Optimization of Scan Delay for Routine Abdominal 64-slice CT with Body Weight-Adapted Application of Contrast Material

Abstract

This data suggests an optimal scan delay for routine abdominal 64-slice CT of 85 sec regardless of scan direction.

Challenges to Protocol Optimization Due to Unexpected Variation of CT Contrast Dose Amount and Flow

“…Patient-related factors such as cardiac output, intravascular volume, patient weight, patient height, renal function, and concurrent comorbidities are known to affect contrast enhancement timing, with the most important factors being patient weight, cardiac output, and intravascular volume affecting arterial enhancement [3,8,9]. Acquisition parameters including mA, kVp, noise index, bolus tracking technique, and reconstruction algorithms have a significant effect on study quality and have been studied extensively [2,3,7,8,10].…”

“…Most evaluation to date regarding contrast administration has been centered on contrast timing using manual delays, a test bolus, or bolus tracking technology [8,9,12,13]. Although static contrast volume and flow rates based on patient weight have traditionally been used, recently there has been more interest in looking at individualized patient protocols to take into account patient physiology which achieves more consistent organ enhancement, decrease overall iodine dose, and reduce costs [5,7,9].…”

“…Studies that compare the degree of organ enhancement achieved with the amount of contrast delivered based on the protocol could thus be flawed as the actual amount delivered has previously been difficult to capture. [9] Recent availability of commercially available informatics devices that automatically capture the specifics of the contrast injection for each patient now enables the evaluation of the actual volumes and flow rates of contrast that each patient receives. We hypothesized that a fair number of routine patient CT exams do not receive the prescribed amount of intravenous contrast, which can affect the diagnostic acceptability of the scan.…”

Radiation Dose and Associated Exposure Parameters in Selected MDCT Scanners in Multiphase Scan of Abdomen- Pelvic Region: A Clinical Study.

“…Normally abdominal or pelvic CT examinations may be performed with multiple acquisitions, which include non-contrast, contrast injection of arterial and venous phases. Further according to the pathological condition delay phase also will be included [7][8][9].…”

“…In scanner B; they were 60 (±14.5), 120(±0)and 1(±0). The median effective dose for patients between multiphase abdomen-pelvic scan of both MDCT, a significant difference (P<0.05) was observed.Multiphase abdomen -pelvic scan of clinical study shows significant variation of effective dose with reference level of phantom studies (8)(9)(10)(11)(12)(13)(14) and it is highly depend on type of vendors.…”