CT of the pancreas: comparison of anatomic structure depiction, image quality, and radiation exposure between 320-detector volumetric images and 64-detector helical images.
CT of the pancreas: comparison of anatomic structure depiction, image quality, and radiation exposure between 320-detector volumetric images and 64-detector helical images.
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DOI：
10.1148/radiol.11101459
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发表时间：
2011-07
期刊：
影响因子：
19.7
通讯作者：
S. Goshima;M. Kanematsu;H. Nishibori;Kota Sakurai;D. Miyazawa;Haruo Watanabe;H. Kondo;Y. Shiratori;M. Onozuka;N. Moriyama;K. Bae
中科院分区：
文献类型：
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作者：
S. Goshima;M. Kanematsu;H. Nishibori;Kota Sakurai;D. Miyazawa;Haruo Watanabe;H. Kondo;Y. Shiratori;M. Onozuka;N. Moriyama;K. Bae
目的前瞻性比较胰腺320排容积和64排螺旋CT图像的解剖结构、图像噪声和辐射暴露。材料和方法本研究由机构审查委员会批准，并获得书面知情同意书。共154名患者（85名男性，69名女性;年龄范围，26-85岁;平均年龄，67岁）接受了双相（动脉期和胰腺期）造影剂增强CT检查，使用320个探测器扫描仪，随机分为两组：320个探测器组和64个探测器组。获得双相轴向多平面重建图像和容积再现CT血管造影。比较了腹主动脉、胰腺和腹壁脂肪组织的CT值、信噪比（SNR）和剂量长度乘积（DLP）。此外，定性确定两组的图像质量和局灶性病变描述（n = 35）。分别使用非配对t检验和Mann-Whitney检验进行定量和定性评估。结果两组患者腹主动脉和胰腺的CT值无显著性差异。320探测器组的平均DLP（675.4 mGy·cm）比64探测器组（1187.8 mGy·cm）低43%（P < .001）。320个探测器组的腹主动脉、胰腺和腹壁脂肪在双相图像上的SNR显著低于64个探测器组（P <0.001）。两组的图像质量均可接受，64探测器组胰腺期轴位图像（P = 0.02）和动脉期多平面重建图像（P <0.01）的图像质量略好。对胰腺实质、主胰管、胰腺局灶性病变、内脏动脉或大部分内脏小动脉分支的显示无显著差异。结论320层螺旋CT扫描有助于快速容积增强扫描整个胰腺，图像质量可接受，即使在320层容积扫描的SNR显着较低。
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.