[Improved image quality of the cervical spine neck CT using an arm traction device]. / Verbesserte Bildqualität der Halswirbelsäulen-CT mittels Armzugvorrichtung.

BACKGROUND: The assessment of the cervico-thoracic junction in the neck CT is frequently hampered by streak artifacts from the shoulder girdles. PURPOSE: To evaluate the effects of an optimized patient positioning through the use of an arm traction device. MATERIALS AND METHODS: 25 patients (age [mean ± standard deviation]: 58.9 ± 11.6 years; sex [m:f]: 15:10) underwent a neck CT using an arm traction device together. Further 25 patients underwent this in standard positioning (59.8 ± 15.2 years; 16:9). An experienced neuroradiologist determined the last free accessible vertebra on the CT scout view and assessed the image quality of the intervertebral disc space of the lower neck on a three-point grading scale. The procedure was evaluated by the medical-technical radiology assistants performing it. RESULTS: The last free accessible vertebra on CT scout was statistically significant one vertebra lower using an arm traction device, yielding on average the sixth cervical vertebra (p = 0.010). Subjective image quality increased in all evaluated intervertebral disc spaces (median and absolute frequencies [good/middle/bad]: 1.0 [53/21/8] vs. 2.0 [41/30/24]), resulting in a statistically significant effect between the cervical vertebra 6/7 (p = 0.0041). The traction device approach was rated to be suitable for daily routine in the categories of patient's cooperation (good), comprehensibility for the patient (84%) and management for the assistants (good). CONCLUSION: Using an arm traction device on neck CT both the accessibility of vertebra on CT scout increased and image quality of the cervico-thoracic junction improved. The simply applicable device could be favourable for cooperative patients with lower neck pathology.

Shape Modification is Common in Woven EndoBridge-Treated Intracranial Aneurysms: A Longitudinal Quantitative Analysis Study.

BACKGROUND AND PURPOSE: After endovascular treatment of intracranial aneurysms with the Woven EndoBridge (WEB) device, worsening of aneurysm occlusion or re-opening was reported to be possibly associated with WEB shape modification. This study analyzed quantitatively the WEB shape modification with time in association with anatomic results. MATERIALS AND METHODS: Thirty patients with 32 WEB-treated intracranial aneurysms fulfilled the inclusion criteria of cranial CT at baseline (day of intervention) and a follow-up CT at least >1 months' later (median follow-up time, 11.4 months; interquartile range, 6.5-21.5 months). Adequate occlusion was observed in 84.4%, and aneurysm remnant, in 15.6%. WEB shape modification was quantified by a semiautomated approach on CT scans. Time courses were evaluated graphically and analytically; association analyses were performed by linear mixed-effects regression models. RESULTS: In 29/32 WEB devices (90.6%), the reduction in height was found to be at least 5%. The decrease in height with time was significantly associated with the time interval in days since the intervention (P < .0001): A stronger decrease in WEB height was associated with a longer time since the intervention (median reduction in 1 year, 19.2%; range, 8.6%-52.3%). No significant association was found with the quality of aneurysm occlusion, device size, rupture status of the aneurysm, aneurysm location, and reintervention rate. CONCLUSIONS: Shape modification was common in WEB-treated intracranial aneurysms with a median height reduction of 19.2% in 1 year. The quality of aneurysm occlusion was not associated with WEB modification.

[Stent-assisted intracranial angioplasty: potentials and limitations of pre- and postinterventional CT angiography]. / Stentgestützte intrakranielle Angioplastie: Möglichkeiten und Grenzen der prä- und postinterventionellen CT-Angiografie.

PURPOSE: CT angiography (CTA) is a noninvasive technique for evaluating intracranial arterial stenoses and for following up on intracranial stents. We analyzed a series of patients to assess the capabilities of CTA with respect to preinterventional und postinterventional diagnostic imaging for stent-assisted intracranial angioplasty. MATERIALS AND METHODS: We examined 8 patients with 9 symptomatic intracranial arterial stenoses before and after stent placement with CTA. CT angiographies were compared to the periprocedural conventional angiography with regard to the quality of the visualization as well as the dimensions of the identified stenoses and the implanted stents. RESULTS: The extent of the preinterventional intracranial stenoses identified with CTA differed between -15% to + 12% from conventional angiography. In any case we were able to assess stent position, expansion, and perfusion with postinterventional CTA. The mean residual stenosis after stent placement was 33% (13 - 48%) measured with conventional angiography and it was accurately estimated with a difference of +/- 15% in 5 of 9 stents by CTA. 4 residual stenoses were underestimated or overestimated between -20% and + 26%. Further CTA controls of several patients showed good visualization of in-stent neointimal hyperplasia. CONCLUSION: CTA is useful for stent planning and follow-up of symptomatic intracranial stenoses. Intracranial stents and their lumina are adequately visualized by CTA, especially in vertebrobasilar vessels. However, residual stenosis and restenosis especially in the intracranial internal carotid artery and in the presence of calcified plaques may be incorrectly estimated by CTA. In case of doubt patients must undergo invasive angiography. In summary the use of CTA is a possibility for the primary follow-up of intracranial stents. It cannot generally prevent further diagnostics, but it is a potential method for reducing invasive angiography.

Evaluation of acute mesenteric ischemia: accuracy of biphasic mesenteric multi-detector CT angiography.

The purpose of this study was to explore the accuracy of multi-detector row helical CT (MDCT), using a biphasic mesenteric angiography protocol for evaluation of acute mesenteric ischemia (AMI). In total, 79 consecutive patients with clinical signs of AMI underwent contrast enhanced 16- or 40-channel MDCT. MDCT findings were correlated with surgery, endoscopy and clinical outcome. Sensitivity, specificity, and positive and negative predictive values were calculated using the patients in which AMI had been excluded as a control group. In 28 patients the final diagnosis was AMI. In 27 patients (96.4%) MDCT correctly diagnosed AMI (specificity of 97.9%). A sensitivity of 93%, specificity of 100%, and positive and negative predictive values of 100% and 94%, respectively were achieved for the CT findings of visceral artery occlusion, intestinal pneumatosis, portomesenteric venous gas or bowel wall thickening in combination with either portomesenteric thrombosis or solid organ infarction. Our findings suggest that mesenteric MDCT angiography is an accurate tool for fast diagnostic work-up of patients with suspected AMI.

MR imaging and quantification of the movement of the lamina terminalis depending on the CSF dynamics.

BACKGROUND AND PURPOSE: Brain pulsation is a well-known observation in neurosurgery, but methods for its visualization on MR imaging, like phase imaging, do not provide a detailed structural view. We prospectively investigated electrocardiographic (ECG)-gated cine true fast imaging with steady-state precession (FISP) sequence on volunteers to test a sequence for demonstrating brain pulsation and movements of intracranial structures related to CSF dynamics. MATERIALS AND METHODS: Eleven healthy volunteers were investigated with prospectively ECG-gated cine true-FISP in the midsagittal plane. A total of 50 phases were recorded per cardiac cycle and per volunteer. The lamina terminalis was chosen to study the pulsatility of the brain, and the optic recess diameter was chosen for means of objective quantification of the degree of pulsatility. RESULTS: Pulsatile motion of the lamina terminalis was apparent in all volunteers on the cine mode. The mean diameter of the optic recess was 2.5 mm. The greatest change in diameter in 1 volunteer was 1.5 mm. The mean change in diameter was 40% during 1 cardiac cycle. CONCLUSIONS: Cine true-FISP sequence is a well-suited method for investigations of passive movements of the ventricular system. It shows pulsations of the brain as well as passive changes caused by CSF dynamics with high temporal and spatial resolution.

Detection and localization of acute upper and lower gastrointestinal (GI) bleeding with arterial phase multi-detector row helical CT.

The purpose of this study was to evaluate the accuracy of multi-detector row helical CT (MDCT) for detection and localization of acute upper and lower gastrointestinal (GI) hemorrhage or intraperitoneal bleeding. Thirty-six consecutive patients with clinical signs of acute bleeding underwent biphasic (16- or 40-channel) MDCT. MDCT findings were correlated with endoscopy, angiography or surgery. Among the 36 patients evaluated, 26 were examined for GI bleeding and 10 for intraperitoneal hemorrhage. Confirmed sites of GI bleeding were the stomach (n = 5), duodenum (n = 5), small bowel (n = 6), large bowel (n = 8) and rectum (n = 2). The correct site of bleeding was identifiable on MDCT in 24/26 patients with GI bleeding. In 20 of these 24 patients, active CM extravasation was apparent during the exam. Among the ten patients with intraperitoneal hemorrhage, MDCT correctly identified the bleeding source in nine patients. Our findings suggest that fast and accurate localization of acute gastrointestinal and intraperitoneal bleeding is achievable on MDCT.

Acute gastrointestinal bleeding: value of MDCT.

Contrast-enhanced multidetector row helical computed tomography (MDCT) scanning is establishing itself as a rapid, noninvasive, and accurate diagnostic method in suspected acute gastrointestinal bleeding. Active bleeding can be depicted as an area of focal high attenuation within the bowel lumen on arterial phase MDCT images. New MDCT technologies facilitate three-dimensional image reconstruction, and higher temporal resolution is available with new MDCT scanner generations. This allows for the acquisition of arterial- and portal-venous phase images of the whole abdomen, revealing potential bleeding sources and simultaneously depict morphological changes in the abdomen, such as intestinal tumors. This article gives an overview of available diagnostic modalities in assessing gastrointestinal (GI) tract hemorrhage, with a special emphasis on new MDCT technology.