Automatic bolus tracking (ABT) vs fixed duration contrast injection (FDCI) at 64-row multidetector computer tomography (MDCT) of the upper abdomen: a comparative study.

Background Multidetector-row Computed Tomography (MDCT), is a rapidly evolving technology suited for high demanding diagnostic skills, especially in cardiovascular and body imaging [1]. Because of the extremely rapid scan speed inherent to MDCT, acquisition protocols must be adjusted accordingly. In particular, since most abdominal examinations require intravenous (i.v.) administration of contrast medium (CM) to enhance lesions’ conspicuity, proper selection of contrast injection technique and acquisition timing represent major technical issues [2,3,4]. Especially for liver imaging, many studies have been focused to achieve optimal CM injection protocol, in order to obtain proper timing and contrast properties of each vascular phase [5,6,7,8]. At present, fixed rate CM injection monitored by automatic bolus-tracking (ABT) is the most commonly used technique in multiphasic liver imaging [6]. ABT compensates for individual variations in circulation time that may affect arterial phase. Nonetheless, this approach determines adjunctive radiation exposure [9]. In the last years, fixed duration contrast injection (FDCI) has been advocated as a valid alternative to ABT in achieving optimal arterial phase without additional radiation dose and by simplifying examinations work-flow [5]. A large amount of literature compares ABT vs. FDCI for liver imaging, mostly on 8 or 16-row MDCT [6,9,10,11,12]. To our knowledge, no previous studies investigated whether these techniques provide comparable liver contrast enhancement by using 64-row MDCT, i.e. at even faster acquisition time. Purpose On these basis, the purpose of our study was to quantitatively and qualitatively evaluate ABT vs. FDCI contrast enhancement of the liver by using a 64-MDCT scanner. Background Multidetector-row Computed Tomography (MDCT), is a rapidly evolving technology suited for high demanding diagnostic skills, especially in cardiovascular and body imaging [1]. Because of the extremely rapid scan speed inherent to MDCT, acquisition protocols must be adjusted accordingly. In particular, since most abdominal examinations require intravenous (i.v.) administration of contrast medium (CM) to enhance lesions’ conspicuity, proper selection of contrast injection technique and acquisition timing represent major technical issues [2,3,4]. Especially for liver imaging, many studies have been focused to achieve optimal CM injection protocol, in order to obtain proper timing and contrast properties of each vascular phase [5,6,7,8]. At present, fixed rate CM injection monitored by automatic bolus-tracking (ABT) is the most commonly used technique in multiphasic liver imaging [6]. ABT compensates for individual variations in circulation time that may affect arterial phase. Nonetheless, this approach determines adjunctive radiation exposure [9]. In the last years, fixed duration contrast injection (FDCI) has been advocated as a valid alternative to ABT in achieving optimal arterial phase without additional radiation dose and by simplifying examinations work-flow [5]. A large amount of literature compares ABT vs. FDCI for liver imaging, mostly on 8 or 16-row MDCT [6,9,10,11,12]. To our knowledge, no previous studies investigated whether these techniques provide comparable liver contrast enhancement by using 64-row MDCT, i.e. at even faster acquisition time. Purpose On these basis, the purpose of our study was to quantitatively and qualitatively evaluate ABT vs. FDCI contrast enhancement of the liver by using a 64-MDCT scanner.