Dual-source CT for chest pain assessment

Comprehensive CT angiography protocols offering a simultaneous evaluation of pulmonary embolism, coronary stenoses and aortic disease are gaining attractiveness with recent CT technology. The aim of this study was to assess the diagnostic accuracy of a specific dual-source CT protocol for chest pain assessment. One hundred nine patients suffering from acute chest pain were examined on a dual-source CT scanner with ECG gating at a temporal resolution of 83 ms using a body-weight-adapted contrast material injection regimen. The images were evaluated for the cause of chest pain, and the coronary findings were correlated to invasive coronary angiography in 29 patients (27%). The files of patients with negative CT examinations were reviewed for further diagnoses. Technical limitations were insufficient contrast opacification in six and artifacts from respiration in three patients. The most frequent diagnoses were coronary stenoses, valvular and myocardial disease, pulmonary embolism, aortic aneurysm and dissection. Overall sensitivity for the identification of the cause of chest pain was 98%. Correlation to invasive coronary angiography showed 100% sensitivity and negative predictive value for coronary stenoses. Dual-source CT offers a comprehensive, robust and fast chest pain assessment

Dual-source computed tomography in patients with acute chest pain: feasibility and image quality

The aim of this study was to determine the feasibility and image quality of dual-source computed tomography angiography (DSCTA) in patients with acute chest pain for the assessment of the lung, thoracic aorta, and for pulmonary and coronary arteries. Sixty consecutive patients (32 female, 28 male, mean age 58.1±16.3 years) with acute chest pain underwent contrast-enhanced electrocardiography-gated DSCTA without prior beta-blocker administration. Vessel attenuation of different thoracic vascular territories was measured, and image quality was semi-quantitatively analyzed by two independent readers. Image quality of the thoracic aorta was diagnostic in all 60 patients, image quality of pulmonary arteries was diagnostic in 59, and image quality of coronary arteries was diagnostic in 58 patients. Pairwise intraindividual comparisons of attenuation values were small and ranged between 1±6 HU comparing right and left coronary artery and 56±9 HU comparing the pulmonary trunk and left ventricle. Mean attenuation was 291±65 HU in the ascending aorta, 334±93 HU in the pulmonary trunk, and 285±66 HU and 268±67 HU in the right and left coronary artery, respectively. DSCTA is feasible and provides diagnostic image quality of the thoracic aorta, pulmonary and coronary arteries in patients with acute chest pain

Combined vascular-excretory phase MDCT angiography in the preoperative evaluation of renal donors.

OBJECTIVE: The objective of our study was to test a dose reduction protocol that uses combined vascular-excretory phase scanning achieved by split IV contrast injection and compare it with conventional multiphase MDCT angiography (MDCTA) in evaluating potential renal donors. MATERIALS AND METHODS: This study is a review of MDCTA examinations of 54 potential renal donors scanned on 16- and 64-MDCT. The IV bolus was split: 50 mL was administered 3 minutes before scanning and a second injection of 70-100 mL was administered at a rate of 4-6 mL/s, with CT angiography started by bolus tracking. The second vascular (venous) phase was acquired 20 seconds later. Two readers reviewed the two phases, assessed vascular and parenchymal anatomy and variants or abnormalities, graded the added value of the venous phase on a 5-point scale, and took attenuation measurements in Hounsfield units. The operative notes of 39 subjects were reviewed as the reference standard for anatomic findings and compared with CT reports. RESULTS: All of the relevant anatomy findings, according to the operative notes, were accurately depicted by MDCTA, and all were well recognized on the arterial phase. The arterial phase combined information from the arterial, venous, parenchymal, and excretory phases. The venous phase was inferior to the arterial phase in assessing the renal arteries without additional venous, parenchymal, or excretory phase information. The mean renal artery attenuation was 355 HU in the first phase versus 173 HU in the second phase (p<0.0001). The mean renal vein attenuation was not significantly different between the two phases. The parenchymal system and excretory system were equally well depicted in both vascular phases. CONCLUSION: Split-bolus contrast injection and combined vascular-excretory phase scanning are adequate for studying potential renal donors and result in a marked decrease in multiphase scanning and, thus, in radiation dose

Routine use of modified CT Enterography in patients with acute abdominal pain

PURPOSE:To evaluate routine use of CT Enterography (CTE) in patients presenting with non-traumatic acute abdominal pain with respect to patient tolerance, imaging of intestinal detail along with conventional abdominal evaluation.MATERIALS AND METHODS:Modified CTE was performed in 165 consecutive patients with acute abdominal pain: ingestion, as tolerated, of 900-1200 ml of 2% barium suspension + 5 ml of Gastrografin over 45 min; 150 ml of iv contrast given in two boluses (50 and 100 ml) 3 min apart (split bolus injection protocol). Axial, coronal and sagittal reformats were reviewed by two radiologists and graded on a 5-point scale (5 best) in regard to GI tract luminal opacification and distension and abdominal organ and vascular enhancement.RESULTS:In 81 patients the cause of abdominal pain was identified (intestinal in 54 and extraintestinal in 27). Oral contrast reached cecum in 76% of the patients and the small bowel was well distended and opacified (medians=4). Mucosa detail was good (median=3) and there was significant (p<0.0001) correlation between bowel opacification and distension for both jejunum and ileum. A combined nephrographic and excretory phase was achieved (medians 4 and 5, respectively), while the great vessels were well opacified, allowing for vascular evaluation (median=5). The rest of the abdominal structures were well visualized.CONCLUSION:Modified CTE is well tolerated by patients with acute non-traumatic abdominal pain, and can be used routinely as a non-invasive examination informative of bowel, vessel and organ pathology in Emergency Department patients.Comment inThe routine use of CT enterography with positive enteric contrast in patients with non-traumatic acute abdominal pain. [Eur J Radiol. 2011

Value of customized scan timing determined by tracking liver enhancement in oncology patients.

PURPOSE: To assess the value of liver parenchyma enhancement tracking for liver multidetector computed tomography (CT) in patients with potential hypoattenuating liver metastases. MATERIALS AND METHODS: Institutional review board approved this Health Insurance Portability and Accountability Act-compliant study. We reviewed the chest-abdomen-pelvis CTs of 120 consecutive patients scanned on 16-/64-row multidetector CT after receiving 52 g I in 50 seconds. Liver scanning started 65 seconds after injection-start in 59 patients, whereas in 61 patients, scanning started automatically when liver enhancement reached 50 Hounsfield units on low-dose continuous attenuation tracking. Enhancement of liver parenchyma, aorta, portal, and hepatic veins was measured. Two readers graded conspicuity and recorded attenuation of hypoattenuating lesions. RESULTS: We identified 663 metastases in 74 patients. Scan-delay range in the triggered group was 53 to 83 seconds. Compared with the fixed-delay group, in the triggered group, mean number of metastases per patient with metastases was larger, liver attenuation and enhancement were higher, and median metastasis conspicuity grade was higher (all P < 0.05). CONCLUSIONS: Automatic scan triggering based on liver parenchyma enhancement tracking produces consistently higher liver parenchymal enhancement and increased metastasis conspicuity than fixed delay

Comprehensive preoperative assessment of pancreatic adenocarcinoma with 64-section volumetric CT

Pancreatic adenocarcinoma is a common gastrointestinal malignancythat has a poor prognosis and for which successful surgical resection isthe only method of cure. Preoperative staging and assessment can beperformed with a number of modalities. Multidetector (64-section)volumetric computed tomography (CT) allows rapid anatomic coveragecoupled with excellent spatial resolution. Understanding the technicalparameters necessary for successful pancreatic CT angiography iscrucial. Carefully timed scan acquisition maximizes the difference inattenuation between the neoplasm and the pancreatic parenchyma andallows accurate local and distant staging as well as assessment of localresectability. In addition, angiographic data sets can be rendered tocreate displays of the local venous and arterial anatomy that are familiarto surgeons. Advanced rendering can also be used to create pancreaticographictype images. The TNM system of staging for pancreaticadenocarcinoma is not frequently included in radiology reporting but isimportant for deciding on optimal therapy and neoadjuvant therapy

Split-Bolus CT for Patients with abdominal Pain

no abstract availabl

Pancreatic adenocarcinoma: value of multidetector CT angiography in preoperative evaluation

PURPOSE: To retrospectively assess the sensitivity and specificity of multidetector computed tomographic (CT) angiography in the preoperative evaluation of pancreatic adenocarcinoma by using surgical findings as the reference standard.MATERIALS AND METHODS: The institutional review board approved this HIPAA-compliant study; informed consent was waived. We reviewed CT reports, surgical notes, and pathology reports from 114 patients with pancreatic or distal cholangiocarcinoma who underwent multidetector CT angiography and surgery at our institution between March 2003 and March 2006. When CT findings and surgical reports were discordant, radiologists experienced in pancreatic imaging retrospectively reviewed images for lesion resectability; four-, eight-, 16-, and 64-row CT scanners were used in 54, 19, 25, and 16 patients, respectively. Collimation of 1.25 mm was used for four- and eight-row CT and 0.5 or 0.625 mm for 16- and 64-row CT. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for resectability were calculated for initial clinical interpretation and blinded retrospective review.RESULTS: Eighty-eight patients had resectable lesions according to CT angiographic criteria (group A: 46 women, 42 men; mean age, 67 years; age range, 39-85 years): resection was aborted in 10 patients (11%). Twenty-six patients underwent surgery despite lesion unresectability assessed according to CT angiographic criteria (group B: 16 women, 10 men; mean age, 62 years; age range, 33-83 years); all lesions were confirmed as unresectable. The initial clinical interpretation of CT angiographic scans in all 114 patients had 100% sensitivity in the detection of resectability, 72% specificity, 89% PPV, and 100% NPV. These parameters did not appear to vary among different types of scanner. With the blinded retrospective evaluation by experienced readers, specificity increased to 94% and PPV to 98%, with no difference in sensitivity and NPV.CONCLUSION: Multidetector CT angiography is an effective preoperative tool that reduces the number of aborted pancreatic resections; there is no evidence from this retrospective study suggesting varying results from the various generations of multidetector CT scanners used

Virtual Whipple: preoperative surgical planning with volume-rendered MDCT images to identify arterial variants relevant to the Whipple procedure

OBJECTIVE: The purposes of this study were to combine a thorough understanding of the technical aspects of the Whipple procedure with advanced rendering techniques by introducing a virtual Whipple procedure and to evaluate the utility of this new rendering technique in prediction of the arterial variants that cross the anticipated surgical resection plane. CONCLUSION: The virtual Whipple is a novel technique that follows the complex surgical steps in a Whipple procedure. Three-dimensional reconstructed angiographic images are used to identify arterial variants for the surgeon as part of the preoperative radiologic assessment of pancreatic and ampullary tumors