Usefulness of TC-99M GSA liver scintigraphy for the evaluation of liver regeneration in donors after living-donor liver transplantation.

BACKGROUND AND AIMS: We evaluated the impact of steatosis on regeneration and function of the remnant liver by using technetium-99m-diethylenetriaminepentaacetic acid-galactosyl human serum albumin scintigraphy. METHODS: Twelve living donors were classified into groups with or without mild hepatic steatosis according to the liver-to-spleen attenuation ratio on computed tomography: six donors had a ratio > or = 1.2 (control group) and six had a ratio < 1.20 (fatty liver group). Scintigraphy was performed to determine the hepatic uptake ratio of the tracer (corrected for disappearance from the blood) and the maximum removal rate of the tracer by hepatocytes as parameters of the hepatic functional reserve. RESULTS: The fatty liver group had a significantly lower corrected hepatic uptake ratio and removal rate compared with the control group at 6 and 12 months after partial hepatectomy. The regenerated liver volume estimated by scintigraphy did not differ significantly between the two groups at any time. CONCLUSIONS: Because donors with mild hepatic steatosis showed impaired liver regeneration at 1 year after partial hepatectomy, management of these donors requires more care.

Usefulness of TC-99M GSA liver scintigraphy for the assessment of recurrent hepatitis C after living-donor liver transplantation: a case report.

BACKGROUND AND AIMS: Recurrence of hepatitis C after living-donor liver transplantation was investigated using technetium-99m-diethylenetriaminepentaacetic acid-galactosyl human serum albumin (Tc-99m-GSA) liver scintigraphy. METHODS: A 55-year-old woman with cirrhosis due to chronic hepatitis C virus (HCV) infection underwent liver transplantation with a graft from her husband. Scintigraphy was used to determine the hepatic uptake ratio of the tracer corrected for disappearance from the blood, as well as the maximal removal rate of the tracer by hepatocytes, as parameters of hepatic functional reserve. RESULTS: Conventional liver function parameters and the graft volume (computed tomography) were almost unchanged up to 18 months after transplantation. Serum HCV RNA was elevated from 3 months after transplantation, and was twofold higher at 12 months compared with 6 months. At 18 months postoperatively, liver biopsy showed an increase of histologic activity, and there was also evidence of recurrent hepatitis C. The corrected hepatic uptake ratio and maximal removal rate were decreased at 3 months postoperatively, and thereafter remained low. CONCLUSIONS: The decrease of scintigraphic parameters at 3 months after transplantation suggested recurrent hepatitis C affecting the graft. Tc-99m-GSA liver scintigraphy is a useful noninvasive method for evaluating graft functional reserve.

Diffusion-weighted imaging for predicting new compression fractures following percutaneous vertebroplasty.

BACKGROUND: Percutaneous vertebroplasty (PVP) is a technique that structurally stabilizes a fractured vertebral body. However, some patients return to the hospital due to recurrent back pain following PVP, and such pain is sometimes caused by new compression fractures. PURPOSE: To investigate whether the apparent diffusion coefficient (ADC) of adjacent vertebral bodies as assessed by diffusion-weighted imaging before PVP could predict the onset of new compression fractures following PVP. MATERIAL AND METHODS: 25 patients with osteoporotic compression fractures who underwent PVP were enrolled in this study. ADC was measured for 49 vertebral bodies immediately above and below each vertebral body injected with bone cement before and after PVP. By measuring ADC for each adjacent vertebral body, ADC was compared between vertebral bodies with a new compression fracture within 1 month and those without new compression fractures. In addition, the mean ADC of adjacent vertebral bodies per patient was calculated. RESULTS: Mean preoperative ADC for the six adjacent vertebral bodies with new compression fractures was 0.55 x 10(-3) mm(2)/s (range 0.36-1.01 x 10(-3) mm(2)/s), and for the 43 adjacent vertebral bodies without new compression fractures 0.20 x 10(-3) mm(2)/s (range 0-0.98 x 10(-3) mm(2)/s) (P < 0.001). Mean preoperative ADC for the six patients with new compression fractures was 0.55 x 10(-3) mm(2)/s (range 0.21-1.01 x 10(-3) mm(2)/s), and that for the 19 patients without new compression fractures 0.17 x 10(-3) mm(2)/s (range 0.01-0.43 x 10(-3) mm(2)/s) (P < 0.001). CONCLUSION: The ADC of adjacent vertebral bodies as assessed by diffusion-weighted imaging before PVP might be one of the predictors for new compression fractures following PVP.

Functional hepatic volume measured by technetium-99m-galactosyl-human serum albumin liver scintigraphy: comparison between hepatocyte volume and liver volume by computed tomography.

OBJECTIVES: We investigated the usefulness of measuring the functional hepatic volume by single-photon emission CT with 99m-technetium galactosyl-human serum albumin scintigraphy (GSA-LV). We then compared this value to the total hepatocyte volume and the hepatic volume determined from CT (CT-LV) in the patients with hepatobiliary tumors. METHODS: Forty-seven patients were divided into two groups, the SM group (subsegmentectomy and monosegmentectomy) and the DT group (disegmentectomy and trisegmentectomy). These groups were further divided into subgroups with or without chronic hepatitis or cirrhosis. The GSA-LV, CT-LV, and the total hepatocyte volume were then calculated. The GSA-LV and CT-LV measurements were performed preoperatively, at 2 and 4 wk, and at 3 and 6 months after surgery. RESULTS: The preoperative GSA-LV values were significantly correlated with the hepatocyte volume and the 15-min retention rate of indocyanine green (ICGR15). Similarly, the hepatocyte volume correlated well with the CT-LV and ICGR15. However, the CT-LV was correlated only with the ICGR15. Recovery of the GSA-LV in the DT group was delayed, and about 90% of the volumetric and functional regeneration was observed within 6 months after the hepatectomy. In contrast, the CT-LV of DT group patients with normal liver remnants returned to approximately 90% of their initial volume within 1 month after the hepatectomy, whereas patients with injured livers regenerated gradually and regained approximately 80% of their preoperative value by 6 months after the hepatectomy. CONCLUSIONS: We conclude that the measurement of functional hepatic volume using the GSA-LV is useful in fully evaluating hepatic function based on hepatocyte volume.

Squamous cell carcinoma arising in a mature teratoma with metastasis to the urinary bladder.

We describe a patient with squamous cell carcinoma arising in a mature teratoma. Magnetic resonance (MR) images revealed a solid lobulated mass attached to the ovarian cyst containing a fat-fluid level. The solid component with extension into pelvic fat showed as hypointensity on T2-weighted MR images with good enhancement. A metastatic tumor to the urinary bladder was also demonstrated.

[Nuclear medicine of the liver--focusing on functional diagnosis].

For evaluating the hepatic function, intrinsic substances are influenced by the physiological activity of homeostasis. Potential reduction of the hepatic reserve can be evaluated by the loading of the extrinsic substances. Asialoglycoprotein (ASGP) receptor reduces its activity according to the grade of hepatic parenchymal injury. The quantitative evaluation was possible with 99mTc-galactosyl HSA (99mTc-GSA) using an index of GSARmax by a multi-compartment analysis. The correlation between GSARmax and the histological activity index (HAI) score of the liver in hepatectomized cases was better than that of the ICGR15. A safe limit of GSARmax was 0.3 mg/min for 1 segment excision and 0.35 mg/min for 2 or 3 segment excision. Some cases showed discrepancies between 99mTc-GSA and ICGR15. ICG mainly reflected hepatic blood flow and GSA was related to both the amount of functional hepatocytes and flow. Regional distribution of GSARmax presented functional SPECT image of the liver. Since the scale was common, the comparison were possible between SPECT images in different studies. In reservoir treatment, the injection of 99mTc-MAA in a catheter made it possible to estimate the distribution of the anticancer agent. The incorrect perfusion to the digestive tracts and shunt flow to the lung were monitored, and it was also useful to predict the therapeutic effect.

Dual radionuclide single-photon emission computed tomography in the prediction of further ischemic risk after acute myocardial infarction.

To evaluate whether the findings of dual single-photon emission computed tomography (SPECT) with technetium-99m pyrophosphate (Tc-99m PPi) and thallium-201 were predictive of further cardiac events in their hospital course, we studied 130 patients recovering from acute myocardial infarction (AMI). Fifty-four patients showed overlapping of Tc-99m PPi and thallium-201 in the same location (overlap positive group), and 76 patients had no overlap (overlap negative group). Of the 130 patients, 36 (28%) had a cardiac event. In patients in the overlap positive group, the incidence of subsequent events was significantly higher than in patients in the overlap negative group (44% versus 16%; p < 0.001). In the overlap positive group, the Tc-99m PPi uptake score and the number of overlap segments in patients with further events was significantly higher than those in patients without further events (10.2 +/- 5.1 versus 6.4 +/- 4.1, p < 0.005 and 5.2 +/- 2.0 versus 3.3 +/- 1.3, p < 0.001, respectively). These results suggest that patients who have a Tc-99m PPi and thallium-201 overlap negative scan can be candidates for early hospital discharge. In contrast, patients who have a greater number of overlap segments may require early catheterization and revascularization, so that simultaneous SPECT imaging Tc-99m PPi and thallium-201 might be useful for identifying patients with further ischemic risk after AMI in their hospital course.

Increased technetium-99m-GSA uptake per hepatocyte in rats with administration of dimethylnitrosamine or hepatocyte growth factor.

UNLABELLED: Technetium-99m-diethylenetriaminepentaacetic acid-galactosyl-human serum albumin (GSA) is a new scintigraphic agent that binds specifically to asialoglycoprotein receptors on hepatocytes, and can be used to evaluate hepatic function. Asialoglycoprotein receptor is a hepatocellular membrane receptor responsible for the endocytosis of asialoglycoproteins, and the function of this receptor is affected in various disease states. The aim of this study was to investigate GSA uptake per hepatocyte in the convalescent stage from hepatic damage. METHODS: We used rats with dimethylnitrosamine (DMN)-induced hepatic injury and rats with recombinant human hepatocyte growth factor (rhHGF) stimulation. Plasma clearance of GSA and the number of hepatocytes in whole liver were calculated. RESULTS: In the DMN-treated rats, the total number of hepatocytes and GSA plasma clearance were reduced significantly at 3 wk after the final administration of DMN. However, calculated GSA uptake per individual hepatocyte was significantly greater by 53.2% than in the normal controls. The area of hepatic nucleus was also significantly greater than in the normal controls. In the rhHGF-treated rats, an increase in the total number of hepatocytes was not demonstrated on the final day of rhHGF administration (Day 4). However, calculated GSA uptake per hepatocyte was significantly greater (59%) than in the controls. CONCLUSION: Augmented GSA uptake per hepatocyte during the convalescent stage after hepatic injury suggests a cellular compensation to the decreased number of hepatocyte. This mechanism may be caused by the secretion of some hepatotropic factors such as HGF.

Successful transcatheter embolotherapy with a new platinum microcoil: the Berenstein Liquid Coil.

PURPOSE: To determine the usefulness of a new platinum microcoil, the Berenstein Liquid Coil for vascular embolization. METHODS: Nine patients underwent transcatheter arterial embolization with liquid coils. The occluded vessels included the splenic artery in four patients, gastroduodenal artery in two, arteriovenous malformation or fistula in two, and middle hepatic artery in one. All coils were delivered with a saline flush through a Tracker-18 catheter. RESULTS: All arteries except one were successfully occluded in a one-stage procedure using liquid coils. No friction was observed between the liquid coils and the microcatheter regardless of the tortuosity of the artery. Platelet counts in all patients had increased after splenic embolization. In two patients with liver tumors, perfusion to the inappropriate area during intraarterial chemotherapy was prevented by selective embolization. Life-threatening bleeding was successfully treated by gastroduodenal artery occlusion. No complications were encountered. CONCLUSION: The Berenstein Liquid Coil provides easy, safe, and rapid vascular occlusion.

An increase in laryngeal aerosol deposition by ultrasonic nebulizer therapy with intermittent vocalization.

In acute or chronic laryngitis as well as pharyngitis, nebulization with steroid and antibiotics is considered to be a safe and effective treatment. However, the optimal dose, frequency, duration, and method of administration by ultrasonic nebulization is not known. To evaluate whether there is continual improvement using ultrasonic nebulizer therapy, the deposition rate of aerosol particles into the upper airway was studied. We analyzed the deposition rate in the upper airway by a counting system of radioactive isotope (99mTc-diethylene triaminepentaacetic acid; 99mTc DTPA). Volunteers in good health inhaled an aerosol containing 99mTc DTPA under various conditions of inhalation. Deep and slow inhalation at a respiratory rate of 12 breaths/minute resulted in a high deposition rate of 99mTc DTPA in the lung and a low deposition rate in the larynx. In contrast, faster inhalation at a respiratory rate of 36 breaths/minute resulted in an increase in the isotope deposition rate in the larynx. Furthermore, when the volunteers vocalized intermittently during the fast inhalation at a respiratory rate of 36 breaths/minute, the isotope deposition rate in the volunteer's larynx was higher than in all other inhalation conditions. These results suggest that fast inhalation with intermittent vocalization is one of the important inhalation methods used to improve the deposition rate of aerosol particles into the upper airway with an ultrasonic nebulizer.

Validation of curve-fitting method for blood retention of 99mTc-GSA: comparison with blood sampling method.

We investigated a curve-fitting method for the rate of blood retention of 99mTc-galactosyl serum albumin (GSA) as a substitute for the blood sampling method. Seven healthy volunteers and 27 patients with liver disease underwent 99mTc-GSA scanning. After normalization of the y-intercept as 100 percent, a biexponential regression curve for the precordial time-activity curve provided the percent injected dose (%ID) of 99mTc-GSA in the blood without blood sampling. The discrepancy between %ID obtained by the curve-fitting method and that by the multiple blood samples was minimal in normal volunteers 3.1 +/- 2.1% (mean+/-standard deviation, n = 77 sampling). Slightly greater discrepancy was observed in patients with liver disease (7.5 +/- 6.1%, n = 135 sampling). The %ID at 15 min after injection obtained from the fitted curve was significantly greater in patients with liver cirrhosis than in the controls (53.2 +/- 11.6%, n = 13; vs. 31.9 +/- 2.8%, n = 7, p < 0.0001). There was a highly linear correlation between the %IDs of 99mTc-GSA and the plasma retention rate for indocyanine green (r = -0.869, p < 0.0001, n = 27). These results indicate that the curve-fitting method provides an accurate %ID of 99mTc-GSA and could be a substitute for the blood sampling method.

Preoperative determination of the surgical procedure for hepatectomy using technetium-99m-galactosyl human serum albumin (99mTc-GSA) liver scintigraphy.

Technetium-99m-diethylenetriaminepentaacetic acidgalactosyl human serum albumin (Tc-GSA) is a new liver scintigraphy agent which binds to the asialoglycoprotein receptors. We evaluated the preoperative assessment for hepatectomy using Tc-GSA liver scintigraphy. Ninety patients with hepatocellular carcinoma were admitted for elective hepatectomy. Tc-GSA scintigraphy was conducted after the intravenous injection of Tc-GSA, and maximal removal rate of Tc-GSA (GSA-Rmax) was calculated using a radiopharmacokinetic model. Measurement of GSA-Rmax, conventional liver function, and 15-minute retention rate of indocyanine green (ICGR15) was carried out preoperatively. The relationships between liver functions, histological activity index (HAI), ICGR15, and GSA-Rmax values were estimated. A significant correlation was obtained between GSA-Rmax and ICGR15 (r = .534, P < .0001). Preoperative discrepancies between GSA-Rmax and ICGR15 values were seen in 15 patients. In these cases, the GSA-Rmax values correlated well with the total HAI scores (r = .595, P < .02), but no significant correlation was seen between the ICGR15 and HAI scores. Two patients died of postoperative liver failure within 2 months of the operation. These two patients were found to have severe discrepancies between their preoperative GSA-Rmax and ICGR15 values. We concluded that GSA-Rmax might be useful for selecting candidates for hepatectomy and that extended hepatectomies (di- and tri-segmentectomy) are high-risk surgical procedures in the case of low GSA-Rmax scores (below 0.35).

Compartmental analysis of asialoglycoprotein receptor scintigraphy for quantitative measurement of liver function: a multicentre study.

A multicentre study on multicompartmental analysis of hepatic scintigraphy using technetium-99m labelled galactosyl serum albumin (GSA), which binds to the asialoglycoprotein receptor, was carried out at seven institutions in Japan. Seventy-four patients with liver disease received 3 mg (185 MBq) of 99mTc-GSA by intravenous injection. Sequential scanning was performed 30 min after injection to obtain anterior images of the heart and liver, followed by single-photon emission tomography (SPET). The indices included in this analysis were hepatic blood flow (Q) and maximal receptor binding rate (Rmax), which showed a good correlation with semiquantitative ratio indices for 99mTc-GSA, namely the retention rate in blood (HH15) and the hepatic uptake rate (LHL15). Q and Rmax also showed a significant correlation with other measures of hepatic function. When patients were grouped according to the severity of chronic liver damage (hepatocellular functional damage), Q was reduced in the moderate and severe groups, while Rmax was reduced in proportion to the functional stage. Both parameters showed no inter-institution difference using analysis of co-variance with the functional stage as a co-variant. With regard to the hepatic uptake rate, anterior planar images and SPET images gave similar results for Q and Rmax. Acquisition times of 15 or 30 min provided the same results. The multicompartmental model analysis permitted comparable results to be obtained at institutions using different gamma cameras, and is therefore considered a universally applicable method. These results indicate that Q and Rmax are useful general indices for evaluating the functional reserve capacity of the liver.

Stimulation of asialoglycoprotein uptake by recombinant human hepatocyte growth factor in normal and damaged rat liver.

BACKGROUND: Hepatocyte growth factor (HGF) is a strong mitogen of hepatocytes. However, little is known about the effect of HGF on the asialoglycoprotein receptors (ASGPR) of hepatocytes. The aim of this study was to identify alterations in binding of ligand to ASGPR by recombinant human HGF (rhHGF) infusion. METHODS: RhHGF was administered to rats with either normal or dimethylnitrosamine (DMN)-damaged livers. Technetium-99m-diethylenetriaminepentaacetic acid-galactosyl-human serum albumin (GSA) blood clearance was used to measure ASGPR activity. RESULTS: In normal and damaged rats, liver weight, hepatocyte nuclear size, and number of hepatocytes (cells/mm2) were not altered by rhHGF, but GSA blood clearance after rhHGF infusion was significantly increased over the preinfusion rate. CONCLUSIONS: Independent of proliferation of hepatocytes, rhHGF stimulates a hepatocytic function of the receptor-mediated uptake of ASGP.

The usefulness of MR in establishing the diagnosis of parotid pleomorphic adenoma.

PURPOSE: To assess the usefulness of MR findings in establishing a specific diagnosis of parotid pleomorphic adenoma. METHODS: T1-weighted and T2-weighted MR images with and without contrast enhancement were obtained in 82 patients with parotid tumors. Imaging findings in the 38 patients in whom surgery subsequently revealed pleomorphic adenomas were compared with findings in the 44 patients who had other types of tumor. Specifically, the homogeneity, signal intensity, contrast enhancement, capsule thickness, lobulation, adenopathy, and infiltration of adjacent fat were compared among the different types of tumor. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated. RESULTS: A low-signal capsule on T2-weighted images and a lobulated contour characterized most pleomorphic adenomas. The sensitivity of the first finding for pleomorphic adenoma was 82%; specificity, 85%; positive predictive value, 82%; and negative predictive value, 84%. For the second finding, the sensitivity was 53%; specificity, 84%; positive predictive value, 74%; and negative predictive value, 67%. CONCLUSION: None of the signs evaluated had perfect sensitivity and specificity. The MR findings of a complete capsule, lobulated contour, or high T2 signal intensity have a high predictive value for the diagnosis of pleomorphic adenoma.

[Visual evaluation of liver function with 99mTc-GSA scintigraphy: interobserver variation and intraobserver variation].

We introduced a new imaging grade to evaluate liver function with 99mTc-GSA and studied its diagnostic value using interobserver variation and intraobserver variation. One hundred four patients with liver disease were injected 185 MBq/3 mg of 99mTc-GSA. Anterior images of cardiac blood-pool and liver at 5 min after injection were divided into four grades on the basis of following four categories. Faint cardiac blood-pool image, without clear demonstration of its peripheral boundary was classed in grade I; weaker cardiac blood-pool than liver was grade II; almost same appearance of blood-pool with liver was grade III and stronger blood-pool than liver was grade IV. Three radiologists reviewed the images independently. They followed the same process three months after initial evaluation. kappa-Test was employed to evaluate the goodness of agreement. Three pairs in the first reading showed excellent interobserver agreement (0.88, mean kappa-value) and another three pairs in the first and second reading also showed excellent intraobserver agreement (0.87, mean kappa-value). Quantitative indices obtained from time-activity curves for blood-pool and liver showed significant differences across four groups. Plasma retention rate of indocyanine green also showed significant difference between grade II and grade III. Imaging grade possesses high intra- and interobserver agreement and provides a good discrimination for liver function.

Comparison of tumour blood flow changes induced by step-up and step-down heating.

The changes in the blood flow in SCC-VII tumours after step-down and step-up heating (SDH and SUH) were compared. SDH was carried out by initial treatment of tumours in a water bath at 44.5 degrees C for 10 min, immediately followed by heating at 41.5 degrees C for 60 min. For SUH, the sequence of these high- and low-temperature treatments was reversed. Tumour perfusion was evaluated by laser Doppler flowmetry (LDF) at 1, 2, and 24h after finishing the hyperthermia. It was shown that the decrease in the blood flow in tumours was more substantial after SDH than after SUH; in the former case, the drop in LDF values was both faster and larger than in the latter. It is concluded that such a "physiological' component may be involved in the difference in the antitumour effect between SDH and SUH.

Use of technetium 99m diethylenetriamine-pentaacetic acid-galactosyl-human serum albumin liver scintigraphy in the evaluation of preoperative and postoperative hepatic functional reserve for hepatectomy.

BACKGROUND: Technetium 99m diethylenetriaminepentaacetic acid-galactosyl-human serum albumin (99mTc-GSA) is a new liver scintigraphy agent that binds to the asialoglycoprotein receptors. We evaluated the clinical use of 99mTc-GSA for the perioperative assessment of hepatectomy. METHODS: Thirty-six patients with hepatocellular carcinoma were admitted for elective hepatectomy. 99mTc-GSA scintigraphy was obtained after the intravenous injection of 99mTc-GSA, and a modified receptor index (MRI) was calculated. 99mTc-GSA scintigraphy, conventional liver function, the plasma disappearance rate, and the 15-minute retention rate of indocyanine green (ICGR15) were carried out before operation and every 1 to 3 months after operation. The relationships between several systemic hemodynamic parameters, histologic activity index (HAI), plasma disappearance rate, and ICGR15 or MRI values were estimated. RESULTS: A significant correlation was obtained between the MRI and ICGR15 (r = 0.6231, p < 0.001). Plasma disappearance rates correlated well with systolic volume and left cardiac work, whereas MRI values did not correlate with these systemic hemodynamics. Preoperative discrepancies between the values of MRI and ICGR15 were seen in eight cases. In these cases the MRI values correlated well with HAI scores (p < 0.05) but there was no significant correlation between ICGR15 values and the HAI scores. CONCLUSIONS: These results suggested the use of 99mTc-GSA scintigraphy as a easy and reliable method for determining liver functional reserve.

[Change in lobar uptake of 99mTc-galactosyl serum albumin after transarterial embolization therapy].

Liver function was studied by hepatic scintigraphy with 99mTc-galactosyl serum albumin (GSA) before and after transarterial embolization (TAE) therapy in 16 patients with hepatocellular carcinoma. The percent uptake of GSA in liver was measured separately in the treated and non-treated areas. GSA uptake increased in both areas. The change was more marked in the non-embolized lobe than the embolized lobe. We conclude that the increase in GSA uptake reflects the regeneration of liver cells after TAE.