CT evaluation of suspected hepatic metastases: comparison of techniques for i.v. contrast enhancement

Dm, Paushter; Zeman, R K; Scheibler, M L; Choyke, P L; Jaffe, M. J.; Lr, Clark

doi:10.2214/ajr.152.2.267

Cited by 32 publications

(10 citation statements)

References 14 publications

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“…CT can provide high-quality three-dimensional (3D) images of the liver intraprocedurally, which help radiologists understand spatial relationship of the tumor with respect to the surrounding structures (4). However, typically only sectional unenhanced CT images are used and hence tumor margins may not be delineated well (5); this limitation may contribute to inadequate ablation (6–10). A recent study showed that the rate of local recurrence following percutaneous radiofrequency ablation of hepatocellular carcinoma decreased significantly from 23% to 0% when the ablation margin, the shortest distance between the outer margin of the tumor and the outer margin of the ablation, was increased from less than 1 mm to larger than 3 mm (11).…”

Section: Introductionmentioning

confidence: 99%

Graphics Processing Unit–Accelerated Nonrigid Registration of MR Images to CT Images During CT-Guided Percutaneous Liver Tumor Ablations

et al. 2015

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Rationale and Objectives Accuracy and speed are essential for the intraprocedural nonrigid MR-to-CT image registration in the assessment of tumor margins during CT-guided liver tumor ablations. While both accuracy and speed can be improved by limiting the registration to a region of interest (ROI), manual contouring of the ROI prolongs the registration process substantially. To achieve accurate and fast registration without the use of an ROI, we combined a nonrigid registration technique based on volume subdivision with hardware acceleration using a graphical processing unit (GPU). We compared the registration accuracy and processing time of GPU-accelerated volume subdivision-based nonrigid registration technique to the conventional nonrigid B-spline registration technique. Materials and Methods Fourteen image data sets of preprocedural MR and intraprocedural CT images for percutaneous CT-guided liver tumor ablations were obtained. Each set of images was registered using the GPU-accelerated volume subdivision technique and the B-spline technique. Manual contouring of ROI was used only for the B-spline technique. Registration accuracies (Dice Similarity Coefficient (DSC) and 95% Hausdorff Distance (HD)), and total processing time including contouring of ROIs and computation were compared using a paired Student’s t-test. Results Accuracy of the GPU-accelerated registrations and B-spline registrations, respectively were 88.3 ± 3.7% vs 89.3 ± 4.9% (p = 0.41) for DSC and 13.1 ± 5.2 mm vs 11.4 ± 6.3 mm (p = 0.15) for HD. Total processing time of the GPU-accelerated registration and B-spline registration techniques was 88 ± 14 s vs 557 ± 116 s (p < 0.000000002), respectively; there was no significant difference in computation time despite the difference in the complexity of the algorithms (p = 0.71). Conclusion The GPU-accelerated volume subdivision technique was as accurate as the B-spline technique and required significantly less processing time. The GPU-accelerated volume subdivision technique may enable the implementation of nonrigid registration into routine clinical practice.

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Section: Introductionmentioning

confidence: 99%

Graphics Processing Unit–Accelerated Nonrigid Registration of MR Images to CT Images During CT-Guided Percutaneous Liver Tumor Ablations

et al. 2015

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“…We have a similar case to reinforce this concept. Tumor differentiation can also be narrowed after contrast enhancement (6,7). Improvement of tumor detection and narrowing of the differential diagnosis are attained with a biphasic contrast-enhanced CT using a helical CT examination (6).…”

Section: Discussionmentioning

confidence: 99%

“…Contrast-enhanced and nonenhanced computed tomographic (CT) studies are also important in the diagnosis of abdominal trauma (4,5) and solid organ minors (6,7). CT has been used as a good imaging modality to evaluate patients who present with acute abdominal pain from such conditions as appendicitis, diverticulitis, mechanical bowel loop obstrucuon, abdominal abscess, acute inflammatory lesions, bowel ischemia, liver abscess, acute pancreatitis, and abdominal trauma (8,9).…”

Section: There Was No Significant Interobserver Difference Among the mentioning

confidence: 99%

Evaluation of significance of clinical information and intravenous contrast administration for diagnostic accuracy during emergent abdominal computed tomographic examination

Yeung

Sheu

Chen

et al. 1997

Emergency Radiology

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The purpose of this study was to evaluate the need for clinical information and intravenous iodine contrast administration for disease diagnosis in patientslinical history is considered to improve the diagnostic rate of plain radiographs (1-3). Contrast-enhanced and nonenhanced computed tomographic (CT) studies are also important in the diagnosis of abdominal trauma (4, 5) and solid organ minors (6, 7). CT has been used as a good imaging modality to evaluate patients who present with acute abdominal pain from such conditions as appendicitis, diverticulitis, mechanical bowel loop obstrucuon, abdominal abscess, acute inflammatory lesions, bowel ischemia, liver abscess, acute pancreatitis, and abdominal trauma (8,9). Patients who present with an acute abdomen are frequently encountered in the emergency room. Emergent abdominal CT provides additional information for prompt diagnosis and management. Interventional or surgical decisions can be made quickly on the basis of the CT results (8). To our knowledge, a comparison study of the importance of clinical history and emergent CT with and without contrast enhancement has not 276 9 Diagnostic Accuracy in Abdominal CT Examination Emergency Radiology 9 September/October 1997 been described. This study was carried out to evaluate the influence of clinical history and nonenhanced and/or enhanced CT examinations on the diagnostic accuracy rate and to examine the possible controversial conditions. MATERIALS AND METHODSA prospective study of emergent abdominal CT examinations was randomly performed. One hundred fifty patients (85 males and 65 females; ages 2-98 years; mean age = 52.4 years) who presented with an acute abdomen were surveyed during a period of 3 consecutive months.The patients were scanned in a helical CT scanner (CT ProSpeed; General Electric Medical Systems, Milwaukee, WI). Nonenhanced and enhanced CT were both obtained for the same region of interest and using the same slice thickness of 10 mm and slice interval of ]0 n~n throughout the abdomen and pelvis. Oral contrast medium was not routinely used in our emergent abdominal CT study. Enhanced CT was obtained with an intravenous infusion of ]00 ml of contrast medium (meglumine iothalamate USR 60%). The nonenhanced and enhanced CT images of the same study were recorded on separate CT films so that the radiologists studying the nonenhanced images would obtain no information from the enhanced study.All diagnostic interpretations were provided sequentially in three phases: (1) nonenhanced CT studies with no available clinical history, (2) nonenhanced CT studies with clinical history provided, and (3) combined nonenhanced and enhanced CT studies with available clinical information. A total of 450 CT studies were thus evaluated. Three radiology specialists (G-C. L., K-W. Y., and Y-T. K.) participated in the research. At first, they interpreted the nonenhanced CT films with no available clinical information. Second, with clinical information provided, they studied the nonenhanced CT images again, but they were not ...

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“…The generally accepted optimal way for contrast medium administration and timing of C T scanning is a high dose of contrast medium given as a bolus and a rapid incremental scanning throughout the liver ( I , 6,8,19). In the case of a suggested haemangioma or other equivocal findings a supplementary one-level scanning should also be performed (8,9).…”

Section: Discussionmentioning

confidence: 99%

Comparison of Non-Enhanced, Bolus Enhanced, and Delayed Scanning Techniques in Computed Tomography of Hepatic Tumours

Tidebrant¹,

Asztely²,

Lukes³

et al. 1990

Acta Radiol

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Non-enhanced, bolus contrast medium enhanced and 4 to 6 hours delayed computed tomography of the liver was performed in a prospcctivc study of 53 patients. Forty patients had focal lesions, in 12 of these they were hypervascular. Contrast medium was administered as an initial bolus followed by a rapid injection of meglumine metrizoate (Isopaque Cerebral). The total iodine dose varied between 56 and 63 g, which gave an average increase in attenuation of 14 HU in normal parenchyma comparing delayed with nonenhanced scanning. Presence and extent of focal lesions were evaluated in a randomized and independent analysis by two radiologists. The percentage of examinations with correct tumour description was higher with bolus scanning (observer I 73%. observer I1 75%) and delayed scanning (observer I 75%, observer I1 78%) than with non-enhanced scanning (observers I and I1 67%). An optimal bolus technique requires an exact timing of the contrast medium administration and scanning. Delayed scanning provides an excellent supplement when the bolus examination is suboptimal or shows equivocal findings.

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CT evaluation of suspected hepatic metastases: comparison of techniques for i.v. contrast enhancement

Cited by 32 publications

References 14 publications

Graphics Processing Unit–Accelerated Nonrigid Registration of MR Images to CT Images During CT-Guided Percutaneous Liver Tumor Ablations

Graphics Processing Unit–Accelerated Nonrigid Registration of MR Images to CT Images During CT-Guided Percutaneous Liver Tumor Ablations

Evaluation of significance of clinical information and intravenous contrast administration for diagnostic accuracy during emergent abdominal computed tomographic examination

Comparison of Non-Enhanced, Bolus Enhanced, and Delayed Scanning Techniques in Computed Tomography of Hepatic Tumours

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