Dual-energy CT angiography in peripheral arterial occlusive disease-accuracy of maximum intensity projections in clinical routine and subgroup analysis.

OBJECTIVE: To evaluate the accuracy of dual-energy CT angiography (DE-CTA) maximum intensity projections (MIPs) in symptomatic peripheral arterial occlusive disease (PAOD). METHODS: In 58 patients, DE-CTA of the lower extremities was performed on dual-source CT. In a maximum of 35 arterial segments, severity of the most stenotic lesion was graded (<10%, 10-49% and 50-99% luminal narrowing or occlusion) independently by two radiologists, with DSA serving as the reference standard. RESULTS: In DSA, 52.3% of segments were significantly stenosed or occluded. Agreement of DE-CTA MIPs with DSA was good in the aorto-iliac and femoro-popliteal regions (κ = 0.72; κ = 0.66), moderate in the crural region (κ = 0.55), slight in pedal arteries (κ = 0.10) and very good in bypass segments (κ = 0.81). Accuracy was 88%, 78%, 74%, 55% and 82% for the respective territories and moderate (75%) overall, with good sensitivity (84%) and moderate specificity (67%). Sensitivity and specificity was 82% and 76% in claudicants and 84% and 61% in patients with critical limb ischaemia. CONCLUSION: While correlating well with DSA above the knee, accuracy of DE-CTA MIPs appeared to be moderate in the calf and largely insufficient in calcified pedal arteries, especially in patients with critical limb ischaemia.

Feasibility and potential value of flat-panel detector-based computed tomography in myelography after spinal surgery.

OBJECT: The purpose of this study was to assess the value of myelography using flat-panel detector-based computed tomography (fpCT) in 5 patients in whom the image quality of multislice CT (MSCT) or MR imaging was limited by metal artifacts. METHODS: The application of fpCT to myelographic imaging of the lumbar spine and cervicothoracic junction after surgery was feasible. Multiplanar, preferably sagittal, and 3D reconstructions adequately depicted disc space implants and provided high resolution images of osseous structures. RESULTS: The images obtained with fpCT allowed evaluation of anatomical details such as single nerve roots and proved especially valuable in a patient with impaired MR imaging results caused by metal artifacts from an intraoperative abrasion. In a case of recurrent disc herniation, imaging results of myelographic fpCT and MSCT scanning were in good agreement. CONCLUSIONS: The novel imaging technique the authors describe yielded adequate results in patients with a history of spinal surgery, may be superior to MSCT scanning in depicting osseous structures and metallic implants, and has the potential to provide multilevel spinal images. Myelographic fpCT scanning may be the preferred modality in patients with expected or known metal artifacts on myelographic MSCT scans and/or MR images.

When coughing can cause stroke--a case-based update on cerebral air embolism complicating biopsy of the lung.

Introducing gas to the circulation is a largely iatrogenic problem which can result in serious morbidity and even death. We report a case of CT-guided needle biopsy of a pulmonary lesion complicated by acute stroke. The English literature on cerebral air embolism is reviewed, including an update of current opinions on its pathomechanism, diagnostic findings, therapeutic strategies, and means of prevention.

Aortic development and anomalies.

Development of the aorta takes place during the third week of gestation. It is a complex process that can lead to a variety of congenital variants and pathological anomalies. In diagnostic and interventional radiology, knowledge of aortic abnormalities and variant branching sequence is crucially important. This article gives a systematic overview of anatomical variability of the aorta.