Switzerland. Furthermore, requirements for lung cancer screening centers are defined, and recommendations for both the CT technique and the algorithm for lung nodule assessment are provided. In addition, related issues such as patient management, registry, and funding are addressed. Based on the current state of the knowledge, the panel concludes that lung cancer screening in Switzerland should be undertaken exclusively within a national observational study in order to provide answers to several critical questions before considering broad population-based screening for lung cancer.