CT During Arterial Portography Research Articles

Effect of temporary occlusion of the hepatic vein on dual blood in the liver: evaluation with spiral CT.

To evaluate the contribution of hepatic veins to the dual blood supply in the liver under temporary hepatic venous occlusion. Selected hepatic veins in 23 patients with liver tumors were temporarily occluded with a balloon catheter. Computed tomography (CT) arteriography, CT during arterial portography (CTAP), or both were performed with a spiral technique with and without temporary occlusion of a hepatic vein. After hepatic vein occlusion, a well-demarcated, wedge-shaped area of hypoattenuation was seen at CTAP and/or hyperattenuation was seen at CT arteriography in the following regions: left lobe (left hepatic vein), ventral part of the anterior segment and the medial segment except for the ventromedial part (middle hepatic vein), dorsal part of the anterior segment and the ventral part of the posterior segment (right hepatic vein), and dorsocaudal part of the right lobe (inferior right hepatic veins). After hepatic venous occlusion, the portal veins become draining veins and the occluded area is supplied with arterial blood alone.

New technique for CT during arterial portography performed with left brachial artery approach

A new technique of CT during arterial portography (CTAP) performed with a left brachial artery approach is presented. We used 4-F, 50-cm J-shaped sheath introducer with a straight dilator and angled 4-F catheter with side holes. Catheter insertion to the superior mesenteric artery (SMA) can be performed without any trouble by the help of a J-shaped long sheath introducer positioned in the aortic arch. In our experience, 10 min compression of the puncture site and 2 h observation after catheter removal brought no local complication. This method can be performed safely on outpatient basis.

F6-3 Use of color doppler energy in the diagnosis of small liver tumor

To assess and compare the accuracy and inter-observer agreement for the detection of liver lesions using Primovist magnetic resonance imaging (pMRI) and computed tomography during arterial portography (CTAP).Patients evaluated at St George Hospital Liver Unit for colorectal liver metastases (CRCLM) underwent CTAP as part of standard staging. pMRI was added to the pre-operative assessment. Two radiologists reported CTAP and two reported pMRI. The sensitivity and specificity of CTAP and pMRI were calculated using histopathology as the gold standard.Complete data were available for 62 patients corresponding to 219 lesions confirmed on histopathology. Agreement on the detection of lesions between the two radiologists that reported pMRI was higher than for CTAP (Kappa = 0.80 versus 0.74). Specificity of lesion detection for pMRI was 0.88 and 0.83 for CTAP (P = 0.112). Sensitivity for pMRI was 0.83 and 0.81 for CTAP. For patients who had chemotherapy before evaluation, pMRI had a significantly higher specificity than CTAP (0.79 versus 0.63, P = 0.011).pMRI is less invasive, has a good inter-observer agreement, has comparable sensitivity and specificity to CTAP in the pre-chemotherapy population and demonstrates better specificity in patients assessed post-chemotherapy. pMRI is a valid alternative to CTAP in the assessment of CRCLM.

Spiral CT during arterial portography: technique and applications.

Spiral computed tomography during arterial portography (CTAP) combines rapid scanning with selective imaging during the portal phase of enhancement of the liver, resulting in an effective method for evaluation of liver neoplasms prior to partial hepatic resection. Compared with dynamic incremental CTAP, spiral CTAP results in improved quality of three-dimensional and multiplanar reconstructions, facilitating presurgical planning. Accurate volumetric analysis of the tumor can be performed, and subsegmental tumor localization is facilitated by the high levels of hepatic and portal venous enhancement. Additional advantages of spiral CTAP include small reconstruction intervals for improved lesion detection. However, the specificity of spiral CTAP is low because both benign and malignant tumors appear as hypoattenuating perfusion defects. In addition, both focal and geographic nontumorous perfusion defects may be seen more frequently with spiral CTAP than with dynamic CTAP. Knowledge of common diagnostic pitfalls is necessary for accurate interpretation of spiral CTAP images.

Nontumorous low-attenuation defects in the liver on helical CT during arterial portography: frequency, location, and appearance.

Low-attenuation defects in the liver that are caused by variations in the portal perfusion of the liver rather than by intrahepatic tumor can be detected using helical CT during arterial portography (CTAP). The purpose of this study was to characterize these nontumorous low-attenuation defects detected with helical CTAP in terms of their frequency, location, and appearance. Helical CTAP examinations of 89 patients referred for preoperative evaluation of metastatic or primary liver tumors performed over a 20-month period were retrospectively reviewed by three radiologists. The frequency, appearance, and location of focal (within a subsegment) and diffuse (affecting more than one subsegment) nontumorous perfusion defects were determined. Findings on helical CTAP images were correlated with surgical findings (53 patients), results of MR examinations (25 patients), and follow-up CT examinations (11 patients). Ninety-seven nontumorous perfusion defects were identified in 68 patients. The most frequent defects were located adjacent to the gallbladder fossa (35), anterior to the porta hepatis (34), in the subcapsular portion of the liver (13), and adjacent to the falciform ligament (12). Nontumorous perfusion defects characteristically appeared wedge-shaped or flat and ranged in size from 8-20 mm. Nontumorous perfusion abnormalities have characteristic appearances and locations on helical CTAP examinations and are more common than previously reported with conventional CTAP. Familiarity with the locations and characteristic appearances of these defects is essential to prevent false-positive diagnoses, so that operative candidates are not mistakenly denied surgical therapy.

Helical CT during arterial portography: optimization of contrast enhancement and scanning parameters.

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.

Hepatocellular carcinoma: CT appearance of parenchymal changes after percutaneous ethanol injection therapy.

To evaluate the changes in surrounding liver parenchyma after treatment of hepatocellular carcinoma (HCC) and borderline malignant lesions with percutaneous ethanol injection (PEI). The authors reviewed the findings at computed tomography (CT) and CT during arterial portography (CTAP) obtained before and after PEI therapy for 32 lesions in 26 patients with HCC or adenomatous hyperplasia. Two surgically resected specimens were also histologically examined. In 10 (77%) of 13 lesions, decreased portal vein-related enhancement indicative of reduced portal blood flow in the periphery of the tumor was found at CTAP. Mild atrophy (concave liver surface), segmental atrophy, and lobar atrophy were found in 40%, 17%, and 3%, respectively. Histologic examination of the resected specimens revealed organized thrombi in the peripheral portal vein in the surrounding liver. PEI may cause decreased portal blood flow and atrophy in the noncancerous liver parenchyma that surrounds the tumor being treated.

Variations in the intrahepatic portions of the hepatic and portal veins: findings on helical CT scans during arterial portography.

The goals of this study were to describe variations in the intrahepatic portions of the hepatic and portal veins as visualized by helical CT during arterial portography (CTAP) and to examine the surgical implications of these findings. A retrospective review of 69 helical CTAP scans of 69 patients with small hepatic tumors and no evidence of vascular invasion or distortion was done. Axial helical CTAP scans were reviewed to determine the presence, number, and location of intrahepatic portions of the hepatic and portal veins. Among the 60 patients (87%) in whom the right, middle, and left hepatic veins were visualized, 19 (32%) had supernumerary hepatic veins. Right inferior hepatic veins were found in six (9%) of the 69 patients. Variations in intrahepatic portal anatomy were found in four patients (6%) and involved an immediate trifurcation of the portal vein in three patients (4%) and a left main portal vein originating from the right anterior portal branch in one patient (2%). Variations in the intrahepatic portions of the hepatic and portal veins are frequently seen on helical CTAP scans. Recognition of such variations is important in the preoperative evaluation of patients with hepatic tumors because these variations may have implications for tumor resection and for planning the operative approach.

CT during arterial portography for the preoperative evaluation of hepatic tumors: how, when, and why?

CT during arterial portography (CTAP) is the most sensitive technique for the detection of intrahepatic tumors. CTAP is based on portal enhancement of the liver by infusion of contrast material through the superior mesenteric artery. This technique provides clear delineation of intrahepatic vessels, allowing segmental location of tumors to be accurately determined and relationships between tumors and intrahepatic vessels to be assessed. CTAP must be limited to patients for whom noninvasive preoperative imaging examinations have shown a potential for hepatic resection. In the majority of the cases, CTAP is performed in patients with hepatic metastases from colorectal cancer, but other types of tumor (either primary or secondary) may be an indication for CTAP. Visualization of nontumorous perfusion defects is a limitation of this technique, but such defects have been well described and have characteristic locations and appearance. In difficult cases, correlation with sonographic, CT, and MR imaging findings helps characterize portal perfusion defects. CTAP data can be viewed as multiplanar and three-dimensional reconstructions that allow preoperative planning of the extent of resection and determination of the volume of the remaining liver. The use of spiral CT shows promise in the performance of CTAP.

Segmental iron deposition in the liver due to decreased intrahepatic portal perfusion: findings at MR imaging.

To evaluate the causes of intrahepatic segmental areas of signal hypointensity [corrected] on T1- and T2-weighted spin-echo (SE) and gradient-echo (GRE) magnetic resonance (MR) images. Six patients in whom wedge-shaped hypointense areas were seen on hepatic MR images underwent examination with ultrasound (US), computed tomography (CT), angiography, and CT during arterial portography (CTAP). Histologic examination was performed in three patients. The affected liver parenchymas were best depicted as segmental or lobar hypointense areas on GRE images. Angiography and CTAP revealed that portal blood supply to the hypointense areas was absent or decreased due to portal vein tumor thrombus and arterioportal shunt (n = 1), compression of a portal branch by tumor (n = 2), portal vein thrombosis (n = 1), or arterioportal shunt (n = 2). Iron deposition in the hepatocytes was evident in all three patients with histologic correlation. Segmental signal hypocoagulability was generally due to hepatocyte iron deposition and was accompanied and possibly caused by a disturbance in portal flow.

Chondroitin Sulfate Iron Colloid-Enhanced MR Imaging in Patients with Hepatocellular Carcinoma

Chondroitin sulfate iron colloid (CSIC) was used as an MR contrast agent for the detection of hepatocellular carcinoma (HCC). The findings of 25 surgically confirmed HCCs in 19 patients were retrospectively analyzed. T1-, T2- and proton density-weighted spin echo MR images were obtained before and after i.v. injection of 23.6 μM Fe/kg of CSIC. Unenhanced and CSIC-enhanced MR images and images obtained by CT during arterial portography (CT-AP) were correlated with surgical pathology findings. The sensitivities of CSIC-enhanced and unenhanced MR imaging, and CT-AP were 92%, 80%, and 88%, respectively. No significant differences were noted. Portal flow abnormalities demonstrated by CT-AP did not affect the detection of HCC by CSIC-enhanced MR imaging. CSIC-enhancement at MR imaging was a disadvantage in the detection of lesions less than 1 cm in diameter. CSIC-enhanced MR imaging is a supplemental method for the detection of HCC.

Chondroitin Sulfate Iron Colloid-Enhanced MR Imaging in Patients with Hepatocellular Carcinoma

Chondroitin sulfate iron colloid (CSIC) was used as an MR contrast agent for the detection of hepatocellular carcinoma (HCC). The findings of 25 surgically confirmed HCCs in 19 patients were retrospectively analyzed. T1-, T2- and proton density-weighted spin echo MR images were obtained before and after i.v. injection of 23.6 μM Fe/kg of CSIC. Unenhanced and CSIC-enhanced MR images and images obtained by CT during arterial portography (CT-AP) were correlated with surgical pathology findings. The sensitivities of CSIC-enhanced and unenhanced MR imaging, and CT-AP were 92%, 80%, and 88%, respectively. No significant differences were noted. Portal flow abnormalities demonstrated by CT-AP did not affect the detection of HCC by CSIC-enhanced MR imaging. CSIC-enhancement at MR imaging was a disadvantage in the detection of lesions less than 1 cm in diameter. CSIC-enhanced MR imaging is a supplemental method for the detection of HCC.

Intrahepatic cholangiocarcinoma: findings on spiral CT during arterial portography

To attempt to determine the characteristic imaging features of intraheptic cholangiocarcinoma on spiral CT during arterial portography (CTAP), spiral CTAP examinations of 17 patients with pathologically confirmed intrahepatic cholangiocarcinoma were reviewed in consensus by three radiologists. The diameter of the tumors ranged from 1 to 12 cm (mean diameter, 6.6 cm). All tumors (100%) were hypoattenuating masses on spiral CTAP. In 11 cases, the tumor was homogeneous in attenuation (65%). Tumor margins were smooth and regular in 11 cases (65%). Vascular invasion was found in 14 cases (82%). Intrahepatic bile duct dilatation was present in seven cases (41%). This review shows that intrahepatic cholangiocarcinoma is associated with a constellation of findings on spiral CTAP. The presence of a low attenuation homogeneous intrahepatic mass with vascular invasion and intrahepatic bile duct dilatation on spiral CTAP images should raise the possibility of intrahepatic cholangiocarcinoma. However, these findings can be associated with other types of primary and secondary malignant hepatic tumors.

Small hepatocellular carcinoma: evaluation of portal blood flow with CT during arterial portography performed with balloon occlusion of the hepatic artery.

To evaluate portal blood flow in small hepatocellular carcinomas (HCCs) by means of computed tomography during arterial portography (CTAP) and CTAP with hepatic arterial obstruction (CTP-HAO) achieved by means of balloon occlusion. Thirteen patients with small HCC (< 20 mm in diameter) underwent CTAP, CTP-HAO, carbon dioxide-enhanced ultrasound (CEUS), and digital subtraction angiography (DSA). The imaging findings were correlated with histologic features. The first group of patients (n = 3) had tumors with portal blood flow at both CTAP and CTP-HAO and no hypervascularity at CEUS. The second group (n = 3) had tumors with portal blood flow at CTP-HAO but not at CTAP and hypervascularity at CEUS only. The third group (n = 7) had tumors without portal blood flow at CTAP or CTP-HAO and hypervascularity at DSA and CEUS. The first and second groups had well-differentiated HCCs; six of seven patients in the third group had moderately differentiated HCCs. Lack of portal blood flow was reversible in well-differentiated HCCs but irreversible in the other tumors.

Hepatic metastases from colorectal cancer: detection and false-positive findings with helical CT during arterial portography.

To determine the sensitivity and false-positive rate of helical computed tomography during arterial portography (CTAP) in the detection of hepatic metastases from colorectal cancer. Preoperative helical CTAP was performed to examine 23 patients (10 men and 13 women, aged 43-77 years [mean, 63 years]) who later underwent surgical tumor resection. Imaging findings were retrospectively reviewed by two radiologists and were correlated with intraoperative and histologic findings. Helical CTAP demonstrated 33 of 35 metastases, with diameters of 4-95 mm, that were identified in resected specimens (sensitivity, 94%). The two metastases not demonstrated were 4 and 5 mm in diameter. Five false-positive lesions were found in four patients, yielding a false-positive rate of 17% by patient analysis and 13% by lesion analysis. The sensitivity of helical CTAP in the preoperative detection of hepatic metastases is high, and its false-positive rate compares favorably with that of conventional CTAP, but future comparative studies are needed to determine which is the better modality.

Pseudolesion in segment IV of the liver at CT during arterial portography: correlation with aberrant gastric venous drainage.

To analyze the correlation between pseudolesions seen in segment IV of the liver and aberrant gastric venous drainage (AGVD). 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. 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). AGVD is the main cause of pseudolesions in the posterior edge of segment IV of the liver.

Involvement of superior mesenteric vessels and portal vein in pancreatic adenocarcinoma: detection with CT during arterial portography.

A prospective study was designed to determine the utility of computed tomography (CT) during arterial portography (CTAP) in the detection of superior mesenteric vessels and portal vein involvement in patients with pancreatic adenocarcinoma. Eighteen patients with adenocarcinoma of the head of the pancreas and eight patients with benign pancreatic disease were investigated with CTAP, dynamic contrast-enhanced CT, and angiography. Appropriate review was made to determine presence or absence of superior mesenteric vessels and portal vein involvement. Final diagnosis was obtained in all cases by surgical explorations. The overall accuracy rate for detecting or excluding superior mesenteric vessels and portal vein involvement was 96% (25 of 26 patients) with CTAP, 88% (23 of 26 patients) with dynamic contrast-enhanced CT, and 85% (22 of 26 patients) with angiography. No statistically significant difference in accuracy was found among the three techniques. Our results suggest that the use of CTAP is not indicated in the preoperative detection of superior mesenteric vessels and portal vein involvement in patients with pancreatic adenocarcinoma.

Primary malignant neoplasms of the liver: detection with helical CT during arterial portography.

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.

Surgical segmental anatomy of the liver: demonstration with spiral CT during arterial portography and multiplanar reconstruction.

A major role of imaging in the evaluation of hepatic tumors is to assist surgeons in the preoperative determination of the feasibility of hepatic resection. Although the segmental location of tumors is not the sole criterion for determining resectability, such knowledge is useful for preoperative planning of the type of resection. This essay illustrates the surgical segmental and subsegmental anatomy of the liver as shown by spiral CT during arterial portography (CTAP) with multiplanar reformation.

A One-Stage Method for Obtaining CT during Arterial Portography and Hepatic Arteriography

We describe a new technique for performing CT during arterial portography (CTAP) and during hepatic arteriography (CTHA) in a one-stage procedure, using a coaxial balloon catheter system and slip-ring CT equipment. This technique was employed in 10 patients with liver neoplasms. Both CTAP and CTHA images were obtained in all patients.