American Journal of Roentgenology, Vol 165, 73-78, Copyright © 1995 by American Roentgen Ray Society

ARTICLES

Helical CT of the liver: clinical application of an automated computer technique, SmartPrep, for obtaining images with optimal contrast enhancement

PM Silverman, S Roberts, MC Tefft, B Brown, SH Fox, C Cooper and RK Zeman
Department of Radiology, Georgetown University Medical Center, Washington, DC 20007, USA.

OBJECTIVES. The purpose of this study was to evaluate an automated computer technique (SmartPrep) for achieving a consistently high level of contrast enhancement in the liver with helical CT. The technique compensates for variability between patients by indicating graphically the time at which scanning should be initiated to reach a desired level of hepatic enhancement. MATERIALS AND METHODS. One hundred nine consecutive patients undergoing helical CT of the abdomen were randomly evaluated, using either a standard 70-sec delay from the start of the injection of contrast material to scanning or a newly developed, commercially available automated technique, SmartPrep. A series of multiple low-dose scans was performed until an arbitrary threshold of hepatic enhancement (50 H) over baseline was achieved. Three regions of interest (ROIs) were imaged on a baseline scan and on contrast-enhanced scans at the upper, mid, and lower liver. Average hepatic enhancement and the standard deviation over baseline was calculated for each group at all anatomic levels. For the SmartPrep group, the range of time between scan initiation and onset of scanning was calculated. RESULTS. The mean hepatic enhancement for the control group (n = 56) was 59.8 +/- 20.1 H, which differed significantly (p = .0002) from that for the SmartPrep group (n = 53), which was 71.6 +/- 15.2 H. Comparison of the variability between the two groups' enhancement levels was also significant (p = .02). The range of delay times for the SmartPrep group was 48-86 sec. In two additional cases, abnormal graphically displayed enhancement curves were the first indication of an improper injection. CONCLUSION. Use of SmartPrep yields a greater and more consistent level of hepatic enhancement from patient to patient than does use of a conventional fixed delay time. The ability to scan more efficiently to achieve greater hepatic enhancement using SmartPrep has significant implications for potential contrast cost savings.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				L. L. Chu, B. N. Joe, A. C. A. Westphalen, E. M. Webb, F. V. Coakley, and B. M. Yeh Patient-specific Time to Peak Abdominal Organ Enhancement Varies with Time to Peak Aortic Enhancement at MR Imaging Radiology, December 1, 2007; 245(3): 779 - 787. [Abstract] [Full Text] [PDF]

				K. S. Lee, C. A. Yi, S. Y. Jeong, Y. J. Jeong, S. Kim, M. J. Chung, H. Y. Kim, Y. K. Kim, and K. H. Lee Solid or Partly Solid Solitary Pulmonary Nodules: Their Characterization Using Contrast Wash-In and Morphologic Features at Helical CT Chest, May 1, 2007; 131(5): 1516 - 1525. [Abstract] [Full Text] [PDF]

				K. T. Bae, C. Tao, S. Gurel, C. Hong, F. Zhu, T. A. Gebke, M. Milite, and C. F. Hildebolt Effect of Patient Weight and Scanning Duration on Contrast Enhancement during Pulmonary Multidetector CT Angiography Radiology, February 1, 2007; 242(2): 582 - 589. [Abstract] [Full Text] [PDF]

				M.-J. Kim, Y. E. Chung, K. W. Kim, J.-J. Chung, J. S. Lim, Y. T. Oh, and J. H. Kim Variation of the Time to Aortic Enhancement of Fixed-Duration Versus Fixed-Rate Injection Protocols Am. J. Roentgenol., January 1, 2006; 186(1): 185 - 192. [Abstract] [Full Text] [PDF]

				S Fenchel, T R Fleiter, A J Aschoff, R van Gessel, H-J Brambs, and E M Merkle Effect of iodine concentration of contrast media on contrast enhancement in multislice CT of the pancreas Br. J. Radiol., October 1, 2004; 77(922): 821 - 830. [Abstract] [Full Text] [PDF]

				L. M. Ho, R. C. Nelson, J. Thomas, E. I. Gimenez, and D. M. DeLong Abdominal Aortic Aneurysms at Multi-Detector Row Helical CT: Optimization with Interactive Determination of Scanning Delay and Contrast Medium Dose Radiology, September 1, 2004; 232(3): 854 - 859. [Abstract] [Full Text] [PDF]

				M. Kanematsu, A. Mallouhi, E. M. Gassner, I. Steingruber, and W. R. Jaschke How Should We Evaluate CT During Arterial Portography in Patients with Cirrhosis? Am. J. Roentgenol., February 1, 2004; 182(2): 529 - 530. [Full Text] [PDF]

				M. J. Siegel Multiplanar and Three-dimensional Multi-Detector Row CT of Thoracic Vessels and Airways in the Pediatric Population Radiology, December 1, 2003; 229(3): 641 - 650. [Abstract] [Full Text] [PDF]

				A. J. Megibow, G. Jacob, J. P. Heiken, E. K. Paulson, K. D. Hopper, G. Sica, S. Saini, B. A. Birnbaum, R. Redvanley, and E. K. Fishman Quantitative and Qualitative Evaluation of Volume of Low Osmolality Contrast Medium Needed for Routine Helical Abdominal CT Am. J. Roentgenol., March 1, 2001; 176(3): 583 - 589. [Abstract] [Full Text] [PDF]

				K. D. Hopper, K. Singapuri, and A. Finkel Body CT and Oncologic Imaging Radiology, April 1, 2000; 215(1): 27 - 40. [Abstract] [Full Text]

				G. T. Sica, H. Ji, and P. R. Ros CT and MR Imaging of Hepatic Metastases Am. J. Roentgenol., March 1, 2000; 174(3): 691 - 698. [Full Text] [PDF]

				R. D. Ernst, H. S. Kim, A. Kawashima, M. R. Middlebrook, and C. M. Sandler Near Real-Time CT Fluoroscopy Using Computer Automated Scan Technology in Nonvascular Interventional Procedures Am. J. Roentgenol., February 1, 2000; 174(2): 319 - 321. [Full Text] [PDF]

				D. Fleischmann, G. D. Rubin, A. A. Bankier, and K. Hittmair Improved Uniformity of Aortic Enhancement with Customized Contrast Medium Injection Protocols at CT Angiography Radiology, February 1, 2000; 214(2): 363 - 371. [Abstract] [Full Text]

				L. N. Nazarian, J. H. Park, E. J. Halpern, L. Parker, P. T. Johnson, A. S. Lev-Toaff, and R. J. Wechsler Size of Colorectal Liver Metastases at Abdominal CT: Comparison of Precontrast and Postcontrast Studies Radiology, December 1, 1999; 213(3): 825 - 830. [Abstract] [Full Text]

				T. Kim, T. Murakami, S. Takahashi, A. Okada, M. Hori, Y. Narumi, and H. Nakamura Pancreatic CT Imaging: Effects of Different Injection Rates and Doses of Contrast Material Radiology, July 1, 1999; 212(1): 219 - 225. [Abstract] [Full Text]

				B. A. Birnbaum, J. E. Jacobs, C. P. Langlotz, and P. Ramchandani Assessment of a Bolus-tracking Technique in Helical Renal CT to Optimize Nephrographic Phase Imaging Radiology, April 1, 1999; 211(1): 87 - 94. [Abstract] [Full Text]

				L. F. Donnelly, J. N. Foss, D. P. Frush, and G. S. Bisset III Heterogeneous Splenic Enhancement Patterns on Spiral CT Images in Children: Minimizing Misinterpretation Radiology, February 1, 1999; 210(2): 493 - 497. [Abstract] [Full Text]