CT of the pancreas: comparison of anatomic structure depiction, image quality, and radiation exposure between 320-detector volumetric images and 64-detector helical images.

PURPOSE To prospectively compare 320-detector volumetric and 64-detector helical computed tomographic (CT) images of the pancreas for depiction of anatomic structures, image noise, and radiation exposure. MATERIALS AND METHODS This study was approved by the institutional review board, and written informed consent was obtained. A total of 154 patients (85 men, 69 women; age range, 26-85 years; mean age, 67 years) who underwent biphasic (arterial and pancreatic phase) contrast material-enhanced CT performed with a 320-detector scanner were randomized into two groups: the 320-detector group and the 64-detector group. Biphasic transaxial multiplanar reformatted images and volume-rendered CT angiograms were obtained. CT numbers in the abdominal aorta, pancreas, and abdominal wall fat tissue; signal-to-noise ratio (SNR); and dose-length product (DLP) were compared. In addition, image quality and focal lesion depiction (n = 35) were qualitatively determined in the two groups. Unpaired t and Mann-Whitney tests were used for quantitative and qualitative assessment, respectively. RESULTS No significant difference in CT numbers of the abdominal aorta and pancreas was noted between the two groups. Mean DLP was 43% lower in the 320-detector group (675.4 mGy·cm) than in the 64-detector group (1187.8 mGy·cm) (P < .001). SNR of the abdominal aorta, pancreas, and abdominal wall fat on biphasic images was significantly lower in the 320-detector group than in the 64-detector group (P < .001). Image quality was acceptable in both groups and was slightly better in the 64-detector group for pancreatic phase axial images (P = .02) and arterial phase multiplanar reformatted images (P < .01). No significant difference was found in the depiction of pancreatic parenchyma, main pancreatic duct, focal pancreatic lesions, splanchnic arteries, or most of the small splanchnic arterial branches. CONCLUSION A 320-detector CT scan facilitates fast volumetric contrast-enhanced CT of the entire pancreas with acceptable image quality, even though SNR was significantly lower at 320-detector volumetric scanning.

[1]  M. McNitt-Gray,et al.  Precision of dosimetry-related measurements obtained on current multidetector computed tomography scanners. , 2010, Medical physics.

[2]  R Klingebiel,et al.  320-slice CT neuroimaging: initial clinical experience and image quality evaluation. , 2009, The British journal of radiology.

[3]  M. Kanematsu,et al.  Pancreas: optimal scan delay for contrast-enhanced multi-detector row CT. , 2006, Radiology.

[4]  K Murase,et al.  Comparison of patient doses in 256-slice CT and 16-slice CT scanners. , 2006, The British journal of radiology.

[5]  Joel G Fletcher,et al.  Pancreatic malignancy: value of arterial, pancreatic, and hepatic phase imaging with multi-detector row CT. , 2003, Radiology.

[6]  K. Bae,et al.  Peak contrast enhancement in CT and MR angiography: when does it occur and why? Pharmacokinetic study in a porcine model. , 2003, Radiology.

[7]  J. Platt,et al.  Multi--detector row helical CT of the pancreas: effect of contrast-enhanced multiphasic imaging on enhancement of the pancreas, peripancreatic vasculature, and pancreatic adenocarcinoma. , 2001, Radiology.

[8]  K. Lehmann,et al.  Pancreatic cancer: value of dual-phase helical CT in assessing resectability. , 1998, Radiology.

[9]  C. Reinhold,et al.  A comparison of two injection protocols using helical and dynamic acquisitions in CT examinations of the pancreas. , 1996, AJR. American journal of roentgenology.

[10]  H. Pitt,et al.  Potentially resectable pancreatic adenocarcinoma: spiral CT assessment with surgical and pathologic correlation. , 1995, Radiology.

[11]  F. Cobelli,et al.  Pancreatic Carcinoma: MR Assessment of Tumor Invasion of the Peripancreatic Vessels , 1995 .

[12]  L. Crabo,et al.  Carcinoma of the head of the pancreas: evaluation of the pancreaticoduodenal veins with dynamic CT--potential for improved accuracy in staging. , 1995, Radiology.

[13]  R. Jeffrey,et al.  Quantitative evaluation of pancreatic enhancement during dual-phase helical CT. , 1995, Radiology.

[14]  A. Aisen,et al.  Pancreatic adenocarcinoma: CT versus MR imaging in the evaluation of resectability--report of the Radiology Diagnostic Oncology Group. , 1995, Radiology.

[15]  B. Marincek,et al.  Pancreatic tumors: evaluation with endoscopic US, CT, and MR imaging. , 1994, Radiology.

[16]  C. Charnsangavej,et al.  Thin-section contrast-enhanced computed tomography accurately predicts the resectability of malignant pancreatic neoplasms. , 1994, American journal of surgery.

[17]  L. Traverso,et al.  Diagnosis and staging of pancreatic adenocarcinoma with dynamic computed tomography. , 1993, American journal of surgery.

[18]  D E Dupuy,et al.  Spiral CT of the pancreas. , 1992, Radiology.

[19]  A. Megibow,et al.  Pancreatic adenocarcinoma: designing the examination to evaluate the clinical questions. , 1992, Radiology.

[20]  J. Zeiss,et al.  CT presentation and staging accuracy of pancreatic adenocarcinoma , 1990, International journal of pancreatology : official journal of the International Association of Pancreatology.

[21]  Freeny Pc.  Radiologic diagnosis and staging of pancreatic ductal adenocarcinoma. , 1989 .

[22]  P. Freeny.  Radiologic diagnosis and staging of pancreatic ductal adenocarcinoma. , 1989, Radiologic clinics of North America.

[23]  L. Traverso,et al.  Pancreatic ductal adenocarcinoma: diagnosis and staging with dynamic CT. , 1988, Radiology.

[24]  J. R. Landis,et al.  The measurement of observer agreement for categorical data. , 1977, Biometrics.