No delayed imaging or CCK administration is needed in most cases when bowel excretion does not occur but gallbladder fills promptly.

OBJECTIVE: On hepatobiliary scintigraphy, "preferential gallbladder (GB) filling without tracer excretion into the small bowel (SB) [p-GB-no-SB]" is occasionally seen on images obtained up to an hour. In such cases, many practitioners administer cholecystokinin (CCK) (even when the measurement of GB ejection fraction is not indicated) or obtain delayed images (DI) to exclude common bile duct (CBD) obstruction. We aimed (1) to assess the prevalence of clinically relevant CBD obstruction found by CCK administration or DI in this circumstance and (2) to find imaging findings and/or parameters that can be used to triage patients who do or do not need such maneuvers. METHODS: Of 1244 scans reviewed, 1089 were excluded because of one or more of the following reasons: SB visualized within 60 min, GB not visualized within 60 min, severely decreased hepatic function, and less than 1 month of clinical follow-up after scanning. The remaining 155 showed p-GB-no-SB with clinical follow-up available for ≥ 1 month. For the 155 scans, clearance of liver parenchymal activity was assessed. RESULTS: Of the 155 scans, 142 showed visually prompt clearance of liver parenchymal activity (group A), while 13 scans showed mild to moderately delayed clearance of liver parenchymal activity with or without initial decreased hepatic uptake (group B). 134 of 142 in group A had additional imaging (99 CCK or 35 DI); all 134 showed SB visualization. Eight remaining scans were terminated without additional imaging. None of the 142 had any event attributable to CBD obstruction on follow-up. All 13 in group B had additional imaging (9 CCK, 4 DI); SB visualized in 11, but not in two; clinical follow-up revealed no CBD obstruction in 11. ERCP revealed CBD obstruction in the latter two. CONCLUSIONS: When a HIDA scan shows p-GB-no-SB, the probability of identifying clinically relevant CBD obstruction by additional imaging with CCK or DI is virtually zero in an acute clinical setting if clearance of liver parenchymal activity is prompt. Additional imaging with CCK or DI can be reserved for only those showing abnormal clearance of liver parenchymal activity.

Detection of a suspected bronchobiliary fistula by hepatobiliary scintigraphy.

Bronchobiliary fistula (BBF) represents a rare but severe complication in patients affected by liver metastases. Although a clinical suspicion can arise when specific clinical signs, in particular biliptysis, are present, conventional imaging modalities often fail to confirm the diagnosis. We present a case of a patient affected by colon cancer with liver metastases previously treated with partial right-sided hepatectomy and multiple thermo-ablative treatments combined with chemotherapy, who manifested a septic fever associated with productive cough and biliptysis. Diagnosis of BBF was confirmed only by hepatobiliary scintigraphy with (99m)Tc-heptoiminodiacetic acid.

In vivo imaging of hepatobiliary transport function mediated by multidrug resistance associated protein and P-glycoprotein.

Multidrug resistance associated proteins (MRPs) and P-glycoprotein (P-gp) are involved in hepatobiliary transport of various compounds. Our aim was (1) to define transporter specificity of the cholescintigraphic agents 99mTc-HIDA and 99mTc-MIBI, which are used clinically for myocardial perfusion measurements; and (2) to deduce MRP and P-gp functions in vivo from hepatic 99mTc kinetics. Accumulation of radioactivity was measured in the human tumor cell lines GLC4, GLC4/ADR150x (MRP1-overexpressing/P-gp-negative) and GLC4/P-gp (P-gp-overexpressing). Bile secretion was quantified in untreated and in glutathione-depleted control and MRP2-deficient (GY/TR-) rats. Hepatobiliary transport was measured using a gamma camera in both types of rats. 99mTc-HIDA accumulated 5.8-fold less in GLC4/ADR150x calls than in GLC4 or GLC4/P-gp cells. In GLC4/ADR150x, the cellular 99mTc-HIDA content was increased 3.4-fold by the MRP1,2 inhibitor MK571 (50 microM), while MK571 had no measurable effect in GLC4 and GLC4/P-gp cells. 99mTc-MIBI accumulated less in GLC4/P-gp and GLC4/ADR150x cells than in GLC4 cells. Bile secretion of 99mTc-HIDA was impaired in GY/TR- compared to control rats and not affected by glutathione depletion in GY/TR- rats. Hepatic secretion of 99mTc-HIDA was slower in GY/TR- (t1/2 40 min) than in control rats (t1/2 7 min). Bile secretion of 99mTc-MIBI was similar in both rat strains and impaired by glutathione depletion in control rats only, indicating compensatory activity of additional transporter(s) in GY/TR- rats. 99mTc-HIDA is transported only by MRP1,2 only, while 99mTc-MIBI is transported by P-gp and MRP1,2. The results indicate that hepatic P-gp and MRP1,2 function can be assessed in vivo by sequential use of both radiopharmaceuticals.

The value of radionuclide studies in children with autosomal recessive polycystic kidney disease.

PURPOSE: To describe and analyze the appearances of autosomal recessive polycystic kidney disease (ARPKD) on Tc-99m DMSA and Tc-99m HIDA scintigraphy. MATERIALS AND METHODS: The authors evaluated scintigraphic findings for 13 boys and 9 girls (age range, 2 months to 22.75 years; mean, 7.5 years) with ARPKD. Fourteen children underwent Tc-99m DMSA and 20 underwent Tc-99m HIDA scintigraphy according to European guidelines. Kidney outline, internal structure, tracer uptake, and differential function were analyzed on Tc-99m DMSA images, whereas relative liver lobe sizes, hepatocyte tracer uptake, time to peak, and excretion into the biliary tree and gut were evaluated on Tc-99m HIDA scans. RESULTS: On Tc-99m DMSA images, loss of kidney outline and internal structure was seen in 75% of the scans, and patchy tracer uptake with focal defects throughout the kidneys, particularly at the poles, was evident in 93%. In 85% of the cases, the Tc-99m DMSA changes did not correlate with the ultrasonographic findings where the kidneys are uniformly affected. Characteristic findings on Tc-99m HIDA scans were enlarged left liver lobe in 80%, a delay in maximal hepatocyte uptake in 68%, delayed tracer excretion into the biliary tree in 32% (with stasis in the prominent intrahepatic biliary ducts in 50% or pooling into the segmentally dilated biliary ducts in 25%), and delayed excretion into the gut in 40% of patients. CONCLUSIONS: In a child with clinically enlarged kidneys that appear diffusely hyperechoic on ultrasound, the appearances on Tc-99m DMSA imaging strongly support the diagnosis of ARPKD. The Tc-99m HIDA findings, especially of an enlarged left lobe of the liver with bile stasis or dilatation, further support the diagnosis.