Application of stereology in liver volume measurements using computed tomography scan / Aplicación de la estereología en mediciones de volumen hepático mediante tomografía computarizada

SUMMARY: The application of stereology in hepatobiliary conditions is essential in liver volume estimation. Computerized topographic scan with contrast is a reliable method in liver scanning for precise boundaries demarcation. Liver volumetry varies in relation to different factors. Reports showed a correlation of liver volume with sex and body mass index. Steady relation between age and ethnicity is not established. This study aimed to design a protocol for liver volume measurement and apply it in the estimation of volume among the Sudanese population use stereology. Recruitment of the study population was obtained in the royal scan clinic in Khartoum by making an announcement for participation in the study. Patients with a history of hepatobiliary diseases were excluded. CT abdomen with contrast was obtained in DICOM format and transferred to computer-based software for image analysis. A protocol was designed and validated and then applied in volume estimation using software MRIcro for image display, ImageJ for volume estimation, and Onis 2.6 as image viewer. 300 apparently healthy volunteers were recruited. The protocol reliability result was 0.805. Absolute mean liver volume was 3261.32 ± 1365.313 cm3. High liver volume among females was detected than among males. A positive correlation was detected between volume and body mass index (p-value 0.001) regardless of sex. Relation with age showed a rough steady rise till the age of 50 years then it started to decline steadily. The relationship was detected in liver volume with sex and body mass index. More studies are needed to investigate the relationship between ethnicity and age groups.

RESUMEN: La aplicación de la estereología en condiciones hepatobiliares es fundamental en la estimación del volumen hepático. El escaneo topográfico computarizado con contraste es un método confiable en el escaneo del hígado para la demarcación precisa de sus límites. La volumetría hepática varía en función de diferentes factores. Los informes mostraron una correlación del volumen del hígado con el sexo y el índice de masa corporal. No se establece una relación estable entre la edad y la etnia. Este estudio tuvo como objetivo diseñar un protocolo para la medición del volumen hepático de la población sudanesa usando la estereología. El reclutamiento de la población de estudio fue realizado en la clínica de exploración real en Jartum mediante un anuncio de participación. Se excluyeron los pacientes con antecedentes de enfermedades hepatobiliares. Se obtuvo TC de abdomen con contraste en formato DICOM y se transfirió a un software informático para el análisis de imágenes. Se diseñó y validó un protocolo y luego se aplicó en la estimación de volumen utilizando el software MRIcro para la visualización de imágenes, ImageJ para la estimación de volumen y Onis 2.6 como visor de imágenes. Se reclutaron 300 voluntarios sanos. El resultado de la fiabilidad del protocolo fue 0,805. El volumen hepático medio absoluto fue 3261,32 ± 1365,313 cm3. Se detectó un volumen más elevado de hígado en las mujeres que en los hombres. Se detectó una correlación positiva entre el volumen y el índice de masa corporal (valor de p 0,001) independientemente del sexo. La relación con la edad mostró un aumento continuo y brusco hasta los 50 años, luego comenzó a disminuir de manera constante. Se detectó la relación del volumen hepático con el sexo y el índice de masa corporal. Se necesitan más estudios para investigar la relación entre la etnia y los grupos etarios.

Application of liver volumetry in hepatectomy / 中华肝胆外科杂志

Liver volume can reflect the change of parenchyma volume and functional reserve of liver.Liver volumetry is commonly achieved by imaging methods such as ultrasound,CT and MRI,while CT volumetry is most commonly used in clinical practice.This article discussed the decision making among different liver volumetry methods and associated applications in hepatectomy.

Comparison of remnant to total functional liver volume ratio and remnant to standard liver volume ratio as a predictor of postoperative liver function after liver resection

BACKGROUNDS/AIMS: The future liver remnant (FLR) is usually calculated as a ratio of the remnant liver volume (RLV) to the total functional liver volume (RLV/TFLV). In liver transplantation, it is generally accepted that the ratio of the graft volume to standard liver volume (SLV) needs to be at least 30% to 40% to fit the hepatic metabolic demands of the recipient. The aim of this study was to compare RLV/TFLV versus RLV/SLV as a predictor of postoperative liver function and liver failure. METHODS: CT volumetric measurements of RLV were obtained retrospectively in 74 patients who underwent right hemihepatectomy for a malignant tumor from January 2010 to May 2013. RLV and TFLV were obtained using CT volumetry, and SLV was calculated using Yu's formula: SLV (ml)=21.585 x body weight (kg)0.732 x height (cm)0.225. The RLV/SLV ratio was compared with the RLV/TFLV as a predictor of postoperative hepatic function. RESULTS: Postheptectomy liver failure (PHLF), morbidity, and serum total bilirubin level at postoperative day 5 (POD 5) were increased significantly in the group with the RLV/SLV 30% (p=0.002, p=0.004, and p<0.001, respectively). But RLV/TFLV was not correlated with PHLF and morbidity (p=1.000 and 0.798, respectively). RLV/SLV showed a stronger correlation with serum total bilirubin level than RLV/TFLV (RLV/SLV vs. RLV/TFLV, R=0.706 vs. 0.499, R2=0.499 vs. 0.239). CONCLUSIONS: RLV/SLV was more specific than RLV/TFLV in predicting the postoperative course after right hemihepatectomy. To determine the safe limit of hepatic resection, a larger-scaled prospective study is needed.