99mTc-mebrofenin Hepatobiliary Scintigraphy Research Articles

Hepatobiliary scintigraphy to evaluate liver function and short-term outcome for patients undergoing major liver resection

Introduction: While post hepatectomy liver failure (PHLF) was shown to be accurately predicted by liver volumetry based on computed tomography (CT), the role of 99mTc-mebrofenin hepatobiliary scintigraphy is not well assessed. Methods: Patients who underwent hepatectomy of ≥4 Couinaud's segments at the University Medical Center Freiburg in 2017 were analyzed. 99mTc-mebrofenin hepatobiliary scintigraphy and liver volumetry based on CT of the future liver remnant (FLR) were performed preoperatively. A FLR < 20% for healthy livers and < 30% for previously injured livers was determined insufficient to maintain an adequate liver function. The impact of estimated liver function vs CT volumetry on short-term outcome was analyzed. PHLF was defined acording to PeakBil >7 mg/dl, the “50:50 criteria” and ISGLS classification. Results: The study included 20 patients. One patient underwent ALLPS procedure due to an insufficient FLR and liver function. However, critical liver function (< 2.7 %/min/m2) was observed in 15 patients (75%). 5 patients (25%) developed ISGLS-defined PHLF (2 patients grade A, 3 patients grade B), including 4 patients (20%) with PeakBil >7 mg/dl. Of these, 3 patients showed critical preoperative liver function but only one had an insufficient FLR. Postoperative complications according to Dindo-Clavien ≥ IIIb occurred in 3 patients (15%), 30-day mortality was 0%. Conclusion: 99mTc-mebrofenin hepatobiliary scintigraphy may be a helpful tool to improve the estimation and accuracy of PHLF prediction, but the impact still remains unclear. Therefore further investigations are necessary.

The measured hepatic function increase after portal vein embolization measured by 99mTc-mebrofenin hepatobiliary scintigraphy is not attributed by an increased microvascular blood flow

Introduction: Patients scheduled for major liver resection and found unresectable due to insufficient FRL function and volume can undergo portal vein embolization (PVE) to increase resectability. Hereby inducing hypertrophy in the non-embolized lobe with concomitant atrophy in the embolized lobe. The functional gain of the FRL can be assessed with hepatobiliary scintigraphy (HBS). The aim of this study is to determine whether the measured increase in FRL function is the result of an increased hepatic microvascular flow, rather than solely an increase in functional mass by assessing the microcirculatory parameters of both lobes. Methods: Eight patients were included. FRL function was assessed with HBS before and after PVE. During resection, the hepatic microcirculation was assessed with intravital handheld microscope (Cytocam) in both the embolized and non-embolized lobe. Microvascular density parameters (respectively total vascular density (TVD) and perfused vessel density (PVD)) and flow parameters (respectively proportion of perfused vessels (PPV) and red blood cell velocity (RBCv)) were measured. Results: Three weeks after PVE, there was a significant increase function of the non-embolized lobe (P < 0.01). Subsequently, for the microvascular parameters, the non-embolized lobe showed a significantly higher microvascular density (TVD, P < 0.001 and PVD, P < 0.001), without differences in the microvascular flow (PPV, P = 0.43 and RBCv, P = 0.32). Conclusion: This increase in measured hepatic function with HBS after PVE is not attributed by an increase in hepatic microvascular blood flow. This indicates that the measured hepatic function after PVE reflects the increase in hepatic function.

Abstract No. 540 Correlation of pretreatment 99mTc-mebrofenin hepatobiliary scintigraphy with clinical status prior to hepatic radioembolization

Abstract No. 540 Correlation of pretreatment 99mTc-mebrofenin hepatobiliary scintigraphy with clinical status prior to hepatic radioembolization

Feasibility of Percutaneous Intrahepatic Split by Microwave Ablation (PISA) After Portal Vein Embolization for Hypertrophy of Future Liver Remnant: The Radiological Stage-1 ALPPS.

To assess the feasibility of radiological stage-1 ALPPS, associating liver partition and portal vein ligation for staged hepatectomy, by combining portal vein embolization (PVE) with percutaneous intrahepatic split by ablation (PISA). Three patients (mean age 65.0±7.3years) underwent PVE and PISA. PISA was performed 21days after PVE by microwave ablation to create a continuous intrahepatic cutting plane. Abdominal CT examinations were performed before and after PVE and PISA. The future liver remnant (FLR) volume was calculated by semiautomatic segmentation, and increase was reported as a percentage of the pre-procedural volume. The FLR/body weight (FLR/BW) ratio was calculated; a ratio greater than 0.8% was considered sufficient for guaranteeing adequate liver function after surgery. The liver function before and after PISA was also evaluated by 99mTc-mebrofenin hepatobiliary scintigraphy. Patients' laboratory tests, performance status, ability to walk were assessed before and after PVE and PISA procedures. No procedure-related complications were recorded. The FLR volume increase in each patient was 42.0, 33.1 and 30.4% within 21days of PVE and 109.3, 68.1 and 71.7% within 10days after PISA. The FLR/BW ratios were 0.76, 0.66, 0.63% and 1.13, 0.83, 0.83% after PVE and PISA procedures, respectively. Two patients underwent successful right hepatectomy; in one patient, despite 1.13% FLR/BW, surgery was not performed because of the absolute rejection of blood transfusion due to the patient's religious convictions. Radiological stage-1 ALPPS is a feasible, minimally invasive option to be further investigated to become an effective alternative to surgical stage-1 ALPPS.

Liver Functional Volumetry by Tc-99m Mebrofenin Hepatobiliary Scintigraphy before Major Liver Resection: A Game Changer.

Future remnant liver function (FRL-F) estimation is important before major liver resection to avoid posthepatectomy liver failure (PHLF). Conventionally, it is estimated by global dynamic liver function tests which assume homogeneous liver function and unable to calculate regional function. Computed tomography is another method to estimate FRL volume but assumes that volume is equivalent to function. Hence, a global and regional non-invasive liver function test is desirable. Studies were identified by MEDLINE, PubMed, and Google Scholar for articles from January 1990 to December 2017 using the following keywords “Mebrofenin, hepatobiliary scintigraphy (HBS), FRL-F, PHLF, portal vein embolization (PVE).” HBS with technetium-99 m galactosyl human serum albumin (Tc-99m GSA) and Tc-99m Mebrofenin is a known test for functional liver assessment. Restricted availability of Tc-99m GSA only in Japan is a main drawback for its global acceptance. However, Tc-99m Mebrofenin is routinely available to the rest of the world. A unique protocol for FRL-F estimation by Tc-99m Mebrofenin is described in detail in this review. Tc-99m Mebrofenin HBS has shown a strong correlation to 15 min indocyanine green clearance. HBS has been reported better in predicting the risk of PHLF with a 2.69%/min/m2 cutoff of FRL-F. Tc-99m Mebrofenin HBS has been found better in stratification of PVE before major liver surgery as well. We concluded, Tc-99m Mebrofenin HBS was unique in calculating global and regional liver function and takes nonuniformity and underlying pathology in the account. Moreover, a single cutoff might fit in all for PHLF risk assessment and PVE stratification.

Functional shift with maintained regenerative potential following portal vein ligation

Selective portal vein ligation (PVL) allows the two-stage surgical resection of primarily unresectable liver tumours by generating the atrophy and hypertrophy of portally ligated (LL) and non-ligated lobes (NLL), respectively. To evaluate critically important underlying functional alterations, present study characterised in vitro and vivo liver function in male Wistar rats (n = 106; 210–250 g) before, and 24/48/72/168/336 h after PVL. Lobe weights and volumes by magnetic resonance imaging confirmed the atrophy-hypertrophy complex. Proper expression and localization of key liver transporters (Ntcp, Bsep) and tight junction protein ZO-1 in isolated hepatocytes demonstrated constantly present viable and well-polarised cells in both lobes. In vitro taurocholate and bilirubin transport, as well as in vivo immunohistochemical Ntcp and Mrp2 expressions were bilaterally temporarily diminished, whereas LL and NLL structural acinar changes were divergent. In vivo bile and bilirubin-glucuronide excretion mirrored macroscopic changes, whereas serum bilirubin levels remained unaffected. In vivo functional imaging (indocyanine-green clearance test; 99mTc-mebrofenin hepatobiliary scintigraphy; confocal laser endomicroscopy) indicated transitionally reduced global liver uptake and -excretion. While LL functional involution was permanent, NLL uptake and excretory functions recovered excessively. Following PVL, functioning cells remain even in LL. Despite extensive bilateral morpho-functional changes, NLL functional increment restores temporary declined transport functions, emphasising liver functional assessment.

Estimation of the future remnant liver function is a better tool to predict post-hepatectomy liver failure than platelet-based liver scores

IntroductionRecently, there has been increasing interest in the preoperative prediction and prevention of post-hepatectomy liver failure (PHLF). This is a particular concern in colorectal liver metastases (CRLM), when surgery follows potentially hepatotoxic chemotherapy. Platelet-based liver scores (PBLS) such as APRI and FIB-4 are predictive of chemotherapy-associated liver injury (CALI) and PHLF. Estimation of the future liver remnant function (eFLRF) by combining 99mTc-Mebrofenin Hepatobiliary Scintigraphy (HBSBSA) with future liver remnant volume ratio (FLRV%), is predictive of PHLF and related mortality. We hypothesized that a HBSBSA based formula was a better predictor for PHLF than PBLS in chemotherapy-pretreated CRLM. MethodsBetween 2012 and 2016, 140 patients underwent liver resection for CRLM following systemic therapy. HBSBSA, FLRV%, eFLRF and PBLS were calculated and compared for their value in predicting PHLF. ResultseFLRF and FLRV% had a better predictive value for PHLF than HBSBSA alone and APRI and FIB-4 (AUC = 0.800, 0.843 versus 0.652, 0.635 and 0.658 respectively). In a subgroup analysis (Oxaliplatin all, Oxaliplatin ≥ 6 cycles, Irinotecan all and Irinotecan ≥ 6 cycles), eFLRF was the only factor predictive for PHLF in all subgroups (all: p ≤ 0.05). Prediction of HBSBSA for chemotherapy associated steato-hepatitis (CASH) reached almost significance (p = 0.06). FIB-4 was predictive for sinusoidal obstruction syndrome (SOS) (p = 0.011). Only weak correlation was found between HBSBSA and PBLS. ConclusioneFLRF is a better predictor of PHLF than PBLS or HBSBSA alone. PBLS seem to measure other aspects of liver function or damage than HBSBSA.

99mTc-mebrofenin hepatobiliary scintigraphy predicts liver failure following major liver resection for perihilar cholangiocarcinoma

BackgroundPosthepatectomy liver failure (PHLF) is a threatening complication after liver surgery, especially in perihilar cholangiocarcinoma (PHC). This study aimed to assess the value of preoperative assessment of liver function using 99mTc-mebrofenin hepatobiliary scintigraphy (HBS) to predict PHLF in comparison with liver volume in PHC patients. MethodsAll patients who underwent resection of suspected PHC in a single center between 2000 and 2015 were included in the analysis. PHLF was graded according to the ISGLS criteria with grade B/C considered clinically relevant. A cut-off value for the prediction of PHLF was calculated using the receiver operating characteristic curve (ROC) analysis. ResultsA total of 116 patients were included of which 27 (23%) suffered of PHLF. ROC values for the prediction of PHLF were 0.74 (0.63–0.86) for future liver remnant function and 0.63 (0.47–0.80) for volume. A cut-off for liver function was set at 8.5%/min, which resulted in a negative predictive value of 94% and positive predictive value of 41%. ConclusionsAssessment of liver function with HBS had better predictive value for PHLF than liver volume in patients undergoing major liver resection for suspected PHC. The cut-off of 8.5%/min can help to select patients for portal vein embolization and might help to reduce postoperative liver failure.

Gallbladder Ejection Fraction and Sphincter of Oddi Dysfunction in Acute Idiopathic and Acute Recurrent Pancreatitis in Children

Background and Aim: Gallbladder (GB) dysfunction leading to biliary sludge formation and sphincter of Oddi dysfunction (SOD) are the important causes of idiopathic acute pancreatitis (idiopathic AP) and acute recurrent pancreatitis (ARP) in adults. However, this is not investigated in children. We prospectively evaluation for gallbladder (GB) dysfunction and sphincter of Oddi dysfunction (SOD) in children with idiopathic and recurrent AP. Methods: All consecutive patients of idiopathic AP and ARP underwent 99mTc Mebrofenin Hepatobiliary Scintigraphy with intravenous tracer injection for 1 h. Subsequent premeal and postmeal static images following standard fatty meal administration were acquired up to 4 h for maximum gallbladder ejection fraction (GBEF) and hold up of radiotracer in the CBD. GBEF ≤ 35% is considered abnormal. Results: At total of 14 AP (male 50%) and 20 ARP (male 45%) patients underwent scintigraphy. Over all 11.7% (4 of 34) of the patients had poor GB contraction. The mean ± SD of GBEF in AP and ARP were 55.45 ± 24.05 and 56.10 ± 16.92 respectively. In AP and ARP groups, 21.4% (3 of 14) and 5% (1 of 20) had GB dysfunction (GBEF≤35%) respectively. There were no confirmed cases of sphincter of Oddi dysfunction (SOD). There was no stone or sludge in 4 patients with low GBEF. Conclusion: Among AP and ARP, 11.7% of patients had poor GB contraction. There was no sludge, microlithiasis or GB stone in patients with poor GBEF. The authors have none to declare.

Future remnant liver function as predictive factor for the hypertrophy response after portal vein embolization

Preoperative portal vein embolization is widely used to increase the future remnant liver. Identification of nonresponders to portal vein embolization is essential because these patients may benefit from associating liver partition and portal vein ligation for staged hepatectomy (ALPPS), which induces a more powerful hypertrophy response. 99mTc-mebrofenin hepatobiliary scintigraphy is a quantitative method for assessment of future remnant liver function with a calculated cutoff value for the prediction of postoperative liver failure. The aim of this study was to analyze future remnant liver function before portal vein embolization to predict sufficient functional hypertrophy response after portal vein embolization. Sixty-three patients who underwent preoperative portal vein embolization and computed tomography imaging were included. Hepatobiliary scintigraphy was performed to determine pre-portal vein embolization and post-portal vein embolization future remnant liver function. Receiver operator characteristic analysis of pre-portal vein embolization future remnant liver function was performed to identify patients who would meet the post-portal vein embolization cutoff value for sufficient function (ie, 2.7%/min/m2). Mean pre-portal vein embolization future remnant liver function was 1.80%±0.45%/min/m2 and increased to 2.89%±0.97%/min/m2 post-portal vein embolization. Receiver operator characteristic analysis in 33 patients who did not receive chemotherapy revealed that a pre-portal vein embolization future remnant liver function of ≥1.72%/min/m2 was able to identify patients who would meet the safe future remnant liver function cutoff value 3weeks after portal vein embolization (area under the curve=0.820). The predictive value was less pronounced in 30 patients treated with neoadjuvant chemotherapy (area under the curve=0.618). A total of 45 of 63 patients underwent liver resection, of whom 5 of 45 developed postoperative liver failure; 4 of 5 patients had a post-portal vein embolization future remnant liver function below the cutoff value for safe resection. When selecting patients for portal vein embolization, future remnant liver function assessed with hepatobiliary scintigraphy can be used as a predictor of insufficient functional hypertrophy after portal vein embolization, especially in nonchemotherapy patients. These patients are potential candidates for ALPPS.

Hepatic parenchymal transection increases liver volume but not function after portal vein embolization in rabbits

Associating liver partition with portal vein ligation for staged hepatectomy induces more extensive liver hypertrophy than ligation alone; however, the mechanisms underlying the accelerated liver regrowth and the functional quality of the hypertrophic liver are presently elusive. This study, therefore, investigated the effect of parenchymal transection on liver volume and function after portal vein embolization in a standardized rabbit model. Twelve rabbits were subjected to portal vein embolization of the cranial liver lobes and randomized between parenchymal transection of the left lateral liver lobe versus no transection (portal vein embolization only). Liver volume of the nonembolized liver lobe was assessed using computed tomography-volumetry, and liver uptake function was determined by 99mTc-mebrofenin hepatobiliary scintigraphy before and 3 and 7days after portal vein embolization. The increase in nonembolized liver volume 3days after portal vein embolization was 2.7-fold greater in the transected group compared with the portal vein embolization only group (56 ±16% vs 21 ±12%, respectively, P<.01) and 1.7-fold greater 7days after portal vein embolization (113 ±34% vs 68 ±24%, P<.01). Liver uptake function did not differ between groups before portal vein embolization (8.4 ±3.7%/min in the transection group vs 8.9 ±1.6%/min) on day 3 (33.2 ±4.7% after transection vs 30.3 ±4.6%/min, respectively) and day 7 after portal vein embolization (42.6 ±8.4% vs 39.1 ±5.3%/min, respectively). Parenchymal transection after portal vein embolization increases liver growth in terms of volume but not function. These results indicate that the rapid volume increase observed after associating liver partition with portal vein ligation for staged hepatectomy does not coincide with the clinically more relevant functional increase. Quantitative liver function tests might be essential in associating liver partition with portal vein ligation for staged hepatectomy to better assess the hypertrophy response and improve clinical decision-making.

Liver function declines with increased age

IntroductionAge itself is not considered a contraindication for high impact surgery. However, the aging process of the liver remains largely unknown. This study evaluates age-dependent changes in liver function using a quantitative liver function test. MethodsBetween January 2005 and December 2014, 508 patients underwent 99mTc-mebrofenin hepatobiliary scintigraphy (HBS) for the assessment of liver function. These included 203 patients with healthy livers (group A) and 57 patients with HCC and Child-Pugh A (group B). 99mTc-mebrofenin-uptake-rate of the whole liver corrected for body surface area (cMUR) was calculated for all patients. Linear regression analysis was performed to assess the relationship between age and cMUR. ResultsThe mean cMUR was 8.50 ± 2.05%/min/m2 and 6.94 ± 2.03%/min/m2 in group A and B, respectively. A negative linear correlation was found between patient's age and cMUR in group A, r = 0.244, p = 0.000. In group B, there was no correlation between age and cMUR, however, a trend in decline of liver function with age was noted. ConclusionThis study shows that liver function deteriorates with age. Since the regenerative capacity of the liver correlates with liver function, this finding should be taken into account when assessing surgical risk in patients considered for major liver resection.

Future remnant liver function estimated by combining liver volumetry on magnetic resonance imaging with total liver function on 99mTc-mebrofenin hepatobiliary scintigraphy: can this tool predict post-hepatectomy liver failure?

IntroductionPosthepatectomy liver failure (PHLF) is a major complication after hepatectomy with a high mortality rate and is likely to happen in insufficient liver remnant. We hypothesize that assessment of the estimated future liver remnant function (eFLRF), combining future remnant liver volume (FLRV) with total liver function (TLF), is an accurate formula for prediction of PHLF. Methods88 patients undergoing hepatectomy were included. The ratio of the future liver remnant volume (FLRV%) was measured on MRI. TLF was estimated by liver clearance of 99mTechnetium (Tc)-mebrofenin on hepatobiliary scintigraphy (HBS). eFLRF was calculated by multiplying FLRV% by TLF. Cut-off values of FLRV% and eFLRF predicting PHLF, were defined by receiver-operating-characteristic (ROC) analysis. ResultsPHLF occurred in 12 patients (13%). Perioperative mortality was 5/12 (41%). Multivariate analysis showed that FLRV% cut off at 40% was not an independent predictive factor. eFLRF cut off at 2.3%/min/m2 was the only independent predictive factor for PHLF. For FLRV% vs. eFLRF, positive predictive value was 41% vs. 92% and Odds Ratio 26 vs. 836. ConclusionFRLF measured by combining FLRV% and TLF is a more valuable tool to predict PHLF than FLRV% alone. The cutoff of eFLRF can be used in clinical decision making.

Potential Pitfalls on the (99m)Tc-Mebrofenin Hepatobiliary Scintigraphy in a Patient with Biliary Atresia Splenic Malformation Syndrome.

Biliary atresia (BA) is an obliterative cholangiopathy affecting 1:10.000–14.000 of newborns. Infants with Biliary Atresia Splenic Malformation syndrome (BASM) are a subgroup of BA patients with additional congenital anomalies. Untreated the disease will result in fatal liver failure within the first years of life. Kasai portoenterostomy restores bile flow and delay the progressive liver damage thereby postponing liver transplantation. An early diagnosis is of most importance to ensure the effectiveness of the operation. The 99mTc-Mebrofenin hepatobiliary scintigraphy is part of the diagnostic strategy when an infant presents jaundice due to conjugated hyperbilirubinemia (>20 µmol/L total bilirubin of which 20% is conjugated) with its high sensitivity of 97%–100% in refuting BA. Rapid extraction of tracer by the liver and no visible tracer in the small bowl after 24 h is indicative of BA. Laparotomy with antegrade cholangiography is then performed giving the final diagnosis when the remains of the obliterated biliary tree are revealed in the case of BA. We present a case demonstrating some of the challenges of interpreting the 99mTc-Mebrofenin hepatobiliary scintigraphy in an infant with BASM and stress the importance that the 99mTc-Mebrofenin hepatobiliary scintigraphy is part of a spectrum of imaging modalities in diagnosing BA.

Évaluation des reproductibilités inter- et intra-observateurs de la mesure du futur foie restant par tomoscintigraphie hépato-biliaire à la 99mTc-mébrofénine avant hépatectomie majeure

PurposePerformances of 99mTc-mebrofenin hepatobiliary scintigraphy (HBS) are currently evaluated before major hepatic resection for early detection of liver failure in high risk patients. Published studies included small numbers of patients with planar scintigraphy, and more recently SPECT data. Our aim was to evaluate intra- and interobserver reproducibility of HBS in planar and SPECT modalities for functional assessment of the future remnant liver (FRL) before major hepatic resection. We also evaluated the impact of potential variability factors such as biliary excretion and isocontour threshold choice. MethodsAll the scans were processed twice by three observers. Two regions of interest were drawn around total liver (TL) and FRL, on the planar dataset and with a threshold based algorithm on SPECT after registration with contrast-enhanced CT. Intra- and interobserver reproducibility of the FRL/TL ratio were calculated. When biliary excretion was already visible on SPECT acquisition, it was corrected and the ratio compared before and after correction. The results were also compared between different thresholds of the maximum liver value (−4%, −2%, +2%, +4% of the optimal threshold chosen by the observer). ResultsThirty patients were included. The intraobserver reproducibility was good (R2=0.847, 0.830 and 0.966) when calculated on planar modality and better with SPECT (R2=0.957, 0.962 and 0.984). There was no significant difference after biliary excretion correction (P=0.29, P=0.99 and P=0.61 for the three observers). The threshold modification caused significant but minor differences (1% on average) for the evaluated thresholds. ConclusionsThe FRL functional evaluation with HBS including a SPECT acquisition provides a reproducible assessment, hardly affected by potential variability factors, allowing its use in multicentric studies.

Optimized separation of left and right liver lobe in dynamic 99mTc-mebrofenin hepatobiliary scintigraphy using a hybrid SPECT-CT scanner

To correctly display the left and right liver lobe separately on dynamic projection scintigraphy, it is essential to adjust the collimator to the angle of the plane between the two liver lobes. We propose an optimized protocol for separating left and right liver lobe in (99m)Tc-mebrofenin hepatobiliary scintigraphy in a hybrid SPECT-CT device. The protocol uses the inherent attenuation correction low-dose CT (AC-CT) for individually adjusting gamma camera head angulation. The results of this protocol are compared with hypothetical results based on previous MRI, fixed angle, and traditional frontal projection. The absolute and relative degrees of overlapping volume between left and right liver lobe parenchyma for frontal projection, 45° right anterior oblique (RAO) projection, RAO angulation based on previously acquired MRI, and RAO based on the AC-CT were measured in 14 patients who underwent (99m)Tc-mebrofenin hepatobiliary scintigraphy. Relative degree of overlap was 31.3±15.2% for frontal projection, 8.2±6.5% for 45° RAO, 5.5±3.5% for RAO based on previous MRI, and 3.6±2.5% for RAO based on AC-CT. The relative overlap of RAO projections based on previous MRI was significantly lower than for frontal projection (p<0.05). Use of the angle from the prior AC-CT, however, resulted in an even lower degree of overlap (p<0.05). Performing (99m)Tc-mebrofenin hepatobiliary scintigraphy using RAO detector alignment with an angle derived from a prior CT obtained in the SPECT-CT scanner can significantly reduce the degree of overlap between right and left liver lobe. If SPECT-CT is not available, previous CT or MRI or a fixed angle of 45° may be used.

Biliary Flow in Septate Gallbladder on Hepatobiliary Scintigraphy with SPECT/CT.

Septate gallbladder is in the shape of an hourglass and is characterised by the presence of a transversely oblique septum that separates the gallbladder fundus from the rest of the body. The septum is most probably congenital in origin and bears a minute to moderate opening that connects the two isolated chambers [1]. Septate gallbladder has not been well documented because it is usually asymptomatic or discovered accidentally during the evaluation of abdominal pain [2]. Ultrasonography, computed tomography, or MRI is usually applied to detect the morphological abnormalities [3], but these modalities have limitations in the delineation of biliary flow or assessment of the function of septate gallbladder. Once the bile has been made visible through radiolabeling with Tc-99m hepatic iminodiacetic acid analogues (Tc-99m mebrofenin), it should theoretically be possible to investigate functional abnormalities associated with bile formation and flow [4]. Recently, the hybrid single-photon emission computed tomography/computed tomography (SPECT/CT) systems have been widely used for improving anatomical certainty in interpretation. Here, we demonstrate a case of the septate gallbladder in which the flow of bile was clearly shown by Tc-99m mebrofenin hepatobiliary scintigraphy with the hybrid SPECT/CT systems (Figs. 1 and ​and22). Fig. 1 A 47-year-old woman complained of intermittent colicky abdominal pain in the right upper quadrant for about a year. Physical examination and laboratory studies (complete blood count, liver function tests, and electrolytes) revealed no abnormalities. Tc-99 m ... Fig. 2 The contrast-enhanced computed tomographic image (a) showed an hourglass-shaped gallbladder with transverse septum. The gallbladder wall of the fundus was evenly thickened by chronic inflammatory change. There were no gallstones or dilatation of the bile ...

Added value of SPECT/CT over planar Tc-99m mebrofenin hepatobiliary scintigraphy in the evaluation of bile leaks

To determine the added value of single-photon emission computed tomography/computed tomography (SPECT/CT) over planar hepatobiliary scintigraphy (HBS) in suspected cases of bile leak. An analysis of the data of all patients who had undergone HBS for suspected bile leak during the last 3 years was carried out. All patients had undergone an initial 45 min dynamic study after an intravenous injection of Tc-99m mebrofenin, following which they underwent multiple static imaging studies for up to 24 h and SPECT/CT imaging whenever needed. A total of 203 patients had undergone an HBS for evaluation of a suspected bile leak. HBS was positive for bile leak in 110 patients, among whom 42 had undergone additional SPECT/CT. In 32 patients SPECT/CT was useful in (i) defining the exact location of collection [intracapsular vs. extracapsular vs. intraparenchymal leak (n=18/25)], (ii) defining the extent of intraparenchymal collections (n=6/6), (iii) characterizing large abdominal collections (n=2/2), and (iv) characterizing suspected contamination (n=4/4), (v) suspected collection (n=0/3), (vi) and other miscellaneous conditions (n=2/2). Defining the extent and exact localization of collection can have therapeutic implications such as the accurate site of placement of the drain for drainage. In approximately one-third of the bile leak-positive HBS studies (32/110), SPECT/CT images were helpful for better characterization of biliary collection. In all, 76% (32/42) of the SPECT/CT studies were found to provide additional useful information over planar imaging. Hybrid SPECT/CT offers the unique advantage of combining the anatomical information from CT with the functional information provided by HBS. It is most useful in characterization of biliary collections, which give important scintigraphic evidence of the severity of bile leak with therapeutic implications such as placement of a drain or surgical exploration.

Preoperative liver function assessments to estimate the prognosis and safety of liver resections

Liver function assessment is important to ensure safe surgical procedures in patients with hepatocellular disease. Because the liver influences a wide variety of functions, including protein synthesis and metabolic, immune and storage functions, no single parameter is sufficient to adequately address all of these functions. We reviewed the relevant literature concerning the scoring systems, functional tests, plasma parameters and imaging modalities currently used to evaluate the liver function in an attempt to determine which parameters provide the most comprehensive and useful results. While the Child-Pugh scoring system is the gold standard for liver disease assessment, the liver damage grading system recommended by the Liver Cancer Study Group of Japan is also useful. Various models for end-stage liver disease scoring are used for organ allocation. While the indocyanine green clearance test is widely accepted throughout the world, other assessments have not been used routinely for clinical evaluations. The levels of plasma proteins, including albumin, prealbumin, retinol binding protein, apolipoprotein, coagulation factors and antithrombin III, represent the liver productivity. Liver fibrotic markers also correlate with liver function. Imaging modalities such as (99m)Tc-galactosyl serum albumin scintigraphy, (99m)Tc-mebrofenin hepatobiliary scintigraphy and transient elastography are also available, but future studies are needed to validate their clinical efficacy.

Physiological and Biochemical Basis of Clinical Liver Function Tests

To review the literature on the most clinically relevant and novel liver function tests used for the assessment of hepatic function before liver surgery. Postoperative liver failure is the major cause of mortality and morbidity after partial liver resection and develops as a result of insufficient remnant liver function. Therefore, accurate preoperative assessment of the future remnant liver function is mandatory in the selection of candidates for safe partial liver resection. A MEDLINE search was performed using the key words "liver function tests," "functional studies in the liver," "compromised liver," "physiological basis," and "mechanistic background," with and without Boolean operators. Passive liver function tests, including biochemical parameters and clinical grading systems, are not accurate enough in predicting outcome after liver surgery. Dynamic quantitative liver function tests, such as the indocyanine green test and galactose elimination capacity, are more accurate as they measure the elimination process of a substance that is cleared and/or metabolized almost exclusively by the liver. However, these tests only measure global liver function. Nuclear imaging techniques ((99m)Tc-galactosyl serum albumin scintigraphy and (99m)Tc-mebrofenin hepatobiliary scintigraphy) can measure both total and future remnant liver function and potentially identify patients at risk for postresectional liver failure. Because of the complexity of liver function, one single test does not represent overall liver function. In addition to computed tomography volumetry, quantitative liver function tests should be used to determine whether a safe resection can be performed. Presently, (99m)Tc-mebrofenin hepatobiliary scintigraphy seems to be the most valuable quantitative liver function test, as it can measure multiple aspects of liver function in, specifically, the future remnant liver.