Cerebral control of bladder storage in patients with detrusor overactivity.

OBJECTIVE: To identify the brain areas that control bladder storage by technetium-99m hexamethylpropyleneamine oxime single-photon emission computed tomography (SPECT) with the Neurological Statistical Image Analysis software (NEUROSTAT) in patients with detrusor overactivity (DO). METHODS: SPECT scans were performed on 19 patients with DO. Eight patients with normal detrusor function, who had some storage symptoms of the lower urinary tract as the patients with DO, also had a SPECT scan, as controls. All the patients were male and right handed, and were scanned twice under two conditions: resting state and urine withholding state. NEUROSTAT was adopted to analyze the difference in brain--blood perfusion between groups and states. The results were displayed on Z score images at a significance threshold of P value of less than 0.05 with correction for multiple comparisons. RESULTS: No region reached the significant threshold in comparison with patients with DO and normal detrusor function in resting state. Significant increases in tracer activity in the right inferior frontal gyrus and the right middle temporal gyrus during urine withholding state as compared with resting state in patients with normal detrusor function were observed. Among the regions, the right inferior frontal gyrus was distinctly prominent at both Z score and the extent. The regions that were significantly activated in patients with normal detrusor function did not reach a significant threshold during urine withholding in patients with DO. CONCLUSION: The study indicated that the right inferior frontal gyrus and the right middle temporal gyrus, especially the right inferior frontal gyrus, played a role in the cerebral control of bladder storage, inhibiting the contraction of detrusor in urine storage.

Quantitative regional blood flow measurements in exercising leg skeletal muscle based on 99mTc-pertechnetate clearance.

BACKGROUND AND AIM: Skeletal muscle blood flow (SMBF) is a crucial indicator of impaired peripheral circulation. Although 133Xe has long been used for estimation of regional SMBF, its lipophilic and volatile nature hampers precise measurement. Therefore, we established an improved method based on 99mTc-pertechnetate ion (99mTcO-4) clearance. METHODS: Ten healthy male volunteers including five rugby players and five non-athletes (each group aged 25-35 years) received injection of 99mTcO-4 into the bilateral tibialis anterior muscles and gastrocnemius muscles (GCMs). The radioactivity of 99mTcO-4 before, during, and after toe-up or treadmill exercise was traced using a gamma-camera. Regional SMBF in absolute values (in ml/min/100 g muscle) was then calculated based on the half-time obtained from the time-activity curve. RESULTS: In both the groups, SMBF in tibialis anterior muscle changed similarly with values at the same levels. In contrast, SMBF in GCM showed marked difference between the two groups: in rugby players, SMBF in GCM returned to the baseline level (6.5+/-1.7, n=10) immediately after treadmill exercise, whereas that in non-athletes remained high (16.2+/-3.2, n=10). CONCLUSION: Regional SMBF measured by 99mTcO-4 clearance can indicate effectiveness of exercise training, and would be a diagnostic tool and prognostic indicator for use in patients with impaired peripheral circulation.

A compartment model analysis for investigation of myocardial fatty acid metabolism in patients with hypertrophic cardiomyopathy.

OBJECTIVE: The purpose of this study was to investigate the myocardial fatty acid metabolism in patients with hypertrophic cardiomyopathy (HCM) from dynamic SPECT through a compartment model analysis. METHODS: Twenty-four normal controls, seven patients with left ventricular hypertrophy (LVH) due to essential hypertension (eHT), and 30 patients with HCM were studied. 123I-BMIPP and 99mTc-tetrofosmin SPECT were performed. All the myocardium was divided into 13 segments, and a total of 390 segments of HCM were categorized into early, moderately and severely advanced HCM segments, based on these SPECT imaging. By using the myocardial and blood pool time-activity curves, BMIPP pharmacokinetics were analysed through a two-compartment model. We defined k1 and k2 as influx and outflux rate constants between blood and myocardial reversible component, and k3 as the specific uptake rate constant between myocardial reversible and irreversible compartments. RESULTS: The averages of k3 in HCM were higher than in normal. In contrast, the averages of k1/k2 in HCM were lower than in normal, and gradually decreased with progression of HCM. There are no significant differences in these indexes between normal controls and patients with LVH due to eHT. CONCLUSION: k3 might be a sensitive predictor for early detection of HCM, and k1/k2 could be a useful index to evaluate its progression. A mathematical compartment model analysis with a BMIPP SPECT study might be useful not only for identification of HCM in very early stage, but also for evaluation of the progression of HCM.

Intraperitoneal radioimmunotherapy to treat the early phase of peritoneal dissemination of human colon cancer cells in a murine model.

BACKGROUND AND AIM: In patients with a high risk of peritoneal dissemination of colon cancer, a treatment adjuvant to surgical resection would improve their prognosis. We aimed to determine whether radioimmunotherapy employing radiolabelled monoclonal antibody would work in this situation. METHODS: A murine model of peritoneal dissemination was established in female Balb/c nu/nu mice by intraperitoneal injection of LS180 human colon cancer cells. Radioimmunotherapy with 7.4 MBq of a murine IgG1, anti-colorectal A7 monoclonal antibody, radiolabelled with (131)I by the chloramine-T method was conducted intraperitoneally on days 0, 3, 7 and 14 after cell inoculation, respectively. RESULTS: Radioimmunotherapy at any timing improved survival of mice as compared with those of non-treated mice and mice treated with a daily dose of 30 mg x kg(-1) of 5-fluorouracil for 4 consecutive days. The best improvement was obtained when radioimmunotherapy was conducted on day 0. CONCLUSION: These results indicate that intraperitoneal radioimmunotherapy may effectively kill colon cancer cells disseminated in the peritoneal cavity before formation of tumours and, therefore, may work as an adjuvant treatment to prevent peritoneal metastasis of colon cancer.

Cerebral activation during withholding urine with full bladder in healthy men using 99mTc-HMPAO SPECT.

UNLABELLED: The aim of this study was to identify the brain areas that control urinary continence in healthy men by 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO) SPECT. METHODS: SPECT scans were performed on 15 right-handed healthy male volunteers, 24-45 y old. Each subject was scanned twice without movement in a supine position, and 444 and 555 MBq 99mTc-HMPAO were separately injected intravenously during the following 2 conditions: resting state with an empty bladder and urine-withholding state with a full bladder. The final image during urine withholding was obtained by subtracting the first scan data from the second scan data. The images were analyzed by statistical image analysis software and displayed on Z-score images at a significance threshold of P < 0.05 with correction for multiple comparisons. RESULTS: In the urine-withholding state, as compared with resting, there was a significant increase in tracer activity in the bilateral inferior frontal gyri and the right superior and the middle temporal gyri. Among the regions, the right inferior frontal gyrus was distinctly prominent. When the threshold value was decreased to P < 0.005 without correction, there was a vast network of cortical and subcortical regions involved during urine withholding. CONCLUSION: Our results suggest that the right inferior frontal gyrus plays an important role in brain control of urinary continence. This study also suggests that brain control of continence can be confirmed by statistical image analysis software using SPECT.

99mTc-sestamibi to monitor treatment with antisense oligodeoxynucleotide complementary to MRP mRNA in human breast cancer cells.

OBJECTIVE: Technetium-99m sestamibi (MIBI) has been utilized to evaluate multi-drug resistance (MDR) phenomenon of malignant tumors and to predict chemotherapeutic effects on them. The current investigation examined the possibility of monitoring changes with respect to mRNA expression of multi-drug resistance associated protein (MRP) following antisense oligodeoxynucleotide (AS-ODN) treatment involving 99mTc-MIBI. METHODS: The human breast cancer MCF-7 cell line and its MDR-induced MCF-7/VP cell line were employed. Cell suspensions of the two cell lines at 1 x 10(4) cells/ml were inoculated in 24-well plates (0.2 ml/well) and incubated for one day. Antisense (AS) 20-mer phosphorothioate ODN complementary to the coding region of MRP mRNA and its sense (S) ODN were administered at final concentrations up to 25 microM, followed by a 5-day incubation. 99mTc-MIBI solution was added to each well and incubated for 30 min. Cellular 99mTc-MIBI uptake was corrected for protein concentration. MRP mRNA expression levels were analyzed via the reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Cellular uptake of 99mTc-MIBI in MCF-7/VP cells was only 15% of that of MCF-7 cells. Following AS-ODN treatment at 25 microM for five days, 99mTc-MIBI uptake in MCF-7/VP cells increased 2.4-fold in comparison with non-treated control cells. 99mTc-MIBI uptake in MCF-7 cells was unaffected by AS-ODN administration. Sense ODN did not alter uptake in either cell line. RT-PCR confirmed reduction of MRP mRNA in MCF-7/VP cells following AS-ODN treatment. CONCLUSION: Effects of AS-ODN administration on MRP function can be monitored via assessment of cellular uptake of 99mTc-MIBI.

Locoreginal radioimmunotherapy with 186Re-labeled monoclonal antibody in treating small peritoneal carcinomatosis of colon cancer in mice in comparison with 131I-counterpart.

The efficacy of locoregional radioimmunotherapy (RIT) in treating peritoneal tumors of colon cancer of <2 mm in diameter was examined at maximum tolerated doses, focusing the comparison between 186Re and 131I labeled to an anti-colorectal cancer IgG1. Estimated radiation doses to tumors were considerably higher with 186Re-RIT than with 131I-RIT. The advantage of 186Re-RIT decreased with decreasing tumor size, but 186Re-RIT delivered 1.6-times higher radiation to tumors of 1 mm. Consequently, 186Re-RIT attained better survival of mice than 131I-RIT or chemotherapy with 5-fluorouracil did. Therefore, locoregional 186Re-RIT may be an option in an adjuvant setting of colon cancer with high risk of peritoneal dissemination.

Anti-angiogenic therapy and chemotherapy affect 99mTc sestamibi and 99mTc-HL91 accumulation differently in tumour xenografts.

BACKGROUND: Favourable effects of cytotoxic chemotherapy for tumours are characterized by the reduced accumulation of radiotracers such as 99mTc sestamibi (MIBI). Anti-angiogenic therapy is primarily cytostatic; consequently, its influence on tracer accumulation may differ from that of cytotoxic treatments. METHODS: Anti-angiogenic therapy employing 2-methoxyestradiol was administered in mice bearing subcutaneous xenografts of LS180 colon cancer cells. The effects of chemotherapy with 5-fluorouracil were examined as a cytotoxic counterpart. Treatments were conducted for 4 days from day 8. Distribution of 99mTc-MIBI and Tc-HL91, a hypoxic marker, was observed on days 8 and 12. Oxygen tension (PO2) in tumours was measured by a microelectrode. Cellular uptake of tracers was examined in vitro in normoxic and hypoxic conditions. RESULTS: 99mTc-MIBI accumulation decreased with increasing tumour weight when no treatment was conducted. Tumour growth was suppressed by anti-angiogenic therapy and chemotherapy. 99mTc-MIBI accumulation in tumours decreased after chemotherapy as compared to pre-therapeutic values, whereas accumulation of 99mTc-HL91 increased. In contrast, accumulation of tracers did not significantly change after anti-angiogenic therapy as compared to that observed pre-therapeutically. Tumour PO2 decreased with increasing tumour volume when no treatment was conducted. Chemotherapy reduced PO2 in tumours. PO2 in tumours treated with anti-angiogenic therapy was as high as that observed before treatment. 2-Methoxyestradiol or 5-fluorouracil did not significantly affect tracer accumulation in cells under both normoxic and hypoxic conditions in vitro. CONCLUSION: These findings indicate that scintigraphic assessment of therapeutic efficacy of anti-angiogenic therapy should be performed from a perspective distinct from that of cytotoxic treatment.

The radiotoxicity of 131I therapy of thyroid cancer: assessment by micronucleus assay of B lymphocytes.

UNLABELLED: We investigated cytologic radiation damage in thyroid cancer after (131)I therapy using micronucleus assay (MNA) of B lymphocytes exclusively, as opposed to our previous study in which MNA of all lymphocyte subsets was used. METHODS: We studied 22 thyroid cancer patients treated with 3.7 GBq of (131)I. Peripheral lymphocytes were harvested, and B lymphocytes were isolated by an immunomagnetic method and assayed for the frequency of micronuclei. RESULTS: The frequency of micronuclei among B cells after (131)I therapy was significantly increased relative to that in untreated control subjects, and the (131)I-induced increase in micronuclei frequency among B cells was significantly greater than that among all lymphocytes. CONCLUSION: Compared with the MNA of all lymphocytes, the MNA among specifically B cells may more sensitively detect cytologic radiation damage associated with (131)I therapy of thyroid cancer.

Functional mapping of regional liver asialoglycoprotein receptor amount from single blood sample and SPECT.

UNLABELLED: The objective of this study was to validate a method for estimating regional liver asialoglycoprotein (ASGP) receptor amount from single blood samples using static SPECT with (99m)Tc-diethylenetriaminepentaacetic acid galactosyl human serum albumin ((99m)Tc-GSA). METHODS: Based on a 2-compartment nonlinear model, regional ASGP receptor amount could be calculated from total liver ASGP receptor amount (Ro) and regional GSA uptake at a specific time. Because Ro could be estimated from single blood samples using an empiric formula, regional GSA uptake obtained as a SPECT voxel count could be converted to regional ASGP receptor amount by solving a nonlinear model equation. To validate this method, data from 62 patients with chronic liver disease underwent dynamic SPECT (30 rotations per 30 min) and simultaneous multiblood sampling and were analyzed by this method. Ro was calculated as the sum of voxel values of parametric receptor images generated from plasma concentration of GSA at 20 min and of static SPECT images generated by merging dynamic SPECT data (12-20 min). Ro was also estimated by fitting time-activity curves (4-30 min) of plasma and whole liver to the nonlinear model using the nonlinear regression method. Ro obtained from the receptor image was compared with that from curve fitting in relation to the results of hepatic function tests (indocyanine green test, hepaplastin test, and branched-chain amino acids/tyrosine plasma concentration ratio) and Child's classification. RESULTS: Ros from the 2 methods showed a significant linear correlation (r(2) = 0.938; P < 0.0001; slope = 0.90; y-intercept = 1.5). Both Ros had significant correlations with the results of hepatic function tests (P < 0.001) and differed significantly among the 3 groups of Child's classification (P < 0.0001). CONCLUSION: The present method could provide a quantitative ASGP receptor image without dynamic data acquisition. This approach could be useful for quantitative evaluation of regional liver function and estimation of residual liver function in hepatectomy.

Cooperative effect of radioimmunotherapy and antiangiogenic therapy with thalidomide in human cancer xenografts.

UNLABELLED: Antiangiogenic therapy may prolong the dormancy of cancer lesions. Moreover, radioimmunotherapy (RIT) may eradicate this population of cells. This study dealt with determining the benefits associated with the combined usefulness of these 2 therapies with respect to inhibition of tumor growth. METHODS: Antiangiogenic therapy using oral thalidomide (daily dose, 200 mg/kg) and RIT involving a single intravenous injection (4.63 MBq (131)I-A7, an IgG1 murine monoclonal antibody) were conducted in mice bearing LS180 human colon cancer xenografts. RIT with an irrelevant IgG1, HPMS-1, was also performed as a control. Antiangiogenesis of thalidomide was investigated by immunohistochemical analysis of tumor sections. RESULTS: Antiangiogenic therapy and RIT with (131)I-A7 significantly suppressed the growth of xenografts. This combination produced more efficient tumor growth inhibition than did the monotherapy (P < 0.005). RIT using (131)I-HPMS-1 was far less effective than (131)I-A7, even when combined with thalidomide administration. Immunohistochemistry revealed a decrease in the microvessel number within tumors treated with thalidomide (P < 0.0001). Combined therapy further reduced the microvessel number (P < 0.01 vs. thalidomide monotherapy). CONCLUSION: The combination of RIT and thalidomide antiangiogenic therapy produces a better response of tumors than does monotherapy. Acting in concert, antiangiogenic therapy may prolong the dormancy of cancer lesions and RIT may eradicate this population of cells.

Feasibility of 186Re-radioimmunotherapy for treatment in an adjuvant setting of colon cancer.

PURPOSE: (186)Re displays abundant intermediate energy beta emission, and possesses an appropriate physical half-life of 3.7 days. We compared the efficacy of radioimmunotherapy (RIT) with an anti-colorectal cancer monoclonal IgG1, (186)Re-A7, with that of RIT employing (131)I in a mouse liver metastasis model. METHODS: Liver metastases were established by intrasplenic injection of LS180 human colon cancer cells. Based on the results of toxicity assessment with escalated administration doses, 21 MBq (186)Re-A7 and 7 MBq (131)I-A7 were chosen as maximum tolerated doses. In the first experiment, mice underwent RIT at 2 weeks when metastases attain a diameter of several millimeters, and were killed 2 weeks later to assess metastatic burden in the liver. In the second experiment, RIT was conducted at 1 week when metastases of several hundred micrometers in diameter were observed, and survival of mice was examined. RESULTS: (186)Re-A7 RIT inhibited the growth of liver metastases better than (131)I-A7 RIT ( P<0.02). Furthermore, (186)Re-A7 RIT induced better improvement in survival of mice than (131)I-A7 RIT ( P<0.002). (186)Re-A7 RIT caused slightly more severe myelotoxicity in mice, but they eventually recovered. Radiation dose estimation demonstrated a significant advantage of (186)Re-A7 RIT over (131)I-A7 RIT. CONCLUSION: These results support the use of RIT with (186)Re-MAb in an adjuvant setting in cases involving minimal disease.

Radioimmunotherapy with 186Re-labeled monoclonal antibody to treat liver metastases of colon cancer cells in nude mice.

The efficacy of radioimmunotherapy (RIT) in the treatment of minimal disease has been previously shown, despite the limitation of beta-emitters suggested by a mathematical model. In the present study, the efficacy of RIT with an anti-colorectal cancer IgG1 A7 conjugated with 186Re was examined in a liver metastasis model established by intrasplenic inoculation of human colon cancer cells. In this model, small metastases of less than 1 mm in diameter can be observed 1 week after cell inoculation. Metastases attain a diameter of several millimeters at 2 weeks. 186Re-A7 accumulated exclusively in metastases, displaying a value of 24.1 +/- 8.7% ID/g 2 days after the injection. 186Re-A7 accumulation in liver metastases increased with decreasing size. RIT with 7 MBq 186Re-A7 at 2 weeks significantly suppressed the growth of metastases; weight of metastases 4 weeks after cell inoculation was 5.96 +/- 0.87 g in nontreated control mice and 1.25 +/- 0.75 g in mice receiving 186Re-A7 RIT (p < 0.0001). RIT at 1 week more effectively inhibited metastatic growth to 0.08 +/- 0.05 g (p < 0.002 vs. RIT at 2 weeks). RIT with a class-matched irrelevant MAb 186Re-HPMS-1 at 1 week after cell inoculation somewhat suppressed metastatic growth, 3.39 +/- 0.25 g at 4 weeks, as compared with the control; however, 186Re-HPMS-1 RIT was far less effective than 186Re-A7 RIT (p < 0.0001). These results support the use of RIT with 186Re-MAb in an adjuvant setting in cases involving minimal disease. Factors such as higher and homogeneous MAb accumulation in small nodules, better perfusion, and subsequent better oxygenation likely compensate for the loss of beta radiation outside small metastases.

Optimization of the uptake method for estimating renal clearance of 99mTc mercaptoacetyltriglycine.

OBJECTIVE: To improve the estimation of 99mTc mercaptoacetyltriglycine clearance in the renal uptake method by optimizing the conditions of renal depth, background, threshold for renal boundary determination, and time interval for integrating renal counts. METHODS: Dynamic renal imaging was performed in 232 patients with dual energy window acquisition (main, 140 +/- 14keV; sub, 122.5 3.5keV). For drawing renal regions of interest (ROIs), cut-off methods with 50% and 70% of the highest renal pixel counts were used. For drawing the backgrounds, circumferential and lateral-inferior quadrant peri-renal ROIs were used. For setting the time interval, periods of 1-2, 1-2.5, 1.5-2.5, 1.5-3 and 2-3 min post-injection were used. For determining renal depth, three methods of a theoretical exponential function using scatter fraction, Tønnesen's formula, and linear combination of scatter fraction and Tønnesen's formula were used. The scatter fraction was calculated using the counts in renal ROIs in the two energy windows. Using every combination of these conditions, renal uptake was calculated. As a reference, one-sample clearance was calculated from a blood sample taken at 30 min post-injection following Bubeck's formula. According to the methods for estimating renal depth, three non-linear regression models were derived to convert renal uptake to clearance. Using one-sample clearance and integrated renal counts as dependent and independent variables, data were fitted to the models to determine the necessary constants. The correlations between the model estimated clearances and one-sample clearance were investigated. RESULTS: One-sample clearance ranged from 11 to 404 ml x min(-1) per 1.73 m2. More than half of the regression using renal depth determined by the scatter fraction alone failed to converge. Among the successfully converged regressions, all model estimated clearances showed significant correlations (P<0.01) with one-sample clearance. The best correlation was observed in the model using renal depth determined by the combination of scatter fraction and Tønnesen's formulas, renal ROIs by 50% cut-off, lateral-inferior background and time interval of 2-3 min (r=0.898, P<0.001). CONCLUSION: The renal uptake method for estimating the clearance of mercaptoacetyltriglycine can be improved by the processing conditions proposed here.

Limitations of (99m)Tc tetrofosmin in assessing reversal effects of verapamil on the function of multi-drug resistance associated protein 1.

BACKGROUND: Previous reports have demonstrated the feasibility of scintigraphic assessment of the multi-drug resistance (MDR) of tumours caused by ATP binding cassette (ABC) transporters by using Tc cationic tracers such as Tc tetrofosmin (TF). Furthermore, the potential of these tracers for evaluating the effects of reversal agents for MDR has been documented. However, most reversal agents simultaneously affect cationic ion transporters related to tracer accumulation in tumours. METHODS: The uptake of Tc-TF was examined in the MCF7/WT cell line, a wild-type breast cancer cell line that does not exhibit MDR, and its subclonal etoposide resistant cell line MCF7/VP, which expresses high levels of MRP1, one of the multi-drug resistance associated proteins (MRPs), in the presence of increasing concentrations of verapamil, a classical MDR modulator. In the absence of verapamil, MCF7/VP cells showed significantly lower Tc-TF uptake than did MCF7/WT cells, indicating that Tc-TF is a substrate for MRP1. The presence of verapamil enhanced the uptake of Tc-TF in MCF7/VP cells. On the other hand, verapamil also increased tracer uptake in MCF7/WT cells, which was readily appreciated when the uptake values were corrected by viable cell numbers: an approximately 100% increase of Tc-TF uptake was observed in comparison with that in the absence of verapamil in viable MCF7/WT cells whereas a 100-200% increase occurred in viable MCF7/VP cells. In addition, verapamil prolonged the retention of radioactivity in both MCF7/WT cells and MCF7/VP cells. CONCLUSION: These results suggest that cellular functions other than MRP1 function, probably cationic ion transporters, are simultaneously and significantly involved in the verapamil induced changes of cellular uptake of Tc-TF. Tc-TF scintigraphy may overestimate the reversal effects of modulators on chemoresistance caused by MRP1 when the modulators simultaneously affect ion transporters.

Improved accuracy in estimation of left ventricular function parameters from QGS software with Tc-99m tetrofosmin gated-SPECT: a multivariate analysis.

UNLABELLED: The purpose of this study was to verify whether the accuracy of left ventricular parameters related to left ventricular function from gated-SPECT improved or not, using multivariate analysis. METHODS: Ninety-six patients with cardiovascular diseases were studied. Gated-SPECT with the QGS software and left ventriculography (LVG) were performed to obtain left ventricular ejection fraction (LVEF), end-diastolic volume (EDV) and end-systolic volume (ESV). Then, multivariate analyses were performed to determine empirical formulas for predicting these parameters. The calculated values of left ventricular parameters were compared with those obtained directly from the QGS software and LVG. RESULTS: Multivariate analyses were able to improve accuracy in estimation of LVEF, EDV and ESV. Statistically significant improvement was seen in LVEF (from r = 0.6965 to r = 0.8093, p < 0.05). Although not statistically significant, improvements in correlation coefficients were seen in EDV (from r = 0.7199 to r = 0.7595, p = 0.2750) and ESV (from r = 0.5694 to r = 0.5871, p = 0.4281). CONCLUSION: The empirical equations with multivariate analysis improved the accuracy in estimating LVEF from gated-SPECT with the QGS software.

Correct localization of epileptogenic focus with I-123 iomazenil cerebral benzodiazepine receptor imaging: a case report of temporal lobe epilepsy with discordant ictal cerebral blood flow SPECT.

A 26-year-old female with intractable epileptic seizures was studied with I-123 iomazenil cerebral benzodiazepine receptor, I-123 IMP inter-ictal and Tc-99m ECD ictal cerebral blood flow SPECT. The ictal cerebral blood flow SPECT indicated the location of the seizures to be in the left temporal lobe, where increased regional cerebral blood flow was noted in marked contrast to the inter-ictal SPECT. Ictal electroencephalograms (EEGs) recorded with scalp and sphenoidal electrodes also suggested the left temporal lobe as the location of the seizures. On I-123 iomazenil SPECT, however, decreased benzodiazepine receptor density was demonstrated in the right temporal lobe. MRI showed mild atrophy and abnormal signal intensity in the right temporal lobe. Ictal EEGs recorded with intracranial electrodes revealed that abnormal electrical activity of the brain always emerged from the right temporal lobe and then propagated to the contralateral side. Based on the findings of intracranial EEGs, partial resection of the right anterior temporal lobe including hippocampus was performed. After the surgery, no seizure occurred. Pathological examination of the surgical specimens revealed hippocampal sclerosis. This case suggested that cerebral benzodiazepine receptor imaging with I-123 iomazenil can be helpful for correct localization of epileptogenic foci.

Comparison of myocardial fatty acid metabolism with left ventricular function and perfusion in cardiomyopathies: by 123I-BMIPP SPECT and 99mTc-tetrofosmin electrocardiographically gated SPECT.

OBJECTIVE: To investigate myocardial fatty acid metabolism and its relationship with left ventricular (LV) function and perfusion in hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). METHODS: Thirty-nine patients with cardiomyopathies (58 +/- 14 y), comprising 15 DCM and 24 HCM, and 9 age-matched healthy controls were studied with 123I-15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) and 99mTc-tetrofosmin (TF) electrocardiographically gated SPECT. As parameters of myocardial fatty acid metabolism, the heart-to-mediastinum ratio (H/M) and global washout of BMIPP were calculated from early and delayed planar images, while regional BMIPP uptake and washout were calculated from SPECT. In TF study, the H/M (H/M-TF) and LV ejection fraction (LVEF) were calculated as global parameters of perfusion and function, while regional TF uptake and wall thickening index were calculated as regional parameters of perfusion and function using the Quantitative Gated SPECT software. The differences in the parameters and the correlations between the parameters from the 2 studies were investigated by one-way ANOVA and multiple linear regression analysis. RESULTS: BMIPP uptake was decreased (p < 0.05), and its washout was increased (p < 0.05) in DCM and HCM. In multiple linear regression analysis, global BMIPP parameters showed no significant correlation with LVEF (p > 0.05), but showed a significant correlation with H/M-TF (p < 0.05) in DCM and HCM. According to the partial correlation coefficient, early H/M was the only significant factor (p < 0.05) for predicting H/M-TF in DCM and HCM. Multiple linear regression analysis on regional parameters showed regional BMIPP parameters had no correlation with regional function (p > 0.05) but had a significant correlation with regional perfusion (p < 0.0001) in DCM. In HCM, regional BMIPP parameters showed significant multiple linear correlations with both regional function (p < 0.005) and perfusion (p < 0.0001). According to the partial correlation coefficients, delayed regional BMIPP uptake was the most significant factor for predicting regional function in HCM, while early regional BMIPP uptake was the only or the most significant factor for predicting regional perfusion in DCM and HCM, respectively. CONCLUSION: In DCM, BMIPP uptake and washout could not reflect LV function. In HCM, regional delayed BMIPP uptake might be useful for evaluating regional function. In DCM and HCM, early BMIPP uptake might be largely determined by myocardial perfusion.

Asialoglycoprotein receptor concentration in tumor-bearing livers and its fate early after their sectorial resection.

UNLABELLED: The aim of the present study was to investigate asialoglycoprotein receptor (ASGP-R) status in tumor-bearing livers and early after their sectorial resection employing 99mTc-DTPA-galactosyl human serum albumin (99mTc-GSA) dynamic SPECT. METHODS: Ten normal liver controls and 44 liver tumor patients who underwent sectorial hepatectomy were included in the study. 99mTc-GSA dynamic SPECT study was performed 7 +/- 3 d before (pre-operative) and 34 +/- 13 d after surgery (post-operative) in liver tumour patients. Pre- and post-operative parameters including hepatic functional volume and 99mTc-GSA clearance of unit hepatic functional volume, representing ASGP-R concentration, were measured. The sum of functional volume of the sectors uninvolved in hepatectomy was defined as residual functional volume. Subsequently, post-operative change in functional volume (the ratio of post-operative to residual functional volume), post-operative change in 99mTc-GSA clearance of unit hepatic functional volume (the ratio of post- to pre-operative 99mTc-GSA clearance of unit hepatic functional volume) and percent resection of functional volume were calculated. RESULTS: Pre-operative 99mTc-GSA clearance of unit hepatic functional volume in tumor-bearing livers was significantly lower than that in non-tumor bearing control liver. The ratio of post- to pre-operative 99mTc-GSA clearance of unit hepatic functional volume showed marked variation from 0.57 to 2.14, which negatively correlated with the percent resection of functional volume (r = -0.58, p < 0.0001). The ratio of post- to pre-operative 99mTc-GSA clearance of unit hepatic functional volume exhibited a negative correlation with the ratio of post-operative to estimated residual functional volume (r = -0.67, p < 0.0001). CONCLUSION: ASGP-R concentration is reduced in the presence of liver tumor. ASGP-R concentration reveals variable changes early after sectorial resection; the change negatively correlates with percent resection of hepatic functional volume. Post-operative change in ASGP-R concentration negatively correlates with change in functional volume.

Estimation with Tc-99m tetrofosmin SPECT of salvaged myocardial mass after emergent reperfusion therapy in acute myocardial infarction.

OBJECTIVES: The purpose of this study was to validate a new quantitative index of salvaged myocardial mass calculated from Tc-99m tetrofosmin SPECT for evaluating the therapeutic effect of emergent reperfusion therapy in acute myocardial infarction (AMI). METHODS: Tc-99m tetrofosmin SPECT was performed before and after emergent percutaneous transluminal coronary angioplasty (PTCA) in eight patients with AMI. In the pre-PTCA study, Tc-99m tetrofosmin was injected before emergent PTCA. Two weeks after the PTCA, post-PTCA study was performed. As a quantitative index of salvaged myocardial mass, salvaged myocardial volume (SMV) was defined as the difference of myocardial functional volume between the SPECT studies before and after the PTCA. To investigate the clinical significance of SMV, SMV was compared with the grade of therapeutic efficacy determined visually from pre- and post-PTCA SPECT images and clinical parameters, namely peak creatine phosphokinase level (pCK) and the time from the onset of the AMI to reperfusion (RPT). RESULTS: SMV showed a significant correlation with the visual grade of therapeutic efficacy (r = 0.737, p < 0.037) and a trend toward significant correlation with pCK (r = -0.622, p < 0.1). SMVs in early- and late-reperfusion groups (RPT < or = 6 hr and RPT > 6 hr) were 30.0 +/- 14.0 and -6.2 +/- 25.5 ml, showing a greater mean SMV value in the early-reperfusion group (p < 0.07). CONCLUSION: SMV could be used as a quantitative index of salvaged myocardial mass for evaluating the therapeutic effect of emergent reperfusion therapy.