CT Arterial Portography Research Articles

During liver regeneration following right portal embolization the growth rate of liver metastases is more rapid than that of the liver parenchyma.

The relative growth rates of human liver metastases are not known. The aim of this study was to determine in humans the growth rate of liver parenchyma during regeneration and the growth rate of liver metastases during the same process. Among 556 patients hepatectomized for a malignant lesion, 48 underwent preoperative selective right portal vein embolization to induce hypertrophy of the left lobe. Five cases were selected because a liver metastasis was present inside the regenerating left lobe. The volumes of the liver metastasis and left lobe were measured with a three-dimensional technique on pre-embolization and postembolization computed tomography (CT) or CT arterial portography. The median interval between the two measurements was 34 (range 28-40) days. An increase occurred in the volume of the liver metastasis and the left lobe in the four patients with functionally intact liver parenchyma, but not in the patient with an impaired parenchyma. The volumetric increase of the normal liver varied from 59 to 127 per cent, compared with 60 to 970 per cent for the liver metastases. The ratio between the growth rate of the left lobe and the liver metastasis varied from 1.0 to 15.6. The growth rates of two metastases in the left lobe of a single patient were different. In functionally intact liver parenchyma, during hepatic regeneration or hypertrophy, the growth rate of metastases is more rapid that that of the liver parenchyma. However, a wide variation in growth rate is observed between patients and between metastases.

CT arterial portography and CT hepatic arteriography in detection of micro liver cancer.

AIM:To recognize the characteristic findings of micro-liver cancer (MLC) and to evaluate the effect of CT arterial portography (CTAP) and CT hepatic arteriography (CTHA) in diagnosis of MLC.METHODS:Between April 1996 to December 1998, CTAP and CTHA were performed in 12 patients with MLC, which were not detected by conventional CT examinations. After CTHA, 3mL-5mL mixture of lipiodol, doxorubicin and mitoycin C were injected into hepatic artery through the catheter, and the followed up by CT three or four weeks later (Lipiodol CT Lp-CT).RESULTS:A total of 22 micro-tumors (0.2cm-0.6cm in diameter) were detected in 12 patients, which manifested as small perfusion defects in CTAP and small round enhancement in CTHA. The rate of detectability of CTAP and CTHA was 68.2% (15/22) and 77.3% (17/22) respectively, and the rate of the simultaneous use of both procedures reached 86.4% (19/22).All micro-tumors were demonstrated as punctate lipiodol deposit foci in Lp-CT. After Lp-CT, the elevated serum level of alpha-fetoprotein (AFP) dropped to the normal level in all patients.CONCLUSION:The CTAP and CTHA are the most sensitive imaging methods for detecting micro-liver cancer.Confirmed by the change of the elevated serum AFP level and lipiodol deposit foci in Lp-CT, small perfusion defects in CTAP and puntuate enhancement in CTHA may suggest micro-liver cancer.

The Imaging Findings of Small(< or =15mm) Portal Defects in the Liver on CT Arterial Portography: Evaluationwith CT Hepatic Arteriography and Lipiodol CT

Purpose : To assess the malignant potential of small(≤15mm) portal defects seen on CT arterial portography,the findings of CT hepatic arteriography and lipiodol CT CT were reviewed. Materials and Methods : In 91 patientswho underwent both CTAP and CTHA, small portal defects were re-viewed for frequency, multiplicity and location. Weprospectively evauluated changes in the size and enhance-ment pattern of malignant lesions on follow up CTaccording to density on CTHA, location, lipiodol deposits on lipiodol CT, and multiplicity. Results : Among the 91patients, 102 small defects were defected in 42 patients(46%). Small portal defects were benign, malignant, and ofundetermined malignant potential in 77%, 20% and 3% of cases, respectively. Small portal defects that werehyperattenuated on CTHA, and lipiodol deposits on lipiodol CT, were malignant in 42% and 70% of cases,respectively. Location and multiplicity did not show statistically significant variation between benign andmalignant defects. Conclusion : Small portal defects are common and there is a high probability that portaldefects smaller than 15mm are benign, even in patients with a known hepatic mass and defect that washyperattenuated on CTHA. If a small defect showed lipiodol deposit on lipiodol CT, malignancy must be suspected.

Entrance skin dose estimates derived from dose-area product measurements in interventional radiological procedures.

Patient skin doses resulting from interventional radiological procedures have the potential to exceed threshold doses for deterministic effects such as erythema and epilation. If the irradiation geometry is known, the entrance skin dose can be estimated from the measured dose-area product. For each of 10 non-coronary interventional procedures, a nominal geometry was identified. From a previous survey of patient dose-area products, the entrance skin doses were estimated under the assumption that all procedures were performed with the nominal geometry specific to it. An analysis of the uncertainties in these doses caused by realistic deviations from the nominal geometry was also performed and it was shown that the estimated entrance skin dose values are at least to within 40%, and generally to within about 30%, of those actually received. For example, the median estimated entrance skin doses for the posteroanterior and lateral projections of cerebral angiography were 100 and 110 mGy. respectively, and for hepatic angiography 425 mGy. The largest entrance skin dose estimate for a single projection was for the angiography component of a CT arterial portography procedure at 670 mGy. Comparisons between entrance skin dose estimates obtained from this study are made with data from other interventional radiology patient dose surveys.

Findings of non-pathologic perfusion defects by CT arterial portography and non-pathologic enhancement of CT hepatic arteriography.

AIM:To recognize the characteristic findings of non-pathologic perfusion defects with CT arterial portography (CTAP) and nonpathologic enhancement found in CT hepatic arteriography (CTHA).METHONDS:The manifestations of nonpathologic perfusion defects with CTAP and non pathologic enhancement found in CTHA were analyzed in 50 patients with primary hepatocellular carcinoma.RESULTS:The false-positive rate of perfusion defects detected in CTAP was 15.1% The shapes of perfusion defects were peripheral wedge, small, round, and patchy. The occurrence rate of non-pathologic enhancement found in CTHA was 22.0%. The shapes of non-pathologic enhancement were small, round, irregular, and wedge.CONCLUSION:There was high frequency of non-pathologic perfusion defects detected with CTAP and non-pathologic enhancement found in CTHA. The simultaneous use of both procedures may help decrease the false-positive rate, and increase the veracity of diagnosis for hepatocellular carcinoma.

Double Uncture fo Single Common Femoral Artery for CT Hepatic Arteriography and CT Arterial Portography

Double Uncture fo Single Common Femoral Artery for CT Hepatic Arteriography and CT Arterial Portography

Pseudolesion in Segment IV of the Liver on CT Arterial Portography

Pseudolesion in Segment IV of the Liver on CT Arterial Portography

Methodological assessment of combined spiral CT angiography and CT arterial portography

To assess an optimal methodology of combined spiral computed tomographic (CT) angiography (CTA) and CT arterial portography (CTAP) for detection and characterization of liver tumors. We performed spiral CTAP only in five patients with 30-32% contrast (subset A), CTAP combined with preceding spiral CTA using 30-32% contrast in 19 (subset B), and CTAP combined with preceding spiral CTA with 60-64% contrast in seven (subset C). The CT numbers of the aorta immediately before preceding CTA and subsequent CTAP and the CT numbers of malignant tumor and liver parenchyma with CTAP were measured. The differences of the CT number between the malignant tumor and liver parenchyma on CTAP were 61.1-161.8 (mean +/- SD, 114.5 +/- 39.3) HU, 50.7-164.8 (104.2 +/- 31.2) HU, and 101.2-368.3 (219.5 +/- 90.5) HU in subsets A, B, and C, respectively. Two cavernous hemangiomas showed pathognomonic findings with preceding CTA. Combination of preceding spiral CTA and subsequent spiral CTAP using 30% contrast with a 5-min interval is an optimal method for detection and characterization of liver tumors.

CT arterial portography and CT arteriography with a triple-lumen balloon catheter.

To evaluate the usefulness of the triple-lumen balloon catheter in the serial performance of CT arterial portography (CT-AP) and CT arteriography (CT-A). A combined CT-AP and CT-A examination of 58 patients was carried out in which a cobra-type triple-lumen balloon catheter was used. CT-AP was performed by injecting contrast medium either into the splenic artery through a side-hole in the catheter proximal to the balloon inflated in the common hepatic artery, or into the superior mesenteric artery through an end-hole in the catheter. Then CT-A was serially performed by delivering contrast medium either to the common hepatic artery or the proper hepatic artery from the end-hole, or to the accessory right hepatic artery through a side-hole proximal to the inflated balloon. Sufficient CT-APs were obtained in 53 of the 58 patients (91%), CT-A in 42 (72%), and both in 42 (72%). Incomplete CT-AP was due to technical failure or anatomical anomaly, as was incomplete CT-A. No complications were seen. The triple-lumen balloon catheter technique is useful and convenient in the serial performance of CT-AP and CT-A.

Use of spiral and non-spiral computed tomography arterial portography in the detection of potentially malignant liver masses.

The present study assesses the usefulness of computed tomography (CT) arterial portography (CTAP) in detecting and defining the number and anatomy of potentially malignant liver lesions. One hundred and one adults studied in 1993 and 1994 were retrospectively reviewed, including patients with primary or secondary tumours for possible resection and patients with non-hepatic malignancies in whom the detection of liver metastases would preclude surgery. Twenty-three patients underwent non-spiral CT studies and 78 had studies on a spiral unit, with 22 of these having single phase and 56 having dual phase studies to overcome artefact problems. The relationship between lesion size and detection sensitivity is critical. On non-spiral studies, the overall lesion detection sensitivity and positive predictive value was 69 and 90%, respectively. Detection sensitivity was 100 and 20% for lesions > 1 cm and < 1 cm, respectively. On single phase spiral CTAP the overall detection sensitivity and positive predictive value was 80 and 66%, respectively. Detection sensitivity for lesions > 1 cm and < 1 cm was 100 and 0%, respectively. On dual phase spiral CTAP the overall detection sensitivity and positive predictive value was 76 and 71%, respectively. For lesions > 1 cm and < 1 cm the sensitivity was 81 and 55%, respectively. Eighteen patients with non-hepatic malignancies with unsuspected metastatic spread did not proceed to major surgery because of liver metastases detected on CTAP. Perfusion artefacts occurred in 30 and 64% of non-spiral and of initial portal venous spiral CTAP studies, respectively. By using the double-phase technique, these artefacts were substantially diminished. In conclusion, CTAP is a valuable tool for assessing the presence, site and size of possible liver tumours and confers a benefit even when previous ultrasound and conventional CT have already been used. In addition, CTAP has a lower limit of useful resolution of approximately 1 cm. Perfusion artefacts can be reduced by a dual phase protocol.

Zebra pattern: a diagnostically challenging hepatic parenchymal enhancement pattern at CT arterial portography.

To investigate the effect of arterial injection site and splenic volume on the hepatic zebra pattern seen at computed tomographic (CT) arterial portography. Images from CT arterial portographic examinations, performed via either the splenic artery (SA)(n = 47) or superior mesenteric artery (SMA)(n = 51) in 98 patients, were reviewed. The hepatic parenchymal enhancement pattern was assessed by three blinded reviewers. Splenic volume was determined. Twenty-two of 98 (22%) CT arterial portographic studies showed a zebra pattern: 10 of 47 (21%) with injection via the SA and 12 of 51 (24%) with injection via the SMA. The mean percentage of hepatic parenchyma with nontumorous perfusion defects was 55% with the zebra pattern versus 12% without (P < .001). For SA injections, the mean splenic volume was lower in patients with the zebra patterns (321 vs 409 cm3, P = .09). For SMA injections, it was higher in patients with zebra patterns (372 vs 291 cm3, P = .10). The zebra pattern can cause difficulties in interpreting images. It is due to alternating, well-defined regions of portal venous hyper- and hypoperfusion; it likely has a multifactorial cause and is likely due to technical parameters such as the injection site, the volume of the spleen, and the hemodynamic effects of the tumor.

Role of computed tomographic arterial portography and intraoperative ultrasound in the evaluation of patients for resectability of hepatic lesions

Computed tomographic arterial portography (CTAP) has been shown to be the most sensitive preoperative test for determining resectability of hepatic lesions but we have shown it to have low specificity. Intraoperative ultrasound (IOUS) evaluation of the liver has also been proposed as an accurate means of assessing resectability. We sought to compare the effectiveness of the two modalities. Fifty-six patients who had been deemed candidates for liver resection based on CTAP findings underwent systematic exploration, liver mobilization, and IOUS examination. Ultrasound findings were compared with results of CTAP. In 46 patients the IOUS findings were in complete agreement with those of CTAP. In 10 patients CTAP lesions could not be verified by IOUS and these patients did not undergo resection. Follow-up of these 10 patients revealed eight who did not have progression of malignancy at the CTAP-predicted site (CTAP false positive). Two patients did have progression at a CTAP-positive IOUS-negative site (IOUS false negative). Sensitivity for CTAP and IOUS was 100% and 96%, respectively. Specificity for IOUS was 100%. These findings demonstrate the high sensitivity of CTAP and the high sensitivity and specificity of IOUS. CTAP may “overcall” hepatic lesions but IOUS can correctly identify these false positives in most instances. Because CTAP is useful for determining which patients might benefit from surgical exploration, we conclude that the two modalities are complementary for the assessment of resectability of hepatic lesions. The false positive rate for CTAP implies that caution must be used when declining to operate on patients on the basis of this test.

Nonpathological focal enhancements on spiral CT hepatic angiography.

To assess the frequency and characteristics of nonpathological focal enhancements seen on spiral computed tomographic (CT) hepatic angiography (CTA). Spiral CTA and spiral CT arterial portography (CTAP) were performed in 31 patients with suspected liver malignancy prior to potential liver resection. The CTA images were retrospectively reviewed for focal enhancements by two radiologists. After determining nonpathological focal enhancements on CTA images based on the other radiographic tests, surgical exploration including intraoperative sonography, follow-up imagings, the frequency, size, site, and shape of nonpathological focal enhancements with CTA were assessed. Thirty-six nonpathological focal enhancements with CTA from 4 to 23 (mean = 11. 4) mm were seen in 14 (45.2%) of 31 patients. Thirteen (36.1%) of 36 nonpathological focal enhancements with CTA were not depicted with CTAP. Nonpathological focal enhancements with CTA were frequent in Couinaud segments III (27.8%), V (22.2%), and VI (19.4%). Twenty-three (63.9%) of 36 nonpathological focal enhancements were located in the edge of the liver. Shapes of 36 nonpathological focal enhancements with CTA included circular (n = 16), worm (n = 7), irregular (n = 6), dot (n = 6), and wedge (n = 1). In nearly half of patients, spiral CTA shows various shapes of small nonpathological focal enhancements more frequently in the liver edge.

Nontumorous Perfusion Defects in the Liver during CT Arterial Portography: Correlation with Hepatic Arteriography

Nontumorous Perfusion Defects in the Liver during CT Arterial Portography: Correlation with Hepatic Arteriography

CT Arterial Portography and CT Arteriography with a Triple-Lumen Balloon Catheter

CT Arterial Portography and CT Arteriography with a Triple-Lumen Balloon Catheter

Portal Vein Evaluation with US: Comparison to Angiography Combined with CT Arterial Portography

Portal Vein Evaluation with US: Comparison to Angiography Combined with CT Arterial Portography

Ciliated foregut cyst in cirrhotic liver

We encountered a patient with a ciliated hepatic foregut cyst with accompanying liver cirrhosis, which was hard to distinguish from well-differentiated hepatocellular carcinoma. A lesion 2 cm in diameter was found in the subcapsular region of the medial segment of the liver. It was slightly hypoechoic on ultrasonography, of high attenuation on nonenhanced computed tomography (CT), of high intensity on T1-weighted spin echo images of magnetic resonance imaging (MRI), and of isointensity on T2-weighted spin echo images. It was not enhanced in the arterial phase images of MRI, and was shown as a complete perfusion defect on CT arterial portography. The cyst was enucleated and found to be filled with bloody mucinous fluid.

Malignant Hepatic Hilar Tumors: Can Ultrasonography be Used as an Alternative to Angiography with CT Arterial Portography for Determination of Resectability?

Malignant Hepatic Hilar Tumors: Can Ultrasonography be Used as an Alternative to Angiography with CT Arterial Portography for Determination of Resectability?

The frequency, appearance, and significance of splenic perfusion defects in CT arterial portography.

The purpose of this study was to determine the frequency, appearance, and significance of splenic perfusion defects on computed tomographic arterial portography (CTAP). CTAP was performed with dynamic scanning at 1-cm increments on 46 consecutive patients prior to laparotomy. Two readers retrospectively reviewed these studies in consensus and recorded the number, size, and shape of focal splenic perfusion defects. These defects were later correlated with surgical findings and at least one of the following imaging modalities: delayed CT 4-6 h after CTAP, intravenously enhanced CT, sonography, or magnetic resonance imaging (MRI). Splenic perfusion defects were present in 14 of 46 CTAP studies (30%), and in seven patients these defects were multiple. Most defects were wedge-shaped and peripherally located, although several round defects simulating metastases were also present. The spleen was normal at surgery in all patients, and comparison imaging revealed only a small splenic infarct in one patient on MRI. Splenic perfusion defects occur in about one-third of patients referred for CTAP, are usually wedge-shaped but may be round, and should not be interpreted as metastases without other evidence of a space-occupying mass.

Correlation of perfusion abnormalities on CTAP and immediate postintravenous gadolinium-enhanced gradient echo MRI.

The purpose of this study was to evaluate patients with wedge-shaped perfusion defects seen on spiral CT arterial portography for the presence of transient increased wedge-shaped enhancement on dynamic gadolinium-enhanced gradient echo MR images. Nineteen patients underwent CTAP and MRI within a 2-week interval. All patients with wedge-shaped perfusion defects on CT arterial portography were evaluated in a separate review session for the presence of transient increased segmental hepatic enhancement on dynamic gadolinium-enhanced spoiled gradient echo (SGE) MR images. Eight patients were identified to have subsegmental, segmental, or lobar wedge-shaped perfusion defects by CT arterial portography. In 8/8 patients, there was transient wedge-shaped increased hepatic enhancement on MR images which corresponded to the perfusion defects identified on CT arterial portography. Transient increased enhancement on MR images was observed on immediate postgadolinium images as high-signal intensity of the involved subsegment, segment, or lobe. This relatively high-signal area faded to near isointensity in all cases on images obtained at 45 s. Wedge-shaped perfusion defects demonstrated by CT arterial portography corresponded to wedge-shaped increased hepatic enhancement following gadolinium administration on SGE MR images.