Screening for colon cancer.

Colorectal cancer screening reduces mortality in individuals 50 years and older. Each of the screening tests currently available has advantages and limitations, and there is no consensus as to which test or combination of tests is best. What is clear, however, is that the rates of colorectal cancer screening remain low. This review summarizes the clinical evidence supporting colorectal cancer screening in the average risk population and in high risk groups, discusses the advantages and disadvantages of the available screening tests, outlines the currently recommended guidelines for screening based on risk category, and discusses new and emerging technologies for colorectal cancer screening.

Late recurrence of malignant melanoma presenting as peritoneal "carcinomatosis".

Malignant melanoma is a relatively rare malignancy that arises from melanocytes and accounts for approximately 1% of all malignancies reported in the United States. Malignant melanoma can develop in any part of the skin or mucosal membranes. It metastasizes to all organs of the body and often demonstrates unpredictable metastatic behavior. Late recurrence of malignant melanoma, defined as occurring 10 or more years after diagnosis and treatment, is a rare but characteristic metastatic behavior of malignant melanoma. We present a case of a late recurrence of malignant melanoma presenting with diffuse peritoneal studding.

Spiral CT colonography: reader agreement and diagnostic performance with two- and three-dimensional image-display techniques.

PURPOSE: To assess the diagnostic performance and reader agreement with two-dimensional (2D) and three-dimensional (3D) display techniques for detecting colorectal polyps with spiral computed tomographic (CT) colonography. MATERIALS AND METHODS: A test set of 30 colonic segments was developed from spiral CT colonographic studies (12 with polyps and 18 without). The 12 segments with polyps contained 22 lesions (11 polyps <10 mm, 11 polyps or cancers >/=10 mm), with all findings verified with colonoscopy. Three specific 2D and 3D image-display techniques were tested. Three experienced abdominal radiologists independently analyzed each test case and were retested 6 weeks later. RESULTS: The results of readings 1 and 2 were similar for all image-display techniques among the readers. Pooled segment results were sensitivity of 89%-92% and specificity of 72%-83%. Pooled polyp size results for sensitivity and positive predictive value were 77%-86% and 74%-86% (all polyps, n = 22), 91%-100% and 85%-100% (polyps or cancers >10 mm, n = 11), and 61%-73% and 61%-80% (polyps 5-9 mm, n = 11), respectively. Overall intraobserver agreement was good for the three display techniques (kappa, 0.60-1.00); however, interobserver agreement for 2D multiplanar reformation was lower (kappa, 0.53-0.80). CONCLUSION: Among experienced abdominal radiologists, similar diagnostic performance in polyp detection was found among 2D multiplanar reformation and 3D display techniques, although individual cases showed improved characterization with 3D display techniques. Evaluation of reader agreement demonstrated good intraobserver agreement, with variable interobserver agreement.

Renal cysts: is attenuation artifactually increased on contrast-enhanced CT images?

PURPOSE: To determine if the attenuation values of simple renal cysts are artifactually increased on contrast material-enhanced, clinically acquired spiral computed tomographic (CT) images. MATERIALS AND METHODS: Dual-phase renal spiral CT studies (5-mm collimation; pitch, 1.0) were retrospectively analyzed in 24 consecutive patients who had ultrasonographic (US) documentation of simple renal cysts. Forty-eight cysts were identified. The attenuation values of each cyst were measured on nonenhanced, cortical phase, and nephrographic phase images. The size and the location of each cyst in relation to the renal parenchyma were also recorded. RESULTS: The cysts were 0.6-10.8 cm in diameter (mean, 2.6 cm; SD, 2.0). The mean attenuation change in the cysts from nonenhanced to contrast-enhanced images was statistically significant in a comparison of cortical phase and nephrographic phase images (P: <.01): +1.8 HU (SD, 3.8) for cortical phase and +3. 6 HU (SD, 5.6) for nephrographic phase images. Renal cysts 1.0 cm or smaller showed a higher attenuation increase (mean, +4.0 HU for cortical phase and +11.0 HU for nephrographic phase). None of the renal cysts larger than 1.0 cm demonstrated an increase greater than 10 HU (mean, +1.4 HU for cortical phase and +2.3 HU for nephrographic phase). Intraparenchymal cysts showed higher mean attenuation changes than the exophytic cysts. CONCLUSION: Attenuation values in the renal cysts increased artifactually on contrast-enhanced images, but this pseudoenhancement was not substantial and was less than 10 HU when the cyst was larger than 1. 0 cm in diameter.

Visualization of colorectal polyps with spiral CT colography: evaluation of processing parameters with perspective volume rendering.

PURPOSE: To evaluate two key processing steps for detection of colon polyps with spiral computed tomographic (CT) colography with perspective volume rendering (PVR): image reconstruction and opacity assignment of the attenuation data. MATERIALS AND METHODS: Spiral CT was performed in 10 patients with known polyps confirmed at colonoscopy, and detailed quantitative analyses were performed of data obtained in four. First, anatomic fidelity of three-dimensional (3D) images generated from two-dimensional (2D) source images with equal voxel dimensions (87%-90% overlap) was compared with 3D images generated from 2D source images with unequal voxel dimensions (0%-80% overlap). Next, the relative dimensions of colorectal polyps to adjacent structures were evaluated for various opacity threshold settings. Then, step and sigmoidal opacity functions were compared with respect to image smoothness and edge sharpness. RESULTS: PVR images generated after interpolation of image data reconstructed with at least 60% overlap were equivalent in image quality to PVR images generated from source images with equal voxel dimensions. Relative polyp-to-haustral fold dimensions demonstrated substantial distortions with opacity thresholds below -700 HU. The 3D PVR images generated with the sigmoidal opacity function were significantly smoother than those generated with the step opacity function (paired t test, P < .02), with small differences noted in edge sharpness. CONCLUSION: Use of highly overlapping source images (87%-90%) was not necessary to generate 3D PVR images of colorectal polyps. Image artifacts were suppressed with use of an appropriate opacity threshold and a sigmoidal opacity function without substantial loss in edge sharpness.

CT of cystic renal masses: analysis of diagnostic performance and interobserver variation.

OBJECTIVE: Our objective was to assess the clinical usefulness and interobserver variability of the Bosniak classification scheme for characterizing a series of pathologically proven cystic renal lesions imaged with CT. MATERIALS AND METHODS: Seventy pathologically proven cystic renal masses (38 benign, 32 malignant) in 46 patients were reviewed independently by three radiologists. The cystic masses were categorized by each reviewer according to both the Bosniak classification and the receiver operating characteristic (ROC) analysis. Both the individual results for each reader and the pooled results for all three readers were analyzed. Interobserver agreement and discordance in classifying lesions as Bosniak categories I-II or III-IV were assessed. RESULTS: The distribution of the 70 lesions (based on the average of the three readers) was 22 Bosniak I (0% malignant), eight Bosniak II (13% malignant), 11 Bosniak III (45% malignant), and 29 Bosniak IV (90% malignant). All readers agreed on the Bosniak classification in 59%, or 41 of the 70 lesions (I, 17; II, one: III, four: and IV, 19). Eleven (16%) of the 70 lesions were classified as Bosniak I or II by one reader and as Bosniak III or IV by at least one other reader. The area under the curve for the pooled ROC analysis was calculated to be 0.957. Individual reader values ranged from 0.914 to 0.981. The sensitivities, specificities, and accuracies for the three readers ranged from 94% to 100%, 71% to 92%, and 84% to 93%. Assessment of interobserver variability by kappa analysis yielded scores of .571 and .477 for the Bosniak and ROC analyses, respectively. CONCLUSION: Overall, the Bosniak classification scheme is useful for evaluating renal masses: however, interobserver variation in distinguishing. Bosniak II and Bosniak III lesions may present difficulties in recommending surgical versus conservative management.

Spiral computed tomographic colonography: determination of the central axis and digital unraveling of the colon.

RATIONALE AND OBJECTIVES: The authors developed and tested automated and semiautomated bowel-lumen tracking and colon-unraveling techniques for determining the central axis of the bowel. METHODS: A computer-simulated gastrointestinal tract phantom was used to test the accuracy of an automated algorithm for central axis determination and bowel unraveling. Variations in cross-sectional features between straight and unraveled formats were compared in a canine bowel segment in vitro and a human colon in vivo by using spiral computed tomography. Three readers each performed three semiautomated evaluations. RESULTS: Accuracy of the automated algorithm was confirmed by the high degree of correlation in the cross-sectional feature measurements (length error, < 1%). For the canine colon segment, accuracy of the semiautomated algorithm was confirmed by comparison with the automated tracing. For the human colon, readings were reproducible with 3.3% (+/- 1.9 standard deviation) mean variation in length. CONCLUSION: An automated algorithm for central axis deterioration and unraveling the colon has been validated in a gastrointestinal tract phantom. A semiautomated algorithm has been shown to be reproducible and time-efficient.

Radical resection of tumors of the inferior vena cava with vascular reconstruction and kidney autotransplantation.

BACKGROUND: Tumors of the inferior vena cava (IVC) are rare tumors. Although often locally confined, juxtaposed vital structures usually limit the extent of resection. However, complete surgical resection has been shown to be the most important positive prognostic factor. METHODS: Four patients had resection of primary vena caval tumors. In two patients with locally extensive vena caval tumors the limits of conventional resection were extended by means of complete resection of the involved infrahepatic IVC, aorta, and both kidneys. The IVC and aorta were reconstructed with synthetic grafts, and the uninvolved kidney was autotransplanted for both patients. RESULTS: Of the two patients treated with more extensive resection, one patient had no evidence of disease 26 months after operation, and the second patient died of recurrent disease 23 months after operation. CONCLUSIONS: Primary tumors of the IVC may extend locally without distant metastasis. Radical surgical excision as the primary mode of treatment provides the best chance for prolonged survival in appropriately selected patients with tumors of the IVC. After surgical excision the patient with the leiomyosarcoma was treated with radiation therapy and the patient with rhabdomyosarcoma by chemotherapy. Although leiomyosarcomas of the IVC are rare tumors, the first patient is only the third reported case of the even rarer rhabdomyosarcoma of the IVC.

Adrenal adenomas: relationship between histologic lipid and CT and MR findings.

PURPOSE: To assess the relationship between the quantity of lipid in resected adrenal adenomas and the unenhanced computed tomographic (CT) attenuation number and the relative change in signal intensity on chemical shift magnetic resonance (MR) images. MATERIALS AND METHODS: The percentage of lipid-rich cortical cells in histologic sections from 20 resected adrenal adenomas was assessed. The results were correlated with the corresponding unenhanced CT attenuation number or the relative change in signal intensity on chemical shift MR images, or both. RESULTS: There was an inverse linear relationship between the percentage of lipid-rich cortical cells in the adrenal adenomas and the unenhanced CT attenuation number (R2 = .68, P = .0005). There was a similar inverse linear relationship to the relative change in MR signal intensity on chemical shift images by using both quantitative (R2 = .83, P = .004) and qualitative (R2 = .70, P = .019) assessment. CONCLUSION: The presence and amount of histologic lipid in many adrenal adenomas accounts for their low attenuation on unenhanced CT scans and their loss in relative signal intensity on chemical shift MR images.

CT and MR imaging in the staging of colorectal carcinoma: report of the Radiology Diagnostic Oncology Group II.

PURPOSE: To prospectively evaluate the relative accuracy of computed tomography (CT) and magnetic resonance (MR) imaging in the staging of colorectal carcinoma. MATERIALS AND METHODS: CT and MR studies were independently interpreted in a group of 478 patients with colorectal carcinoma in a study conducted from 1989 to 1993. The accuracy of each modality was assessed in a subset of 365 patients with primary tumors with respect to staging of local extent of tumor, status of local-regional lymph nodes, and the presence of liver metastases. RESULTS: In the staging of local extent of tumor, CT is more accurate than MR imaging, particularly in the definition of penetration of the muscularis propria by rectal cancer (74% vs 58%). Accuracies of CT and MR imaging were equivalent in depiction of transmural extent in colon cancers. CT and MR imaging exhibited accuracies of 62% and 64% in assessment of lymph node involvement with sensitivities of 48% and 22%, respectively. The accuracy of MR imaging and of CT (85% for each) are better for evaluation of liver metastases; lower sensitivities (62% and 70%, respectively) than specificities (97% and 94%, respectively) were demonstrated for both modalities. CONCLUSION: CT was more accurate than MR imaging in detection and characterization of transmural penetration of rectal tumors. Recent technologic advances in MR imaging may affect these results.

Helical (spiral) CT angiography for identification of crossing vessels at the ureteropelvic junction.

OBJECTIVE: The purpose of this study was to determine the feasibility of imaging crossing vessels at the ureteropelvic junction (UPJ) with helical (spiral) CT angiography for planning surgical repair of symptomatic UPJ obstruction. SUBJECTS AND METHODS: Twenty-four consecutive patients with symptomatic UPJ obstruction were imaged with dual-phase, contrast-enhanced helical CT (collimation, 3 mm; pitch, 1.3-1.7; reconstruction interval, 2 mm; early phase, 20-42 sec; and delayed phase, 90-112 sec after initiation of IV contract material injection [125 ml of ioversol containing 320 mg of iodine per ml, delivered at 4-5 ml/sec]). All imaging data were viewed interactively on an imaging workstation. Prospective on-line interpretations were correlated with subsequent surgical and clinical findings at laparoscopy (n=3), open surgical repair (n=2), or ureteronephroscopic endopyelotomy (n=11). Vessels at the UPJ that were 2 mm or more in diameter were believed to be significant. Review of the transaxial images was performed to determine qualitatively the relative usefulness of the early versus the delayed phases for distinguishing arteries from veins. Multiplanar reformations also were retrospectively reviewed and compared with direct pyelograms to determine the accuracy with which the location of the UPJ and the proximal ureteral course were depicted with helical CT. RESULTS: Eleven of 24 (46%) patients collectively had 11 anterior and three posterior vessels (> or = 2 mm in diameter) crossing the UPJ on helical CT. Distinction between arteries and veins was significantly better on early-phase than on delayed-phase images (p=.01). Visualization of the UPJ and the proximal ureteral course was good or excellent for 18 (78%) of 23 patients for whom pyelograms were available, regardless of the presence of a ureteral stent (p>.05). Laparoscopy and open surgery findings were in agreement with helical CT angiograms for five of five patients. Uncomplicated endopyelotomy was performed for 11 patients in whom no significant vessels were seen posterior or posterolateral to the UPJ. CONCLUSION: Helical CT angiography can depict vessels crossing the UPJ and is valuable in planning surgical management.

Pancreatic adenocarcinoma: CT versus MR imaging in the evaluation of resectability--report of the Radiology Diagnostic Oncology Group.

PURPOSE: To compare findings with computed tomography (CT) and magnetic resonance (MR) imaging in pancreatic adenocarcinoma and to determine optimal pulse sequences for MR imaging. MATERIALS AND METHODS: CT scans and MR images were compared of 189 adult patients with known or suspected adenocarcinoma of the pancreas. Levels of confidence were correlated with surgical and pathologic results. RESULTS: The accuracy of CT was 0.73 and of MR imaging was 0.70. The negative predictive value of CT was 0.28 and of MR imaging was 0.23. The positive predictive value of CT was 0.89 and of MR imaging was 0.88. Gradient-echo and T1-weighted spin-echo sequences ranked equally in evaluation of vascular invasion, T1-weighted spin-echo sequences were preferred for assessing lymphadenopathy, and T2-weighted spin-echo sequences were preferred for detecting hepatic metastases. CONCLUSIONS: Cross-sectional imaging modalities are useful in the identification of unresectable pancreatic carcinoma. CT is recommended for initial imaging assessment.

Abnormalities of the diaphragm and adjacent structures: findings on multiplanar spiral CT scans.

Abnormalities of the diaphragm and surrounding tissues have been notoriously difficult to image with conventional axial CT. During the past 10 years, the multiplanar imaging capabilities of MR have been used to clarify the organ of origin of masses near the diaphragm. Spiral CT now offers a similar capability. With spiral CT, the peri-diaphragmatic region can be scanned in a single breath-hold, minimizing motion artifacts and virtually eliminating respiratory mis-registration. Axial images of closely spaced, overlapping sections are reconstructed retrospectively from the volumetric spiral CT projection data set. From these images, one can generate high-detail multiplanar reformations through the diaphragm and adjacent abnormalities. As the CT attenuation values inherent to the chest and abdomen cover a wide range, three-dimensional reformations are not expected to depict this anatomy better than two-dimensional reformations can. This is because three-dimensional images generally render structures at the extremes of CT attenuation, or within a narrow window of CT attenuation values. This pictorial essay illustrates the importance of two-dimensional sagittal and coronal reformations of spiral CT scans in evaluating the peri-diaphragmatic area. With these reformations, peri-diaphragmatic abnormalities seen on axial images are localized to the lung, pleura, pericardium, cardiophrenic space, or intraabdominal viscera.

Does CTAP prior to hepatic resection improve patient survival rates?

The purpose of our study was to compare survival rates of colon carcinoma patients who had undergone attempted curative hepatic resection based on liver staging by computed tomographic angiography (CTA) or portography (CTAP) with previously reported survival rates of patients who underwent similar surgery without preoperative CTAP evaluations. A total of 404 CTAP studies performed at three institutions were reviewed. Of this group, 197 had colon carcinoma. Sixty-nine of the colon patients went to surgery. Actuarial adjusted yearly survival rates were calculated for the prior CTAP colon group and compared to historical controls. The control survival data were taken from reports published prior to the CTAP era. Our study demonstrated no difference in the 1-year survival data between the groups. However, the CTAP patients had greater survival in years 2-4. This greater survival may be multifactorial but in part due to better surgical selection caused by CTAP.

MR imaging of Crohn disease: use of perflubron as a gastrointestinal contrast agent.

This study was undertaken to evaluate the use of perflubron (perfluorooctylbromide) as an oral contrast agent for magnetic resonance (MR) imaging of patients with Crohn disease. MR examinations were performed before and after perflubron administration in 12 patients with documented Crohn disease. Glucagon was administered intramuscularly before the post-perflubron examinations. Each patient also underwent abdominal computed tomography within 48 hours of MR imaging. The imaging studies were analyzed for effectiveness of bowel marking with oral contrast agent, clarity bowel wall visualization, and presence of bowel wall thickening and extraluminal manifestations of Crohn disease such as abscess or fistula formation. Analysis of the imaging studies showed effective marking of the bowel with perflubron and improved bowel wall visualization on postcontrast MR images. Detection of bowel wall thickening and extraluminal complications of Crohn disease was not significantly improved on postcontrast MR images. The authors conclude that perflubron administration effectively marked the bowel and increased the clarity of bowel wall visualization but did not significantly increase the detection of abnormalities related to Crohn disease in the study population.

CT screening for comorbid disease in patients with prostatic carcinoma: is it cost-effective?

OBJECTIVE: The role of imaging in patients with newly diagnosed prostatic carcinoma is controversial. Currently, 35% of patients with prostatic carcinoma undergo CT at the time of diagnosis, despite reports of the lack of efficacy of CT in staging the disease. We sought to evaluate the cost-effectiveness of CT in detecting unrelated comorbid disease (significant disease unrelated to prostatic carcinoma) that might affect decisions on treatment in this population of patients. MATERIALS AND METHODS: We reviewed the medical records of 273 consecutive patients with newly diagnosed prostatic carcinoma who had CT of the abdomen and pelvis as part of their preoperative evaluation. Using costs based on Medicare reimbursements, we assessed the impact of the CT findings (related to comorbid disease) on overall costs and savings related to the workup and treatment of these patients. RESULTS: Sixty-six patients (24%) had findings suggestive of comorbid disease. The CT findings had near-term impact on only four patients (two in whom large abdominal aortic aneurysms were detected and two in whom second primary cancers were found), despite nearly $155,000 spent on the screening CT scans and more than $4400 spent on further evaluation of false-positive CT findings. The clinical impact varied from intervening semiurgent surgery to cancellation of prostatic surgery and institution of radiation therapy. CONCLUSION: CT is not cost-effective in screening for comorbid disease that would affect treatment in patients with newly diagnosed prostatic carcinoma.

Colitis: use of CT findings in differential diagnosis.

PURPOSE: To determine whether colitides can be differentiated based on computed tomographic (CT) features. MATERIALS AND METHODS: The CT scans of 117 patients with documented colitis and colon wall thickening were reviewed. Features evaluated included mural thickness and homogeneity, distribution of bowel involvement, and associated mesenteric and small bowel disease. RESULTS: The mean colon wall thickness in Crohn colitis (11.0 mm +/- 5.1) was significantly greater than in ulcerative colitis (7.8 mm +/- 1.9) (P < .002). Submucosal fat deposition, not observed in the acute colitides, was present significantly more often in ulcerative (61%) than in Crohn colitis (8%) (P = .0001). Exclusive involvement of the right colon and small bowel was most frequent with Crohn and infectious colitis. Abscess was associated almost exclusively with Crohn colitis (35%) but was seen in one patient with radiation colitis. CONCLUSION: Although many CT findings in patients with colitis are nonspecific, some features are helpful in suggesting a specific diagnosis.

Evaluation of fat saturation technique for T2-weighted endorectal coil MRI of the prostate.

The use of fat suppression has been found to improve tissue contrast and artifact control for performance of body coil MR imaging of the pelvis. The objective of this study was to evaluate whether use of fat suppression confers similar advantages when endorectal coil MR examinations are performed for staging of prostate cancer. Sixty consecutive patients were evaluated with conventional T1-weighted (TR 600, TE 20) and conventional and fat saturation proton density-/T2-weighted (TR 2500, TE 35/80) sequences. Thirteen of 60 patients underwent subsequent radical prostatectomy and constituted the study group for which conventional and fat suppressed long TR images were directly compared by three reviewers. Criteria assessed included the relative ability of each sequence to demonstrate zonal distinction, periprostatic venous plexus, fibromuscular stroma, capsule definition, seminal vesicle architecture, tumor conspicuity, capsular penetration and/or seminal vesicle tumor invasion, artifact control, and overall image quality. There was no statistically significant improvement in factors relating to image quality with use of fat saturation. In addition, depiction of the anatomic and pathologic features listed above was not significantly improved for fat-suppressed as compared with conventional endorectal coil images. It is concluded that fat saturation does not result in significant improvement over conventional T2-weighted images in endorectal MR imaging of the prostate.

Neoplasms of the bladder, prostate, and testis.

As a group, carcinomas of the urinary bladder, prostate, and testis account for more than one third of all cancers occurring in men. Computed tomography is the imaging procedure of choice for postorchiectomy staging of testicular cancers. Transrectal ultrasonography and magnetic resonance imaging play important roles in the staging of prostate cancer. Magnetic resonance imaging, computed tomography, and transurethral ultrasonography are all capable of providing important information in the staging of bladder cancer. Carefully designed clinical trials will be needed to provide a sound scientific basis for guiding the judicious use of imaging tests for staging bladder and prostate cancer in the future.

Preoperative determination of the resectability of hepatic tumors: efficacy of CT during arterial portography.

OBJECTIVE: A multiinstitutional study was performed to evaluate the efficacy of CT during arterial portography for determining the resectability of hepatic tumors. The impact of findings from CT during arterial portography on patients' treatment (i.e., surgical vs nonsurgical) was assessed. In patients considered to have resectable tumors, the accuracy of CT during arterial portography for predicting surgical findings was also evaluated. MATERIALS AND METHODS: A retrospective study was done of 404 patients from three institutions who had CT during arterial portography during the period 1985-1991 as part of preoperative staging to determine the resectability of hepatic tumors. The tumors included metastases from colorectal carcinoma in 197 patients (49%); other hepatic metastases, mostly from adenocarcinoma of the stomach, pancreas, and biliary tree in 123 (30%); and primary hepatocellular carcinoma in 84 (21%). Imaging results were correlated with results of percutaneous biopsy of at least one hepatic lesion in patients whose tumors were considered unresectable. In patients whose tumors were considered resectable, results were correlated with preoperative percutaneous biopsy (obtained in almost all cases) and pathologic examination of a surgical specimen (all cases). Although each case was considered individually, four criteria were used for resectability: (1) accessibility of all lesions to lobar or wedge resection that would yield clear margins, (2) anticipation that residual liver tissue after resection would provide sufficient function, (3) the absence of invasion of central hepatic vascular or biliary structures, and (4) the absence of extrahepatic disease. No specific restriction was made with respect to the number of hepatic lesions present. The accuracy of findings by CT during arterial portography for predicting resectability was assessed in the 146 patients who had tumors that were considered resectable on the basis of imaging findings and had surgery. RESULTS: Of 404 patients, only 146 (36%) were thought to be candidates for resection on the basis of findings from CT during arterial portography. Of these, 122 (84%) actually had resection. The 24 patients who did not have resection included 22 patients with disease understaged or overstaged by CT during arterial portography, one with true-negative findings by CT during arterial portography, and one who died during surgery. The accuracy of findings by CT during arterial portography for predicting results at surgery was 85% for all patients and 91% for the subset of patients who had primary colorectal tumors with hepatic metastases. CONCLUSION: Our experience shows that CT during arterial portography is a useful procedure for assessing the resectability of hepatic tumors. In our study, 64% of patients were spared unnecessary surgery.(ABSTRACT TRUNCATED AT 400 WORDS)