Preoperative evaluation of hepatic functional reserve by converted ICGR15 calculated from 99mTc-GSA scintigraphy

Background and Aim:  Conversion of data from technetium 99 m diethylenetriaminepentaacetic acid galactosyl human serum albumin (^99mTc-GSA) scintigraphy to ICGR15 (indocyanin green retention at 15 min) is an easy and convenient method for obtaining parameters to determine the appropriate and safe extent of liver resection. We investigated a conversion method which also accounts for LHL15 (receptor index: uptake ratio of the liver to the liver plus heart at 15 min) and HH15 (blood clearance index: uptake ratio of the heart at 15 min to that at 3 min) characteristics.
Methods:  Cases included 282 patients undergoing hepatic resection following ^99mTc-GSA scintigraphy and an ICG tolerance test. Degree of liver dysfunction was classified as A, B, or C according to criteria of the Liver Cancer Study Group of Japan.
Results:  HH15 demonstrated a larger distribution in patients with liver damage A, while LHL15 demonstrated a larger distribution in patients with liver damage B. In liver damage A, the conversion formula ICGR15 = 87.0–79.6 × LHL15 was obtained, and in liver damage B, the conversion formula ICGR15 = −23.3 + 72.4 × HH15 was obtained, and correlation with ICGR15 was higher ( r  = 0.61, P  < 0.0001) than when the data were not segregated by liver damage severity. Furthermore, postoperative hyperbilirubinemia significantly occurred in cases where both ICGR15 and converted ICGR15 were high.
Conclusions:  Conversion models based on data segregated by severity of liver damage were more closely correlated with ICGR15 than conversion models not based on segregated data. By using this converted ICGR15, preoperative estimation of hepatic functional reserve can become more reliable.     

99mTc-sestamibi can improve the inferior attenuation of TL-201 myocardial spect imaging

Tl-201 myocardial scintigraphy (Tl study) tends to be attenuated by soft tissues (such as the diaphragm) due to its low energy emission. 99mTc-sestamibi (2-methoxy isobutyl isonitrile) is a relatively new agent with a higher energy emission and this characteristic accounts for the higher quality of 99mTc-sestamibi images. The purpose of this study is to evaluate the ability of 99mTc-sestamibi in alleviating the inferior attenuation of Tl studies. 99mTc-sestamibi SPECT myocardial scintigraphy was performed on 13 patients with inferior wall perfusion defects as determined by Tl study (but with normal coronary artery as evidenced by cardiac catheterization). All patients underwent Tl SPECT study using a standard procedure. Same-day protocol (rest-stress sequence) was used for 99mTc-sestamibi SPECT imaging. All images were analyzed by two independent observers. The results of our study reveal that 99mTc-sestamibi produced better images. The inferior wall perfusion defects in the Tl study were noted in one case only (l/13)in the 99mTc-sestamibi study. Our study suggests that 99mTc-sestamibi can remarkably reduce the inferior attenuation of Tl study.     

Scintigraphic evaluation of the haemopoietic bone marrow using a 99mTc-anti-granulocyte antibody: a validation study with 52Fe

To specify the validity of bone marrow scanning using a monoclonal anti-granulocyte antibody labelled with ^99mTc (BW 250/183) for the functional assessment of haemopoiesis, we compared this method with ⁵²Fe scan in 16 patients with haematological disorders. The examinations were performed using a rectilinear whole-body scanner and the distribution of the two tracers was assessed visually and quantitatively in anatomical bone marrow segments, the spleen and liver. Qualitative comparison showed concordance in the bone marrow distribution of the two tracers in 83% of the segments. Discrepancies were found in six patients with hypoplastic or aplastic marrow. The spleen was visualized in all cases with the ^99mTc-Moab, including nine patients without splenic haemopoiesis (i.e. without spleen uptake of ⁵²Fe). The uptake of the two tracers, quantified in bone marrow segments and the spleen, correlated well (PO-0001), but not in the liver (NS). The correlation between the uptake values for each patient was excellent, except in cases of aplastic bone marrow. In conclusion, bone marrow scanning using a ^99mTc labelled anti-granulocyte monoclonal antibody enables functional evaluation of the distribution of haemopoiesis. Limitations include the evaluation of bone marrow aplasia and identification of splenic haemopoiesis, for which ⁵²Fe remains the tracer of choice.     

Intestinal Permeability to 99mTc-Diethylenetriaminopentaacetic Acid in Inflammatory Bowel Disease

Intestinal permeability in inflammatory bowel disease and its relation to periods of disease activity has been investigated by measuring the urinary excretion of DTPA labeled with 99mTc. Urine excretion in 10 control subjects was 2.7 +/- 1% of the test dose. Twelve patients with ulcerative colitis excreted 5.08 +/- 1.6% in remission, 10.61 +/- 2% during periods of mild activity, 19.41 +/- 0.9% during moderate activity, and 15.41 +/- 6.3% with severe activity. Sixteen patients with Crohn's disease excreted 5.7 +/- 1.9% in remission, 8.47 +/- 2.8% during mild activity of the disease, and 14.29 +/- 5.8% during moderate activity. No differences were observed between ulcerative colitis and Crohn's disease, or between ileal and colonic forms of Crohn's disease. Excretion in remission was significantly greater than in control subjects and there was a correlation between excretion and disease activity. In serial determinations done in seven patients we found that urine excretion of the test substance correlated with disease activity. We also studied DTPA excretion in 10 cases with gastric or duodenal ulcer (2.28 +/- 1.4%), six cases of acute gastroenteritis (4.87 +/- 3.1%) and nine cases with other intestinal diseases (3.6 +/- 1.1%). In all these cases, DTPA excretion was lower than in inflammatory bowel disease. Our results show that the urinary excretion of DTPA is a simple test that measures accurately the degree of activity of inflammatory bowel disease. The test is useful in Crohn's disease as well as in ulcerative colitis, and detects intestinal permeability abnormalities even in clinical remission. Significantly lower excretions are found in other intestinal diseases. The test may be recommended as a screening test for use in clinical practice.     

Sidestream smoke inhalation decreases respiratory clearance of 99mTc-DTPA acutely

Background: The permeability of the alveolar-capillary barrier to an inhaled aerosol of technetium ^99m labelled diethylenetriamine penta-acetate (^99mTc-DTPA) is used as an index of alveolar epithelial injury. Permeability is greatly increased in active smokers.
Aims: To determine the effect of sidestream smoke inhalation on permeability as this has not been described previously.
Methods: We measured lung clearance of inhaled ^99mTc-DTPA aerosol in 20 normal nonsmoking subjects before and after exposure to one hour's sidestream smoke inhalation.
Results: Measured carbon monoxide (CO) levels rose to a maximum of 23.5±6.2 ppm (mean ±D) from baseline values of 0.6± 1.3 (p<0.001) and plasma cotinine levels to a maximum of 9.5± 4.5 nmol/L (mean ± SD). The half time (T1/2 in minutes) for ^99mTc-DTPA clearance rose from baseline 69.1± 15.6 (mean ± SD) to 77.4± 17.8 ( p <0.05) after smoke exposure. No effect of ^99mTc-DTPA scanning or of sidestream smoke was demonstrated on lung function.
Conclusions: We conclude that low level sidestream smoke inhalation decreases ^99mTc-DTPA clearance acutely in humans. The mechanism of this unexpected result is not established but may include differences in constituents between sidestream and mainstream smoke, alterations in pulmonary microvascular blood flow, or changes in surfactant due to an acute phase irritant response.     

An Examination of the Labelling of Intact Human Erythrocytes with 99mTc

S ummary . ^99mTc radiopharmaceuticals are now in common use in diagnostic nuclear medicine although rather little is known about the chemical structure of the Tc-ligand complexes formed when Tc is bound to organic compounds. We examine ^99mTc-labelled erythrocytes and find that proteins in addition to haemoglobin are labelled with ^99mTc, possibly through their sulphydryl groups. This contrasts markedly to the labelling of erythrocytes with ⁵¹Cr where only haemoglobin is labelled.     

Use of scintigraphy with 99mtechnetium galactosyl human serum albumin for staging of primary biliary cirrhosis and assessment of prognosis

BACKGROUND: Conventional models for prediction of survival in patients with primary biliary cirrhosis (PBC) are based on the results of blood tests and on the clinical condition, which may be affected by treatment. We evaluated the usefulness of hepatic receptor imaging with [99mtechnetium]-diethylenetriaminepentaacetic acid galactosyl human serum albumin (GSA) for the staging and prognosis of PBC without the need for reference to laboratory test results. METHODS: The subjects were 45 patients with PBC, 10 healthy subjects, 62 patients with chronic hepatitis and 144 patients with cirrhosis. Computer acquisition of gamma-camera data was started just before the injection of 185 MBq [99mTc]-GSA and was stopped 20 min later. Time-activity curves were generated from regions of interest (ROI) for the heart and liver. A receptor index was calculated by dividing the radioactivity of the liver ROI by that of the liver-plus-heart ROI 15 min after the injection. An index of blood clearance was calculated by dividing the radioactivity of the heart ROI 15 min after the injection by that of the heart ROI 3 min after the injection. RESULTS: The median receptor index was higher in patients with PBC than in those with cirrhosis. Among patients with PBC, the receptor index was lower in those with stage IV disease than in those in stages I, II or III. The index of blood clearance was lower in patients with PBC than in those with cirrhosis. Among patients with PBC, the index of blood clearance was higher in those with stage IV disease than in those in stages I, II or III. The receptor index was correlated significantly both to the risk score of the Mayo model and to the prognostic index of the Japanese model. The index of blood clearance was also correlated significantly to this score and prognostic index. CONCLUSIONS: Hepatic receptor imaging with [99mTc]-GSA is useful for the evaluation of hepatic functional reserve, staging of PBC and assessment of prognosis.     

Biliary Scintigraphy with a New Scanning Agent, 99mTc-(SN)-pyridoxylidene-isoleucine

99mTechnetium-pyridoxylidene-isoleucine (hereinafter referred to as 99mTc-PI) is a new biliary scintiscanning agent. It has been evaluated in both health volunteers and patients with known surgical biliary tract diseases. It results in imaging of the liver in three minutes and the common bile duct and duodenum in 10-20 minutes. Its advantages as a diagnostic tool in disease of the hepatobiliary systems are in reducing the amount of radiotracer required, in shortening examination time and in producing scintigrams of higher resolution.     

Assessment of disease activity and localization in inflammatory bowel disease using 99mTc-labelled leucocytes

Abstract Disease activity and regional extent of disease was studied in 20 patients with inflammatory bowel disease (13 with Crohn's disease and seven with ulcerative colitis). Autologous white cells from patients and controls were labelled with ^99mTc-stannous colloid, reinjected, and the faecal excretion of the labelled leucocytes was assessed over 48 h. In patients with Crohn's disease, the faecal excretion correlated with severity of disease as judged by the Harvey-Bradshaw index. In 18 of the 20 patients the extent of the inflammatory bowel disease as indicated by the scan image corresponded with the radiological and colonoscopic findings. The ^99mTc-stannous colloid label has advantages over indium-111 and the faecal excretion of labelled leucocytes has potential as a simple, objective measure of disease activity.     

Cholecystokinin-stimulated mebrofenin (99mTc-Choletec) hepatobiliary scintigraphy in asymptomatic postcholecystectomy individuals: assessment of specificity, interobserver reliability, and reproducibility

OBJECTIVES: Cholecystokinin-stimulated hepatobiliary scintigraphy (CCK-HBS) is a noninvasive method reported to be highly accurate in the diagnosis of sphincter of Oddi dysfunction. Our primary aim was to assess the specificity of CCK-HBS by evaluating its ability to exclude disease in 20 asymptomatic postcholecystectomy individuals. Secondary aims were to assess the interobserver reliability in scoring the CCK-HBS examinations between three blinded observers and to assess reproducibility of CCK-HBS repeated in the same individuals. METHODS: Twenty asymptomatic postcholecystectomy individuals with normal liver serum chemistries underwent CCK-HBS on two separate occasions. Three nuclear medicine specialists read each CCK-HBS study in a blinded fashion. RESULTS: There was good agreement between the three observers reading the same scans for both the first scan (kappa = 0.554) and the second scan (kappa = 0.507). There was poor agreement between the first and second scans on the same patient, read by the same nuclear medicine specialist (kappa = 0.062-0.385). The overall specificity of the CCK-HBS score was 77.5%; however, the specificity was only 60% when a true negative was defined as two negative CCK-HBS examinations. CONCLUSIONS: Quantitative CCK-HBS is of poor specificity in asymptomatic postcholecystectomy individuals. Hence, it is of questionable value in excluding sphincter of Oddi dysfunction in patients suspected to suffer from this disorder.     

A Simple and Efficient Method of Labelling Red Cells with 99mTc for Determination of Red Cell Volume

It has been shown by others that treatment of red cells with very small amounts of tin in the form of stannous citrate or stannous pyrophosphate before incubation with ^99mTc results in the subsequent binding of almost all the added technetium and that when the labelled cells are injected into the circulation the rate of elution of ^99mTc is less than when cells are labelled by first adding ^99mTc, then tin. Because of the instability of stannous salts in solution, methods have previously been described for the freeze-drying of very small aliquots of tin in 'kits', specially designed for the labelling of red cells with ^99mTc. The present paper confirms the advantage of'pre-tinning'in labelling red cells with ^99mTc and describes a method for which no special kit is needed and in which even smaller amounts of tin than have been used previously give optimal results. A dilution of stannous chloride which provides the requisite very low concentration of tin is prepared by a simple two-stage procedure. Since uptake of ^99mTc is about 95%, only a single wash is necessary after labelling. Estimates of red cell volume based on a single sample at 10 or 20 min after an injection of labelled cells, uncorrected for loss of label, agree very closely with those obtained with ⁵¹Cr. Loss of label in the first hour after injection is only about 4% which is significantly less than that observed with a post-tinning procedure. Because of the much lower rate of toxicity of ^99mTc compared with ⁵¹Cr, ^99mTc-labelled red cells should be used for estimating red cell volume whenever practicable.     

A new dual-label technique for platelet survival studies with the use of 111indium and 114mindium tropolonate

Summary A dual-label technique to study the survival of two different populations of platelets within one individual was developed using ¹¹¹indium and ^114mindium. The validity of the technique was demonstrated in seven individuals with an expected equal survival time of two platelet populations and in two persons with an expected difference in platelet survival time.
Since the energy spectra of the two indium isotopes are very close, a well-type germanium semiconductor detector was applied. By adaptation of the counting time the effective dose equivalent of the dual-label procedure could be restricted to 1·6 mSv.
The dual-label technique provides an instrument for studying the survival of two different populations of platelets simultaneously within one individual.     

Measurement of Red Cell Volume and Splenic Red Cell Pool using 113mIndium

S ummary . Using the lipophilic chelating agent, acetylacetone, red cells have been radiolabelled with the short-lived, generator-produced isotope, ^113mIn. Following re-injection of these labelled cells, red cell volume has been measured and compared with corresponding values using ^99mTc labelled red cells in 18 patients, and with ⁵¹Cr labelled red cells in five patients. ^99mTc slightly overestimated red cell volume in relation to ^113mIn, but ⁵¹Cr values were identical to ^113mIn values. There was a close correlation between splenic red cell pool measured with ^99mTc and with ^113mIn. It was concluded that the intracellular stability and gamma emission of ^113mIn make this isotope a superior alternative to ^99mTc and ⁵¹Cr in measurements of red cell volume and splenic red cell pool.     

Evaluation of 51Cr as a Leucocyte Label

S ummary . A double label technique has been developed to compare the behaviour of ⁵¹Cr labelled leucocytes with DF³²P labelled leucocytes. Whole blood is divided into two aliquots and the leucocytes in each are labelled with a different isotope. After infusion of labelled cells, the radioactivity of each isotope can be determined simultaneously on the same blood sample using liquid scintillation counting. In studies of seven patients with solid tumours and one with leukaemia, the intravascular disappearance of autologous leucocytes labelled with ⁵¹Cr and DF³²P appeared similar in five of the eight patients during the initial 6 hr following infusion. Thereafter in all but one instance, ⁵¹Cr labelled leucocytes had slightly higher specific activities. ⁵¹Cr labelled lymphocytes and DF³²P labelled lymphocytes also behaved in the same manner. It is concluded that⁵¹Cr is a suitable leucocyte label and may be substituted for DF³²P under certain circumstances.     

Utility of 3D magnetic resonance imaging in preoperative evaluation of hepatobiliary diseases

Three-dimensional (3D) imaging is playing an increasingly important role in modern diagnostic radiology. The recent improvements in magnetic resonance (MR) hardware, scanning protocols and 3D volumetric reconstruction software have facilitated great expansion of the role of 3D imaging for use in hepatobiliary surgery. In this review, we address the various 3D reconstruction techniques used in MRI and demonstrate the value of 3D imaging in preoperative evaluation of hepatobiliary diseases.     

Ultrasonography for preoperative localization of enlarged parathyroid glands in primary hyperparathyroidism: comparison with (99m)technetium sestamibi scintigraphy

OBJECTIVE: To determine the utility of ultrasonography for the preoperative localization of enlarged parathyroid glands in primary hyperparathyroidism, and to compare this method with (99m)technetium sestamibi scintigraphy. DESIGN: The results of ultrasonography for localization of enlarged parathyroid glands were determined in 120 consecutive patients with primary hyperparathyroidism and compared with findings at surgery (n = 86) and with the results of (99m)technetium sestamibi scintigraphy (n = 99). PATIENTS: All patients had biochemically documented primary hyperparathyroidism based on elevated serum calcium and 'intact' parathyroid hormone measured by immunoassay. Patients with prior parathyroid surgery or secondary hyperparathyroidism were excluded. MEASUREMENTS: High-resolution ultrasonography was performed by a single observer. (99m)Technetium sestamibi scintigraphy was performed using early and delayed (2-h) views, and correlated with simultaneous thyroidal 123I uptake in most patients. RESULTS: Ultrasonography detected putative enlarged parathyroid glands in 92 of 120 unselected patients (77%). It correctly predicted surgical findings in 64 of 86 patients undergoing surgery (74%), including 61 of 72 patients with solitary eutopic parathyroid adenomas (84%), but only two of eight patients with solitary ectopic adenomas, and only one of six patients with multigland parathyroid disease. Sestamibi scintigraphy was positive in 87 of 99 unselected patients (88%), a higher proportion than ultrasonography (P < 0.05), reflecting superior sensitivity for the detection of ectopic parathyroid adenomas. For 74 patients undergoing parathyroid surgery who underwent both imaging tests there was no statistically significant difference between ultrasonography and sestamibi scintigraphy in ability to correctly predict surgical findings (74%vs. 82%, respectively) or in positive predictive value (93%vs. 90%, respectively). However, sestamibi scintigraphy was clearly more sensitive for ectopic parathyroid adenomas, providing correct localization in 8/8 cases. When one test was negative, testing with the second method was usually positive, improving the likelihood of a positive result to 98% when both tests were employed. CONCLUSIONS: Ultrasonography can be a sensitive and accurate method for preoperative localization of enlarged parathyroid glands in primary hyperparathyroidism, comparable in overall utility to sestamibi scintigraphy. These results suggest that a strategy of initial testing with one or the other method, followed by the alternate imaging test if the first test is negative, would provide correct parathyroid imaging in most patients without prior parathyroid surgery.     

A case of antibody formation against octreotide visualized with 111In-octreotide scintigraphy

A case of antibody formation in a patient with carcinoid syndrome is described. The patient was treated with octreotide in dosages up to 1 5 mg/day. Serum samples were analysed for the presence of octreotide antibodies before and after 20 months of octreotide treatment. In-vivo ¹¹¹ln-octreotide scintigraphy was performed before and during therapy, and after antibodies had developed. Before treatment, no serum antibodies against octreotide were detected. After 20 months of treatment, they were detectable up to a 1:115 serum dilution. The serum binding of ¹²⁵I-Tyr³-octreotide was blocked by adding excess unlabelled Tyr³-octreotide, indicating the presence of specific octreotide antibodies. Before treatment, a normal distribution of radioactivity in the spleen and kidneys, irregular uptake in the liver due to metastases, and a hot spot in the lower abdomen were found during ¹¹¹ln-octreotide scintigraphy. After antibodies had developed, increased radioactivity over the heart and high background radioactivity in the abdomen with only faint visualization of the spleen, liver, and kidneys were found, indicating a prolonged presence of ¹¹¹ln-octreotide in the blood resulting from its being bound to antibodies. Increased radioactivity was also seen at the injection sites of the drug in the upper legs. In-vitro incubation of biopsy tissue from this site with ¹²⁵l-Tyr³-octreotide revealed diffuse guanosine triphosphate (GTP) independent specific binding, indicating non-G-protein linked binding of labelled octreotide. This report describes the characteristic abnormalities during in-vivo ¹¹¹ln-octreotide scintigraphy in a patient with octreotide antibodies. These consisted of high back ground radioactivity due to prolonged circulation of antibody coupled ¹¹¹ln-octreotide together with visualization of the injection sites, which most probably results from local accumulation of antibodies.