| 特集名 | 肝の画像診断 | |
|---|---|---|
| 題名 | CT (1) CTによる肝腫瘍診断 | |
| 発刊年月 | 2002年 01月 | |
| 著者 | 木村 誠志 | 和歌山県立医科大学放射線医学教室 |
| 著者 | 佐藤 守男 | 和歌山県立医科大学放射線医学教室 |
| 著者 | 中井 資貴 | 和歌山県立医科大学放射線医学教室 |
| 著者 | 南口 博紀 | 和歌山県立医科大学放射線医学教室 |
| 著者 | 塩山 靖和 | 和歌山県立医科大学放射線医学教室 |
| 【 要旨 】 | 近年のCT画像診断法の進歩には目をみはるものがあり，ヘリカルCT装置の出現で，20秒前後の息止めで肝全体を撮像することができ，造影剤の急速静注によるdynamic studyが標準的な撮像法である． さらに，1998年に登場したマルチスライスCTでは，薄いスライス厚画像の高速撮像が可能であり，体軸方向の空間分解能の向上とdynamic studyでの時間分解能の向上が得られる．また，再構成可能な横断像のスライス厚の選択肢が広く，追加スキャンなしにさまざまなスライス厚画像の再構成も可能である． 本稿では，これらのCT装置を用いたdynamic studyで得られた肝腫瘤性病変のCT画像を呈示し，概説する． |
|
| Theme | Imaging Diagnostics of Liver Disease | |
|---|---|---|
| Title | Diagnosis of Hepatic Tumors with CT Scanning | |
| Author | Masashi Kimura | Department of Radiology, Wakayama Medical University |
| Author | Morio Sato | Department of Radiology, Wakayama Medical University |
| Author | Motoki Nakai | Department of Radiology, Wakayama Medical University |
| Author | Hiroki Minamiguchi | Department of Radiology, Wakayama Medical University |
| Author | Yasukazu Shioyama | Department of Radiology, Wakayama Medical University |
| [ Summary ] | Improvements in CT technology have dramatically increased our ability to detect and diagnose liver abnormalities, particularly neoplastic disease. Because of the high prevalence of hepatic tumors in patients referred for abdominal CT examinations, contrast administration and scanning techniques are usually optimized for detection of hepatic tumors with abdominal CT scanning. The ability of CT contrast techniques to show hepatic tumors is enhanced by the dual blood supply to the liver. The liver is different from all other abdominal organs because of this dual blood supply. The hepatic artery delivers 25% of the blood flow to the liver, and the portal vein delivers 75%. This, and the fact that most tumors of the liver have only a hepatic arterial blood supply and receive little or no flow from the portal vein, are the key physiological parameters which make contrast-enhanced CT scanning so successful in detecting tumors. Compared with the slow, prolonged rates of contrast administration or unenhanced CT, dynamic incremental bolus, contrast-enhanced CT has been found to be the most sensitive method of contrast administration for detecting hepatic tumors. This technique requires the use of a power injector to ensure a rapid and sustained rate of infusion of contrast material and to avoid scanning during the equilibrium phase of contrast enhancement. Concerning scanning time, images covering thin slices may now be obtained quickly, due to the advent of multi detector helical CT (MDHCT), with multiple detectors. This results in improvements in the spatial resolution of the axial direction and also of temporal resolution in dynamic studies. |
|