Extravascular incidental findings in run-off CT angiography in patients with acute limb ischaemia: incidence and clinical relevance.

AIM: To evaluate the incidence and clinical relevance of extravascular incidental findings (EVIFs) in CT angiography of the abdominal aorta and lower extremities (run-off CTA) in patients presenting with acute limb ischaemia (ALI). MATERIALS AND METHODS: In this institutional review board-approved, retrospective study, 141 run-off CTA examinations conducted between 2005 and 2013 of patients (67 women, mean age 80 years; 74 men, mean age 69 years) presenting with clinical symptoms of ALI were re-evaluated by two radiologists (2 and 7 years of experience in interpreting run-off CTA). Imaging was conducted using 16- and 64-section CT systems. Image acquisition ranged from the costodiaphragmatic recess to the forefoot. The medical history form of each patient served as the standard of reference for assessment of incidence of EVIFs. CT morphology was assessed to assign EVIFs to one of three categories of clinical relevance: (I) immediate, (II) potential, and (III) no clinical relevance. RESULTS: Thirty-eight patients had category I findings, including four patients (2.8%) with previously unknown malignancy and 67 patients with category II EVIFs. In total 473 extravascular EVIFs were found in 141 patients: 52 category I, 163 category II and 258 category III. CONCLUSION: EVIFs with immediate clinical relevance are very common in run-off CTA in patients presenting with acute peripheral artery disease. Therefore, it is important to evaluate all body regions included in a CT examination carefully, even if the clinical focus is on vascular evaluation. The adequate classification of these EVIFs is required to avoid possible unnecessary diagnostic work-up with associated risks and costs.

Topographic analysis and evaluation of anatomical landmarks for placement of central venous catheters based on conventional chest X-ray and computed tomography.

BACKGROUND: Positioning central venous catheters (CVCs) in the proper part of the superior vena cava (SVC) is difficult. The aim of this exploratory study was to analyse topographic relationships of the extrapericardial SVC using chest X-ray (CXR) and computed tomography (CT). This included an appraisal of rules for optimal CVC tip placement. METHODS: We retrospectively evaluated 100 patients with CVCs who underwent bedside CXR and CT on the same day. Distances between the sternoclavicular joint (SCJ), tracheal carina, SVC origin, pericardial reflection, and CVC tip were analysed on CT and, if visible, on CXR. These measurements served to locate the extrapericardial SVC in relation to anatomical landmarks. Different strategies for CVC tip positioning were evaluated. RESULTS: The mean (standard deviation) extrapericardial length of the SVC was 26 (12) mm. The average position of the pericardial reflection was 5 mm below the carina (range, 29 mm below to 25 mm above). In our patient population, the best results in terms of tip positions in the extrapericardial SVC would have been achieved by using 85% of the SCJ-to-carina distance (in 86%) or by positioning the CVC tip 9 mm above the carina (in 84% of patients). CONCLUSIONS: The extrapericardial part of the SVC varies considerably in length and position, and rules of thumb based on anatomical landmarks should be used cautiously. In our series, using 85% of the SCJ-to-carina distance or placing the CVC tip 9 mm above the carina would have resulted in a high percentage of positions in the extrapericardial SVC.

Optimal table feed in run-off CT angiography in patients with abdominal aortic aneurysms.

OBJECTIVES: To assess the influence of different table feeds (TFs) on vascular enhancement and image quality in patients with an abdominal aortic aneurysm (AAA) undergoing computed tomography (CT) angiography of the lower extremities (run-off CTA). METHODS: Seventy-nine patients (71 ± 8 years) with an AAA (>30 mm) who underwent run-off CTA between January 2004 and August 2011 were included in this retrospective institutional review board-approved study. Run-off CTA was conducted using 16- and 64-row CT. The range of TFs was 30-86 mm/s and was categorised in quartiles TF1 (32.6 ± 1.9 mm/s), TF2 (38.9 ± 0.9 mm/s), TF3 (43.9 ± 3.1 mm/s) and TF4 (57.4 ± 10.5 mm/s). Image quality was rated independently by two radiologists and vessel enhancement was assessed. RESULTS: Image quality was diagnostic at all aortic, pelvic and almost all thigh levels. Below the knee, the number of diagnostic levels was highest for TF1 and decreased to TF4. Arterial enhancement between the aorta and fibular trunk was not different in all TF groups, P > 0.05. At the calf and foot strongest arterial enhancement was noted for TF1 and TF2 and decreased to TF4, P < 0.01. CONCLUSION: Results indicate that the highest image quality of run-off CTA in patients with an AAA may be obtained using table feeds measuring 30-35 mm/s. KEY POINTS: • CTA has become a key investigation for peripheral vascular disease. • Run-off CTA is more complex in patients with an abdominal aortic aneurysm. • Run-off CTA is feasible with a short bolus of intravenous contrast medium. • A constant 30-35 mm/s table feed provides the highest likelihood of diagnostic images.

New insights into peripartum cardiomyopathy using cardiac magnetic resonance imaging.

PURPOSE: The aim of this study was to evaluate a comprehensive cardiac magnetic resonance (MR) imaging approach in patients with peripartum cardiomyopathy (PPCM). The focus was on inflammatory myocardial changes. MATERIALS AND METHODS: Retrospective analysis of 12 cardiac MR examinations was performed in 6 patients with PPCM. The protocol comprised cine sequences for the determination of chamber sizes and function. T 2-weighted sequences for determination of edema (T 2 ratio), T 1-weighted images for measurement of early gadolinium enhancement ratio (EGER), and late gadolinium enhancement (LGE) sequences were used for tissue characterization. 5 examinations were performed during the acute stage, and 7 examinations were performed during the course of the disease. RESULTS: Initially, 3 of 5 patients presented with an elevated left ventricular end-diastolic volume (LVEDV); in one patient, the LVEDV was in the upper range. In 4 of 5 subjects, the left ventricular ejection fraction (LVEF) was decreased. The T 2 ratio and EGER values were initially elevated in all women. No LGE was detected in initial scans. In follow-up examinations, the LVEDV decreased and the LVEF increased in all patients. Tissue-characterizing parameters decreased to normal in all but 1 patient. 2 patients showing LGE did not present a favorable clinical course. CONCLUSION: Myocardial inflammation was detected in the acute stage of PPCM, which was mostly transient. In our small group, patients showing LGE had a non-favorable clinical course. Future studies should include tissue-characterizing parameters, such as T 2 ratio and EGER. Thus, further insights into pathophysiology can be gained and therapeutic effects can be measured in a more extensive manner.

High-resolution T2-weighted abdominal magnetic resonance imaging using respiratory triggering: impact of butylscopolamine on image quality.

BACKGROUND: Respiratory triggering allows the acquisition of high-resolution magnetic resonance (MR) images of the upper abdomen. However, the depiction of organs close to the gastrointestinal tract can be considerably impaired by ghosting artifacts and blurring caused by bowel peristalsis. PURPOSE: To evaluate the effect of gastrointestinal motion suppression by intramuscular butylscopolamine administration on the image quality of a respiratory-triggered T2-weighted turbo spin-echo (T2w TSE) sequence of the upper abdomen. MATERIAL AND METHODS: Images of 46 patients were retrospectively analyzed. Twenty-four patients had received intramuscular injection of 40 mg butylscopolamine immediately before MR imaging. Fourteen of the 24 patients in the butylscopolamine group underwent repeat imaging after a mean of 29 min. Quantitative analysis of the ghosting artifacts was done by measuring signal intensities in regions of interest placed in air anterior to the patient. In addition, image quality was assessed qualitatively by two radiologists by consensus. RESULTS: Spasmolytic medication with butylscopolamine reduced ghosting artifacts and significantly improved image quality of the respiratory-triggered T2w TSE sequence. The most pronounced effect of butylscopolamine administration on image quality was found for the pancreas and the left hepatic lobe. The rate of examinations with excellent or good depiction of the pancreas and the left hepatic lobe in the group without premedication and in the butylscopolamine group was 55% vs. 96% (pancreatic head), 35% vs. 88% (pancreatic body), 43% vs. 96% (pancreatic tail), and 45% vs. 83% (left hepatic lobe), respectively. Regarding the duration of the effect of intramuscular butylscopolamine, repeat imaging after a mean of 29 min did not result in a significant deterioration of image quality. CONCLUSION: Intramuscular butylscopolamine administration significantly improves image quality of respiratory-triggered T2-weighted abdominal MR imaging by persistent reduction of peristaltic artifacts. MR imaging of the liver and pancreas in particular benefits from the suppression of gastrointestinal peristalsis by butylscopolamine.

The exocytotic signaling pathway induced by nerve growth factor in the presence of lyso-phosphatidylserine in rat peritoneal mast cells involves a type D phospholipase.

Nerve growth factor (NGF) has been previously shown to induce exocytosis in rat peritoneal mast cells (RPMCs) in the presence of lyso-phosphatidylserine (lysoPS) by interacting with high-affinity NGF receptors of the TrkA-type. In RPMCs, type D phosphatidylcholine-selective phospholipases (PLDs) have been postulated to be involved in some exocytotic signaling pathways induced by different agonists. The aim of the present study was to assess a putative functional role of PLD for NGF/lysoPS-induced exocytosis in RPMCs. In 1-[14C]palmitoyl-2-lyso-3-phosphatidylcholine-labelled RPMCs, NGF/lysoPS stimulated the formation of diacylglycerol (DAG) and, in the presence of ethanol (1% [v/v]), phosphatidylethanol (PEtOH). These data indicate PLD-activation by NGF/lysoPS in RPMCs. Preincubation of RPMCs for 2 min with ethanol, an inhibitor of PLD-derived DAG-formation, dose-dependently (IC(50): 0.6% [v/v]) and agonist-selectively inhibited the NGF/lysoPS induced release of [3H]serotonin ([3H]5-HT) in [3H]5-HT-loaded RPMCs, confirming the functional importance of PLD-action. Exocytosis and PEtOH-production was potently inhibited by the broad-spectrum serine/threonine kinase inhibitor staurosporine and activated by the protein kinase C(PKC)-activator PMA (phorbol-12-myristate-13-acetate) suggesting a role for PKC as mediator for NGF/lysoPS-induced activation of PLD.