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To clarify the changes that occur in drainage vessels of dysplastic nodules and hepatocellular carcinoma (HCC) during hepatocarcinogenesis by using computed tomography (CT) during arterial portography (CTAP) and CT during hepatic arteriography (CTHA), with histologic findings as the reference standard.Institutional ethics committee approval and informed consent were obtained. According to the findings at CTAP and CTHA, 46 surgically resected hepatocellular nodules were classified into three types: type A (n = 18) (equivalent or decreased portal perfusion compared with background liver at CTAP, decreased arterial perfusion, and no corona enhancement [perinodular contrast material drainage] at CTHA), type B (n = 13) (no portal perfusion, increased arterial perfusion, and thin (or = 2-mm) corona enhancement), or type C (n = 15) (no portal perfusion, increased arterial perfusion, and thick (2-mm) corona enhancement). We compared the histopathologic features and microangioarchitecture between the types.Type A nodules histologically consisted of dysplastic nodules and well-differentiated HCC; type B and C nodules were moderately differentiated HCC. Replacing growth was commonly observed in type A nodules, whereas compressing growth was more frequently seen in types B and C. Sixty percent of type C nodules had a fibrous capsule. There were significantly fewer intranodular hepatic veins in types B and C. Serial pathologic slices demonstrated continuity from intranodular capillarized sinusoids to hepatic veins in type A nodules and to surrounding hepatic sinusoids in type B nodules. In type C nodules, intranodular capillarized sinusoids were connected to extranodular portal veins either directly or through portal venules within the fibrous capsule.Drainage vessels of HCC change from hepatic veins to hepatic sinusoids and then to portal veins during multistep hepatocarcinogenesis.

To evaluate the portal and arterial blood supplies to dysplastic nodules in the cirrhotic liver with computed tomography (CT) during arterial portography (CTAP) and CT hepatic arteriography (CTHA).Nineteen histopathologically proved low-grade dysplastic nodules and 13 high-grade dysplastic nodules in 17 patients with liver cirrhosis were evaluated with CTAP and CTHA for the presence of portal and arterial blood supplies to the nodules. The nodules ranged from 0.4 to 4.5 cm in diameter (mean, 1.6 cm).The portal supply was present in 14 of the 19 (74%) low-grade dysplastic nodules and in seven of the 13 (54%) high-grade dysplastic nodules. The hepatic arterial supply was increased in four of the 19 (21%) low-grade dysplastic nodules, present in nine (47%), and absent in six (32%). The arterial supply was increased in four of the 13 (31%) high-grade dysplastic nodules, present in four (31%), and absent in five (38%).The portal and arterial supplies to the low- and high-grade dysplastic nodules were variable and inconsistent. Therefore, it is difficult to detect and characterize the dysplastic nodules on the radiologic images on the basis of the blood supply.

To evaluate the segmental anatomy of the right anterosuperior area (segment 8) of the liver by using helical computed tomography during arterial portography (CTAP).Twenty-seven patients without lesions at segment 8 underwent helical CTAP. Three-dimensional portograms were reconstructed to verify the course of the portal veins. The number of subsegmental branches, in addition to the branching point and the distribution in segment 8, was assessed.In 25 (93%) patients, the dorsal branch of segment 8 gave rise to dorsally directed branches posterior to the right hepatic vein. In only four (25%) of 16 patients in whom the medial branch of segment 8 arose near the porta hepatis, the long paracaval portal branch of the caudate lobe extended upward above the interval between the middle and right hepatic veins.In most of the patients, the dorsal branches of segment 8 supplied the dorsocranial area of the right lobe posterior to the right hepatic vein. The paracaval portion of the caudate lobe was limited to below the interval between the middle and right hepatic veins in the majority of patients who showed medial branches of segment 8 arising near the porta hepatis. Recognition of this vascular anatomy is clinically important for preoperative evaluation of hepatic tumors in segment 8 because it may contribute to a safer surgical approach.

To compare specific findings at T1-weighted gradient-echo (GRE) magnetic resonance (MR) imaging performed after administration of superparamagnetic iron oxide (SPIO) with nontumorous regional portal perfusion abnormalities seen at computed tomography (CT) during arterial portography (CTAP).The results of CTAP, MR imaging, and surgery were compared in 19 patients with liver metastases and five with benign liver tumors. MR imaging was performed by using turbo spin-echo (SE) sequences and a GRE sequence before and after infusion of SPIO.At CTAP, 34 nontumorous portal perfusion defects ("straight line sign," pseudolesions) were seen. After intravenous administration of SPIO, 18 nontumorous signal intensity differences were seen on T1-weighted GRE images in corresponding locations. No corresponding nontumorous signal intensity differences were seen on unenhanced MR images. The mean signal-to-noise ratio on the SPIO-enhanced GRE images was reduced from 26.3 to 16.6 in the areas of nontumorous signal intensity differences, whereas that in areas of normal portal perfusion (normal CTAP findings) was reduced to 10.2.Impaired portal perfusion decreased the uptake of SPIO in histopathologically normal regions of liver parenchyma. Resultant differences in signal intensity were better visualized on GRE than on turbo SE images.

To assess the role of helical biphasic computed tomography (CT) versus CT during arterial portography (CTAP) in the detection of hepatocellular carcinoma (HCC).Helical biphasic CT and CTAP examinations were performed in 33 patients with biopsy-proved HCC. Three blinded radiologists retrospectively evaluated portal venous phase images, portal venous phase plus hepatic arterial phase images (helical biphasic CT), and CTAP plus portal venous phase images at separate sittings. In 23 patients with pathologic proof of total tumor burden, the readers conducted a consensus matched-pair reading to determine the sensitivity of each method.In the 23 patients with a proved tumor burden of 100 HCC lesions, the observers detected 74 tumors on portal venous phase images, 82 tumors on hepatic arterial phase images, 87 tumors on CTAP images, 87 tumors on helical biphasic CT images, and 96 tumors on portal venous phase plus CTAP images. Hepatic arterial phase images and CTAP images, respectively, depicted 13 and 23 tumors not seen on portal venous phase images in eight (35%) and 13 (56%) of 23 patients. Ten tumors were seen on portal venous phase images but not on CTAP images owing to the presence of central tumors or segmental portal venous thrombi that obstructed the flow of contrast material to more peripheral portions of the liver.The addition of hepatic arterial phase imaging to portal venous phase imaging (helical biphasic CT) provided an incrementally increased yield in HCC tumor detection. Helical biphasic CT should be used as the initial screening examination in patients with suspected or known HCC.

To determine the anatomy of the portal venous system in the posterior aspect of segment IV of the liver by using helical computed tomography (CT) during arterial portography (CTAP).One hundred consecutive patients underwent CTAP. Helical CT during hepatic arteriography was performed in 20 patients. In seven patients with hepatocellular carcinoma in the posterior aspect of segment IV, the feeding arteries were also analyzed.A venule from the intrahepatic portal vein to segment IV was seen in all patients. Other findings included a tiny venule from the distal part of the main left portal vein (n = 36), from the proximal left main portal vein (n = 20), and from the right portal vein (n = 18). Aberrant right gastric venous drainage and/or parabiliary venous drainage directly into the posterior aspect was present in 14 patients. In two patients, a tiny accompanying artery was seen on images from CT during hepatic arteriography. In seven patients with hepatocellular carcinoma, the main feeding artery branched from the right (n = 2) or left (n = 5) hepatic artery.CTAP adequately demonstrates the tiny portal venous and arterial branches from the main right or left portal vein that distribute to the posterior aspect of segment IV. Knowledge of this vascular anatomy is clinically important.

To determine whether the diagnostic quality of computed tomography (CT) during arterial portography (CTAP) performed via the splenic artery (SA) is better than that performed via the superior mesenteric artery (SMA).The authors evaluated CTAP images obtained in 98 patients from 1991 to 1994; 47 examinations were performed via the SA and 51 were performed via the SMA. Images were reviewed, by consensus, by three radiologists blinded to catheter location. Hepatic enhancement was quantitatively assessed in 53 patients (31 in the SA group, 22 in the SMA group).The numbers of low-attenuation non-tumor-related perfusion defects (19 in the SA group, 17 in the SMA group), high-attenuation non-tumor-related perfusion defects (six in the SA group, six in the SMA group), diffuse mottled perfusion abnormalities (six in the SA group, five in the SMA group), and portal venous flow defects (20 in the SA group, 20 in the SMA group) were similar in both groups (P.05). Peak hepatic enhancement was similar in both groups (SMA group = 111 HU; SA group = 112 HU) (P.05).There is no difference in quality between CTAP performed via the SA versus CTAP performed via the SMA.

Retrospective analysis of findings at double-phase helical computed tomography (CT) during arterial portography was performed in 42 hepatocellular carcinomas (HCCs) in 31 patients. Phase 1 scanning started 30-35 seconds after the beginning of injection of contrast material; phase 2 scanning started 10-18 seconds after the end of phase 1. The overall detection rate for HCCs was 83% (35 of 42) in phase 1, 81% (34 of 42) in phase 2, and 90% (38 of 42) for combined phase 1 and 2 findings.

PURPOSE: To determine the optimal time window for scanning the liver with computed tomography (CT) during arterial portography (CTAP). MATERIALS AND METHODS: After vasodilation and contrast medium injection into the superior mesenteric artery (80 mL at 5 mL/sec), 25 repeated scans were obtained at a single level within 83 seconds in 13 patients. Attenuation was measured on every scan, and time-attenuation curves were created. Enhancement characteristics of the portal vein, liver parenchyma, aorta, and tumors were evaluated. RESULTS: Parenchymal enhancement of more than 60 HU was achieved between 18 seconds +/- 4 (standard deviation) and 67 seconds +/- 15, and high parenchyma-to-tumor contrast of more than 50 HU occurred between 18 seconds +/- 3 and 62 seconds +/- 14. CONCLUSION: To scan the liver within such a narrow time window, a spiral CT technique is necessary. When the above injection parameters are used in CTAP, the spiral CT sequence should be started 20 seconds after the beginning of the injection.

A prospective study was performed to compare the sensitivities of intraoperative ultrasound (US) and computed tomography during arterial portography (CTAP) in the depiction of hepatic metastases from colorectal cancer. Twenty-five patients with hepatic metastases from colorectal cancer were evaluated. All patients underwent partial hepatectomy, and 56 metastases were pathologically proved. Preoperatively, CTAP depicted 51 of the 56 metastases (91%). Intraoperative US depicted 54 of the 56 metastases (96%). Intraoperative US depicted three metastases (5%) that were not depicted with CTAP and two that were missed with palpation (3%). Furthermore, intraoperative US did not demonstrate any false-positive lesions. There was no statistically significant difference in sensitivity between the two techniques. The authors concluded that intraoperative US does not enable detection of more liver metastases from colorectal cancer when CTAP is considered as the preoperative standard of reference. Nevertheless, the results of the study suggest that intraoperative US and CTAP are complementary techniques, and the preoperative use of CTAP for determining the feasibility of hepatic resection cannot prevent the use of intraoperative US.

Fifty computed tomographic (CT) arterial portography (CTAP) examinations were retrospectively reviewed to determine the prevalence of a pseudolesion, defined as a focal low-attenuation area located in the medial segment of the left hepatic lobe immediately anterior to the porta hepatis. This pseudolesion was considered to be present if the described low-attenuation area was detected with CTAP but was not confirmed with one or more of the following: delayed-iodine hepatic CT (DICT), magnetic resonance (MR) imaging, surgery, and routine follow-up abdominal CT. A pseudolesion was suspected in seven of 50 (14%) cases. Correlation was made with findings at DICT in all seven cases and at MR imaging in five of the seven cases. In addition, correlation with findings at pathologic examination was made in four of the seven cases (57%). Correlation with findings on one or more follow-up abdominal CT scans was also made in three of the seven cases.

To evaluate gadobenate dimeglumine (Gd-BOPTA) for dynamic and delayed magnetic resonance (MR) imaging of focal liver lesions.In 126 of 214 patients, MR imaging was performed before Gd-BOPTA administration, immediately after bolus administration of a 0.05- mmol/kg dose of Gd-BOPTA, and 60-120 minutes after an additional intravenously infused 0.05-mmol/kg dose. In 88 patients, imaging was performed before and 60-120 minutes after a single, intravenously infused 0.1-mmol/kg dose. T1- and T2-weighted spin-echo and T1-weighted gradient-echo images were acquired. On-site and blinded off-site reviewers prospectively evaluated all images. Intraoperative ultrasonography, computed tomography (CT) during arterial portography, and/or CT with iodized oil served as the reference methods in 110 patients.Significantly more lesions were detected on combined pre- and postcontrast images compared with on precontrast images alone (P. 01). All reviewers reported a decreased mean size of the smallest detected lesion and improved lesion conspicuity on postcontrast images. All on-site reviewers and two off-site reviewers reported increased overall diagnostic confidence (P.01). Additional lesion characterization information was provided on up to 109 (59%) of 184 delayed images and for up to 50 (42%) of 118 patients in whom dynamic images were assessed. Gd-BOPTA would have helped change the diagnosis in 99 (47%) of 209 cases and affected patient treatment in 408 (23%) of 209 cases.Gd-BOPTA increases liver lesion conspicuity and detectability and aids in the characterization of lesions.

To compare spiral computed tomography during arterial portography (CTAP) with current magnetic resonance (MR) imaging, including hepatic arterial-dominant phase, gadolinium-enhanced, spoiled gradient-echo imaging, for the prospective detection of liver metastases in 20 patients who subsequently underwent surgery to confirm findings.Twenty patients underwent spiral CTAP and MR imaging within 1 week. Spiral CTAP and MR images were interpreted separately in blinded fashion. All patients subsequently had intraoperative confirmation. Sensitivity, specificity, and positive and negative predictive values were determined for lesion detection and segmental distribution.CTAP and MR images demonstrated, respectively, 54 and 60 true-positive lesions, six and one false-positive lesions, 15 and 22 true-negative (i.e., benign) lesions, and eight and two false-negative lesions. CTAP and MR images demonstrated, respectively, 57 and 62 true-positive segmental involvements, six and one false-positive segmental involvements, 89 and 95 true-negative segmental involvements, and eight and two false-negative segmental involvements. No significant difference in lesion detection was observed.Spiral CTAP and MR imaging were approximately equivalent for lesion detection in patients who were evaluated preoperatively for resection of liver metastases. The lower cost and fewer problems with artifacts may suggest that MR imaging is the preferred modality for preoperative assessment of patients for surgical treatment of liver metastases.

To prospectively compare the diagnostic accuracy of computed tomography (CT) during arterial portography (CTAP) with that of unenhanced and ferumoxides-enhanced magnetic resonance (MR) imaging at 0.5 T in the detection of hepatic metastases.Four pairs of radiologists independently assessed the metastatic involvement of 134 hepatic segments (31 with and 103 without metastasis) in 17 patients at unenhanced and ferumoxides-enhanced spin-echo and gradient-echo MR imaging (alone and in combination) and at CTAP. The diagnostic performance of the various imaging modalities was assessed by means of receiver operating characteristic analysis.The accuracy of CTAP, unenhanced MR imaging (combined unenhanced sequences), and ferumoxides-enhanced MR imaging (combined contrast material-enhanced sequences) was 0.925, 0.908, and 0.951, respectively. Ferumoxides-enhanced MR imaging was significantly more accurate (P.05) than unenhanced MR imaging and CTAP. When 14 segments containing cysts were excluded, the difference between ferumoxides-enhanced MR imaging and CTAP was no longer statistically significant (P = .1).Ferumoxides-enhanced MR imaging is more accurate than unenhanced MR imaging and at least as accurate as CTAP for the detection of hepatic metastases.

To analyze imaging finding in focal areas of liver parenchyma with aberrant gastric venous drainage (AGVD) in cirrhotic livers.Eighteen patients with AGVD confirmed with computed tomography (CT) during arterial portography and arteriography underwent ultrasound (US) (n = 18), CT (n = 18), magnetic resonance (MR) imaging (n = 12), dynamic CT (n = 14), and dynamic MR imaging (n = 8). Imaging and histologic (n = 2) findings were analyzed.The focal area with AGVD was hypoechoic on US scans (n = 7), hypoattenuating on CT scans (n = 4), hyperintense on T1-weighted MR images (n = 6), and hypointense on T2-weighted MR images (n = 5). Early enhancement was seen with dynamic CT (n = 8) and with dynamic MR imaging (n = 6), without definite staining on arterial phase of arteriography. Histologic findings revealed hyperplastic changes of liver.The imaging findings, except for early enhancement, were very similar to those of adenomatous hyperplasia or well-differentiated hepatocellular carcinoma. The early enhancement was considered due to early venous return compared with that of the surrounding liver.

To use computed tomography (CT) during arterial portography (CTAP) and CT arteriography to compare the hemodynamic properties of early hepatocellular carcinoma (HCC) with those of small HCC.Forty-four early HCCs (mean diameter, 1.5 cm) in 37 patients (26 men and 11 women aged 52-74 years; mean age, 59.2 years) were studied. CTAP was performed on 35 early HCCs, CT arteriography on 20, and both studies on 11. CTAP, CT arteriography, or both were performed on 90 small HCCs (mean diameter, 2.0 cm) in 57 patients (44 men and 13 women aged 48-71 years; mean age, 61 years). The findings for small HCC were compared with those for early HCC.CTAP depicted 23 early HCCs as hypoattenuating masses and 12 as isoattenuating. CT arteriography depicted 11 early HCCs as hypoattenuating masses, six as isoattenuating, and three as hyperattenuating. CTAP depicted 85 of 88 small HCCs as hypoattenuating masses and three as isoattenuating. CT arteriography depicted 13 of 14 small HCCs as hyperattenuating masses.CTAP, the standard of reference for the detection of small HCC, is not sensitive enough for the detection of early HCC.

To determine the optimal scanning parameters for helical computed tomography during arterial portography (CTAP) of the liver.Single- and double-helix CTAP were performed in 11 and 20 adult patients, respectively, with 200 mL of contrast material (300 mg of iodine per milliliter) injected at a rate of 3 mL/sec via the superior mesenteric artery. Scanning delays were adjusted for single-helix CTAP so the last scan was obtained at 66 seconds. Delays were adjusted for double-helix CTAP so the last scan during the first helix (CTAP-1) was obtained 10 seconds before the end of the injection at 56 seconds and the first scan during the second helix (CTAP-2) was obtained at the end of the injection at 66 seconds.Single-helix CTAP scans were of poor quality owing to multiple perfusion abnormalities. Lesion detection for double-helix CTAP-1 was 93.2% and was 100% for CTAP-2, and CTAP-2 scans had significantly fewer perfusion abnormalities.A scanning delay of 60-66 seconds appears to be optimal. The CTAP-1 scans showed no useful information and need not be acquired.

PURPOSE: To analyze the correlation between pseudolesions seen in segment IV of the liver and aberrant gastric venous drainage (AGVD). MATERIALS AND METHODS: Twenty-two patients with a pseudolesion in the posterior edge of segment IV of the liver (group A) and 100 randomly selected patients without pseudolesions (group B) underwent computed tomography during arterial portography (CTAP) and hepatic arteriography. The frequency of the visualization of AGVD to segment IV was compared for groups A and B. RESULTS: AGVD was seen at arteriography in 18 of 22 patients in group A. None of the patients in group B had AGVD. The difference in the frequency of angiographically visible AGVD was statistically significant (chi 2 test, P < .01). CONCLUSION: AGVD is the main cause of pseudolesions in the posterior edge of segment IV of the liver.

To assess the sensitivity of helical computed tomography during arterial portography (CTAP) in the detection of primary malignant neoplasms of the liver.Preoperative helical CTAP examinations of 19 patients (13 men, six women, aged 33-78 years) with primary malignant neoplasms of the liver (hepatoma, n = 12; cholangiocarcinoma, n = 4; angiosarcoma, n = 1; biliary cystadenoma, n = 1; hepatoblastoma, n = 1) were retrospectively reviewed by three radiologists. Imaging findings were correlated with intraoperative and pathologic findings.A total of 29 separate malignant neoplastic nodules (mean diameter, 6.6 cm) were identified in the resected specimens (16 patients) or intraoperatively in three patients. The overall sensitivity of helical CTAP was 72%; for neoplasms with a diameter less than 1.0 cm, 25%; for neoplasms 1.1-2.0 cm and 2.1-4.0 cm, 25% and 67%, respectively; and for neoplasms over 4.0 cm, 100%.The overall sensitivity of helical CTAP in the preoperative detection of primary malignant hepatic neoplasms is low.

A prospective study was performed to compare the sensitivity and specificity of magnetic resonance (MR) imaging and computed tomography (CT) both performed during arterial portography in depicting focal hepatic masses.Eleven patients with 31 pathologically proved focal hepatic masses were prospectively evaluated. MR arterial portography was performed with 4 mL of a 0.5 mmol/kg solution of gadolinium tetraazacyclododecanetetraacetic acid (DOTA) injected through a catheter into the superior mesenteric artery during multisection gradient-echo imaging.MR arterial portography depicted 29 of the 31 masses (sensitivity, 94%). CT arterial portography depicted 27 of the 31 masses (sensitivity, 87%). Two masses not depicted with either CT or MR had a diameter of 3 and 7 mm, respectively. Neither MR nor CT demonstrated a false-positive finding (specificity, 100%). The difference in sensitivity and specificity between the two techniques was not statistically significant.MR arterial portography does not enable detection of significantly more focal hepatic masses than does CT arterial portography.

To determine whether the addition of computed tomographic (CT) angiography to CT arterial portography would improve lesion detection and heighten confidence in interpreting perfusion abnormalities.The two examinations were performed sequentially in 10 candidates for surgical resection of hepatic tumors. Arterial vascular access was obtained with bilateral punctures of the common femoral artery and selective placement of angiographic catheters in the hepatic artery and superior mesenteric artery (SMA). CT scans were obtained first during injection of contrast material into the SMA, followed by repeated imaging of the liver during injection of contrast material into the hepatic artery.The procedure demonstrated, among other results, three additional lesions in two patients, a possibly nontumorous abnormality as tumorous in one, and a suspected tumorous abnormality as nontumorous in one. Suspected nontumorous abnormalities in four patients were confirmed at CT angiography.These preliminary data support a trial of this technique in a larger population.

PURPOSE: To determine the feasibility and sensitivity of multisection fast low-angle shot (FLASH) magnetic resonance (MR) imaging in the depiction of hepatic metastases. MATERIALS AND METHODS: The cases of 10 patients with 39 surgically proved hepatic metastases were prospectively evaluated. After unenhanced T1- and T2-weighted spin-echo (SE) and FLASH imaging, 4 mL of a 0.5 mol/L solution of a gadolinium chelate (tetraazacyclododecanetetraacetic acid) was injected into the superior mesenteric artery during FLASH imaging in a single breath-holding period. RESULTS: No side effects were noted. With multisection FLASH MR arterial portography, tumor-to-liver contrast-to-noise ratio (34.5 +/- 4.4) was significantly increased compared with unenhanced MR imaging. Sensitivity was 74% (29 of 39) for combined SE and multisection FLASH imaging and 95% (37 of 39) for multisection FLASH MR arterial portography (McNemar test, P < .02). CONCLUSION: Multisection FLASH MR arterial portography is a safe, feasible, and sens...

The enhancement characteristics of the liver, aorta, and hepatic vein were evaluated during computed tomography with arterial portography (CTAP) performed with spiral technique in 10 patients. The attenuation of the liver was nearly constant over the scanning interval (average attenuation, 168 HU +/- 16). The attenuation of the aorta increased by an average of 54 HU +/- 31, and the average attenuation of the hepatic vein was 250 HU +/- 34. These data indicate that high levels of liver parenchymal and vascular enhancement can be reliably obtained with CTAP performed with spiral technique.

Fourteen patients with hepatocellular carcinoma (HCC) were examined with computed tomography (CT) during arterial portography (CTAP) and with CT after intraarterial injection of iodized oil. The detectability of main lesions and associated daughter nodules or intrahepatic metastases was assessed. Hepatic resection was subsequently performed in all 14 patients. The results of the imaging studies were compared with the surgical and pathologic findings by means of a lesion-by-lesion analysis. A total of 34 masses were identified in the resected specimens: 18 main tumor masses and 16 intrahepatic metastases. For CTAP, the detection rate of main tumors was 94%; for iodized-oil CT, 82%. However, the daughter-nodule detection rates for both techniques were poor-only 38% detected for CTAP and 50% for iodized-oil CT. Although these two techniques remain important preoperative imaging methods in patients with HCC, the results of this study suggest that small daughter nodules (less than 5 mm in diameter) may go undetected with both techniques.

Dynamic sequential computed tomography with table incrementation during arterial portography (DSCTI-AP) of the entire liver was performed in an attempt to improve the detection of hepatic neoplasms. In 13 of 17 patients, DSCTI-AP detected more hepatic lesions than were detected by other imaging methods, including radionuclide liver scans, ultrasound, computed tomography, and hepatic angiography. In only one case, an extremely hypervascular hepatocellular carcinoma, hepatic angiography was superior to DSCTI-AP. DSCTI-AP is a simple technique that may be carried out as a part of hepatic angiography. We believe that DSCTI-AP is a sensitive and useful method for the accurate detection of hepatic neoplasms.

The clinical experience with selective superior mesenteric arterial portography employing an alpha blocking agent (phentolamine) and beta stimulating agent (isoproterenol) used in combination to produce improved portal venous system opacification is described. In fourteen of sixteen studies, a greater degree of opacification of the portal venous system occurred utilizing this drug combination. Various anatomic and physiologic factors, including superior mesenteric artery pressure and peripheral blood pressure before and immediately after the injection of the drug combination were used to evaluate the results. Side effects were minimal and usually consisted of transient tachycardia.

High-dose left gastric angiography gave consistent demonstration of esophageal varices in 11 patients. In addition, in comparisons with splenoportography and other types of arterial portography, results of high-dose left gastric angiography were consistently superior. The method is safe and relatively simple and should be used when demonstration of esophageal varices is the object of arterial portography.

The effects of increasing single selective doses of prostaglandin E1 (PGE1) on superior mesenteric arterial flow and portal and systemic blood pressures were studied in dogs to assess its value as a vasodilatory agent for pharmacoangiography. PGE1 consistently increased blood flow, with an average increase of 187%, but had minimal effect on portal and systemic blood pressure. 25 mug of PGE1 gave an ideal flow curve for pharmacoangiography, with a maximum effect 30 seconds after injection.

The sensitivities of contrast medium-enhanced computed tomography (CT), delayed CT (DCT), CT during arterial portography (CTAP), and magnetic resonance (MR) imaging for detecting focal liver lesions were prospectively evaluated in eight patients who subsequently underwent hepatic lobectomy or transplantation. Pathologic evaluation of the resected liver specimens demonstrated 37 lesions. The sensitivities were 81% (30 of 37 lesions) for CTAP, 57% (21 of 37 lesions) for MR imaging, 52% (12 of 23 lesions) for DCT, and 38% (14 of 37 lesions) for contrast-enhanced CT. The difference between the sensitivity of CTAP and the sensitivities of the other imaging tests was statistically significant (P less than .004). Of the lesions smaller than 1 cm in diameter, CTAP depicted 61% (11 of 18 lesions), MR imaging 17% (three of 18 lesions), CT 0% (zero of 18 lesions), and DCT 0% (zero of nine lesions). It is concluded that for preoperative detection of focal hepatic masses, CTAP is the most accurate technique available to most radiologists. Patients with primary or secondary hepatic neoplasms who are being considered for hepatic resection should undergo CTAP as part of their preoperative examination.

Forty-three patients with known primary or secondary neoplastic involvement of the liver underwent evaluation to determine the number, size, and location of focal lesions before possible tumor resection. Imaging studies included computed tomography (CT) during arterial portography (CTAP), delayed CT, and magnetic resonance (MR) imaging at various pulse sequences. Results of radiologic studies were compared with surgical and pathologic findings. In the combined group of surgical and nonsurgical patients, CTAP was significantly more sensitive (85%) than all other techniques except 1.5-T T2-weighted spin-echo imaging (64%). Combining the information from all MR pulse sequences yielded a cumulative sensitivity of 68%. Combining the information from two modalities yielded sensitivity of 96% for CTAP plus MR imaging, 85% for CTAP plus delayed CT, and 77% for delayed CT plus MR imaging. The authors conclude that when it is vital to know the precise number, size, and location of focal hepatic lesions before tumor resection, CTAP has the highest sensitivity, but MR imaging is an important adjuvant.

A prospective, blinded comparison of three methods of hepatic contrast enhancement in computed tomography (CT) was conducted in 15 patients with colorectal carcinoma metastatic to the liver. Arterial portography (AP-CT) was performed with injection of contrast material into the superior mesenteric artery during CT. Delayed scanning (DS-CT) was performed 4 hours after intravascular administration of contrast material (mean dose, 280 mL). CT with an ethiodized oil emulsion (EOE-CT) was performed 1 hour after slow intravenous infusion of the emulsion. All patients underwent laparotomy following imaging studies. A lesion-by-lesion analysis of 56 metastases showed no significant differences in sensitivity (AP-CT, 77%; DS-CT, 83%; EOE-CT, 82%), but the false-positive rate for AP-CT was significantly higher than that for DS-CT (P less than .001) or EOE-CT (P less than .01). False-positive rates for EOE-CT and DS-CT were not significantly different. The predictive value of a positive test was 63% for AP-CT, 90% for DS-CT, and 81% for EOE-CT. AP-CT does not appear to be clinically useful for detection of hepatic metastases because of the high false-positive rate. No difference could be demonstrated between DS-CT and EOE-CT. DS-CT is a valuable method for hepatic contrast enhancement.

A total of 45 metastases to the liver from colorectal cancer were resected in 22 patients. The detectability of these lesions with the following modalities was determined: real-time ultrasound (US), computed tomography (CT), selective celiac arteriography (SCA), infusion hepatic angiography (IHA), CT during arterial portography (CTAP), and CT following intraarterial injection of iodized poppyseed oil (Lipiodol). The total detection rate (sensitivity) was 58% for US, 63% for CT, 27% for SCA, 50% for IHA, 84% for CTAP, and 38% for CT with iodized oil. Ten of 18 lesions less than 15 mm in largest diameter were demonstrated preoperatively by CTAP only. CTAP is useful in clarifying the locations of the lesions in the liver and should always be performed before liver metastases from colorectal cancer are resected.