Hepatic Venous Phase Research Articles

Triple-phase MDCT of liver: Scan protocol modification to obtain optimal vascular and lesional contrast.

Context:With advances in 16-slice multidetector computed tomography (MDCT), the entire liver can be scanned in 4–6 s and a single breath-hold dual-phase scan can be performed in 12–16 s. Consequently, optimizing the scan window has become critical.Aim:The purpose of our study was to optimize scan delays using bolus-tracking techniques for triple-phase CT of the liver.Settings and Design:Fifty patients with liver lesions were randomly divided into two groups with 25 patients each. The patients were subjected to triple-phase MDCT of liver with two different scan protocols.Materials and Methods:They were administered 1.5 mL/kg of 300 mg/mL of iohexol at a rate of 3.0 mL/s with a pressure injector. Using bolus-tracking program, scans were commenced at 4, 19, and 44 s and 8, 23, and 48 s for the first, second, and third phases, respectively. The mean CT values [Hounsfield unit (HU)] were measured in the aorta, hepatic artery, portal vein, hepatic vein, liver parenchyma, and lesion using circular region of interest cursor ranging in size from 5 to 20 mm in diameter on all phases.Statistical Analysis Used:Statistical analysis was carried out using paired Student's t-test.Results:In hepatic arterial phase, hepatic artery has shown better enhancement in Group B (8 s) (P = 0.0498) compared with Group A (4 s). In portal venous phase, there were no significant differences in contrast enhancement index (CEI) values at any of the six measured regions between the groups. In the hepatic venous phase, liver parenchyma has shown nearly significant (P = 0.0664) higher CEI values in Group B (48 s) when compared with Group A (44 s).Conclusion:A scan delay of 8 s, after trigger threshold (100 HU) is reached in the lower thoracic aorta, is optimal for the early arterial phase imaging, this phase being most helpful for assessment of hepatic arterial tree (CT angiography). The liver parenchyma showed maximum enhancement at 48 s scan delay.

Liver Imaging Reporting and Data System: Discordance Between Computed Tomography and Gadoxetate-Enhanced Magnetic Resonance Imaging for Detection of Hepatocellular Carcinoma Major Features.

The goal of this study was to compare agreement between computed tomography (CT) and magnetic resonance imaging (MRI) in the evaluation of the major Liver Imaging Reporting and Data System (LI-RADS) features used in assessment of hepatocellular carcinoma: arterial phase hyperenhancement (APHE), portal venous phase washout (WO), capsule appearance (capsule), and largest diameter (diameter). Patients with liver protocol CT and gadoxetate-enhanced MRI within 1 month of each other and at least 1 discrete untreated liver lesion were included. Two readers independently reviewed hepatic arterial phase and portal venous phase of each lesion on both CT and MRI, presented at random. The APHE, WO, capsule, and diameter were assessed for each lesion on CT and MRI. The LI-RADS category was assigned based on the recorded major features. Interobserver agreements between the readers for both imaging modalities and for each of the major features were assessed using κ statistics. Agreement between CT and MRI for each reader and for each feature was assessed using κ statistics. Agreement was interpreted based on κ as follows: 0.20 or less, slight agreement; 0.21 to 0.40, fair agreement; 0.41 to 0.60, moderate agreement; 0.61 to 0.80, substantial agreement; and 0.81 to 1.00, almost perfect agreement. Intraclass correlation coefficient was used to assess concordance of diameter measurements. There were 42 patients (mean age, 62.2 ± 7.0 years; 33 men [78.6%]) with 50 lesions. On CT, the interobserver agreement between the readers was almost perfect for APHE (κ = 0.85), WO (κ = 0.83), and capsule (κ = 0.86). On MRI, the interobserver agreement between the readers was almost perfect for APHE (κ = 0.86) and WO (κ = 0.83) and moderate for capsule (κ = 0.59). Intraclass correlation coefficient for diameter measurement was 0.99 for CT and 0.98 for MRI. For reader 1, the agreement between CT and MRI was fair for APHE (κ = 0.39) and capsule (κ = 0.26) and moderate for WO (κ = 0.49). For reader 2, the agreement between CT and MRI was moderate for APHE (κ = 0.43) and capsule (κ = 0.43) and fair (κ = 0.38) for WO. Agreement between readers for final LI-RADS category was substantial for CT (κ = 0.79) and moderate for MRI (κ = 0.60). Agreement for final LI-RADS categories between MRI and CT was fair for both reader 1 (κ = 0.33) and reader 2 (κ = 0.39). Interobserver agreement for the major LI-RADS features varies from moderate to almost perfect, for both CT and MRI. However, the agreement between CT and MRI for each of the major LI-RADS features is poor, ranging from fair to moderate. This poor agreement contributes to substantial differences between final LI-RADS category assigned on CT versus MRI.

Dynamic enhanced CT: is there a difference between liver metastases of gastroenteropancreatic neuroendocrine tumor and adenocarcinoma.

This study proposed to evaluate the feasibility of dynamic enhanced CT in differentiation of liver metastases of gastroenteropancreatic well-differentiated neuroendocrine tumors (GEP NETs) from GEP adenocarcinomas based on their characteristic features. CT images of 23 well-differentiated (G1 or G2) GEP NETs and 23 GEP adenocarcinomas patients with liver metastases were retrospectively reviewed. The distribution type, shape, intra-tumoral neovascularity, enhancement on hepatic artery phase, dynamic enhancement pattern and lymphadenopathy were subjective analyzed. Meanwhile, the size, number, CT value of tumor and adjacent normal liver parenchyma were measured and the metastasis-to-liver ratios were calculated objectively. Compared with GEP adenocarcinomas, the liver metastases of GEP NETs more frequently demonstrated a hyper enhancement on hepatic artery phase, washout dynamic enhancement pattern, absence of lymphadenopathy and higher metastasis-to-liver ratios on both hepatic artery phase and portal venous phase (P=0.017, P<0.001, P =0.038, P <0.001 and P =0.008, respectively). Logistic regression analysis showed that the dynamic enhancement pattern (P=0.012), and the metastasis-to-liver ratios on hepatic artery phase (P=0.009) were independent CT predictors for liver metastases of GEP NETs. The sensitivity and specificity of combing the two predictors in differentiation of liver metastases of GEP adenocarcinomas from GEP NET were 82.6% (19 of 23) and 91.3% (21 of 23), respectively. CT features are helpful in differentiating liver metastases of well-differentiated GEP NETs from that of GEP adenocarcinomas.

A Method for Quickly and Exactly Extracting Hepatic Vessel

It is of vital importance that providing detailed and accurate information about hepatic vessel for liver surgery planning, such as pre-operative planning of living donor liver transplantation (LDLT). Due to the different blood flow rate of intra-hepatic vascular systems and the restrictions of CT scan, it is common that hepatic vessels are filled with contrast medium during the scan and in high intensity in the hepatic venous phase images. As a result, the hepatic vessel segmentation result obtained from the hepatic venous phase images is always contaminated which makes accurate hepatic vessel modeling difficult. In this paper, we proposed a method for quick and accurate hepatic vessel extraction. Firstly, the Hessian method is used to enhance the vessel areas. Then, a region growing vessel segmentation algorithm can obtain the hepatic vessel. Experiments show that the proposed method can segment the liver vessels accurately with a certain practicability and operability.

Does injection flow rate have an impact on arterial phase image degradation in liver MRI? A comparison of gadoxetic acid versus gadobutrol

To evaluate retrospectively the impact of injection flow rate on arterial phase image degradation in liver magnetic resonance imaging (MRI) with gadoxetic acid (Gd-EOB-DTPA) compared to gadobutrol. Two hundred consecutive patients who had undergone liver MRI were enrolled in this Health Insurance Portability and Accountability Act (HIPAA)-compliant institutional review board (IRB)-approved study and were divided into three groups. Group 1 (50 patients) and 2 (50 patients) had undergone MRI performed with gadoxetic acid (fixed 10ml) at flow rate of 1 and 2ml/s, respectively. Group 3 (100 patients) had undergone MRI performed with gadobutrol (0.1mmol/kg) at 1ml/s. Precontrast and post-contrast (arterial, portal venous, and hepatic venous phases) image degradation was assessed by two blinded independent readers using a four-point rating scale. The numbers of patients with arterial phase image degradation were compared using the Fisher exact test among the three groups. The incidence of arterial phase image degradation was 12% (6/50) in group 1 and 16% (8/50) in group 2 for both readers, 6% (6/100) for reader 1 and 5% (5/100) for reader 2 in group 3. Group 2 had a higher incidence of arterial phase image degradation when compared with group 3 for reader 2 (p=0.032). Severe arterial phase image degradation, resulting in non-diagnostic image quality, occurred in 4% (2/50) of patients when performed with gadoxetic acid administration at 2ml/s and 2% (1/50) at 1ml/s. A slower injection flow rate has a trend to reduce the incidence and severity of arterial phase image degradation during liver MRI with gadoxetic acid when compared to gadobutrol.

An Individually Optimized Protocol of Contrast Medium Injection in Enhanced CT Scan for Liver Imaging.

Objective To investigate the effectiveness of a new individualized contrast medium injection protocol for enhanced liver CT scan. Methods 324 patients who underwent plain and dual phase enhanced liver CT were randomly assigned to 2 groups: G1 (n = 224, individualized contrast medium injection protocol); G2 (n = 100, standard contrast medium injection with a dose of 1.5 ml/kg). CT values and ΔHU (CT values difference between plain and enhanced CT) of liver parenchyma and tumor-liver contrast (TLC) during hepatic arterial phase (HAP) and portal venous phase (PVP) and contrast medium dose were measured. The tumor conspicuity of hepatocellular carcinoma (HCC) between two groups was independently evaluated by two radiologists. Results The mean contrast medium dose of G1 was statistically lower than that of G2. There were no significantly statistical differences in CT values and ΔHU of liver parenchyma during HAP, TLC values during HAP, and PVP between two groups. The CT values and ΔHU of liver parenchyma during PVP of G2 were significantly higher than those of G1. Two independent radiologists were both in substantial conformity in grading tumor conspicuity. Conclusion Using the individually optimized injection protocol might reduce contrast medium dose without impacting on the imaging quality in enhanced liver CT.

Research on registration and fusion of CT liver images in artery and vein phase

Objective To study the extraction, registration and fusion of the image contour of liver CT scan sequence. Methods Filtering method was used to remove the noise and enhance the edge of the image, and then the contour of the CT image was extracted. According to the optimal registration parameters, the hepatic arterial phase and venous phase images were registered, and the corresponding relationship between the arterial and venous images was determined. At last, the CT images of the arterial and venous phase were fused. Results After fusing the corresponding arterial and venous images, condition of liver artery and vein of the same cross section in different phase periods could be observed. Conclusions Fused image can offer richer image information to doctors for diagnosis. Key words: Liver; CT image; Vascellum; Registration; Fusion

Minimally Required Iodine Dose for the Detection of Hypervascular Hepatocellular Carcinoma on 80-kVp CT.

The objective of our study was to determine the iodine dose per unit of body weight (BW) or body surface area (BSA) that is minimally required to detect hypervascular hepatocellular carcinoma (HCC) on 80-kVp CT. One hundred eleven patients (78 men and 33 women; mean age, 68 years; age range, 43-85 years) with chronic hepatitis were randomized into three groups with different iodine loads (0.5, 0.4, and 0.3 g I/kg BW) and underwent contrast-enhanced CT at 80 kVp. Enhancement of the liver and of hypervascular HCCs was quantitatively and qualitatively assessed on hepatic arterial, portal venous, and equilibrium phase images and compared between the groups. Values for iodine dose per unit of BSA (g I/m(2)) were also computed and analyzed. No significant differences in the contrast-to-noise ratio (CNR) of hypervascular HCCs in any phase were found between the groups (p = 0.34-0.99). In the portal venous phase, the mean increase in hepatic contrast enhancement (ΔHU) of the 0.5 g I/kg group (80.3 HU) was higher than those of the 0.4 g I/kg (63.4 HU) and 0.3 g I/kg (53.3 HU) groups (p < 0.001). Linear correlation equations for the increase in hepatic contrast enhancement were as follows: ΔHU = 5.9 + 150.0 × IL(BW) (r = 0.69, p < 0.001), where IL(BW) is the iodine load per unit of BW (g I/kg), and ΔHU = 13.0 + 3.68 × IL(BSA) (r = 0.66, p < 0.001), where IL(BSA) is the iodine load pre unit of BSA (g I/m(2)). The minimal iodine dose required to achieve a tumor-to-liver CNR that is acceptable for the detection of hypervascular HCCs on 80-kVp CT was 0.3 g I/kg BW or 11.0 g I/m(2) BSA.

Liver Malignancies Treated With Intra-Arterial Therapy

The aim of the study was to evaluate the value of volumetric contrast-enhanced magnetic resonance imaging (MRI) using gadoxetate disodium in early assessment of treatment response after intra-arterial therapy (IAT). This prospective study included 21 patients (32 malignant lesions) who underwent MRI using gadoxetate disodium before and early after IAT. Two reviewers reported response by anatomic criteria including Response Evaluation Criteria in Solid Tumor (RECIST), Modified RECIST (mRECIST), and European Association for the Study of Liver Disease and functional criteria including volumetric enhancement in hepatic arterial phase and portal venous phase. Treatment end point was RECIST at 6 months. A 2-sample paired t test was used to compare the mean changes after IAT. A P value of less than 0.05 was considered statistically significant. Responders by RECIST at 6 months did not fulfill partial response by conventional criteria at 1 month, except for mRECIST by reader 2. The mRECIST and European Association for the Study of Liver Disease could not be assessed in a total of 4 and 3 lesions for readers 1 and 2, respectively. However, volumetric measurements were obtained in all lesions and the changes were statistically significant at 1 month for hepatic arterial phase (P = 0.02 and P = 0.008) and portal venous phase (P < 0.0001 and P < 0.0001), as assessed by both readers, respectively. Volumetric contrast-enhanced MRI using gadoxetate disodium may be a helpful tool to evaluate early treatment response after IAT in malignant liver tumors.

Optimization of the Timing of the Portal Venous Phase in Preoperative 3DCT for Malignant Liver Tumors.

Preoperative three-dimensional computed tomography (3DCT) of the liver is the most important examination in performing preoperative simulation. Detailed visualization of the portal vein using the workstation is critical to enable accurate liver segmentation. However, the timing of imaging in the portal venous phase has mostly been reported equivalent to that of the liver screening examinations commonly performed. The purpose of this study was to examine the optimal timing of image capture to create the best portal vein visualization in preoperative 3DCT of the liver. Seventy-nine patients who underwent hepatectomy for malignant liver tumors were enrolled in this study. All patients were preoperatively examined using protocol A (imaging method separated into a portal venous phase and a hepatic venous phase) and then examined 1 week after surgery using protocol B (normal liver screening protocol). We first established the regions of interest in the portal vein and the hepatic vein and then compared CT values for these regions under protocol A and protocol B. The average CT value of the portal vein in protocol A and B was 239.8±28.1 HU and 202.2±18.5 HU, respectively. The average CT value of the portal vein in protocol A was significantly higher compared with protocol B (p<0.01). By introducing separate timing for portal venous phase imaging before preoperative 3DCT (protocol A), it is possible to satisfactorily depict the portal vein.

Ad Integrum Functional and Volumetric Recovery in Right Lobe Living Donors: Is It Really Complete 1 Year After Donor Hepatectomy?

The partial liver's ability to regenerate both as a graft and remnant justifies right lobe (RL) living donor liver transplantation. We studied (using biochemical and radiological parameters) the rate, extent of, and predictors of functional and volumetric recovery of the remnant left liver (RLL) during the first year in 91 consecutive RL donors. Recovery of normal liver function (prothrombin time [PT] ≥70% of normal and total bilirubin [TB] ≤20 µmol/L), liver volumetric recovery, and percentage RLL growth were analyzed. Normal liver function was regained by postoperative day's 7, 30, and 365 in 52%, 86%, and 96% donors, respectively. Similarly, mean liver volumetric recovery was 64%, 71%, and 85%; whereas the percentage liver growth was 85%, 105%, and 146%, respectively. Preoperative PT value (p = 0.01), RLL/total liver volume (TLV) ratio (p = 0.03), middle hepatic vein harvesting (p = 0.02), and postoperative peak TB (p < 0.01) were predictors of early functional recovery, whereas donor age (p = 0.03), RLL/TLV ratio (p = 0.004), and TLV/ body weight ratio (p = 0.02) predicted early volumetric recuperation. One-year post-RL donor hepatectomy, though functional recovery occurs in almost all (96%), donors had incomplete restoration (85%) of preoperative total liver volume. Modifiable predictors of regeneration could help in better and safer donor selection, while continuing to ensure successful recipient outcomes.

FDG PET and Split-Bolus Multi-Detector Row CT Fusion Imaging in Oncologic Patients: Preliminary Results.

To assess the incremental value of split-bolus multidetector computed tomography (CT) combined with fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) for follow-up of oncologic patients. The institutional ethics committee approved the use of this protocol. Thirty-eight oncologic patients who underwent FDG PET/unenhanced multidetector CT and split-bolus multidetector CT for restaging were investigated retrospectively. The split-bolus CT protocol included imaging during the hepatic arterial and portal venous phases in one scan. Software was used for fusion of the independently acquired FDG PET and split-bolus CT data, and fused datasets were compared with FDG PET/unenhanced CT data. The standard of reference for diagnosis of lesions in all patients was a combination of histologic results (if available), clinical results (medical history, physical examination, and laboratory test results), and the results of follow-up imaging (conventional CT, magnetic resonance imaging, and/or ultrasonography) for at least 6 months. Descriptive statistics were used. Fifty-nine true-positive lesions were identified with fused FDG PET/split-bolus CT; 41 were concordant and detected with both split-bolus CT and PET/unenhanced CT, 16 with split-bolus CT only, and two with PET/unenhanced CT. Two different false-positive lesions were identified with PET/unenhanced CT and PET/split-bolus CT. Furthermore, in 20 of 38 (53%) patients, FDG PET/split-bolus CT allowed detection of important additional findings (n = 40) not detected at FDG PET/unenhanced CT. Both the tumor-related findings (n = 13, 32.5%) and the non-tumor-related findings (n = 27, 67.5%) were important to the clinical treatment of these patients. Fused FDG PET/split-bolus multidetector CT provides additional information compared with FDG PET/unenhanced multidetector CT in oncologic patients.

Multiple-phase spiral CT findings of pancreatic vasoactive intestinal peptide-secreting tumor: A case report.

The present study reports a case of pancreatic vasoactive intestinal peptide-secreting tumor (VIPoma), of 2.2 cm in diameter, arising from the region of the uncus of the pancreas with liver metastases in a 50-year-old patient, which demonstrated unusual multiple-phase spiral computed tomography (MPSCT) results. The pancreatic lesion was isodense compared with the pancreatic parenchyma. During the hepatic artery phase and portal venous phase, the mass was hypodense compared with the enhanced pancreas, with the mean CT attenuation (HU) values being 56 HU and 66 HU, respectively. During the hepatic parenchymal phase, the mass became hyperdense with the mean CT attenuation values being 74 HU. The process of contrast-enhanced MPSCT demonstrated progressive strengthening. Pancreaticoduodenectomy and wedge resection of a number of the liver metastases was performed. There are only a limited number of studies reporting CT findings of pancreatic VIPoma and no MPSCT findings have been described previously.

Application of computed tomography virtual noncontrast spectral imaging in evaluation of hepatic metastases: a preliminary study.

Objective:The objective was to qualitatively and quantitatively evaluate hepatic metastases using computed tomography (CT) virtual noncontrast (VNC) spectral imaging in a retrospective analysis.Methods:Forty hepatic metastases patients underwent CT scans including the conventional true noncontrast (TNC) and the tri-phasic contrast-enhanced dual energy spectral scans in the hepatic arterial, portal venous, and equilibrium phases. The tri-phasic spectral CT images were used to obtain three groups of VNC images including in the arterial (VNCa), venous (VNCv), and equilibrium (VNCe) phase by the material decomposition process using water and iodine as a base material pair. The image quality and the contrast-to-noise ratio (CNR) of metastasis of the four groups were compared with ANOVA analysis. The metastasis detection rates with the four nonenhanced image groups were calculated and compared using the Chi-square test.Results:There were no significant differences in image quality among TNC, VNCa and VNCv images (P > 0.05). The quality of VNCe images was significantly worse than that of other three groups (P < 0.05). The mean CNR of metastasis in the TNC and VNCs images was 1.86, 2.42, 1.92, and 1.94, respectively; the mean CNR of metastasis in VNCa images was significantly higher than that in other three groups (P < 0.05), while no statistically significant difference was observed among VNCv, VNCe and TNC images (P > 0.05). The metastasis detection rate of the four nonenhanced groups with no statistically significant difference (P > 0.05).Conclusions:The quality of VNCa and VNCv images is identical to that of TNC images, and the metastasis detection rate in VNC images is similar to that in TNC images. VNC images obtained from arterial phase show metastases more clearly. Thus, VNCa imaging may be a surrogate to TNC imaging in hepatic metastasis diagnosis.

Split-bolus versus triphasic multidetector-row computed tomography technique in the diagnosis of hepatic focal nodular hyperplasia: a case report

IntroductionComputed tomography and magnetic resonance imaging are able to demonstrate and to diagnose hepatic focal nodular hyperplasia when a typical pattern of a well-circumscribed lesion with a central scar is present.Our aim is to propose the split-bolus multidetector-row computed tomography technique as an alternative to the conventional triphasic technique in the detection and characterization of focal nodular hyperplasia to reduce the radiation dose to the patient.To the best of our knowledge, this is the first report regarding the application of the split-bolus computed tomography technique in the evaluation of hepatic focal nodular hyperplasia.Case presentationWe describe a case of focal nodular hyperplasia of the liver in a 53-year-old Caucasian woman (weight 75Kg) with a colorectal adenocarcinoma histologically confirmed. An innovative split-bolus multidetector-row computed tomography technique was used that, by splitting intravenous contrast material in two boli, combined two phases (hepatic arterial phase and portal venous phase) in a single pass; a delayed (5 minutes) phase was obtained to compare the findings with that of triphasic multidetector-row computed tomography.ConclusionsSplit-bolus multidetector-row computed tomography was able to show the same appearance of the lesion as the triphasic multidetector-row computed tomography technique.This is the first case demonstrating the effectiveness of the split-bolus multidetector-row computed tomography technique in the detection and characterization of focal nodular hyperplasia with a significant reduction in radiation dose to the patient with respect to triphasic multidetector-row computed tomography technique.

MR imaging in hepatocellular carcinoma: correlations between MRI features and molecular marker VEGF

The aim of this paper was to investigate the correlations between magnetic resonance imaging (MRI) features and vascular endothelial growth factor (VEGF) in hepatocellular carcinoma (HCC). Thirty-six patients with HCC included in this study underwent dynamic contrast-enhanced MR imaging and diffusion-weighted MR imaging. Signal intensity characteristics of HCCs were reviewed independently by two experienced radiologists. ADC maps were automatically computed. VEGF expression was evaluated by immunohistochemical staining. The grades of the VEGF expression were correlated inversely with the ADC values of the HCCs (r = -0.435, p = 0.008). Intensity heterogeneity correlated with VEGF expression (r = 0.571, p = 0.039). There is a significant correlation between the intensity of arterial enhancement and VEGF expression (r = -0.386, p = 0.02). However, no correlation was found between the VEGF grades and the intensity of enhancement in the hepatic portal venous and late phases, as well as equilibrium phase. Our results indicate that ADC value on DW-MRI, the signal intensity in arterial phase and intensity heterogeneity correlate with the degree of VEGF expression in hepatocellular carcinomas.

Impaired visibility of the hepatic veins on the multi-detector computed tomography in patients with cirrhosis.

To determine the prevalence and associations of the impaired visibility of the hepatic veins (HV) on the multi-detector row computed tomography (MDCT) in cirrhotic patients. Eighty-seven consecutive cirrhotic patients undergoing triphasic liver MDCT were enrolled. The patency of the HV and the direction of the blood flow in the main portal vein, inhomogeneity of the liver, portal vein thrombosis (PVT), a spontaneous splenorenal shunt, splenic indexes (cm(3)), contour abnormalities, and enlargement of the fissure were evaluated. The prevalence of the impaired visibility of the HV was 38% in the patients with cirrhosis. No significant associations exist between the impaired visibility of the HV and age (p=0.96), sex (p=0.14), portal vein thrombosis (p=0.29), or splenic indexes (p=0.32). Inhomogeneity of the liver (p=0.0001), marked contour abnormalities, (p=0.0001), splenorenal shunt (p=0.02), enlargement of fissure (p=0.0001), and hepatofugal flow (p=0.01) were significantly associated with the impaired visibility of the HV. Inhomogeneity of the liver, marked contour abnormalities, and hepatofugal flow are independently associated with the impaired visibility of the HV in cirrhotic patients on hepatic venous phase CT.

Irreversible Electroporation Ablation of Malignant Hepatic Tumors: Subacute and Follow-up CT Appearance of Ablation Zones

PurposeTo describe findings on contrast-enhanced computed tomography (CT) images of malignant hepatic tumors 24–72 hours after percutaneous ablation by irreversible electroporation (IRE) and at midterm follow-up. Materials and MethodsRetrospective analysis of 52 malignant liver tumors—30 primary hepatic tumors and 22 hepatic metastases—in 34 patients (28 men and 6 women, mean age 64 y) treated by IRE ablation was performed. Ablation zones were evaluated by two examiners in a consensus reading by means of a dual-phase CT scan (consisting of a hepatic arterial and portal venous phase) performed 24–72 hours after IRE ablation and at follow-up. ResultsDuring the portal venous phase, ablation zones either were homogeneously hypoattenuating (n = 36) or contained heterogeneously isoattenuating or hyperattenuating (n = 16) foci, or both, in a hypoattenuating area. Of 52 lesions, 38 included gas pockets. Peripheral contrast enhancement of the ablation defect was evident in 23 tumors during the arterial phase and in 36 tumors during the portal venous phase. Four tumors showed intralesional abscesses after the intervention. At follow-up (mean, 4.7 mo), the mean volume of the ablation defects was reduced to 29% of their initial value. ConclusionsBecause normal findings on contrast-enhanced CT images after IRE ablation may be very similar to the typical characteristics of potential complications following ablation, such as liver abscesses, CT scans must be carefully analyzed to distinguish normal results after intervention from complications requiring further treatment.

Spectral CT imaging in patients with Budd-Chiari syndrome: investigation of image quality.

To assess the image quality of monochromatic imaging from spectral CT in patients with Budd-Chiari syndrome (BCS), fifty patients with BCS underwent spectral CT to generate conventional 140 kVp polychromatic images (group A) and monochromatic images, with energy levels from 40 to 80, 40 + 70, and 50 + 70 keV fusion images (group B) during the portal venous phase (PVP) and the hepatic venous phase (HVP). Two-sample t tests compared vessel-to-liver contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) for the portal vein (PV), hepatic vein (HV), inferior vena cava. Readers' subjective evaluations of the image quality were recorded. The highest SNR values in group B were distributed at 50 keV; the highest CNR values in group B were distributed at 40 keV. The higher CNR values and SNR values were obtained though PVP of PV (SNR 18.39 ± 6.13 vs. 10.56 ± 3.31, CNR 7.81 ± 3.40 vs. 3.58 ± 1.31) and HVP of HV (3.89 ± 2.08 vs. 1.27 ± 1.55) in the group B; the lower image noise for group B was at 70 keV and 50 + 70 keV (15.54 ± 8.39 vs. 18.40 ± 4.97, P = 0.0004 and 18.97 ± 7.61 vs. 18.40 ± 4.97, P = 0.0691); the results show that the 50 + 70 keV fusion image quality was better than that in group A. Monochromatic energy levels of 40-70, 40 + 70, and 50 + 70 keV fusion image can increase vascular contrast and that will be helpful for the diagnosis of BCS, we select the 50 + 70 keV fusion image to acquire the best BCS images.

The evaluation of potential donors' hepatic vascular anatomy in liver transplantation with multislice computed tomography

The purpose of this study is to assess the role of multislice computed tomography angiography in the evaluation and determination of variations in hepatic arterial, portal and hepatic venous anatomy in potential liver donors before transplantation. Total 48 healthy liver donor candidates (11 female and 37 male) who applied for liver transplantation donation between March 2010 and July 2013 were included in our study. Donors scanned with 0.625-mm thickness, 64 detector computed tomography (CT) scanner. Unenhanced CT and CT angiography in arterial, portal and hepatic venous phases were performed. From axial images two dimensional multiplanar reformats and with maximum intensity projection and volume rendering techniques three dimensional images were obtained. Hepatic vascular system anatomy and variants were demonstrated. In 34 cases of 48 donor candidates arterial branching were detected compatible with the classic hepatic artery anatomy (Michels type I). Hepatic arterial variations were viewed in 14 cases. In four cases Michels type II and III cases Michels type III variations were present. Michels type IV in one case and Michels type V variations in one another case were detected. Five cases had rare anomalies not classified by Michels (left hepatic artery originating before the gastroduedonal artery and the common hepatic artery arising directly from the aorta). In twenty-five patients from donor candidates, normal main portal venous bifurcation branching (type I); in twenty-three patients, portal venous variations were detected. While middle and left hepatic veins separately drained into vena cava inferior in 32 donor candidates, main hepatic vein and left hepatic vein was being draining in the form of common trunk in 16 of the donors. Segment V and/or VIII veins which were larger than 5 mm and drained to the middle hepatic vein was detected in 12 patients. Fourteen of donor candidates had accessory inferior hepatic vein, 5 patients had accessory superior hepatic veins greater than 5 mm. Multislice CT is a reliable and useful non-invasive technique; in potential liver donors to provide artery, portal and hepatic venous structures mapping and to determine fairly common vascular variations that may complicate surgery before liver transplantation.