MIBI SPECT Imaging Research Articles

Comparing Different Methods for the Diagnosis of Liver Steatosis: What Are the Best Diagnostic Tools?

Due to the ongoing organ shortage, marginal grafts with steatosis are more frequently used in liver transplantation, leading to higher occurrences of graft dysfunction. A histological analysis is the gold standard for the quantification of liver steatosis (LS), but has its drawbacks: it is an invasive method that varies from one pathologist to another and is not available in every hospital at the time of organ procurement. This study aimed to compare non-invasive diagnostic tools to a histological analysis for the quantification of liver steatosis. Male C57BL6J mice were fed with a methioninecholine-deficient (MCD) diet for 14 days or 28 days to induce LS, and were compared to a control group of animals fed with a normal diet. The following non-invasive techniques were performed and compared to the histological quantification of liver steatosis: magnetic resonance spectroscopy (MRS), CARS microscopy, 99mTc MIBI SPECT imaging, and a new near-infrared spectrometer (NIR-SG1). After 28 days on the MCD diet, an evaluation of LS showed ≥30% macrovesicular steatosis. High correlations were found between the NIR-SG1 and the blinded pathologist analysis (R2 = 0.945) (p = 0.001), and between the CARS microscopy (R2 = 0.801 (p < 0.001); MRS, R2 = 0.898 (p < 0.001)) and the blinded pathologist analysis. The ROC curve analysis showed that the area under the curve (AUC) was 1 for both the NIR-SG1 and MRS (p = 0.021 and p < 0.001, respectively), while the AUC = 0.910 for the Oil Red O stain (p < 0.001) and the AUC = 0.865 for the CARS microscopy (p < 0.001). The AUC for the 99mTc MIBI SPECT was 0.640 (p = 0.013), and this was a less discriminating technique for LS quantification. The best-performing non-invasive methods for LS quantification are MRS, CARS microscopy, and the NIR-SG1. The NIR-SG1 is particularly appropriate for clinical practice and needs to be validated by clinical studies on liver grafts.

Comparison of Tc-99m pertechnetate images with dual-phase Tc 99m MIBI and SPECT images in primary hyperparathyroidism.

Background:The purpose of this study was to evaluate the value of Tc-99m pertechnetate planar, dual-phase MIBI and MIBI-SPECT images in the determination and localization of parathyroid lesions.Materials and Methods:In this study, 38 patients who underwent operation for primary hyperparathyroidism were included. Tc-99m pertechnetate planar-pinhole imaging of the neck and then MIBI planar and SPECT images in supine position was performed. Late SPECT images were acquired 120 minutes after the injection. Early and late MIBI images were quantitatively evaluated.Results:Of the 38 patients, 30 of them had adenoma, 2 patients had hyperplasia and 6 of them were normal on planar images. Thirty-four of 38 patients were positive on SPECT images. SPECT images of the patients with positive results were matched with pathology results.Conclusion:As a result, Tc-99m pertechnetate planar-pinhole, Tc-99m MIBI planar and SPECT images are useful for localization of parathyroid lesions especially in multinodular thyroid gland. However, US or CT images are necessary for more accurate localization and Tc-99m pertechnetate images are useful for interpreting and comparing with the early and late MIBI images.

Cardiac Shock Wave Therapy for Chronic Refractory Angina Pectoris. A Prospective Placebo‐Controlled Randomized Trial

Cardiac shock wave therapy (CSWT) delivered to the myocardium increases capillary density and regional myocardial blood flow in animal experiments. In addition, nonenzymatic nitric oxide production and the upregulation of vascular growth factor's mRNA by CSWT have been described. The aim of the study was therefore to test its potential to relieve symptoms in patients with chronic stable angina pectoris. Twenty-one patients (mean age 68.2 ± 8.3 years, 19 males) with chronic refractory angina pectoris and evidence of inducible myocardial ischemia during MIBI-SPECT imaging, were randomized into a treatment (n = 11) and a placebo arm (n = 10). The region of exercise-induced ischemia was treated with echocardiographic guidance during nine sessions over a period of 3 months. One session of CSWT consisted of 200 shots/spot (9--12 spots/session) with an energy intensity of 0.09 mJ/mm(2) . In the control group acoustic simulation was performed without energy application. Medication was kept unchanged during the whole treatment period. In the treatment group, symptoms improved in 9/11 patients, and the ischemic threshold, determined by cardiopulmonary exercise stress testing, increased from 80 ± 28 to 95 ± 28 W (P= 0.036). In the placebo arm, only 2/10 patients reported an improvement and the ischemic threshold remained unchanged (98 ± 23 to 107 ± 23 W; P= 0.141). The items "physical functioning" (P= 0.043), "general health perception" (P= 0.046), and "vitality" (P= 0.035) of the SF-36 questionnaire significantly improved in the treatment arm, whereas in the placebo arm, no significant change was noted. Neither arrhythmias, troponin rise nor complications were observed during treatment. This placebo controlled trial shows a significant improvement in symptoms, quality of life parameters and ischemic threshold during exercise in patients with chronic refractory angina pectoris treated with CSWT. Thus, CSWT represents a new option for the treatment of patients with refractory AP.

Left coronary arteriovenous malformation with fistulous connections to the left and right ventricles

A 20-year-old man with right bundle branch block in recorded ECG was referred to our department. His physical examination was unremarkable. Transthoracic echocardiography showed a severe hypertrophy of the interventricular septum (22 mm)which contained multiple echo-free spaces of the vascular nature. A flow pattern suggestive to a coronary artery fistula into the left ventricle was recorded. The patient was referred for a coronary angiography, which revealed an arteriovenous malformation starting from the septal branch of the enlarged left anterior descending artery. The malformation communicated with the lumen of the left (arterial phase) and right ventricle(venous phase) as well. The posterior descending artery was fed exclusively from the described arteriovenous malformation.99mTc MIBI SPECT images showed a moderately reversible perfusion defect in the inferior wall, suggesting non-critical ischemia of this region.

Left coronary arteriovenous malformation with fistulous connections to the left and right ventricles

A 20-year-old man with right bundle branch block in recordedECG was referred to our department. His physical examinationwas unremarkable. Transthoracic echocardiography showeda severe hypertrophy of the interventricular septum (22 mm)which contained multiple echo-free spaces of the vascularnature. A flow pattern suggestive to a coronary artery fistulainto the left ventricle was recorded. The patient was referredfor a coronary angiography, which revealed an arteriovenousmalformation starting from the septal branch of the enlarged leftanterior descending artery. The malformation communicatedwith the lumen of the left (arterial phase) and right ventricle(venous phase) as well. The posterior descending artery wasfed exclusively from the described arteriovenous malformation.99mTc MIBI SPECT images showed a moderately reversible perfusiondefect in the inferior wall, suggesting non-critical ischemiaof this region.

The influence of collateral circulation on the detection of coronary artery stenosis by dipyridamole MIBI scintigraphy

Dipyridamole is often used as an alternative to exercise in the detection of coronary artery disease by radionuclide techniques. For analyzing the dipyridamole-induced chest pain encountered during this test we studied a group of 47 patients who underwent MIBI SPECT imaging at rest and after the injection of up to 0.84 mg/kg dipyridamole. Coronary arteriography was available in a subgroup of 21 patients. A significant relation was found between chest pain during dipyridamole injection and ischemic electrocardiogram changes in the study group. In the subgroup of 21 patients with coronary angiography, an association was found between chest pain and the presence of collateral circulation. The MIBI perfusion defects were also more prevalent in the group with collaterals. These findings can be explained by the induction of coronary steal after dipyridamole in the group with a collateral circulation. This coronary steal causes real ischemia in the collateralized region. We conclude that in patients with known coronary artery disease, dipyridamole MIBI imaging allows for the selection of those patients with significant coronary stenosis with a collateral circulation. In this way, dipyridamole selects a group of patients who may be at lower risk in case of acute occlusion of the artery.

Virtual Neck Exploration

Computed tomography (CT) together with 99mTc-sestamibi single photon emission computed tomography (MIBI-SPECT) image fusion (CT-MIBI-SPECT image fusion) allows virtual exploration of the neck. The aim of this study was to evaluate whether CT-MIBI-SPECT image fusion is superior to MIBI-SPECT and CT in detecting abnormal parathyroid glands in patients with primary hyperparathyroidism. CT-MIBI-SPECT image fusion for preoperative localization was performed in 116 patients with primary hyperparathyroidism (pHPT). Both investigations were performed with reproducible fixation of the patient on a vacuum mattress. At a special work station the neck was virtually explored by viewing the CT images in all 3 dimensions. The MIBI-SPECT images were superimposed on underlying CT images. Only patients with single-gland disease were evaluated (pHPT: 112, persistent pHPT: 1, recurrent pHPT: 1, persistent secondary hyperparathyroidism: 1, tertiary HPT after kidney transplantation: 1). CT-MIBI-SPECT image fusion results were compared with those obtained with CT alone and MIBI-SPECT alone. The predicted positions were correlated with the intraoperative findings. CT-MIBI-SPECT image fusion was able to predict the exact position of the abnormal gland in 102 (88%) of the 116 patients, whereas CT alone showed in 75 (65%) patients and MIBI-SPECT alone in 64 (55%) patients the exact position of the abnormal gland. Sixty-two patients underwent minimally invasive surgery, namely in 21 patients with a unilaterally focused approach and in 33 patients with a bilateral approach (27 of these underwent simultaneous thyroid resection). Sensitivity for CT-MIBI-SPECT image fusion was 88%, for CT alone 70%, and for MIBI-SPECT alone 59%. Specificity for CT-MIBI-SPECT image fusion was 99%, for MIBI-SPECT alone 95%, for CT alone 94%. Overall accuracy for CT-MIBI-SPECT image fusion was 97%, for CT alone 89%, for MIBI-SPECT 87%. This study provides evidence that CT-MIBI-SPECT image fusion is superior to CT or MIBI-SPECT alone for preoperative localization of enlarged parathyroid glands in patients with single-gland primary hyperparathyroidism.

Role of Tc99m MIBI SPECT in the Assessment of Treatment Response in Pharyngeal Carcinoma

The purpose of this study was to compare Tc(99m) MIBI SPECT imaging with computed tomography (CT) for assessment of post-radiotherapy treatment response in pharyngeal carcinoma. Twenty-two subjects took part in this study, which included six patients with nasopharyngeal carcinoma (Group I), three patients with oropharyngeal carcinoma and eight patients with hypopharyngeal carcinoma (Group II), and five control patients (Group III). All scans were analyzed qualitatively and quantitatively and correlated with findings on local examination and biopsy. Various indices such as ratios of nasopharynx, oropharynx, and hypopharynx to scalp (NSR, OSR, HSR), to nuchal muscles (NNR, ONR, HNR), and parotid glands (NPR, OPR, HPR) were calculated. The mean values of these above mentioned ratios calculated in the control group (Group III) were used as cutoff values to determine the presence or absence of tumor tissue in the patient groups (Groups I and II). The cutoff values calculated were 2.89 (NSR), 1.39 (NNR), 0.57(NPR), 3.83 (OSR), 1.81 (ONR), 0.83 (OPR), 2.86 (HSR), 1.73 (HNR), and 0.59 (HPR). The results revealed 100% sensitivity for primary nasopharyngeal tumors but less sensitivity for primary oropharyngeal and hypopharyngeal tumors (63.6%). Based on a relative decrease in tracer uptake, Tc(99m) MIBI SPECT scan was able to predict partial remission, complete remission, and no response on post-therapy scans. There were three false-negative results of disease progression in addition to evidence of disease eradication on CT scan. Thus Tc(99m) MIBI SPECT imaging has shown promising results in the detection of primary tumors and evaluation of treatment response much earlier than CT scan, which needs further exploration and large-scale studies.

Early Parathyroid MIBI SPECT Imaging in the Diagnosis of Persistent Hyperparathyroidism

We present a case that demonstrates the utility of early SPECT images associated with fusion images with MRI for presurgical localization in a case of persistent hyperparathyroidism after a first surgery. Three years after that surgery, severe hypercalcemia (14.7 mg/dL) and elevated parathormone (PTH) (944 pg/mL) were detected. MRI and SPECT parathyroid scintigraphy showed an abnormal parathyroid lesion localized behind the inferior pole of the thyroid right lobe. At surgical reexploration a right inferior parathyroid adenoma was removed (258 mg). However, intraoperative PTH remained high and a total thyroidectomy was performed looking for an intrathyroid lesion. After that, the elevated PTH persisted and an ectopic parathyroid gland was identified in the tracheoesophageal groove (958 mg), corresponding with the lesion seen on the fusion image of MRI and SPECT. After removal of this lesion, the PTH dropped to 85%.

TC-99m MIBI Spect Imaging in Patients With Lung Carcinoma

Multidrug-resistance (MDR) phenotype concerns altered membrane transport that results in lower cell concentrations of cytotoxic drug in many cancer types, including lung cancer, and is related to the overexpression of a variety of proteins that act as adenosine triphosphate-dependent extrusion pumps. Tc-99m Sestamibi (MIBI) is a transport substrate for P-glycoprotein (Pgp) pump. In this study, we assessed the uptake and clearance of technetium-99m-2-hexakis 2-methoxyisobutylisonitrile (Tc-99m MIBI) from the tumor and its correlation with messenger RNA (mRNA) levels of Pgp, MDR-associated protein (MRP1), and lung resistance protein (LRP) in lung carcinoma. This study was carried out on 19 patients (mean age, 60.1 +/- 2.07 years) with advanced-stage lung carcinoma. The tumor samples obtained by bronchoscopy were assessed to estimate the levels of Pgp, MRP1, and LRP expression on mRNA level by quantitative real-time reverse-transcription polymerase chain reaction. Tc-99m MIBI chest imaging was performed 15 and 180 minutes after injection of 740 MBq Tc-99m MIBI. The early (T/Be) and delayed (T/Bd) Tc-99m MIBI uptakes and washout rate (WR) of Tc-99m MIBI from the tumor were measured. No correlation was found between the T/Be Tc-99m MIBI uptake of tumors (T/Be) and the levels of Pgp mRNA, MRP1 mRNA, and LRP mRNA by reverse-transcription polymerase chain reaction. There was a correlation between the mean T/Bd Tc-99m MIBI uptake and Pgp expression of the tumors (P = 0.001, Spearman rho = - 0.702). There was a correlation between the WR of Tc-99m MIBI from the tumor and Pgp expression of the tumor (P = 0.000, Spearman rho = 0.875). Washout rate of Tc-99m MIBI was not related to the levels of MRP1 mRNA (P = 0.93, Spearman rho = 0.02) or LRP mRNA (P = 0.47, Spearman rho = 0.177). Increased WR of Tc-99m MIBI is related in Pgp over expression of the tumor. Tc-99m MIBI single photon emission computed tomography imaging may be a functional probe of overexpression of Pgp in patients with lung carcinoma. However, Tc-99m MIBI single photon emission computed tomography imaging cannot be used to identify the MDR involved in the MRP1 or LRP in these patients.

CT-MIBI Image Fusion: Transmission and Emission Tomography for Localization of Bronchogenic Carcinoma and Nodal Metastasis

Tc-99m sestamibi is known to concentrate in bronchogenic cancer but it lacks the anatomic details for proper management of the patient. Tc-99m MIBI SPECT imaging can detect bronchogenic cancer with high specificity and high positive predictive value. Tc-99m sestamibi SPECT/CT was performed with a gamma camera mounted anatomic x-ray tomography (GMAXT-GE Medical Systems, Millenium VG with Hawkeye). For comparison with GMAXT, additional high-resolution CT of the mediastinum was performed. Correct preoperative localization was achieved: The lesions found on the MIBI scan were found to be located in the right lung. Apart from this, another lesion was noted on the MIBI scan. On fusion images, this lesion was found to be in the right anterior axillary fold. CT-nuclear medicine fusion imaging guided fine needle aspiration cytology done from the lesion in the axillary fold gave a diagnosis of metastatic adenocarcinoma. This was later confirmed by surgical biopsy of the lymph node. Later biopsy reports on bronchoscopy confirmed the lung lesion to be adenocarcinoma.

Dobutamine stress tetrofosmin SPECT; evaluation of short rest-stress protocol and head to head comparison with MIBI in detection of coronary artery disease

The purpose of the present study was to evaluate the feasibility and diagnostic accuracy of same day short rest-dobutamine stress Tetrofosmin (TF) SPECT imaging protocol and to compare TF SPECT results with MIBI SPECT in the same subjects who were unable to perform treadmill exercise or were unsuitable for pharmacological vasodilator stress. The study group consisted of 19 patients (2 female and 17 male, with a mean age of 53.8 +/- 7.9 yrs) in whom coronary artery disease (CAD) had been proven or excluded at coronary angiography (CA). MIBI SPECT imaging was performed first. TF SPECT images were obtained one week after MIBI imaging. Immediately after the rest SPECT imaging in both of the MIBI and TF studies, patients underwent dobutamine stress tests. Rest-stress radiotracer doses and dobutamine doses were the same for both TF and MIBI studies. While 60 min waiting periods were applied for MIBI study, only 30 min waiting periods were applied for TF study after the rest and stress injections. Images were evaluated by visual and quantitative analysis. Dobutamine stress parameters were similar for both studies. Although in TF study, the time between radiopharmaceutical injection and imaging was shorter than in MIBI study, there was no significant difference between heart-to-liver (H/Li) and heart-to-lung (H/Lu) ratios. According to CA results, diagnostic accuracy was similar for TF and MIBI. While sensitivity, specificity and accuracy for TF study were calculated as 82%, 84% and 82%, respectively, the corresponding values for MIBI were 82%, 88% and 84%, respectively. This clinical study has shown comparable diagnostic performance for the detection of CAD between MIBI and TF. Good correlation was found between segmental analysis for both studies. MIBI and TF showed similar perfusion defects and good segmental correlation during dobutamine stress with the same quality images. Both radiopharmaceuticals may be acceptable with this imaging protocol. Besides this, TF study showed better reversibility degree (55%) in a shorter time when compared to MIBI study (25%) in perfusion defects (especially in segments with severely decreased perfusion or no uptake).

Gated Tc-99m sestamibi SPECT versus stress-rest SPECT in detecting coronary artery disease: correlation with coronary angiography in patients without myocardial infarction.

It is possible to simultaneously evaluate wall thickening and perfusion abnormalities with radionuclide techniques that use tracers such as Tc-99m MIBI. We presumed that detection of wall thickening by gated MIBI SPECT imaging in the presence of a stress-induced perfusion defect correlates with reversibility of that defect on resting images. Therefore, the aim of our study was to analyze, in patients without myocardial infarction, resting wall thickening and stress perfusion imaging as an alternative to conventional stress-rest imaging. The patients (n = 44) underwent an exercise (n = 37) or pharmacologic (n = 7) stress protocol. All patients had previous coronary angiography within 3 months. Stress-rest MIBI SPECT and gated MIBI SPECT studies were analyzed by visual scoring. The sensitivity and specificity of segmental analysis of both stress-rest MIBI SPECT perfusion and gated MIBI SPECT studies for the overall detection of coronary artery disease were, respectively, 71% and 96%. For patient evaluation for detection of coronary artery disease, stress-rest MIBI SPECT perfusion and gated MIBI SPECT studies showed a sensitivity rate of 96% for both and specificity rates of 84% and 79%, respectively. Our data revealed close agreement between reversible perfusion defects on stress-rest MIBI SPECT scans and significant wall thickening on gated MIBI SPECT stress images in patients without previous myocardial infarction (95%). Gated MIBI SPECT stress, without resting studies, which provide an assessment of wall motion and wall thickening, potentially allows stress defect reversibility to be evaluated in patients without previous myocardial infarction.

Ecocardiografía-MIBI con dobutamina: significado de las alteraciones de la contractilidad en pacientes con alteraciones de la perfusión

In the presence of coronary artery disease and with an appropriate stressor, perfusion defects precede contractility abnormalities. Perfusion defects without contractility abnormalities may be due to the absence of ischemia or mild ischemia. Our purpose has been to compare the clinical characteristics, hemodynamic response and severity of perfusion defects in patients with coronary artery disease and perfusion defects with and without wall motion abnormalities during dobutamine infusion. Eighty two patients with significant coronary artery disease demonstrated by angiography without previous myocardial infarction underwent dobutamine infusion (up to 40 mg/kg/min). Atropine was given when necessary. Stress scientigraphic MIBI-SPECT images were acquired 1 hour after peak stress and rest studies were obtained 24 hours after stress testing. The perfusion score was calculated by dividing the total uptake score between the number of segments affected. Among the 73 patients with perfusion defects, stress echocardiography was positive in 59 (Group A) and was negative in the remaining 14 (Group B). There were more hypertensive patients in Group A (33 vs 4; p = 0.04). There was no significant difference between the two groups with respect to other clinical characteristics. The peak rate-pressure product was similar in both groups (18.520 +/- 5.691 vs 18.680 +/- 5.329; p = NS). The development of electric abnormalities and angina was more common in Group A (42 vs 3, p < 0.001 and 33 vs 1; p < 0.001). Perfusion defects were not more extensive in Group A (abnormal segments 2.15 vs 2.21; p = NS) but they were more severe (segments with severe uptake reduction or no uptake 1.10 vs 0.28; p < 0.05; perfusion score 2.62 vs 2.21; p < 0.05). In patients with severe coronary artery disease and perfusion defects during dobutamine-MIBI-SPECT, the presence of wall motion abnormalities defines patients with more severe perfusion defects.

Preliminary results with technetium-99M MIBI spect imaging in patients with brain tumors: Correlation with histological and neuroradiological diagnoses and therapeutic response

SPECT using Tc-99m MIBI was performed in patients with brain tumors in order to determine Tc-99m MIBI uptake in brain tumors and to evaluate the efficacy of MIBI imaging in the assessment of treatment response. A MIBI uptake index was calculated on SPECT imaging. All tumors with a MIBI-index higher than 7.5 were malignant. In the tumors evaluated before and after radiochemotherapy, the MIBI-index immediately following therapy correlated with treatment response 2 months after therapy. Thus, semiquantitative assessment using Tc-99m MIBI SPECT imaging may be useful in the evaluation of treatment response.

Comparison of dobutamine stress echocardiography and MIBI SPECT imaging for the diagnosis of coronary artery disease in hypertensive patients with and without left ventricular hypertrophy

Comparison of dobutamine stress echocardiography and MIBI SPECT imaging for the diagnosis of coronary artery disease in hypertensive patients with and without left ventricular hypertrophy

Detection of restenosis after percutaneous transluminal coronary angioplasty by dobutamine MIBI SPECT imaging

Detection of restenosis after percutaneous transluminal coronary angioplasty by dobutamine MIBI SPECT imaging

The influence of collateral circulation on the detection of coronary artery stenosis by dipyridamole MIBI scintigraphy

Dipyridamole is often used as an alternative to exercise in the detection of coronary artery disease by radionuclide techniques. For analyzing the dipyridamole-induced chest pain encountered during this test we studied a group of 47 patients who underwent MIBI SPECT imaging at rest and after the injection of up to 0.84 mg/kg dipyridamole. Coronary arteriography was available in a subgroup of 21 patients. A significant relation was found between chest pain during dipyridamole injection and ischemic electrocardiogram changes in the study group. In the subgroup of 21 patients with coronary angiography, an association was found between chest pain and the presence of collateral circulation. The MIBI perfusion defects were also more prevalent in the group with collaterals. These findings can be explained by the induction of coronary steal after dipyridamole in the group with a collateral circulation. This coronary steal causes real ischemia in the collateralized region. We conclude that in patients with known coronary artery disease, dipyridamole MIBI imaging allows for the selection of those patients with significant coronary stenosis with a collateral circulation. In this way, dipyridamole selects a group of patients who may be at lower risk in case of acute occlusion of the artery.

Comparison of TI-201 and Tc-99m MIBI SPECT Imaging in Nasopharyngeal Carcinoma

Both TI-201 and Tc-99m MIBI uptake in nasopharyngeal carcinoma (NPC) have been reported, yet no comparative study of these two agents using SPECT images has been undertaken for NPC. This study compares the relative effectiveness of TI-201 and Tc-99m MIBI SPECT for detecting NPC. In the patients with NPC, 26 of 32 (81%) showed TI-201 tumor uptake, whereas 24 of 32 (75%) showed Tc-99m MIBI tumor uptake. This preliminary study suggests that both Tc-99m MIBI and TI-201 SPECT imaging can be helpful in detecting NPC, and that sensitivity is slightly higher in TI-201 SPECT imaging.

Effect of dipyridamole on myocardial perfusion and function using Technetium-99m MIBI

Myocardial perfusion imaging with dipyridamole is an accepted method for diagnosing coronary artery disease. However, the simultaneous effect of dipyridamole on perfusion and function in the detection of coronary artery disease has not been studied extensively. The aim of this study was to investigate this effect using technetium-99m methoxy isobutyl isonitrile (Tc-MIBI) imaging. Twenty-eight patients with proven coronary artery disease participated in a 2-day protocol (rest and then 0.56 mg/kg dipyridamole i.v.) using Tc-MIBI for first-pass radionuclide ventriculography followed by SPECT imaging. Fifteen patients (54%) demonstrated a decrease in left ventricular ejection fraction from rest to dipyridamole and/or wall motion abnormality, while 21 patients (75%) showed abnormal perfusion by dipyridamole MIBI SPECT imaging. Concordance between perfusion and function was 65%. Correlation for one-, two- and three-vessel disease (coronary angiography) to perfusion versus function were: 54% vs. 38%, 80% vs. 60% and 80% vs. 80%, respectively. Left ventricular dysfunction using dipyridamole was noted in patients with multivessel disease, and with multi-reversible perfusion filling defects. We conclude that dipyridamole in combination with Tc-MIBI for assessment of perfusion and function serves as a valuable tool to identify patients with multivessel disease and a high amount of myocardium at risk.