Outbreak of hepatitis C virus infections originating from a breach in safe injection practices before contrast-enhanced computed tomography scanning.

Four patients who underwent contrast-enhanced computed tomography (CT) scanning were infected with hepatitis C virus from a contaminated multi-dose vial of NaCl. The outbreak likely occurred due to a breach in safe injection practices, resulting in contamination of the vial. Not all patients exposed to the same vial were infected. The uneven distribution of infections could be attributed to a stochastic effect of a low infectious dose. This implies that outbreak investigations need to be extended to all patients scheduled before and after the first identified infected patient to confirm or rule out nosocomial transmission.

Imaging algorithms and CT protocols in trauma patients: survey of Swiss emergency centers.

OBJECTIVES: To identify imaging algorithms and indications, CT protocols, and radiation doses in polytrauma patients in Swiss trauma centres. METHODS: An online survey with multiple choice questions and free-text responses was sent to authorized level-I trauma centres in Switzerland. RESULTS: All centres responded and indicated that they have internal standardized imaging algorithms for polytrauma patients. Nine of 12 centres (75 %) perform whole-body CT (WBCT) after focused assessment with sonography for trauma (FAST) and conventional radiography; 3/12 (25 %) use WBCT for initial imaging. Indications for WBCT were similar across centres being based on trauma mechanisms, vital signs, and presence of multiple injuries. Seven of 12 centres (58 %) perform an arterial and venous phase of the abdomen in split-bolus technique. Six of 12 centres (50 %) use multiphase protocols of the head (n = 3) and abdomen (n = 4), whereas 6/12 (50 %) use single-phase protocols for WBCT. Arm position was on the patient`s body during scanning (3/12, 25 %), alongside the body (2/12, 17 %), above the head (2/12, 17 %), or was changed during scanning (5/12, 42 %). Radiation doses showed large variations across centres ranging from 1268-3988 mGy*cm (DLP) per WBCT. CONCLUSIONS: Imaging algorithms in polytrauma patients are standardized within, but vary across Swiss trauma centres, similar to the individual WBCT protocols, resulting in large variations in associated radiation doses. KEY POINTS: • Swiss trauma centres have internal standardized imaging algorithms for trauma patients • Whole-body CT is most commonly used for imaging of trauma patients • CT protocols and radiation doses vary greatly across Swiss trauma centres.

Relevance of asymptomatic spinal MRI lesions in patients with multiple sclerosis.

BACKGROUND: The impact of new asymptomatic spinal cord lesions (a-SL) in multiple sclerosis (MS) course is poorly characterized. OBJECTIVE: The objective of this research paper is to assess the prognostic value of a-SL in predicting MS course. METHODS: Relapsing-remitting MS patients who received serial MRI (brain and spinal) at baseline (t1) and within 12 to 36 months (t2) during clinical stability, and had a follow-up (t2-t3) ⩾24 months were included. Relapses and disability progression were evaluated between t2 and t3. RESULTS: Of 413 consecutive screened MS patients, 103 patients (65 females, median age 43 years) were included. After a median t1-t2 interval of 17 (IQR 13-26) months, 25.2% and 43.7% patients had ⩾1 new a-SL (a-SL+) and asymptomatic brain lesions (a-BL+), respectively. Relapse risk between t2 and t3 (median interval: 42 (IQR 32-57.5) months) was significantly increased in a-SL+ and/or a-BL+ vs a-BL- and a-SL- (HR = 2.31, 95% CI = 1.13-4.72, p = 0.02). No differences in the risk of disability progression were found in a-SL+ and/or a-BL+ vs a-SL- and a-BL-. CONCLUSION: a-SL occur in one-quarter of clinically stable RRMS, and combined with a-BL contribute significantly in predicting future disease course.

Chemical shift imaging at 3 Tesla: effect of echo time on assessing bone marrow abnormalities.

OBJECTIVE: Our purpose is to test the effect of varied in-phase (IP) and opposed-phase (OP) sequence order on characterizing marrow signal changes at 3T. MATERIALS AND METHODS: The study was HIPAA compliant and IRB approved. Informed consent was waived. At 3T, IP and OP sequences were acquired in three patients with biopsy-proven osteosarcomas, using two methods: approach 1 (OP acquisition before IP acquisition) and approach 2 (OP after IP). Signal intensity (SI) measurements in 12 locations of biopsy-proven osteosarcoma and in six locations with normal bone marrow were performed independently by two experienced musculoskeletal radiologists. The signal intensity ratio (SIR) was measured within the marrow where there was T1 signal lower than skeletal muscle. A SIR < 20 % on the OP compared with IP imaging was considered positive for marrow replacement, while SIR > = 20 % was considered negative. Interobserver agreement was measured by the Lin concordance correlation coefficient (CCC). RESULTS: In 75 % (18/24) of locations within the biopsy-proven tumors, the SIR was >20 % (SI drop more than 20 % in OP compared to IP) using approach 2 and in 100 % (24/24) of the locations the SIR was <20 % (SI drop less than 20 % in OP compared to IP) using approach 1, indicating a high percentage of false-negative results by approach 2, and no false-negative results with approach 1. There was good agreement between observer measurement (CCC = 0.96). CONCLUSIONS: At 3T, the OP sequence should be acquired prior to the IP sequence, because susceptibility artifacts on a later-acquired OP sequence may lead to an erroneous interpretation of marrow signal abnormalities.

Gradient-echo in-phase and opposed-phase chemical shift imaging: role in evaluating bone marrow.

Chemical shift imaging (CSI) provides valuable information for assessing the bone marrow, while adding little to total examination time. In this article, we review the uses of CSI for evaluating bone marrow abnormalities. CSI can be used for differentiating marrow-replacing lesions from a range of non-marrow-replacing processes, although the sequence is associated with technical limitations and pitfalls. Particularly at 3 T, susceptibility artefacts are prevalent, and optimal technical parameters must be implemented with appropriate choices for echo times.

High-resolution 3T MR neurography of the brachial plexus and its branches, with emphasis on 3D imaging.

With advancement in 3D imaging, better fat-suppression techniques, and superior coil designs for MR imaging and the increasing availability and use of 3T magnets, the visualization of the complexity of the brachial plexus has become facile. The relevant imaging findings are described for normal and pathologic conditions of the brachial plexus. These radiologic findings are supported by clinical and/or EMG/surgical data, and corresponding high-resolution MR neurography images are illustrated. Because the brachial plexus can be affected by a plethora of pathologies, resulting in often serious and disabling complications, a better radiologic insight has great potential in aiding physicians in rendering superior services to patients.

Angiosarcoma of the pulmonary trunk mimicking pulmonary thromboembolic disease. A case report.

We report on a 59-year-old male patient who suffered from dyspnea, cough and hemoptysis. Initial chest X-ray revealed a prominent right pulmonary artery (RPA) and MR imaging showed a "filling defect" within the main pulmonary trunk and RPA indicating pulmonary thromboembolic disease. Despite systemic anticoagulation, symptoms progressed. Follow-up CT showed an enlarging "filling defect" with additional extension into the left pulmonary artery as well as multiple intrapulmonary nodules. Lesion biopsy revealed a pulmonary artery angiosarcoma. Imaging findings are presented. Our case illustrates that pulmonary artery angiosarcoma should be included in the differential diagnosis of pulmonary thromboembolic disease in cases where a) symptoms do not respond to anticoagulation, b) no source of thrombi/emboli can be detected and c) pulmonary nodules/metastases develop on follow-up.

Repair of infrapopliteal postembolectomy complications with variant embolization techniques.

Infrapopliteal pseudoaneurysms and arteriovenous fistulae are known complications of Fogarty balloon embolectomy. Management of these complications in two patients with associated critical foot ischemia by modified interventional embolization techniques is described.

[Osteofibrous dysplasia and its differential diagnosis]. / Osteofibröse Dysplasie und ihre Differentialdiagnose.

We present a case of a 13 year old girl with swelling and pain of the right lower leg persisting for four months. The radiological and histological diagnosis is osteofibrous dysplasia. Osteofibrous dysplasia is a rare bone lesion predominantly affecting the cortex of the tibia. Almost all patients are younger than ten years at presentation. Swelling is a typical clinical manifestation. Radiologically and even histologically the distinction between the osteofibrous dysplasia and the more aggressive adamantinoma can be difficult. Other bone lesions potentially mimicking osteofibrous dysplasia include: fibrous dysplasia, osteoid osteoma, osteosarcoma, osteoblastoma and intracortical Brodie's abcess. The natural course of the disease is unpredictable. Lesions with typical radiological appearance are considered to be "no touch lesions". In equivocal cases block resection (with both a diagnostic and therapeutic purpose) should be performed.