CT During Hepatic Arteriography Research Articles

Incidental Ring-hyperenhancing Liver Micronodules at CT Hepatic Arteriography-guided Percutaneous Thermal Ablation of Colorectal Liver Metastases.

CT during hepatic arteriography (CTHA) is a highly sensitive imaging method for detecting colorectal liver metastases (CLMs), which supports its use during percutaneous thermal liver ablation. In contrast to its high sensitivity, its specificity for incidental small CLMs not detected at preablation cross-sectional imaging is believed to be low given the absence of specific imaging signatures and the common presence of pseudolesions. In this retrospective study of 22 patients (mean age, 55 years ± 10.6 [SD]; 63.6% male, 36.4% female) with CLMs undergoing CTHA-guided microwave percutaneous thermal ablation between November 2017 and October 2022, the authors provided a definition of incidental ring-hyperenhancing liver micronodules (RHLMs) and investigated whether there is a correlation of RHLMs with histologic analysis or intrahepatic tumor progression at imaging follow-up after applying a biomechanical deformable image registration method. The analysis revealed 25 incidental RHLMs in 41.7% (10 of 24) of the CTHA images from the respective guided ablation sessions. Of those, four RHLMs were ablated. Among the remaining 21 RHLMs, 71.4% (15 of 21) were confirmed to be CLM with either histology (n = 3) or imaging follow-up (n = 12). The remaining 28.6% (six of 21) of RHLMs were not observed at follow-up imaging. This suggests that RHLMs at CTHA may be an early indicator of incidental small CLMs. Keywords: Colorectal Neoplasms, Liver, Angiography, CT, Incidental Findings, Ablation Supplemental material is available for this article. © RSNA, 2024.

Study Protocol STEREOLAB: Stereotactic Liver Ablation Assisted with Intra-Arterial CT Hepatic Arteriography and Ablation Confirmation Software Assessment.

This study aims to evaluate the technical efficacy and local tumor progression-free survival (LTPFS) of a standardized workflow for thermal ablation of colorectal liver metastases (CRLM) consisting of CT during hepatic arteriography (CTHA)-based imaging analysis, stereotactic thermal ablation, and computer-based software assessment of ablation margins. This investigator initiated, single-center, single-arm prospective trial will enroll up to 50 patients (≤ 5 CRLM, Measuring ≤ 5cm). Procedures will be performed in an angio-CT suite under general anesthesia. The primary objective is to estimate LTPFS with a follow-up of up to 2years and secondary objectives are analysis of the impact of minimal ablative margins on LTPFS, adverse events, contrast media utilization and radiation exposure, overall oncological outcomes, and anesthesia/procedural time. Adverse events (AE) will be recorded by CTCAE (Common Toxicity Criteria for Adverse Events), and Bayesian optimal phase-2 design will be applied for major intraprocedural AE stop boundaries. The institutional CRLM ablation registry will be used as benchmark for comparative analysis with the historical cohort. The STEREOLAB trial will introduce a high-precision and standardized thermal ablation workflow for CRLM consisting of CT during hepatic arteriography imaging, stereotactic guidance, and ablation confirmation. Trial Registration ClinicalTrials.gov identifier: (NCT05361551).

Clinical impact of low tube voltage computed tomography during hepatic arteriography with low iodine to detect hepatocellular carcinoma before transarterial chemoembolization

PurposeThis study aimed to evaluate the clinical impact of low tube voltage computed tomography (CT) during hepatic arteriography (CTHA) using low iodine contrast to detect hepatocellular carcinoma (HCC). Materials and methodsCTHA images were obtained using a dual-spin technique (80 kVp and 135 kVp) with 30 ml of low-dose iodine contrast (75 mgI/ml). Three radiologists reviewed 135 kVp and 80 kVp CTHA images to diagnose HCC, recording their confidence scores and evaluations of sharpness, noise, artifact, and overall image quality. Lesion-to-liver contrast ratios and objective noise were measured by a non-reader radiologist. ResultsWe included 23 patients (body mass index, 23.6 ± 2.6 kg/m2) with 89 HCCs. The mean radiation dose index volume was 21.3 mGy at 135 kVp and 9.4 mGy at 80 kVp (P < 0.001). The overall sensitivity and positive predictive value for diagnosing HCCs at 80 kVp vs. 135 kVp were 0.787 vs. 0.730 and 0.712 vs. 0.756, respectively. The lesion-to-liver contrast ratio at 80 kVp was significantly higher than at 135 kVp in the first (3.1 vs. 2.0; P = 0.008) and second phase (3.1 vs. 2.3; P = 0.016). Objective noise was significantly higher at 80 kVp than at 135 kVp in the first (15. 6 ± 4.9 vs. 11.0 ± 3.1; P < 0.001) and second (16.9 ± 5.2 vs. 15.0 ± 7.3; P = 0.046) phases. ConclusionAn 80 kVp CTHA, with lower-dose iodine, improved the sensitivity and reduced the radiation dose, despite a decreased positive predictive value in comparison with a 135-kVp CTHA with the same iodine dose.

Comparison of local recurrence in transcatheter arterial chemoembolization of hepatocellular carcinoma with or without accumulation of iodized oil beyond corona enhancement area: Short-term results.

BackgroundLocal tumor recurrence of hepatocellular carcinoma (HCC) often occurs in blood drainage areas. Corona enhancement is determined by computed tomography during hepatic arteriography (CTHA) and is considered to represent the blood drainage area. This study aimed to investigate the relationship between embolization of corona enhancement area and local tumor recurrence of patients with HCC who underwent transcatheter arterial chemoembolization (TACE).Patients and methodsThe study retrospectively selected 53 patients with 60 HCC nodules that showed corona enhancement area on late-phase CTHA and showed homogenous accumulation of iodized oil throughout the nodule on non-contrast-enhanced CT performed immediately after TACE. We divided the nodules into two groups, according to whether the accumulation of iodized oil covered the entire corona enhancement area (group A) or not (group B). Local tumor recurrence was compared between the two groups.ResultsThe cumulative local tumor recurrence rates for group A (n = 36) were 2.8%, 2.8%, 8.3% at 3, 6, and 12 months, respectively, whereas the recurrence rates for group B (n = 24) were 20.8%, 45.8%, 75% at 3, 6, and 12 months, respectively. The cumulative local tumor recurrence rates for group A were significantly lower than those for group B (hazard ratio, 0.079; 95% confidence interval, 0.026–0.24; p < 0.001).ConclusionsThe results of the study suggest that the corona enhancement area may be an accurate safety margin in TACE which should be performed until the embolic area covers the entire corona enhancement area.

Improvement of Image Quality Using Hybrid Iterative Reconstruction with Noise Power Spectrum Model in Computed Tomography During Hepatic Arteriography.

Objectives:In CT during hepatic arteriography (CTHA), the addition of a noise power spectrum (NPS) model to conventional hybrid iterative reconstruction (HIR) may improve spatial resolution and reduce image noise. This study aims at assessing the image quality provided by HIR with a NPS model at CTHA.Methods:This institutional review board-approved retrospective analysis included 26 patients with hepatocellular carcinomas (HCCs) who underwent CTHA. In all acquisitions, images were reconstructed with filtered back projection (FBP), adaptive iterative dose reduction 3D (AIDR), and AIDR enhanced (eAIDR) with the NPS model. Four radiologists analyzed the signal-to-noise ratio (SNR) of HCC nodules and its associated feeding arteries. The radiologists used a semiquantitative scale (–3 to +3) to rate the subjective image quality comparing both the FBP and eAIDR images with the AIDR images.Results:The feeding arteries’ attenuation was significantly higher in eAIDR compared to AIDR [514.3 ± 121.4 and 448.3 ± 107.3 Hounsfield units (HU), p < 0.05]. The image noise of eAIDR was significantly lower than that of FBP (15.2 ± 2.2 and 28.5 ± 4.8 HU, p < 0.05) and comparable to that of AIDR. The SNR of feeding arteries on eAIDR was significantly higher than on AIDR (34.1 ± 7.9 and 27.4 ± 6.3, p < 0.05). Subjective assessment scores showed that eAIDR provided better visibility of feeding arteries and overall image quality compared to AIDR (p < 0.05). The HCC nodule visibility was not significantly different among the three reconstructions.Conclusion:In CTHA, eAIDR improved the visibility of feeding arteries associated with HCC nodules without compromising nodule detection.

Feasibility and Techniques of Securing 3D-Safety Margin in Superselective Transarterial Chemoembolization to Improve Local Tumor Control for Small Hepatocellular Carcinoma: An Intend-to-Treat Analysis

Introduction: The aim of this study was to investigate the technical success rate of obtaining 3D-safety margin in superselective conventional transarterial chemoembolization (cTACE) using 3D images for small hepatocellular carcinoma (HCC). Methods: Consecutive 48 HCC nodules (diameter, 1–3 cm) in 44 patients were intentionally treated by superselective cTACE in an attempt to achieve 3D-safety margin. Superselective CT during hepatic arteriography (CTHA) was obtained before cTACE. When negative 3D-safety margin was found, branches supplied into the margin area were detected by using a 3D workstation. The technical success rate to obtain 3D-safety margin was investigated by intend-to-treat analysis. Local tumor recurrence rate and adverse events were also evaluated. Result: Nine of 48 tumors (18.8%) had 3D-safety margin in the initial superselective CTHA. After pulling back of the catheter and/or selection of another branch based on 3D images, 3D-safety margin was finally achieved in 45 (93.8%). There were 8 of 46 tumors (17.4%) with local recurrence after 5-year follow-up. Grade 3–4 of aspartate aminotransferase, alanine aminotransferase, and total bilirubin were found in 38.6, 36.4, and 2.3%, respectively. One portal vein thrombus and 3 biliary dilation or biloma were developed. Conclusion: Superselective cTACE obtaining 3D-safety margin in small HCC was feasible with a high success rate by using 3D images, which could be tolerable and prevent local tumor recurrence.

Change in hepatic hemodynamics assessed by hepatic arterial blood pressure and computed tomography during hepatic angiography with the double balloon technique.

To assess the change in hepatic arterial blood pressure (HABP) and computed tomography during hepatic arteriography (CTHA) using the double balloon technique. Nine patients with hepatocellular carcinoma (HCC) were enrolled. We inserted a 5.2-Fr balloon catheter into the common or proper hepatic artery and a 1.8-Fr microballoon catheter into the lobar or segmental artery feeding the HCC. HABPs were measured with the 1.8-Fr microballoon catheter (usual-HABP), with the 1.8-Fr balloon inflated (B-HABP), and with both the 5.2-Fr and 1.8-Fr balloons inflated (BB-HABP). CTHAs were performed via a 1.8-Fr microcatheter (usual-CTHA), with the 1.8-Fr balloon inflated (B-CTHA selective), with both the 5.2-Fr and 1.8-Fr balloons inflated (BB-CTHA selective), and via the 5.2-Fr catheter with the 1.8-Fr balloon inflated (B-CTHA whole) and with both the 5.2-Fr and 1.8-Fr balloons inflated (BB-CTHA whole). In all cases, B-HABP was lower than usual-HABP. There was a decrease in BB-HABP in comparison with B-HABP in cases with occlusion of the proper hepatic artery. The contrast effect of B-CTHA selective increased in four cases. The contrast effect on B-CTHA whole remained in all cases. This technique can be useful in decreasing HABP and collateral blood flow from the adjacent hepatic segment.

The imaging features in ultrasonography of cholangiolocarcinoma: correlation with pathological findings.

Background: Cholangiolocellular carcinoma (CoCC) is rare primary liver cancer and currently considered to originate from hepatic progenitor cells. The purpose of this study was to evaluate the imaging features in ultrasonography of cholangiolocellular carcinoma of the liver. Methods: Six cases of surgically resected cases of CoCC from 2 institutions were retrospectively evaluated. All of the six patients underwent contrast-enhanced ultrasonography (CEUS), dynamic CT, Gd-EOB-DTPA MRI and angio-CT including CT during arterioportography (CTAP) and CT during hepatic arteriography (CTHA). Histological evaluation was also performed and was correlated with imaging findings. Results: In the early vascular phase of CEUS, the lesions presented diffuse and homogeneous enhancement in 2 cases with less than 2cm in tumor diameter, but in 4 cases with lager than 2cm, the lesions presented heterogeneous enhancement. From the late vascular phase to Kupffer phase, the continued existence of portal veins or tiny spots of portal flow was identified in the tumors. This feature, portal venous penetration within the tumor, was also observed in Angio CT, but not observed in dynamic CT and Gd-EOB-DTPA MRI. Conclusion: The absence of a fibrous capsule, the absence of tumor necrosis and the presence of portal venous penetration within the tumor also appear to be characteristic features in CEUS. But it may be some difference in the enhancement pattern in vascular phase with tumor size. CEUS is considered to be useful in the diagnosis of CoCC.

The imaging features in ultrasonography of cholangiolocarcinoma: correlation with pathological findings

Background: Cholangiolocellular carcinoma (CoCC) is rare primary liver cancer and currently considered to originate from hepatic progenitor cells. The purpose of this study was to evaluate the imaging features in ultrasonography of cholangiolocellular carcinoma of the liver. Methods: Six cases of surgically resected cases of CoCC from 2 institutions were retrospectively evaluated. All of the six patients underwent contrast-enhanced ultrasonography (CEUS), dynamic CT, Gd-EOB-DTPA MRI and angio-CT including CT during arterioportography (CTAP) and CT during hepatic arteriography (CTHA). Histological evaluation was also performed and was correlated with imaging findings. Results: In the early vascular phase of CEUS, the lesions presented diffuse and homogeneous enhancement in 2 cases with less than 2cm in tumor diameter, but in 4 cases with lager than 2cm, the lesions presented heterogeneous enhancement. From the late vascular phase to Kupffer phase, the continued existence of portal veins or tiny spots of portal flow was identified in the tumors. This feature, portal venous penetration within the tumor, was also observed in Angio CT, but not observed in dynamic CT and Gd-EOB-DTPA MRI. Conclusion: The absence of a fibrous capsule, the absence of tumor necrosis and the presence of portal venous penetration within the tumor also appear to be characteristic features in CEUS. But it may be some difference in the enhancement pattern in vascular phase with tumor size. CEUS is considered to be useful in the diagnosis of CoCC.

Clinical Indication for Computed Tomography During Hepatic Arteriography (CTHA) in Addition to Dynamic CT Studies to Identify Hypervascularity of Hepatocellular Carcinoma.

To identify factors benefiting from computed tomographyduring hepatic arteriography (CTHA) in addition to dynamic CT studies at the preoperative evaluation of the hypervascularity of hepatocellular carcinoma (HCC). We retrospectively divided 45 patients with HCC, who underwent both dynamic CT (dCT) and CTHA, into two groups based on the number of hypervascular HCCs identified on dCT and CTHA studies. In group A, the number of HCCs identified by dCT and CTHA was the same and additive CTHA had not been indicated. In group B, fewer HCCs were counted on dCT than on CTHA images, indicating that additive CTHA studies had been appropriate. We compared the patient characteristics, the serum alpha-fetoprotein level, and the tumor-liver contrast (TLC) of the main tumor on dCT scans of both groups. To identify factors alerting to the benefit of additional CTHA studies, we performed univariate logistic regression analysis. Statistically significant parameters were subjected to receiver operating characteristic analysis for obtaining the optimal cutoff value indicative of the benefit of CTHA. Univariate analysis identified only the TLC of the main tumor on dCT images as a significant factor for the benefit of CTHA images (P<0.01). At the optimal cutoff value for the TLC of the main tumor on dCT images (15.9 Hounsfield units), the sensitivity and specificity for the benefit of CTHA were 85.0 and 92.0%, respectively. Evaluation of the TLC of the main tumor on dCT scans identifies patients in whom additive CTHA studies are beneficial.

Extrahepatic Arteries Originating from Hepatic Arteries: Analysis Using CT During Hepatic Arteriography and Visualization on Digital Subtraction Angiography.

To investigate the prevalence and site of origin of extrahepatic arteries originating from hepatic arteries on early phase CT during hepatic arteriography (CTHA) was accessed. Visualization of these elements on digital subtraction hepatic angiography (DSHA) was assessed using CTHA images as a gold standard. A total of 943 patients (mean age 66.9±10.3years; male/female, 619/324) underwent CTHA and DSHA. The prevalence and site of origin of extrahepatic arteries were accessed using CTHA and visualized using DSHA. In 924 (98.0%) patients, a total of 1555 extrahepatic branches, representing eight types, were found to originate from hepatic arteries on CTHA. CTHA indicated the following extrahepatic branch prevalence rates: right gastric artery, 890 (94.4%); falciform artery, 386 (40.9%); accessory left gastric artery, 161 (17.1%); left inferior phrenic artery (IPA), 43 (4.6%); posterior superior pancreaticoduodenal artery, 33 (3.5%); dorsal pancreatic artery, 26 (2.8%); duodenal artery, 12 (1.3%); and right IPA, 4 (0.4%). In addition, 383 patients (40.6%) had at least one undetectable branch on DSHA. The sensitivity, specificity, and accuracy of visualization on DSHA were as follows: RGA, 80.0, 86.8, and 80.4%; falciform artery, 53.9, 97.7, and 80.0%; accessory LGA, 64.6, 98.6, and 92.3%; left IPA, 76.7, 99.8, and 98.7%; PSPDA, 100, 99.7, and 99.9%; dorsal pancreatic artery, 57.7, 100, and 98.8%; duodenal artery, 8.3, 99.9, and 98.7%; and right IPA, 0, 100, and 99.6%, respectively. Extrahepatic arteries originating from hepatic arteries were frequently identified on CTHA images. These arteries were frequently overlooked on DSHA.

Study of Hepatic Artery Cone-beam Imaging by Low-rate Injection in Iodinated Contrast Agent.

CT during hepatic arteriography (CTHA) of cone-beam computed tomography (CBCT) provides valid information in performing transcatheter arterial chemo-embolization (TACE). The usefulness of CTHA with the diluted contrast medium has been reported in some medical conferences. However, the operation becomes somehow complicated for the medical institutions that have angiography injectors with a single head. In this study, we aimed to investigate the clinical equivalence of low-rate injection method and diluted injection method. The relationship between the injection rate and transit time of contrast medium was tested. Then, we measured the signal values of CBCT and CT values both in varying injection rates and in the case of doubling dilution. The transit time of contrast medium became delayed with decreasing injection rate. The signal values of CBCT in the case of doubling dilution showed almost the same as those at a half of injection rate without dilution. We also obtained the same finding from the comparative investigation of CT values. ROC analysis of digital subtraction angiography (DSA) and CBCT was carried out, and the area under the curve (AUC) of CBCT showed a significantly higher value. It is suggested that CTHA with low-rate injection method offers diagnostic image similar in some degree to the diluted injection method.

Haemodynamic changes in hepatocellular carcinoma and liver parenchyma under balloon occlusion of the hepatic artery.

To investigate haemodynamic changes in hepatocellular carcinoma (HCC) and liver under hepatic artery occlusion. Thirty-eight HCC nodules in 25 patients were included. Computed tomography (CT) during hepatic arteriography (CTHA) with and without balloon occlusion of the hepatic artery was performed. CT attenuation and enhancement volume of HCC and liver with and without balloon occlusion were measured on CTHA. Influence of balloon position (segmental or subsegmental branch) was evaluated based on differences in HCC-to-liver attenuation ratio (H/L ratio) and enhancement volume of HCC and liver. In the segmental group (n = 20), H/L ratio and enhancement volume of HCC and liver were significantly lower with balloon occlusion than without balloon occlusion. However, in the subsegmental group (n = 18), H/L ratio was significantly higher and liver enhancement volume was significantly lower with balloon occlusion; HCC enhancement volume was similar with and without balloon occlusion. Rate of change in H/L ratio and enhancement volume of HCC and liver were lower in the segmental group than in the subsegmental group. There were significantly more perfusion defects in HCC in the segmental group. Hepatic artery occlusion causes haemodynamic changes in HCC and liver, especially with segmental occlusion. • Hepatic artery occlusion causes haemodynamic changes in hepatocellular carcinoma and liver. • Segmental occlusion decreased rate of change in hepatocellular carcinoma-to-liver attenuation ratio. • Subsegmental occlusion increased rate of change in hepatocellular carcinoma-to-liver attenuation ratio. • Hepatic artery occlusion decreased enhancement volume of hepatocellular carcinoma and liver. • Hepatic artery occlusion causes perfusion defects in hepatocellular carcinoma.

Prognostic Significance of Concurrent Hypovascular and Hypervascular Nodules in Patients with Hepatocellular Carcinoma.

BackgroundHypovascular nodules often occur together with hypervascular hepatocellular carcinoma (HCC). However, it remains controversial whether hypovascular nodules associated with hypervascular HCC have any prognostic value. This study evaluated the prognostic impact of hypovascular nodules co-existing with hypervascular HCC as diagnosed by computed tomography during arterial portography (CTAP) and computed tomography during hepatic arteriography (CTHA), which can sensitively capture the dynamic changes in blood flow through the portal vein and hepatic artery in patients with early stage HCC.MethodsA total of 152 patients with hypervascular HCC (≤ 30 mm, ≤ 3 nodules), who underwent initial local ablation, were analyzed retrospectively. All patients received CTAP and CTHA prior to treatment. Overall survival (OS) was compared among group A (hypervascular HCC only, 107 patients) and group B (hypovascular nodules and hypervascular HCC, 45 patients).ResultsAmong all hypovascular nodules, 81% (46 of 57) developed hypervascularization within the follow-up period. The 1- and 2-year hypervascularization rates were 17% and 51%, respectively. OS was significantly longer for group A than for group B (P < 0.001). A Cox proportional-hazards model identified the presence of hypovascular nodules concurrent with hypervascular HCC as an independent poor prognostic factor.ConclusionThe prognosis of hypervascular HCC patients with hypovascular nodules detected during CTAP and CTHA is poor. Clinical HCC categories seem to be dissimilar between patients with and without hypovascular nodules.

Genistein Produces Hepatoprotection through Modulating EGFR Expression and Phosphorylation in Experimental Fibrosis

Objectives: We observed the time-course changes of blood flow in non-hypervascular hepatocellular nodules that showed hypointensity in the hepatobiliary phase on Gd-EOB-DTPA-enhanced magnetic resonance imaging (EOB-MRI), and evaluated the relationship between hypervascular change and the status of blood supply in the nodules. Methods: The study included 69 hepatocellular nodules in 33 patients demonstrating hypointensity in the hepatobiliary phase on EOB-MRI and showing non-hypervascular features on CT during hepatic arteriography (CTHA) performed during the same period. Results: In relation to blood flow on CTHA/ CT during arterial portography (CTAP), the cumulative rate of hypervascular change at 52 weeks was 0.0% for iso/iso, 29.7% for hypo/iso, 61.5% for iso/hypo, and 55.0% for hypo/hypo. Multivariate analysis using COX proportional hazards regression showed that CTAP findings (hypodensity) and CTHA findings (hypo-density) were significant variables for hypervascular change. Conclusions: In cases of non-hypervascular hepatocellular tumors, nodules with decreased arterial or portal blood flow that show hypointensity in the hepatobiliary phase on EOB-MRI are likely to develop into typical hepatocellular carcinoma in a shorter time.

Clinical Experience of Dual-phase Cone Beam Computed Tomography during Hepatic Arteriography to Apply 3D-DSA.

We report on the methods and experiences of the dual-phase cone beam computed tomography during hepatic arteriography (CBCTHA) to apply the 3D-DSA. A total of 32 ml contrast medium (150 mgI/ml) was injected at the rate of 2.0 ml/s for 16 s. The early phase scan was initiated 10 s after the start of contrast media injection. The delayed phase scan was started 40 s after that (24 s after the end of CM injection). When using the dual phase CBCTHA, it was able to obtain the classical hepatocellular carcinoma (HCC) images same as computed tomography during hepatic arteriography (CTHA). In the early phase, the tumor can be highly enhanced against the liver parenchyma. In delayed phase, corona enhancement was clearly appeared at the liver parenchyma. Of 58 cases of acquisitions, we experienced six cases with miss breath holding and 14 cases with over the field of view (FOV) due to hepatomegaly. We evaluated the tumor contrast in 18 cases because the other 40 cases were not applied to our criteria. The pixel values of ROIs on the tumor, coronal enhancement, and liver parenchyma were measured, respectively. Then, we calculated tumor-parenchyma contrast (T-P contrast), corona-tumor contrast (C-T contrast), and corona-parenchyma contrast (C-P contrast). The T-P contrast was 358±112, the C-T contrast was 132±51, and the C-P contrast was 168±66. The contrast was clearly visualized among them. The dual-phase CBCTHA that applies the 3D-DSA is a simple and useful technique for hepatocellular carcinoma treatment.

Change in Imaging Findings on Angiography-Assisted CT During Balloon-Occluded Transcatheter Arterial Chemoembolization for Hepatocellular Carcinoma.

To evaluate changes in imaging findings on CT during hepatic arteriography (CTHA) and CT during arterial portography (CTAP) by balloon occlusion of the treated artery and their relationship with iodized oil accumulation in the tumor during balloon-occluded transcatheter arterial chemoembolization (B-TACE). Both B-TACE and angiography-assisted CT were performed for 27 hepatocellular carcinomas. Tumor enhancement on selective CTHA with/without balloon occlusion and iodized oil accumulation after B-TACE were evaluated. Tumorous portal perfusion defect size on CTAP was compared with/without balloon occlusion. Factors influencing discrepancies between selective CTHA with/without balloon occlusion and the degree of iodized oil accumulation were investigated. Among 27 tumors, tumor enhancement on selective CTHA changed after balloon occlusion in 14 (decreased, 11; increased, 3). In 18 tumors, there was a discrepancy between tumor enhancement on selective CTHA with balloon occlusion and the degree of accumulated iodized oil, which was higher than the tumor enhancement grade in all 18. The tumorous portal perfusion defect on CTAP significantly decreased after balloon occlusion in 18 of 20 tumors (mean decrease from 21.9 to 19.1mm in diameter; p=0.0001). No significant factors influenced discrepancies between selective CTHA with/without balloon occlusion. Central area tumor location, poor tumor enhancement on selective CTHA with balloon occlusion, and no decrease in the tumorous portal perfusion defect area on CTAP after balloon occlusion significantly influenced poor iodized oil accumulation in the tumor. Tumor enhancement on selective CTHA frequently changed after balloon occlusion, which did not correspond to accumulated iodized oil in most cases.

Local recurrence of hepatocellular carcinoma in the tumor blood drainage area following radiofrequency ablation

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. HCC is generally considered to spread via the bloodstream and local recurrence often occurs in the blood drainage area determined by computed tomography during hepatic arteriography (CTHA), despite complete ablation of the primary nodule. This study was conducted in order to prospectively assess the rate of local recurrence in the blood drainage area depicted by delayed-phase CTHA. The participants comprised 364 consecutive patients (260 men and 104 women; mean age, 67.4±8.6 years), enrolled between April, 2002 and December, 2011. The participants were divided into two groups, according to whether the ablation area covered the entire blood drainage area as defined by delayed-phase CTHA (group A) or not (group B). Local tumor progression was compared between the two groups. The median time to recurrence was significantly shorter for group B (434 days) compared to that for group A (1,474 days; P=0.0037). The cumulative local recurrence rates for group A were 0, 0 and 1.5% at 1, 3 and 5 years postoperatively, respectively, whereas the recurrence rates for group B were 3.8, 17.0 and 22.8% at 1, 3 and 5 years, respectively (P<0.0001). In conclusion, the safety margin for radiofrequency ablation should be defined as the blood drainage area and ablation should aim at acquiring adequate safety margins.

Hemodynamics and progression of a hypervascular focus in a borderline lesion of hepatocellular carcinoma: analysis by angiography-assisted CT and histopathology

To investigate the hemodynamics and progression of a hypervascular focus (HF) in a borderline lesion by dual-phase CT during hepatic arteriography (CTHA) and reveal the process of the transformation to hypervascular overt hepatocellular carcinoma (HCC). This study was performed with the approval of our institutional ethics committee, and informed consent for the retrospective usage of clinical materials was obtained from all the patients. The 121 nodules in 76 consecutive patients with liver cirrhosis and chronic hepatitis showing an HF in a borderline lesion on angiography-assisted CT were analyzed. Hemodynamic changes were observed in 24 patients who underwent repeated angiography-assisted CT. Histopathological analysis was conducted in eight nodules. HF was classifiable into type A (stain disappeared), B (stain prolonged), C (stain was washed out and corona-like drainage into the outer nodule was seen) and D (stain was washed out and corona-like drainage into the whole outer nodule was seen) on the late phase of CTHA and was seen to progress in this order on follow-up observation. Histopathologically, de-differentiated foci showed significantly higher expression of sinusoidal capillarization and unpaired arteries than background nodules and showed pseudocapsule, compressive and replacing growth at the border of the background nodule. HF showed multi-step progression and transformation to hypervascular overt HCC.

Hepatic pseudolymphoma: imaging–pathologic correlation with special reference to hemodynamic analysis

To clarify radiological findings and hemodynamic characteristics of hepatic pseudolymphoma, as compared with the histopathological findings. Radiological findings of ten histopathologically confirmed hepatic pseudolymphomas in seven patients were examined using US, CT, and MRI. Six patients also underwent angiography-assisted CT, including CT during arterial portography (CTAP) and CT during hepatic arteriography (CTHA) to analyze hemodynamics. The nodules were depicted as hypoechoic on US, hypodense on precontrast CT, hypointense on T1-weighted images, and hyperintense on T2-weighted images. On contrast-enhanced CT/MRI, they showed various degrees of enhancement, and sometimes, perinodular enhancement was observed at the arterial dominant and/or equilibrium phase. On CTAP, the nodules showed portal perfusion defects, including some in the perinodular liver parenchyma. On CTHA, irregular bordered enhancement was observed in perinodular liver parenchyma on early phase, and continued until delayed phase. Some nodules had preserved intra-tumoral portal tracts. Histopathologically, the nodules consisted of marked lymphoid cells. In perinodular liver parenchyma, stenosis or disappearance of portal venules, caused by lymphoid cell infiltration in the portal tracts, was observed. Hepatic pseudolymphoma showed some characteristic radiological findings including hemodynamics on CT, MRI, and angiography-assisted CT. These findings are useful in the differentiation from hepatocellular carcinoma and other tumors.