Liver Volume Measurement

AnalyzeAVW Volume Renderer. To improve liver segmentation at later time points, follow-up scans can be registered to the baseline scans (Hajnal et al. 1995). 

One possible confound for this experiment is that liver weight changes by up to 15 % during the day as glycogen levels drop (Latour et al. 1999) and so care must be taken in longitudinal studies that animals are always imaged at the same time of day to reduce within animal variance. In addition, care must be exercised with the choice of anaesthetic as anaesthetics such as halothane are hepatotoxic and may influence the outcome of the study when there are several imaging sessions. 

---

Kwon, A.H., Matsui, Y., Ha-Kawa, S.K., Kamiyama, Y. Eunctional hepatic volume measured by technetium-99m-galactosyl-human serum albumin liver scintigraphy comparison between hepatocyte volume and liver volume by computed tomography. Amer. J. Gastroenterol. 2001 96 541-546... 

Activity depends on the body surface area (BSA) and the extent of tumor liver involvement. BSA in square meters was calculated using standard nomograms. Tumor liver involvement was measured on CT or MRI. The activity was then calculated using the formula Activity (GBq) = (BSA - 0,2) + (tumor volume/total liver volume). The calculated activity was reduced for patients with lung shunt from 10% to 20% and treatment was contraindicated if the lung shunt was higher than 20%. For those patients receiving lobar therapy, the activity could be reduced proportionally to the relative volume of the treated lobe compared to whole liver volume. 

At our institution preoperative evaluation of potential liver donors is performed using a multi-phasic multidetector CT study that enables accurate assessment of the arterial, portal venous and hepatic venous anatomy and the performance of volume measurements. Oral milk or water (500 ml) is used to opacify the proximal bowel other negative oral contrast mediums (e.g., Volumen, EZEM) can be alternatively used. After a non-intravenously enhanced scan is performed, non-ionic intravenous contrast material (200 ml) is administered. Acquisition timing is guided by bolus tracking in the aorta (enhancement threshold 200 HU) early arterial scan is initiated when the threshold is reached, then a venous (late portal-early venous) scan is initiated with a 60-s delay from threshold a delayed acquisition is performed after 3 min. 

Fig. 4.2.40a-c. Liver regeneration. The accurate volume measurements performed on the MIP reconstructions of the CT angiogram show the regeneration of the left liver lobe (c) after right lobe donation (a, b preoperative volume measurements)... 

Figure 3. Time course of Na+ binding to the exterior surface ( , gill and body combined) of 10 g rainbow trout compared with uptake into the entire plasma volume (O) or whole livers ( ) of the fish. Na+ uptake into the liver is also normalised to 0.325 g of fresh liver weight (A) to enable a direct comparison with the blood volume of the 10 g fish (0.325 ml, see Gingerich and Pityer [87]). Fish were dipped in 500 ml fresh water containing 0.2 mmol l 1Na+ and 10 p,Ci of 22Na+ (see [30] for other water-quality details), and then rinsed in 30 1 of unlabelled freshwater for 15 s to remove excess radio-isotope. Data are means S.E. (n = 6 fish). Note that Na+ measurements in/on tissues are absolute amounts in nmoles, not concentration units...

Figure 2. Distribution of marker enzymes and DEHP-metabolizing enzymes in trout liver homogenate fractions. DEHP esterase and DEHP oxidase were each measured by 1-hr incubations of 0.010 ftmol of UC-DEHP in a total volume of 2 mL. Fraction (A), 2,000 g pellet (B), 10,000 g pellet (C), 100,000 g pellet and (D), 100,000 g supernatant. Relative Specific Activity = percent of total activity/ percent of total protein (14).

Clearance is a measure of the volume of plasma that is cleared of drug per unit time (see Chapter 3). The total clearance for most drugs is the sum of clearances via excretion by the kidneys and metabolism by the liver. In planning a detoxification strategy, it is important to know the contribution of each organ to total clearance. For example, if a drug is 95% cleared by liver metabolism and only 5% cleared by renal excretion, even a dramatic increase in urinary concentration of the drug will have little effect on overall elimination. 

---