Tc-MIBI Single Photon Emission Computed Tomography Research Articles

In vivo validation of gated myocardial SPECT imaging for quantification of small hearts: comparison with cardiac MRI.

BackgroundIn patients with small hearts, the Quantitative Gated single-photon emission computed tomography (SPECT) (QGS) program frequently underestimates the left ventricular (LV) end-systolic volume (ESV) and overestimates the ejection fraction (EF). A newly developed cardiac software program, cardioREPO/EXINI heart (cREPO), has been proposed to more accurately quantify small hearts using active shape modeling and a volume-dependent edge correction algorithm for LV delineation. The aim of this study was to validate cREPO in vivo for measuring the LV volumes and EF of both small and non-small hearts, in comparison with values obtained via cardiac MRI (CMR).MethodsWe performed stress 99mTc-MIBI SPECT and CMR within a 30-day interval for 44 patients (mean age, 66 years; 27 men). Resting EF, end-diastolic volume (EDV), and ESV with QGS and cREPO were compared with values obtained via CMR.ResultsThe subjects consisted of 17 small and 27 non-small hearts. CMR yielded EDV, ESV, and EF values of 135 ± 31 ml (mean ± SD, range 85–217 ml), 57 ± 21 ml (27–105 ml), and 60 ± 6 % (45–70 %), respectively. Compared with CMR, both QGS and cREPO systematically underestimated both EDV and ESV and overestimated EF. The magnitude of the overestimation of EF by QGS, compared with CMR, correlated strongly with the given EF values (r = 0.71, P < 0.0001). In contrast, no significant correlation was seen with cREPO (r = 0.18, P = 0.24). In addition, no significant correlation was found between the magnitude of the underestimation of ESV and heart size with cREPO (r = 0.03, P = 0.83). Thus, cREPO provided a relatively constant 9 % overestimation of EF values relative to CMR, for the studied EF range for both small and non-small hearts.ConclusionsThe use of the new algorithm of cREPO ameliorated exaggerated EF in small hearts but not resolved completely. The program provided a constant 9 % overestimation for both small and non-small hearts, which should be carefully taken into account for clinical assessment of LV function.

Assessment of 99mTc-MIBI SPECT(/CT) to monitor multidrug resistance-related proteins and apoptosis-related proteins in patients with ovarian cancer: a preliminary study

Multidrug resistance (MDR) has been suggested to be a major cause of failure of chemotherapy treatment for cancer. It is associated with the expression of MDR-related and apoptosis-related proteins. Recently, technetium-99m hexakis 2-methoxyisobutylisonitrile ((99m)Tc-MIBI) has been suggested as a tumor-seeking agent for the detection of MDR. The aim of this study was to evaluate (99m)Tc-MIBI single-photon emission computed tomography (SPECT)(/CT) for functional imaging of MDR-related and apoptosis-related proteins in patients with ovarian cancer. Eleven women (mean age 63 years, range 53-76) with a clinical suspicion of ovarian cancer were prospectively studied. All patients were examined with (99m)Tc-MIBI imaging before surgery. After intravenous injection of 740 MBq (99m)Tc-MIBI, SPECT(/CT) imaging at 10 min and 2 h was performed. Based on the semiquantitative analysis of (99m)Tc-MIBI SPECT(/CT), both early and delayed tumor uptake ratios and washout rate % were calculated. The expression of MDR-related and apoptosis-related proteins was assessed in surgically excised tumors. Immunohistochemical staining was performed to quantify the expression levels of multidrug resistance protein 1 (MDR1), multidrug resistance-associated protein1 (MRP1), MRP3, lung resistance protein (LRP), breast cancer resistance protein (BCRP), Y-box-binding protein-1 (YB-1), Bcl-2, Bax and glutathione-S-transferase. (99m)Tc-MIBI imaging results and immunohistochemical results were compared. Laparotomy was performed in all patients. Six ovarian cancers were proven by histopathological examination. Five of the six ovarian cancers were positive for (99m)Tc-MIBI uptake on both early and delayed images with (99m)Tc-MIBI SPECT(/CT). MDR-related and apoptosis-related proteins were found to be expressed in all tumors. For the five positive (99m)Tc-MIBI uptake cases, the washout rate % of (99m)Tc-MIBI uptake showed a significant positive correlation with the expression of YB-1 (r = 0.988, P = 0.0015), and the early tumor uptake ratio showed a significant positive correlation with the expression of Bax (r = 0.882, P = 0.047). Our results suggested that (99m)Tc-MIBI SPECT(/CT) might be a valuable diagnostic imaging technique to evaluate MDR-associated YB-1 and Bax-mediated apoptosis in patients with ovarian cancer.

11C-methionine PET/CT imaging of 99mTc-MIBI-SPECT/CT-negative patients with primary hyperparathyroidism and previous neck surgery.

(99m)Tc-Methoxy-isobutyl-isonitrile (MIBI) scintigraphy is a standard preoperative localization imaging modality in patients with primary hyperparathyroidism (pHPT). Its accuracy in localizing a hyperactive parathyroid gland after previous cervical surgery is limited. Recently, (11)C-methionine has been introduced as a promising radiotracer for pHPT imaging. Yet, few data exist for this technique in patients with persisting or recurrent pHPT before reoperation. We aimed to investigate the ability of (11)C-methionine positron emission tomography (PET)/computed tomography (CT) to localize a parathyroid disorder after cervical surgery and negative postsurgical (99m)Tc-MIBI single-photon emission CT (SPECT)/CT. Fifteen patients (6 males, 9 females; age range, 36-85 years) with pHPT and negative (99m)Tc-MIBI SPECT/CT who had undergone earlier neck surgery because of pHPT and/or thyroid disorder were recruited. Twelve of the 15 patients had thyroidectomy for goiter or differentiated thyroid carcinoma. Ten patients had previous parathyroid surgery for pHPT, and 2 patients had a history of parathyroid carcinoma. Thirteen of 15 patients showed elevated levels of intact PTH at the time of PET/CT imaging, whereas all patients had elevated serum calcium values. Pathological results of contrast-enhanced (11)C-methionine PET/CT and surgical results were evaluated. In 6 of 15 patients (11)C-methionine PET/CT showed a hypermetabolic focus in the upper mediastinum in 2 patients, in the thoracic outlet in 1 patient, and in the cervical region in 3 patients. In 9 of the 15 patients, no hyperactive parathyroid gland could be visualized. Reoperation was performed in 5 of 6 patients without surgical complications. One patient refused surgery. In 2 of the 5 patients, a transsternal procedure was performed. Correlating with the (11)C-methionine PET/CT results, a single parathyroid adenoma was found in 4 patients and parathyroid carcinoma metastasis in 1 patient. (11)C-Methionine PET/CT is a useful complementary imaging technique to localize parathyroid adenoma or carcinoma in (99m)Tc-MIBI SPECT/CT-negative patients.

Evaluation of left ventricular myocardial perfusion and function using gated SPECT in patients with hypertrophic obstruction cardiomyopathy following percutaneous transluminal septal myocardial ablation

This study was designed to evaluate the left ventricular myocardial perfusion and function in hypertrophic obstruction cardiomyopathy patients following percutaneous transluminal septal myocardial ablation (PTSMA) using rest single-photon emission computed tomography (SPECT) myocardial perfusion imaging. Thirty-five patients (24 men and 11 women, 48±11 years old) with hypertrophic obstruction cardiomyopathy underwent rest-gated Tc-MIBI SPECT imaging 4±10 days before (baseline) and 4.7±1.0 days (short-term) and 15.5±8.2 months (mid-term) after PTSMA. Semiquantitative and QGS quantitative evaluations of perfusion and function were carried out in 17 left ventricular segments. Myocardial perfusion of the septum following PTSMA was significantly reduced compared with baseline in all patients (P<0.05), but the myocardial perfusion in the basal septum was significantly higher at mid-term compared with short-term following PTSMA (P<0.05). Left ventricular ejection fraction was significantly decreased following PTSMA (P<0.05). Regional wall motion assessed in the basal anterior, basal septum, and basal inferior areas following PTSMA was significantly reduced compared with baseline (P<0.05), and wall thickening of the interventricular septum was decreased following PTSMA (P<0.05). Rest-gated SPECT imaging can be used to assess left ventricular myocardial perfusion and function and to investigate the efficacy of PTSMA during follow-up.

Assessment of Doxorubicin Cardiac Toxicity Using Gated &lt;sup&gt;99m&lt;/sup&gt;Tc-Hexakis-2-Methoxyisobutylisonitrile Myocardial Single Photon Emission Computed Tomography

Advancement in chemotherapy has significantly improved the prognosis of cancer patients. However, many anticancer drugs have serious cardiovascular side effects. We assessed doxorubicin-induced cardiac toxicity (DCT) during and after preoperative chemotherapy using gated (99m)Tc-hexakis-2-methoxyisobutylisonitrile (MIBI) single photon emission computed tomography (SPECT) in patients with malignant bone and soft tissue tumors. Gated (99m)Tc-MIBI SPECT was performed before, and after the middle and final courses of preoperative chemotherapy. Gated (99m)Tc-MIBI SPECT was quantitatively analyzed with QGS/QPS software. We also assessed the reproducibility of measurements of global and regional functions from gated SPECT images. Twenty-eight patients (19 males and 9 females), eligible for preoperative chemotherapy, were included. All patients had normal myocardial perfusion images based on QPS during preoperative chemotherapy. Wall thickening (WT) and motion (WM) decreased after the middle course of preoperative chemotherapy compared to baseline. After the final course of preoperative chemotherapy, significant decreases of ejection fraction, WT and WM, and one-third mean filling rate were observed compared to baseline. By regression analysis, correlation coefficients of inter- and intra-observer reproducibility of global and regional functions were excellent (r ≥ 0.95). Gated (99m)Tc-MIBI SPECT can monitor the deterioration of cardiac function in asymptomatic patients with possible DCT. WT and WM might be useful as early markers of ventricular dysfunction due to DCT.

Technetium‐99m‐labelled HL91 and technetium‐99m‐labelled MIBI SPECT imaging for the detection of ischaemic viable myocardium: a preliminary study

The assessment of myocardial viability has become an important aspect of the diagnostic and prognostic work-up of patients with coronary artery disease. Technetium-99m labelled sestamibi ((99m)Tc-MIBI) myocardial perfusion imaging may underestimate the viability of ischaemic myocardium. Technetium-99m labelled 4,9-diaza-3,3,10,10-tetramethyldodecan-2,11-dione dioxime ((99m)Tc-HL91) is a hypoxia-avid agent which can identify acutely ischaemic viable myocardium in a canine model using a standard gamma camera. The aim of this study was to evaluate uptake character of ischaemic viable myocardium and diagnostic performance of single-photon emission computed tomography (SPECT) imaging by (99m)Tc-HL91 and (99m)Tc-MIBI in detecting ischaemic viable myocardium in coronary heart disease. A total of 41 patients with coronary artery disease were recruited from March 2008 to May 2009. For detecting ischaemic viable myocardium, SPECT imaging by (99m)Tc-HL91 and (99m)Tc-MIBI were performed in all patients before coronary revascularization. Six patients with single ischaemic myocardial segment received a 2-day SEPCT/CT imaging protocol and the uptake of (99m)Tc-HL91 in ischaemic myocardium was quantitatively analysed. The remaining 35 patients received a 1-day (99m)Tc-HL91 and (99m)Tc-MIBI SPECT imaging protocol. Resting (99m)Tc-MIBI myocardial perfusion imaging in 3-18 months after revascularization was used as the standard methodology to evaluate the myocardial viability. In 41 patients, 66 ischaemic myocardial segments were proven to be viable and 12 to be necrotic by resting (99m)Tc-MIBI myocardial perfusion imaging after coronary revascularization. Furthermore, 60 viable segments with negative uptake of (99m)Tc-MIBI showed positive uptake of (99m)Tc-HL91. The remaining six viable segments and 12 necrotic segments showed both negative uptake of (99m)Tc-HL91 and (99m)Tc-MIBI. The sensitivity, specificity, accuracy, Younden Index, positive predictive value and negative predictive value for evaluating ischaemic viable myocardium were 90·9%, 100%, 92·3%, 90·9%, 100% and 66·7%, respectively. Ischaemic viable myocardium had the negative (99m)Tc-MIBI uptake and positive (99m)Tc-HL91 uptake, which demonstrated a mismatched uptake character. Quantitative analysis indicated the uptake of (99m)Tc-HL91 in viable myocardium was increasing in the first 1-3 h and remained stable at the 3-4 h after injection. Functional SPECT imaging with (99m)Tc-HL91 and (99m)Tc-MIBI can be used to detect the seriously ischaemic but viable myocardium with a mismatched uptake character. The uptake of (99m)Tc-HL91 in the viable myocardium reached a stable level at 3-4 h after injection.

Comparison of Global and Regional Abnormalities in 99mTc-sestamibi and Cardiac Magnetic Resonance Imaging in Dilated Cardiomyopathy

Objective The clinical relevance of perfusion defects and increased washout rate (WOR) in 99mTc-sestamibi (Tc MIBI) imaging has not been well characterized in dilated cardiomyopathy (DCM). We analyzed abnormalities in Tc MIBI imaging in relation to those in cardiac magnetic resonance (CMR) imaging. Methods and Results Nineteen DCM patients underwent both Tc MIBI and CMR imaging. The perfusion defects and global and regional MIBI WORs were evaluated with planar and single photon emission computed tomography (SPECT) images. The left ventricular function and the delayed enhancement (DE) were estimated with the cine- and DE-mode CMR. In the DCM patients, the Tc MIBI SPECT showed perfusion defects in 65 segments of 14 patients. The global and regional Tc MIBI WORs were higher than those in 10 normal volunteers (19.4 ± 9.1% vs. 11.7 ± 6.8% in global and 13.8 ± 8.6% vs. 9.6 ± 8.2% in regional WORs; mean ± SD, P < .01). The DE-mode CMR demonstrated DE in 103 segments of 14 patients. The severity of perfusion defects was correlated with the extent of DE ( r = 0.71, P < .01). The regional Tc MIBI WOR was highest in the segments with perfusion defects or DE, but the Tc MIBI WOR in segments without them was also higher than that in the normal volunteers. There was a weak but significant negative correlation between the regional Tc MIBI WOR and wall thickening ( r = −0.23, P < .01). Conclusions In DCM, the severity of perfusion defects and the increase in Tc MIBI WOR reflect the spread of myocardial fibrosis and/or scar. The increase in Tc MIBI WOR is potentially associated with regional dysfunction of LV wall.

Cardioprotective effect of an L/N-type calcium channel blocker in patients with hypertensive heart disease

Left ventricular (LV) diastolic dysfunction is related to increased cardiac sympathetic activity. We investigated the effect of cilnidipine, an L/N-type calcium channel blocker, on LV diastolic function and cardiac sympathetic activity in patients with hypertensive heart disease (HHD) using radionuclide myocardial imaging. Thirty-two frame electrocardiography (ECG) -gated (99m)Tc-sestamibi (MIBI) myocardial single photon emission computed tomography (SPECT), and (123)I-metaiodobenzylguanidine (MIBG) imaging were performed before and 6 months after drug administration in 32 outpatients with HHD. Sixteen of the patients were treated with cilnidipine and the other 16 were treated with nifedipine retard. The parameters for assessing LV diastolic function evaluated using ECG-gated (99m)Tc-MIBI SPECT were peak filling rate (PFR), first-third filling rate (1/3FR), and time to peak filling (TPF). Cardiac sympathetic activity was assessed as early and delayed heart to mediastinum (H/M) ratios and a washout rate (WR), using (123)I-MIBG imaging. The PFR and 1/3FR significantly increased after 6 months of treatment with cilnidipine (p<0.05 for both), but did not with nifedipine retard. The H/M ratios significantly increased (p<0.05 for both) in conjunction with a decreased WR (p<0.05) in the cilnidipine group. Moreover, a significant positive correlation was seen between the rate of change in PFR and the rate of change in early and delayed H/M ratios in the cilnidipine group (p<0.05 for both). The same results were obtained for the relationship between the rate of change in 1/3FR and the rate of change in H/M ratios (p<0.05 for both). However, no such relationship was seen in the nifedipine group. These data indicate that cilnidipine seems to suppress cardiac sympathetic overactivity via blockade of N-type calcium channels and improves LV diastolic function in patients with HHD.

Important factors for salvaging myocardium in patients with acute myocardial infarction

This study was designed to evaluate the factors that affect myocardial salvage after percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI). One hundred and eighty-three patients with AMI who had undergone successful PCI were recruited for this study. Patients underwent (99m)Tc-pyrophosphate single photon emission computed tomography (SPECT) on the third day and (99m)Tc-MIBI SPECT on the sixth day after admission. In the 20 SPECT segments, the summed defect score (TDS) and extent score (ES) of AMI segments were determined and the percentage of the salvaged myocardium was calculated based on the TDS and ES. We performed multivariate analysis to evaluate factors that can affect myocardial salvage. Multivariate analysis was performed among the value of myocardial salvage rate and the 15 clinical variables. Administration of nicorandil (p=0.006), prodromal angina (p<0.001), and high TIMI grade (p<0.001) had significant positive correlation to myocardial salvage rate. Use of a distal protection device had a significant negative correlation with myocardial salvage rate (p=0.006). The presence of high TIMI grade before PCI and prodromal angina are very important for salvaging myocardium. Furthermore, administration of nicorandil is important in salvaging myocardium in patients with AMI.

Delineation of Target Volume for Radiotherapy of High-Grade Gliomas by 99mTc-MIBI SPECT and MRI Fusion

Computed tomography (CT) and magnetic resonance imaging (MRI) are traditionally used for treatment planning of high-grade glioma. 99m Tc-methoxy-isobutyl-isonitrile (MIBI) single-photon emission computed tomography (SPECT) showed high sensitivity and specificity in literature series. In the present study, it was investigated how the information provided by 99m Tc-MIBI SPECT and MRI fusion could affect target delineation for radiotherapy of high-grade glioma. 21 patients with high-grade glioma were studied by MRI and 99m Tc-MIBI SPECT imaging. The gross tumor volume (GTV) was outlined on MRI (MRI-GTV) and SPECT images (SPECT-GTV). Three additional volumes were analyzed: the (MRI+SPECT)-GTV representing the whole amount of MRI-GTV plus SPECT-GTV, the (MRI&SPECT)-GTV identified by the overlapping region of MRI-GTV and SPECT-GTV, and the (SPECT/MRI)-GTV identified by the extension of SPECT-GTV outside MRI-GTV. MRI contrast-enhanced and 99m Tc-MIBI SPECT-positive lesions were found in all 21 patients. The average SPECT-GTV was slightly larger than the average MRI-GTV, with greater difference for resected than for unresected cases. The average increment of (MRI+SPECT)-GTV compared to MRI-GTV was 33%, being significantly higher for resected than for unresected cases (p = 0.006). The fusion of 99m Tc-MIBI SPECT and MRI significantly affected the delineation of the target volume identified by MRI alone.

Catheter-based management for the congenital coronary arteriovenous fistula indicated by the stress 99 m Tc-MIBI SPECT

A 10-year-old boy, who had suffered Kawasaki disease 7 years ago, presented chest pain, pale face, and cold sweating in the stress 99 m technetium-methoxyisobutylisonitrile ( 99 m Tc-MIBI) single-photon emission computed tomography (SPECT), which showed reversible perfusion abnormality indicative of myocardial ischemia involving the right coronary artery. Angiography identified congenital coronary arteriovenous fistula (CAVF) from the right coronary artery to the main pulmonary artery, to which the patient's symptoms and signs of myocardial ischemia, by means of coronary steal phenomenon that entails reversible perfusion abnormality in the stress 99 m Tc-MIBI SPECT, could be ascribed. The penny shall finally be dropped without sudden cardiac event after coaxial transarterial coil occlusion on this boy with the congenital CAVF that is indicated significantly by the stress 99 m Tc-MIBI SPECT.

Technetium-99m sestamibi single photon emission computed tomography findings correlated with P-glycoprotein expression in pituitary adenoma.

The aim of this study is to evaluate whether the technetium-99m sestamibi ((99m)Tc-MIBI) single photon emission computed tomography (SPECT) characteristics of pituitary adenomas might be correlated with cavernous sinus invasion, proliferative potential or the multidrug-resistance (MDR-1) gene product P-glycoprotein (Pgp) expression in pituitary adenomas. Fifteen patients with pituitary adenomas, including 10 nonfunctioning adenomas, two prolactinomas, two GH producing adenomas, and one ACTH producing adenomas was investigated for this study. SPECT images with (99m)Tc-MIBI were acquired 15 minutes (early) and 3 hours (delayed) after injection. The tumor-to-normal brain ratio was calculated both early (ER) and delayed (DR) images. Retention index (RI) was calculated using the following formula: (DR-ER)/ERx100%. The pituitary adenomas specimens were examined by immunohistochemistry using anti-Pgp and MIB-1 monoclonal antibodies.(99m)Tc-MIBI SPECT findings were not related to MIB-1 labeling index or cavernous sinus invasion. (99m)Tc-MIBI SPECT RI (-38.55+/-20.77) of the Pgp-positive group was significantly lower than that (-15.78+/-19.40) of Pgp-negative group (p=0.0494). No significant difference was observed in the ER and DR of (99m)Tc-MIBI SPECT between Pgp-positive and negative groups. Our study suggests that although (99m)Tc-MIBI SPECT is not useful to evaluate the proliferative potential or cavernous sinus invasion of pituitary adenomas. (99m)Tc-MIBI SPECT could predict anti-cancer drug resistance related to the expression of Pgp in pituitary adenomas.

Usefulness of technetium-99m methoxyisobutylisonitrile single-photon emission computed tomography and computed tomography in the evaluation of cervical lymph node metastasis

The aim of this study was to compare the effectiveness of technetium-99m methoxyisobutylisonitrile ((99m)Tc-MIBI) single-photon emission computed tomography (SPECT) and computed tomography (CT) in evaluating cervical lymph node metastasis of head and neck cancer. Histopathologic results of 166 cervical lymph node levels in 31 neck-dissected patients were compared with pre-operative CT and (99m)Tc-MIBI SPECT findings about cervical lymph node metastasis, retrospectively. Sensitivity, specificity and predictability of CT and (99m)Tc-MIBI SPECT were 68.2, 93.1 and 89.8 per cent and 59.1, 87.5 and 83.7 per cent, respectively. When analysing CT and(99m)Tc-MIBI SPECT together, sensitivity and specificity were 86.4 and 99.3 per cent, respectively. The combined use of (99m)Tc-MIBI SPECT and CT could increase the accuracy of cervical lymph node metastases detection, compared with separate use of either (99m)Tc-MIBI SPECT or CT.

Stress/Rest 99mTc-MIBI SPECT and 123I-BMIPP Scintigraphy for Indication of Surgery With Coronary Artery to Pulmonary Artery Fistula

A 45-year old man was admitted to our hospital with chest pain occurring suddenly upon exercise and disappearing with rest within several minutes. A continuous murmur was heard at the upper sternum border. Conventional electrocardiography showed no evidence of myocardial ischemia. Coronary angiography and cardiac catheterization demonstrated a fistula originating from the left coronary artery to the pulmonary artery with an aneurysm 2 cm in size, and Qp/Qs 1.08. Treadmill exercise testing showed no ST-T change at the maximum heart rate of 160 beats/min. Stress/Rest (99m)Technetium-MIBI single-photon emission computed tomography (SPECT) and 123I-15-(p-iodo-phenyl)-3,R,S-methylpentadecanoic acid (BMIPP) scintigraphy were performed to evaluate myocardial ischemia and ischemia was identified at the perfusion area of the left anterior descending artery. From these results, the patient was diagnosed as having a coronary artery to pulmonary artery fistula with myocardial ischemia. Consequently, surgical treatment was chosen under cardiopulmonary bypass. The determination of a surgical indication using stress/rest (99m)Tc-MIBI SPECT and BMIPP scintigraphy is useful in cases showing normal TMT, such as this case.