Tissue perfusion in pathologies of the pancreas: assessment using 128-slice computed tomography.

PURPOSE: Perfusion CT can provide information regarding blood perfusion and permeability in (tumor) tissues in a non-invasive manner. In this study, values of CT perfusion parameters in several pancreas pathologies were determined and compared to a control population. MATERIALS AND METHODS: Dynamic 128-slice perfusion CT was performed in patients admitted to the radiology department between June 2010 and March 2011. Included pathologies were pancreatic adenocarcinoma, acute and chronic pancreatitis, neuroendocrine tumors, and (pseudo)cystic lesions. Parametric mappings of blood flow, blood volume, and permeability surface area product were generated. RESULTS: Blood flow and blood volume were significantly lower in acute and chronic pancreatitis compared to the control group. In the center of adenocarcinoma tumors, low blood flow and blood volume was observed, gradually increasing toward the tumor rim; perfusion values in pancreatic parenchyma adjacent to the tumor were not significantly different from the control population. In neuroendocrine tumors, significantly increased perfusion values were observed. CONCLUSION: Compared to the control population, significant decreases in perfusion values were observed in all pancreatic pathologies under study, except in neuroendocrine tumors. Perfusion CT values can be used as an additional parameter to differentiate pancreatic pathologies.

Whole body MR imaging in neurofibromatosis type 1.

OBJECTIVE: To assess the value of whole body MR imaging in patients with neurofibromatosis type 1 (NF1). MATERIALS AND METHODS: 24 patients (15-59 years; mean and median 36 years; 7 males; 17 females) with genetically proven neurofibromatosis type 1 were examined with whole body MR imaging. Axial and coronal T1- and fat-suppressed T2-weighted images (slice thickness 6-12 mm) were acquired on a 1.5T MR unit (Symphony; Siemens, Erlangen, Germany). The images were reviewed by 2 radiologists: 1 senior, 1 junior. The criterion for a neurofibroma was a mass lesion with low signal intensity on T1 and high signal intensity on T2, along the course of a nerve. The location, size, general morphology and course along plexuses and nerves were evaluated. Cutaneous and subcutaneous neurofibromas were defined as "superficial" neurofibromas. The other neurofibromas were regarded as "deep" neurofibromas. RESULTS: There were no major problems to differentiate neurofibromas from lymph nodes, vessels or cysts. The latter three were easily recognised by their typical shape and location, whereas neurofibromas occurred in regions where no mass lesion was anatomically expected. There was no relation between age and total number of neurofibromas throughout the body. Classification according to location and number of neurofibromas: 8 patients had only superficial neurofibromas, 1 only deep and 15 both superficial and deep lesions. Twelve patients had less than 15 neurofibromas and 12 had more. Classification according to course: in 8 patients the neurofibromas occurred along plexuses or proximal part of the intercostal nerves; in 16 patients the lesions were more peripheral. Classification according to morphology: 4 patients had plexiform neurofibromas and 20 patients had multiple solitary lesions. Twelve of these 20 patients had less than 15 lesions, and 8 had more. In 2 patients multiple solitary neurofibromas occurred along the nerve in a chain configuration. In one patient a clinically unsuspected brain tumour was found. CONCLUSION: Whole body MR imaging is a reliable method to evaluate the distribution, size and morphology of neurofibromas in patients with NF1.