Assessment of hepatic functional reserve by cirrhosis grading and liver volume measurement using CT

Segmental analysis of liver cirrhosis with different etiologies: a study based on iodine mixed imaging in port-venous phase

BACKGROUND

Computed tomography (CT) in port-venous phase can display the intra-hepatic vessels, and may provide the possibility for segment function evaluation for cirrhosis.

PURPOSE

To assess the value of iodine mixed imaging of dual-source dual-energy CT in port-venous phase in segmental evaluation of liver cirrhosis with different etiologies.

MATERIAL AND METHODS

Patients diagnosed with liver cirrhosis were enrolled. Patients without cirrhosis were included as a control group. Each patient underwent iodine-contrast enhanced multi-phase dual-energy CT scanning. Parameters were analyzed by SPSS, version 22.0, and Medcalc.

RESULTS

In total, 256 patients were investigated, including 114 Child-Pugh A, 51 Child-Pugh B, 41 Child-Pugh C and 50 control patients. Total iodine content (ICt)/body surface area (BSA) in the cirrhosis group was significantly lower than the control group (P < 0.05) and the standardized-iodine parameter (SI) of each segment decreased with cirrhosis progression. In Child-Pugh A and B, SI increased more significantly in the caudal and lateral segment in A (alcholism) than in the V (virus-related) and N (non-alcoholic steatohepatitis) groups (P < 0.001). ICt/BSA showed the best diagnosis power of cirrhosis with an area under the curve of 0.765, sensitivity of 76.0% and specificity of 71.8%.

CONCLUSION

Blood flow compensated in the left lateral and caudal lobe in the early stage of liver cirrhosis. The compensation in alcoholism in the middle and early stages is significantly higher than that of V and N cirrhosis. Iodine mixed imaging in portal phase may provide the possibility of an incremental value in segmented blood flow perfusion and functional evaluation of liver cirrhosis on a morphological basis.

Current evidence on posthepatectomy liver failure: comprehensive review

INTRODUCTION

Despite important advances in many areas of hepatobiliary surgical practice during the past decades, posthepatectomy liver failure (PHLF) still represents an important clinical challenge for the hepatobiliary surgeon. The aim of this review is to present the current body of evidence regarding different aspects of PHLF.

METHODS

A literature review was conducted to identify relevant articles for each topic of PHLF covered in this review. The literature search was performed using Medical Subject Heading terms on PubMed for articles on PHLF in English until May 2022.

RESULTS

Uniform reporting on PHLF is lacking due to the use of various definitions in the literature. There is no consensus on optimal preoperative assessment before major hepatectomy to avoid PHLF, although many try to estimate future liver remnant function. Once PHLF occurs, there is still no effective treatment, except liver transplantation, where the reported experience is limited.

DISCUSSION

Strict adherence to one definition is advised when reporting data on PHLF. The use of the International Study Group of Liver Surgery criteria of PHLF is recommended. There is still no widespread established method for future liver remnant function assessment. Liver transplantation is currently the only effective way to treat severe, intractable PHLF, but for many indications, this treatment is not available in most countries.

Predictors of residual hepatic reserve and hepatic decompensation in cirrhotic patients after ablated hepatocellular carcinoma treated by DDAs or systemic therapy

Background

Therapeutic interventions for hepatocellular carcinoma (HCC) particularly in patients with advanced liver disease may lead to more aggravation of clinical and biochemical parameters of liver functions. We aimed to assess the utilization of easily applied variables which evaluate residual hepatic reserve to predict liability for complications and hepatic decompensation in cirrhotic patients with ablated HCC particularly when these patients were exposed to specific medical treatment such as DAAs and systemic therapy for HCC such as sorafenib.

This study included 3 groups with HCC. Group 1: patients with ablated HCC and Child-Turcotte-Pugh (CTP) class A, who received Sofosbuvir (SOF)-based treatment (n = 250), group 2: HCC patients CTP (A), managed with sorafenib after transarterial chemoembolization (TACE) (n = 250) and group 3 as a control group of non-cirrhotic patients (n = 176). Evaluation for all patients was done by routine laboratory investigations including liver and kidney functions, complete blood count, platelet indices and plasma ammonia, upper gastrointestinal (GI) endoscopy and estimation of liver volume by ultrasound and liver stiffness (LS) by Fibroscan.

Results

Unfavorable outcome and increased incidence of complications during DAAs were independently associated with severity of thrombocytopenia (p = 0.001) at a cut-off 78,000/μl, LS > 20 kPa (p = 0.001), liver volume < 500 ml (p = 0.002), and gamma globulin levels > 4 gm/dl (p = 0.004).

In the sorafenib group, unfavorable outcome and complications were independently associated with PDW/MPV ratio > 2.74 (p = 0.001), level of ammonia > 87 μg/dl (p = 0.001), LS > 25 kPa (p = 0.001), and liver volume < 490 ml (p = 0.001).

Conclusion

Non-invasive parameters of residual hepatic reserve are promising tools to guide therapy and avoid further complications in patients with liver cirrhosis and ablated HCC.

Imaging Evaluation of Living Liver Donor Candidates: Techniques, Protocols, and Anatomy

The need for liver transplants is increasing because the prevalence of liver diseases and the indications for transplants are growing. In response to the shortage of grafts from deceased donors, more transplants are being performed worldwide with grafts from living donors. Radiologic evaluation is an integral component in the assessment of donor candidates to ensure their eligibility and to choose the most appropriate surgical approach. MRI is the preferred modality for evaluation of the liver parenchyma and biliary tree. In most centers, a combination of MRI and CT is used to take advantage of the higher spatial resolution of CT for evaluation of arteries. However, MRI-only assessment is feasible. In addition to assessment of the liver parenchyma for abnormalities such as steatosis, a detailed evaluation of the hepatic vascular and biliary system for pertinent anatomic variants is crucial, because these variants can affect surgical techniques and outcomes in both recipients and donors. In this pictorial article, after a brief review of the most common surgical techniques and postsurgical liver anatomy, the biliary and vascular anatomy are discussed, with specific attention paid to the variants that are pertinent to this surgical procedure. The roles of liver segmentation and volumetric assessment and current imaging techniques and protocols are also discussed. Online supplemental material is available for this article. ©RSNA, 2021.

Lower Ratio of Liver Volume and Body Weight Is a Negative Predictor of Survival after Transjugular Intrahepatic Portosystemic Shunt

Transjugular intrahepatic portosystemic shunt (TIPS) is the most effective measure to treat complications of portal hypertension. However, liver function may deteriorate after TIPS. Predictors of liver function and outcome after TIPS are therefore important for management of TIPS patients. The study aimed to evaluate the impact of liver volume on transplant-free survival (TFS) after TIPS, as well as the evolution of liver volume and its relationship with liver function after TIPS. A retrospective analysis of all consecutive patients who underwent TIPS in a tertiary care university liver center between 2012 and 2017 (n = 216) was performed; n = 72 patients with complete prior and follow-up (FU) computed tomography (CT) imaging studies were included in the study. Volumetry of the liver was performed by a semi-automatic 9-lobe image segmentation algorithm at baseline and FU (FU 1: 90–180 d; FU 2: 180–365 d; FU 3: 365–545 d; FU 4: 545–730 d; FU 5: >730 d). Output variables were total liver volume (TLV, cm³), left liver volume (LLV, cm³), right liver volume (RLV, cm³) and TLV/body weight ratio. CT derived liver volumes were correlated with liver function tests, portosystemic pressure gradient (PPG) measurements and survival. To assess predictors of liver volume change over time we fitted linear mixed models. Kaplan–Meier analysis was performed and validated by matched pair analysis followed by Cox regression to determine independent prognostic factors for survival. The median TLV at baseline was 1507.5 cm³ (773.7–3686.0 cm³). Livers with higher baseline liver volumes and larger TLV/weight ratios retained their volume after an initial loss while smaller livers continuously lost volume after TIPS. At the first follow-up period (90–180 d post-TIPS) lower liver volumes and TLV/weight ratios were associated with higher bilirubin levels. Within the final multivariable model containing time (days since TIPS), baseline INR and baseline TLV, the average loss of liver volume was 0.74 mL per day after TIPS. Twelve-month overall transplant-free survival was 89% and median overall TFS was 33 months. The median TFS for a baseline TLV/body weight ratio > 20 was significantly higher compared with ≤20 (40.0 vs. 27.0 months, p = 0.010) while there were no differences regarding the indication for TIPS or etiology of liver disease in the matched pair analysis. Lower TLV/weight ratios before TIPS were associated with shorter TFS and should therefore be critically considered when selecting patients for TIPS. In addition, this study provides first evidence of an effect of TIPS on subsequent liver volume change and associated liver function.

Clinical characteristics of cirrhosis patients with umbilical vein recanalization: A retrospective analysis

Umbilical Vein Recanalization (UVR) may occur in patients with long-standing portal hypertension and liver cirrhosis. This study aimed to investigate the clinical significance of UVR.Medical records of a cohort of patients with cirrhosis (n = 247) who were hospitalized at the Digestive Medicine Center of the Second Affiliated Hospital of Nanchang University from January 2012 to October 2015 were accessed. The UVR diagnosis was made by ultrasound examination and was confirmed by computerized tomography scan.The UVR incidence was 20.2% (50/247) in the cohort. The size of UVR was 9.9 ± 4.7 mm (range: 5-26.5 mm) in diameter. The UVR and non-UVR groups showed no difference in grades of hepatic encephalopathy (P = .496), Child-Pugh classification (P = .401), the incidence of moderately severe ascites (26% vs 26%, P = 1), the esophageal variceal bleeding rate (32% vs 39%, P = .402), or portal vein thrombosis (8% vs 12%, P = .580). However, the incidence of cavernous transformation of the portal vein was statistically different, that there was 0 case in the UVR group and 8 cases in the non-UVR group (P < .05).Our results suggested that UVR had little impact on the clinical manifestations of patients with liver cirrhosis, the significance of UVR as an intervention method requires further studies.

Feasibility of Automated Volumetric Assessment of Large Hepatocellular Carcinomas' Responses to Transarterial Chemoembolization

Background: Hepatocellular carcinoma (HCC) is the most common liver malignancy and the leading cause of death in patients with cirrhosis. Various treatments for HCC are available, including transarterial chemoembolization (TACE), which is the commonest intervention performed in HCC. Radiologic tumor response following TACE is an important prognostic factor for patients with HCC. We hypothesized that, for large HCC tumors, assessment of treatment response made with automated volumetric response evaluation criteria in solid tumors (RECIST) might correlate with the assessment made with the more time- and labor-intensive unidimensional modified RECIST (mRECIST) and manual volumetric RECIST (M-vRECIST) criteria. Accordingly, we undertook this retrospective study to compare automated volumetric RECIST (A-vRECIST) with M-vRECIST and mRESIST for the assessment of large HCC tumors' responses to TACE. Methods:We selected 42 pairs of contrast-enhanced computed tomography (CT) images of large HCCs. Images were taken before and after TACE, and in each of the images, the HCC was segmented using both a manual contouring tool and a convolutional neural network. Three experienced radiologists assessed tumor response to TACE using mRECIST criteria. The intra-class correlation coefficient was used to assess inter-reader reliability in the mRECIST measurements, while the Pearson correlation coefficient was used to assess correlation between the volumetric and mRECIST measurements. Results:Volumetric tumor assessment using automated and manual segmentation tools showed good correlation with mRECIST measurements. For A-vRECIST and M-vRECIST, respectively, r = 0.597 vs. 0.622 in the baseline studies; 0.648 vs. 0.748 in the follow-up studies; and 0.774 vs. 0.766 in the response assessment (P < 0.001 for all). The A-vRECIST evaluation showed high correlation with the M-vRECIST evaluation (r = 0.967, 0.937, and 0.826 in baseline studies, follow-up studies, and response assessment, respectively, P < 0.001 for all). Conclusion:Volumetric RECIST measurements are likely to provide an early marker for TACE monitoring, and automated measurements made with a convolutional neural network may be good substitutes for manual volumetric measurements.

CT-based peritumoral radiomics signatures to predict early recurrence in hepatocellular carcinoma after curative tumor resection or ablation

OBJECTIVE

To construct a prediction model based on peritumoral radiomics signatures from CT images and investigate its efficiency in predicting early recurrence (ER) of hepatocellular carcinoma (HCC) after curative treatment.

MATERIALS AND METHODS

In total, 156 patients with primary HCC were randomly divided into the training cohort (109 patients) and the validation cohort (47 patients). From the pretreatment CT images, we extracted 3-phase two-dimensional images from the largest cross-sectional area of the tumor. A region of interest (ROI) was manually delineated around the lesion for tumoral radiomics (T-RO) feature extraction, and another ROI was outlined with an additional 2 cm peritumoral area for peritumoral radiomics (PT-RO) feature extraction. The least absolute shrinkage and selection operator (LASSO) logistic regression model was applied for feature selection and model construction. The T-RO and PT-RO models were constructed. In the validation cohort, the prediction efficiencies of the two models and peritumoral enhancement (PT-E) were evaluated qualitatively by receiver operating characteristic (ROC) curves, calibration curves and decision curves and quantitatively by area under the curve (AUC), the category-free net reclassification index (cfNRI) and integrated discrimination improvement values (IDI).

RESULTS

By comparing AUC values, the prediction accuracy in the validation cohort was good for the PT-RO model (0.80 vs. 0.79, P = 0.47) but poor for the T-RO model (0.82 vs. 0.62, P < 0.01), which was significantly overfitted. In the validation cohort, the ROC curves, calibration curves and decision curves indicated that the PT-RO model had better calibration efficiency and provided greater clinical benefits. CfNRI indicated that the PT-RO model correctly reclassified 47% of ER patients and 32% of non-ER patients compared to the T-RO model (P < 0.01); additionally, the PT-RO model correctly reclassified 24% of ER patients and 41% of non-ER patients compared to PT-E (P = 0.02). IDI indicated that the PT-RO model could improve prediction accuracy by 0.22 (P < 0.01) compared to the T-RO model and by 0.20 (P = 0.01) compared to PT-E.

CONCLUSION

The CT-based PT-RO model can effectively predict the ER of HCC and is more efficient than the T-RO model and the conventional imaging feature PT-E.

Resection for Klatskin tumors: technical complexities and results

Klatskin's tumors, actually-redefined as perihilar cholangiocarcinoma (phCCA) do represent 50-70% of all CCAs and develop in a context of chronic inflammation and cholestasis of bile ducts. Surgical resection provides the only chance of cure for this disease but is technically challenging because of the complex, intimate and variable relationship between biliary and vascular structures at this location. Five years survival rates range between 25-45% (median 27-58 months) in case of R0 resection and 0-23% (median 12-21 months) in case of R1 resection respectively. It should be noted that the major costs of high radicality are represented by relative high morbidity and mortality rates (i.e., 20-66% and 0-9% respectively). Considering the fact that radical resection may represent the only curative treatment of phCCA, we focused our review on surgical planning and techniques that may improve resectability rates and outcomes for locally advanced phCCA. The surgical treatment of phCCA can be successful when following aspects have been fulfilled: (I) accurate preoperative diagnostic aimed to identify the tumor in all its details (localization and extension) and to study all the risk factors influencing a posthepatectomy liver failure (PHLF): i.e., liver volume, liver function, liver quality, haemodynamics and patient characteristics; (II) High end surgical skills taking in consideration the local extension of the tumor and the vascular invasion which usually require an extended hepatic resection and often a vascular resection; (III) adequate postoperative management aimed to avoid major complications (i.e., PHLF and biliary complications). These are technically challenging operations and must be performed in a high volume centres by hepato-biliary-pancreas (HBP)-surgeons with experience in microsurgical vascular techniques.

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.

Three-dimensional morphometric analysis for hepatectomy of centrally located hepatocellular carcinoma: A pilot study

AIM: To describe a three-dimensional model (3DM) to accurately reconstruct anatomic relationships of centrally located hepatocellular carcinomas (HCCs).

METHODS: From March 2013 to July 2014, reconstructions and visual simulations of centrally located HCCs were performed in 39 patients using a 3D subject-based computed tomography (CT) model with custom-developed software. CT images were used for the 3D reconstruction of Couinaud’s pedicles and hepatic veins, and the calculation of corresponding tumor territories and hepatic segments was performed using Yorktal DMIT software. The respective volume, surgical margin, and simulated virtual resection of tumors were also estimated by this model preoperatively. All patients were treated surgically and the results were retrospectively assessed. Clinical characteristics, imaging data, procedure variables, pathologic features, and postoperative data were recorded and compared to determine the reliability of the model.

RESULTS: 3D reconstruction allowed stereoscopic identification of the spatial relationships between physiologic and pathologic structures, and offered quantifiable liver resection proposals based on individualized liver anatomy. The predicted values were consistent with the actual values for tumor mass volume (82.4 ± 109.1 mL vs 84.1 ± 108.9 mL, P = 0.910), surgical margin (10.1 ± 6.2 mm vs 9.1 ± 5.9 mm, P = 0.488), and maximum tumor diameter (4.61 ± 2.16 cm vs 4.53 ± 2.14 cm, P = 0.871). In addition, the number and extent of portal venous ramifications, as well as their relation to hepatic veins, were visualized. Preoperative planning based on simulated resection facilitated complete resection of large tumors located in the confluence of major vessels. And most of the predicted data were correlated with intraoperative findings.

CONCLUSION: This 3DM provides quantitative morphometry of tumor masses and a stereo-relationship with adjacent structures, thus providing a promising technique for the management of centrally located HCCs.

Post-hepatectomy liver failure

Hepatectomies are among some of the most complex operative interventions performed. Mortality rates after major hepatectomy are as high as 30%, with post-hepatic liver failure (PHLF) representing the major source of morbidity and mortality. We present a review of PHLF, including the current definition, predictive factors, pre-operative risk assessment, techniques to prevent PHLF, identification and management. Despite great improvements in morbidity and mortality, liver surgery continues to demand excellent clinical judgement in selecting patients for surgery. Appropriate choice of pre-operative techniques to improve the functional liver remnant (FLR), fastidious surgical technique, and excellent post-operative management are essential to optimize patient outcomes.

Evaluation of computer-assisted quantitative volumetric analysis for pre-operative resectability assessment of huge hepatocellular carcinoma

PURPOSE

Hepatic resection is arguably the preferred treatment for huge hepatocellular carcinoma (H-HCC). Estimating the remnant liver volume is therefore essential. This study aimed to evaluate the feasibility of using computer-assisted volumetric analysis for this purpose.

METHODS

The study involved 40 patients with H-HCC. Laboratory examinations were conducted, and a contrast CT-scan revealed that 30 cases out of the participating 40 had single-lesion tumors. The remaining 10 had less than three satellite tumors. With the consensus of the team, two physicians conducted computer-assisted 3D segmentation of the liver, tumor, and vessels in each case. Volume was automatically computed from each segmented/labeled anatomical field. To estimate the resection volume, virtual lobectomy was applied to the main tumor. A margin greater than 1 cm was applied to the satellite tumors. Resectability was predicted by computing a ratio of functional liver resection (R) as (Vresected- Vtumor)/(Vtotal-Vtumor) x 100%, applying a threshold of 50% and 60% for cirrhotic and non-cirrhotic cases, respectively. This estimation was then compared with surgical findings.

RESULTS

Out of the 22 patients who had undergone hepatectomies, only one had an R that exceeded the threshold. Among the remaining 18 patients with non-resectable H-HCC, 12 had Rs that exceeded the specified ratio and the remaining 6 had Rs that were < 50%. Four of the patients who had Rs less than 50% underwent incomplete surgery due to operative findings of more extensive satellite tumors, vascular invasion, or metastasis. The other two cases did not undergo surgery because of the high risk involved in removing the tumor. Overall, the ratio of functional liver resection for estimating resectability correlated well with the other surgical findings.

CONCLUSION

Efficient pre-operative resectability assessment of H-HCC using computer-assisted volumetric analysis is feasible.

Preoperative assessment of postoperative liver function: the importance of residual liver volume

An inadequate volume of future liver remnant (FLR) remains an absolute contraindication to liver resection. FLR measurement correlates with surgical outcome and is fundamental to identify those patients that may benefit from portal vein embolization (PVE) and to assess the liver volume change following embolization. In order to minimize the risk of postoperative liver failure, preoperative analysis of FLR must be included in the surgical planning of every major liver resection. The aims of this review are to describe the use of preoperative volumetric analysis in modern liver surgery and indications for PVE.

Liver volume in the cirrhotic patient: does size matter?

BACKGROUND

While it is established that cirrhosis results in a decrease in liver volume (LV), whether LV itself predicts patient survival is unknown. We hypothesize that estimated LV is an important prognostic indicator in patients with cirrhosis.

METHODS

Data was gathered retrospectively from consecutive patients evaluated for a liver transplant from January 2001 to June 2006. Of 500 patients identified, 323 patients met both inclusion and exclusion criteria. LV per ideal body weight (IBW) was used to correct for body size, and LV/IBW was stratified by median split for survival analyses. Patients were classified into one of three clinical groups: hepatocellular disease (n = 229), cholestatic disease (n = 56), and miscellaneous (n = 38). One of three possible clinical outcomes (survival, liver transplantation, or death) was recorded during the 5-year follow-up, the latter two grouped together as "transplant/death."

RESULTS

Transplant/death occurred in 283 (88 %) subjects. Overall, there was a significant increase in transplant/death in those with lower LV/IBW (χ(2) = 5.27, p = 0.022). When considering the subset with hepatocellular disease, lower LV/IBW was a robust predictor of transplant/death (χ(2) = 9.62, p = 0.002). In multivariate analyses, the LV/IBW trended toward predicting transplant/death (ExpB = 0.943, p = 0.053) independent of Model for End stage Liver Disease (MELD) (ExpB = 1.13, p = 0.001).

DISCUSSION

LV has important predictive value in patients with cirrhosis from hepatocellular disease. This observation appears to be independent of MELD, suggesting LV may impart important prognostic information that is not captured by the MELD score alone. Thus, LV may serve as an important adjunct to the MELD score in patients with hepatocellular disease.

Assessment of liver volume variation to evaluate liver function

In order to assess the value of liver volumetry in cirrhosis and acute liver failure (ALF) patients, we explored the correlation between hepatic volume and severity of the hepatic diseases. The clinical data of 48 cirrhosis patients with 60 normal controls and 39 ALF patients were collected. Computed tomography-derived liver volume (CTLV) and body surface area (BSA) of normal controls were calculated to get a regression formula for standard liver volume (SLV) and BSA. Then CTLV and SLV of all patients were calculated and grouped by Child-Turcotte-Pugh classification for cirrhosis patients and assigned according to prognosis of ALF patients for further comparison. It turned out that the mean liver volume of the control group was 1,058 ± 337 cm(3). SLV was correlated with BSA according to the regression formula. The hepatic volume of cirrhosis patients in Child A, B level was not reduced, but in Child C level it was significantly reduced with the lowest liver volume index (CTLV/SLV). Likewise, in the death group of ALF patients, the volume index was significantly lower than that of the survival group. Based on volumetric study, we proposed an ROC (receiver operating characteristic) analysis to predict the prognosis of ALF patients that CTLV/SLV < 83.9% indicates a poor prognosis. In conclusion, the CTLV/SLV ratio, which reflects liver volume variations, correlates well with the liver function and progression of cirrhosis and ALF. It is also a very useful marker for predicting the prognosis of ALF.

Variation in hepatic segmental volume distribution according to different causes of liver cirrhosis: CT volumetric evaluation

OBJECTIVE

To investigate if there is difference in hepatic segmental volume distribution according to causes of liver cirrhosis (LC) using computed tomography volumetric analysis.

METHODS

On computed tomographic scans, hepatic segmental volumes were measured in 90 patients with LC of 4 different causes (alcohol, hepatitis B virus (HBV), hepatitis C virus (HCV), and cryptogenic cirrhosis). The volumetric indices were compared.

RESULTS

The volume proportion of the lateral segment in the liver in patients with HBV was significantly higher than in the patients with HCV (P = 0.038). Hepatic volume distribution in alcoholic LC showed differences: larger caudate lobe volume than HBV- and HCV-induced LC (P = 0.029 and P = 0.031), larger right lobe volume (P = 0.043) and smaller proportion of the lateral segment in the liver (P = 0.003) than in HBV-induced LC.

CONCLUSIONS

Computed tomography volumetric analysis showed differences in hepatic segmental volume distribution in cirrhotic patients according to causes of LC.

Hepatectomy preoperative planning

Hepatectomy can comprise excision of peripheral tumors as well as major surgeries like trisegmentectomies or central resections. Patients can be healthy, have localized liver disease or possess a cirrhotic liver with high operative risk. The preoperative evaluation of the risk of postoperative liver failure is critical in determining the appropriate surgical procedure. The nature of liver disease, its severity and the operation to be performed should be considered for correct preparation. Liver resection should be evaluated in relation to residual parenchyma, especially in cirrhotic patients, subjects with portal hypertension and when large resections are needed. The surgeon should assess the rationale for the use of hepatic volumetry. Child-Pugh, MELD and retention of indocyanine green are measures for assessing liver function that can be used prior to hepatectomy. Extreme care should be taken regarding the possibility of infectious complications with high morbidity and mortality in the postoperative period. Several centers are developing liver surgery in the world, reducing the number of complications. The development of surgical technique, anesthesia, infectious diseases, oncology, intensive care, possible resection in patients deemed inoperable in the past, will deliver improved results in the future.

Prospective volumetric assessment of the liver on a personal computer by nonradiologists prior to partial hepatectomy

Background

A small remnant liver volume is an important risk factor for posthepatectomy liver failure. ImageJ and OsiriX^® are both free, open-source image processing software packages. The aim of the present study was to compare ImageJ and OsiriX^® in performing prospective computed tomography (CT) volumetric analysis of the liver on a personal computer (PC) in patients undergoing major liver resection.

Methods

Patients scheduled for a right hemihepatectomy were eligible for inclusion. Two surgeons and one surgical trainee measured volumes of total liver, tumor, and future resection specimen prospectively with ImageJ and OsiriX^®. A radiologist also measured these volumes with CT scanner-linked Aquarius iNtuition^® software. Resection volumes were compared with the actual weights of the liver specimens removed during surgery, and differences between the measured liver volumes were analyzed.

Results

A total of 15 patients (8 men, 7 women) with a median age of 63 years (48–79 years) were included. There was a significant correlation between the measured weights of resection specimens and the volumes calculated prospectively with ImageJ and OsiriX^® (r = 0.89; r = 0.83, respectively). There was also a significant correlation between the volumes measured with radiological software iNtuition^® and the volumes measured with ImageJ and OsiriX^® (r = 0.93; r = 0.95, respectively).

Conclusions

There were no major differences in total liver volumes, resection volumes, or tumour volumes for these three software packages. Prospective hepatic CT volumetry with ImageJ or OsiriX^® is reliable and can be accurately used on a PC by nonradiologists. ImageJ and OsiriX^® yield results comparable to the radiological software iNtuition^®.

Virtual liver resection and volumetric analysis of the future liver remnant using open source image processing software

BACKGROUND

After extended liver resection, a remnant liver that is too small can lead to postresection liver failure. To reduce this risk, preoperative evaluation of the future liver remnant volume (FLRV) is critical. The open-source OsiriX PAC software system can be downloaded for free and used by nonradiologists to calculate liver volume using a stand-alone Apple computer. The purpose of this study was to assess the accuracy of OsiriX CT volumetry for predicting liver resection volume and FLVR in patients undergoing partial hepatectomy.

METHODS

Preoperative contrast-enhanced liver CT scans of patients who underwent partial hepatectomy were analyzed by three observers. Two surgical trainees measured the total liver volume, resection volume, and tumor volume using OsiriX, and a radiologist measured these volumes using CT scanner-linked Aquarius iNtuition software. Resection volume was correlated with prospectively determined resection weight, and differences in the measured liver volumes were analyzed. Interobserver variability was assessed using Bland-Altman plots.

RESULTS

25 patients (M/F ratio: 13/12) with a median age of 61 (range, 34-77) years were included. There were significant correlations between the weight and volume of the resected specimens (Pearson's correlation coefficient: R(2) = 0.95). There were no major differences in total liver volumes, resection volumes, or tumor volumes for observers 1, 2, and 3. Bland-Altman plots showed a small interobserver variability. The mean time to complete liver volumetry for one patient using OsiriX was 19 +/- 3 min.

CONCLUSIONS

OsiriX liver volumetry performed by surgeons is an accurate and time-efficient method for predicting resection volume and FLRV.

Morphological and functional MDCT: problem-solving tool and surrogate biomarker for hepatic disease clinical care and drug discovery in the era of personalized medicine

This article explains the significant role of morphological and functional multidetector computer tomography (MDCT) in combination with imaging postprocessing algorithms served as a problem-solving tool and noninvasive surrogate biomarker to effectively improve hepatic diseases characterization, detection, tumor staging and prognosis, therapy response assessment, and novel drug discovery programs, partial liver resection and transplantation, and MDCT-guided interventions in the era of personalized medicine. State-of-the-art MDCT depicts and quantifies hepatic disease over conventional CT for not only depicting lesion location, size, and extent but also detecting changes in tumor biologic behavior caused by therapy or tumor progression before morphologic changes. Color-encoded parameter display provides important functional information on blood flow, permeability, leakage space, and blood volume. Together with other relevant biomarkers and genomics, the imaging modality is being developed and validated as a biomarker to early response to novel, targeted anti-VEGF(R)/PDGFR or antivascular/angiogenesis agents as its parameters correlate with immunohistochemical surrogates of tumor angiogenesis and molecular features of malignancies. MDCT holds incremental value to World Health Organization response criteria and Response Evaluation Criteria in Solid Tumors in liver disease management. MDCT volumetric measurement of future remnant liver is the most important factor influencing the outcome of patients who underwent partial liver resection and transplantation. MDCT-guided interventional methods deliver personalized therapies locally in the human body. MDCT will hold more scientific impact when it is fused with other imaging probes to yield comprehensive information regarding changes in liver disease at different levels (anatomic, metabolic, molecular, histologic, and other levels).

Treatment planning and volumetric response assessment for Yttrium-90 radioembolization: semiautomated determination of liver volume and volume of tumor necrosis in patients with hepatic malignancy

Purpose

The primary purpose of this study was to demonstrate intraobserver/interobserver reproducibility for novel semiautomated measurements of hepatic volume used for Yttrium-90 dose calculations as well as whole-liver and necrotic-liver (hypodense/nonenhancing) tumor volume after radioembolization. The secondary aim was to provide initial comparisons of tumor volumetric measurements with linear measurements, as defined by Response Evaluation Criteria in Solid Tumors criteria, and survival outcomes.

Methods

Between 2006 and 2009, 23 consecutive radioembolization procedures were performed for 14 cases of hepatocellular carcinoma and 9 cases of hepatic metastases. Baseline and follow-up computed tomography obtained 1 month after treatment were retrospectively analyzed. Three observers measured liver, whole-tumor, and tumor-necrosis volumes twice using semiautomated software.

Results

Good intraobserver/interobserver reproducibility was demonstrated (intraclass correlation [ICC] > 0.9) for tumor and liver volumes. Semiautomated measurements of liver volumes were statistically similar to those obtained with manual tracing (ICC = 0.868), but they required significantly less time to perform (p < 0.0001, ICC = 0.088). There was a positive association between change in linear tumor measurements and whole-tumor volume (p < 0.0001). However, linear measurements did not correlate with volume of necrosis (p > 0.05). Dose, change in tumor diameters, tumor volume, and necrotic volume did not correlate with survival (p > 0.05 in all instances). However, Kaplan–Meier curves suggest that a >10% increase in necrotic volume correlated with survival (p = 0.0472).

Conclusion

Semiautomated volumetric analysis of liver, whole-tumor, and tumor-necrosis volume can be performed with good intraobserver/interobserver reproducibility. In this small retrospective study, measurements of tumor necrosis were suggested to correlate with survival.

Clinical application of measurement of liver volume by multi-slice spiral CT

The volume of the liver can not only directly reflect the size of the liver, liver capacity and the quantity of liver cells, but also, to a certain extent, indirectly reflect blood perfusion and metabolic capability of the liver. Therefore, liver volume is an important parameter to evaluate hepatic reserve function. The accurate measurement of liver volume has great significance for the formulation of treatment program, prevention of liver failure, and prediction of prognosis. This article is to review the clinical application of measurement of liver volume by multi-slice spiral CT.

Predicting liver failure following major hepatectomy

Pre-operative determination of the risk of liver dysfunction has come under criticism with regards to its usefulness in clinical practice. Opinion is split between centres which use such tests uniformly on all patients and those where clinical judgment alone is used. Published data would not suggest any difference in mortality, morbidity or liver failure rates between these groups. This review outlines and presents the evidence for pre-operative quantification of functional liver remnant volume.

A new measure to assess the difficulty of liver resection

BACKGROUND

There is no valid measure to assess surgical difficulty and feasibility of a planned liver resection. It is the objective of this study to evaluate a mathematical measure from a 3D graphical analysis.

METHODS

Eleven different 3D models of hepatic tumours were evaluated by experts for resectability and analysed with Amira graphic software taking into consideration the portal and hepatic venous vascular relationships. Virtual resection volumes with increasing resection margins from 1 to 30 mm were determined separately for portal veins, hepatic veins, their intersections and volume unions. The integral of the increasing resection volumes was defined as risk coefficient. The risk coefficients from this volumetric analysis were compared with the expert opinion.

RESULTS

The risk coefficient based on the integral of portal venous and hepatic venous volume unions reproduced the expert opinion highly significantly (correlation coefficient 0.9, p<0.05) and more accurately than volumetric analysis of the planned resection margin.

CONCLUSION

With automated volumetric analysis, anatomically problematic situations in liver surgery can be reproduced and scaled. The risk coefficient obtained is a suitable objective measure for defining risk areas in liver surgery.