Value of three-dimensional reconstructions in pancreatic carcinoma using multidetector CT:Initial results

AIM:To evaluate the use of three-dimensional imaging of pancreatic carcinoma using multidetector computed tomography(CT)in a prospective study.METHODS:Ten patients with suspected pancreatic tumors were examined prospectively using multidetec-tor CT(Somatom Sensation 16,Siemens,Erlangen,Germany).The images were evaluated for the pres-ence of a pancreatic carcinoma and invasion of the peripancreatic vessels and surrounding organs.Using the isotropic CT data sets,a three-dimensional image was created with automatic vascular analysis and semi-automatic segmentation of the organs and pancreatic tumor by a radiologist.The CT examinations and the three-dimensional images were presented to the sur-geon directly before and during the patient's operation using the Medical Imaging Interaction Toolkit-based software "ReLiver".Immediately after surgery,the value of the two images was judged by the surgeon.The operation and the histological results served as the gold standard.RESULTS:Nine patients had a pancreatic carcinoma(all pT3),and one patient had a serous cystadenoma.One tumor inf iltrated the superior mesenteric vein.The inf iltration was correctly evaluated.All carcinomas were resectable.In comparison to the CT image with axial and coronal reconstructions,the three-dimensional image was judged by the surgeons as better for operation planning and consistently described as useful.CONCLUSION:A 3D-image of the pancreas repre-sents an invaluable aid to the surgeon.However,the 3D-software must be further developed in order to be integrated into daily clinical routine.

CT diagnosis of recurrence after pancreatic cancer:Is there a pattern?

AIM:To investigate predilection sites of recurrence of pancreatic cancer by computed tomography(CT)in follow-up after surgery. METHODS:Seventy seven patients with recurrence after pancreatic cancer surgery were retrospectively identified.The operative technique,R-status,T-stage and development of tumor markers were evaluated. Two radiologists analyzed CT scans with consensus readings.Location of local recurrence,lymph node recurrence and organ metastases were noted.Surgery and progression of findings on follow-up CT were con-sidered as reference standard. RESULTS:The mean follow-up interval was 3.9± 1.8 mo,with a mean relapse-free interval of 12.9± 10.4 mo.The predominant site of recurrence was local (65%),followed by lymph node(17%),liver metastasis (11%)and peritoneal carcinosis(7%).Local recurrence emerged at the superior mesenteric artery(n=28),the hepatic artery(n=8),in an area defined by the surrounding vessels:celiac trunk,portal vein,inferior vena cava(n=22),and in a space limited by the mesenteric artery,portal vein and inferior vena cava(n=17). Lymph node recurrence occurred in the mesenteric root and left lateral to the aorta.Recurrence was confirmed by surgery(n=22)and follow-up CT(n=55).Tumor markers[carbohydrate antigen 19-9(CA19-9),carcinoembryonic antigen(CEA)]increased in accordance with signs of recurrence in most cases(86%CA19-9;79.2% CEA). CONCLUSION:Specific changes of local and lymph node recurrence can be found in the course of the cardinal peripancreatic vessels.The superior mesenteric artery is the leading structure for recurrence.

Magnetic resonance angiography for the primary diagnosis of pulmonary embolism: A review from the international workshop for pulmonary functional imaging

Pulmonary contrast enhanced magnetic resonance angiography(CE-MRA) is useful for the primary diagnosis of pulmonary embolism(PE). Many sites have chosen not to use CE-MRA as a first line of diagnostic tool for PE because of the speed and higher efficacy of computerized tomographic angiography(CTA). In this review, we discuss the strengths and weaknesses of CEMRA and the appropriate imaging scenarios for the primary diagnosis of PE derived from our unique multiinstitutional experience in this area. The optimal patient for this test has a low to intermediate suspicion for PE based on clinical decision rules. Patients in extremis are not candidates for this test. Younger women(< 35 years of age) and patients with iodinated contrast allergies are best served by using this modality We discuss the history of the use of this test, recent technical innovations, artifacts, direct and indirect findings for PE, ancillary findings, and the effectiveness(patient outcomes) of CE-MRA for the exclusion of PE. Current outcomes data shows that CE-MRA and NM V/Q scans are effective alternative tests to CTA for the primary diagnosis of PE.