99mTc-MIBI Single-photon Emission Computed Tomography Research Articles

Relationship between transient ischemic dilatation and changes in heart rate during gated SPECT acquisition in a low-risk population without perfusion defects.

Transient ischemic dilatation (TID) in myocardial perfusion single photon emission computed tomography (SPECT) is considered a marker of poor prognosis. However, it has been suggested that some cases are due to apparent volumetric changes secondary to differences in heart rate (HR) at the time of acquisition. We assessed the correlation between transient dilatation and HR in low risk patients with no perfusion defects. We retrospectively analyzed patients sent for 99mTc-MIBI SPECT using a 2-day protocol. We recorded the median HR during acquisition and the HR difference (HRD) between the rest and post-stress. We obtained the medium ventricular volume, end-diastolic volume (EDV), and end-systolic volume (ESV). We included patients in which TID using medium ventricular volume (TIDMV) was ≥1.2. TID was also calculated for the EDV and ESV (TIDEDV, TIDESV). We excluded patients with known coronary artery disease, perfusion defects, various ECG disorders, positive stress test, or ESV < 10 ml. From a total of 2006 patients, 63 (50 exercise, 13 dipyridamole) met the criteria for analysis (age 63.8 ± 9.7, 44 men). TIDMV was 1.29 ± 0.09 and HRD 9.8 beats per minute (BPM) (range -10 to 41). There was positive correlation between HRD and TIDMV ( r = 0.51, P < 0.001) and TIDEDV ( r = 0.5, P < 0.001), but not TIDESV ( r = 0.23, P = 0.07). Correlation was stronger when HRD was ≥10 BPM ( r = 0.67, P < 0.001). TID without perfusion defects should be interpreted with caution in the presence of HRD ≥ 10 BPM during post-stress acquisition.

Left ventricular myocardial cellular perfusion against the background of cardiac contractility modulation in patients with heart failure and atrial fibrillation

Aim. To assess the effect of cardiac contractility modulation (CCM) in patients with heart failure (HF) and atrial fibrillation (AF) on left ventricular (LV) myocardial cellular perfusion using perfusion single photon emission computed tomography (SPECT).Material and methods. 99mTc-MIBI SPECT gated myocardial perfusion imaging was performed in 60 patients with HF and AF before implantation of CCM device and after 6-months follow-up. All patients received long-term optimal medication therapy for HF. Results. The results obtained indicate a significant positive effect of CCM use in patients with HF and AF on LV ejection fraction (increase from 22 [18;30] to 25,5 [19;38] (p=0,002)), LV volume (decrease in LV end-systolic volume from 187 [114;238] to 154 [100;201] (p=0,001), end-diastolic volume from 229 [174;290] to 209 [159;259] (p=0,007)), as well as myocardial perfusion values. There is a favorable myocardial perfusion dynamics, which was more pronounced in nonischemic HF: increase in SRS from 6 [5;9] to 8,0 [6;11] after 6 months (p=0,01)). The extent of impaired perfusion significantly decreases from 12 [9;17] to 9 [6;16] (p=0,04). An indicator reflecting the total impairment of LV myocardial perfusion significantly decreases: total perfusion deficit decreased from 10 [8;14] to 7 [6;14] after 6 months (p=0,02), compared with ischemia-related HF.Conclusion. Perfusion SPECT makes it possible to assess the myocardial cellular perfusion during CCM therapy in patients with HF of various origin and AF. CCM therapy improves myocardial contractility and perfusion in patients with HF and AF.

Colchicine treatment early after infarction attenuates myocardial inflammatory response demonstrated by 14C-methionine imaging and subsequent ventricular remodeling by quantitative gated SPECT.

Colchicine has been used as an anti-inflammatory agent and may be cardioprotective after acute myocardial infarction (AMI). We investigated how colchicine administration after AMI affects the myocardial inflammatory response using 14C-methionine and subsequent ventricular remodeling using single-photon emission computed tomography (SPECT) in a rat model of AMI. The left coronary artery (LCA) was occluded for 30min followed by reperfusion. 14C-methionine was injected at 20min before sacrifice. The LCA was re-occluded at 1min before sacrifice and 99mTc-methoxyisobutylisonitrile (99mTc-MIBI) was injected. Colchicine was administered intraperitoneally from day 1 to the day before 14C-methionine injection. Dual-tracer autoradiography of the left ventricular short-axis slices was performed. The methionine uptake ratio in an ischemic area was calculated. 99mTc-MIBI gated SPECT assessed end-diastolic volume (EDV), end-systolic volume (ESV) and left ventricular ejection fraction (LVEF). On Clusterof Differentiation 68 with 4',6-diamidino-2-phenylindole (CD68/DAPI) staining the positive myocardial cell percentage in an ischemic area was calculated. In control rats, 14C-methionine uptake ratios on day 3 and 7 were 1.87 ± 0.15 and 1.39 ± 0.12, respectively. With colchicine, the uptake was reduced on days 3 (1.56 ± 0.26, p = 0.042) and 7 (1.23 ± 0.10, p = 0.030). Colchicine treated rats showed smaller EDV, ESV, and higher LVEF compared with control rats. At 8weeks, those in control rats were 864 ± 115 μL, 620 ± 100 μL, 28.4 ± 2.5%, and in colchicine rats 665 ± 75 μL, 390 ± 97 μL, 42.2 ± 8.5% (p = 0.012, 0.0061, 0.0083), respectively. In control rats, CD68/DAPI positive myocardial cell percentages on days 3 and 7 were 38.4 ± 1.9% and 24.0 ± 2.4%, respectively. With colchicine, the percentages were reduced significantly on both days 3 (31.5 ± 2.0%, p < 0.0001) and 7 (12.0 ± 1.6%, p < 0.0001) as compared with the control. Short-term colchicine treatment after AMI attenuated the post-AMI inflammatory response and subsequent ventricular remodeling and dysfunction. 14C-methionine imaging and gated 99mTc-MIBI SPECT would be feasible to monitor the effectiveness of anti-inflammatory therapy and left ventricular function.

Four Atypical Parathyroid Adenomas Detected by Dual Phase Tc-99m MIBI SPECT

We report a case of a 55-year-old female with tertiary hyperparathyroidism and osteoporosis who had end stage renal disease and a history of hemodialysis for 15 years. Patient’s informed is taken. Neck ultrasonography showed multinodular goiter together with a hypoechoic lesion compatible with a parathyroid adenoma. Dual phase technetium (Tc) Tc-99m MIBI single photon emission computed tomography (SPECT) showed pathological uptake in four parathyroid gland locations. Total thyroidectomy and subtotal parathyroidectomy revealed nodular hyperplasia and atypical adenomas in four parathyroid glands. Atypical parathyroid adenoma is a rare clinical entity. Multiple atypical adenomas are even less frequent. A very rare condition, detection of atypical adenomas in four of the parathyroid glands by dual phase Tc-99m MIBI SPECT, is presented in this case.

Use of &lt;sup&gt;99m&lt;/sup&gt;Tc-MIBI spect in estimating the efficiency pre-operative treatment of the larynx and laryngopharynx cancer

Purpose of the study. To study the possibilities of 99mTc-MIBI single photon emission computed tomography (SPECT) at the monitoring of the preoperative treatment of patients with laryngeal and hypopharyngeal cancer. Materials and methods. The study included 28 pa tients with cancer of the larynx or laryngopharynx T2–3N0–2M0. 99mTc-MIBI SPECT was performed for all patients before and after preoperative treatment, semi-quantitative indices were calculated, according to SPECT Results. A statistically significant difference was observed in the retention index in patients with complete regression and stabilization. A lower retention index is observed in patients who had a clinically pronounced effect from preoperative treatment. The rate of radiotracer washout from the tumor was faster in patients with no effect of preoperative therapy. The level of radiopharmaceuticals uptake in the tumor tissue after preoperative treatment was significantly lower in the group of patients without progression than in the group of patients with progression of the disease. In addition, the accumulation of the radioindicator after preoperative chemotherapy increased in the group of patients with progression, and decreased in the group without progression.Conclusion. The 99mTc-MIBI SPECT for tumor monitoring during treatment can be used. Semi-quantitative indices can be used as predictive criteria of results of preoperative treatment, as well as prognostic criteria for monitoring of such patients.

Wartość prognostyczna scyntygrafii perfuzyjnej mięśnia sercowego metodą SPECT z użyciem 99mTc-MIBI w grupie pacjentów po przebytym w przeszłości zawale serca

Introduction. Data describing prognostic utility of SPECT (single-photon emission computed tomography) among patients with history of myocardial infarction (MI) is scarce. We aimed to compare prognostic value of SPECT scans in patients with vs. without history of myocardial infarction (MI) prior to perfusion imaging. Material and methods. 151 consecutive patients with history of myocardial infarction, who underwent exercise 99mTc-MIBI SPECT examination were enrolled in the study (group 1). Next, based on clinical and demographic baseline characteristics, SPECT result and duration of follow-up period, a matching control subgroup (group 2) of 151 patients without history of MI was formed. During a mean follow-up of 60 ± 15 months in group 1 and a mean follow-up of 60 ± 13.5 months in group 2, we analyzed prevalence of cardiovascular events rates (cardiac deaths, myocardial infarctions and cardiac revascularizations). Results. We observed the following rates of cardiac deaths, myocardial infarctions and cardiac revascularizations: 4%, 15% and 26%, respectively in group 1 and 1%, 13% and 17%, respectively in group 2. In patients without history of MI (group 2) presence of mixed perfusion defects on SPECT was associated with significantly higher rate of myocardial infarctions (p = 0.05), hospitalizatons (p = 0.0001) and revascularizations (p = 0.0002). Fixed perfusion defects were associated with significantly higher occurrence of deaths (p = 0.012) and hospitalizations (p = 0.02), but not myocardial infarctions (p = 0.52) or cardiac revascularizations (p = 0.10). In contrast, among patients with history of MI (group 1) there was no statistically significant relationship between any type of perfusion defects and cardiovascular events. Conclusions. Long term follow-up demonstrates that prognostic value of 99mTc-MIBI SPECT is different in patients with and without history of MI.

Radiopharmaceuticals for SPECT Cancer Detection

The purpose of the study was to assess the efficacy of single photon emission computed tomography (SPECT) with 199Tl and 99mTc-MIBI in the detection of breast, laryngeal and hypopharyngeal cancers. Materials and Methods: a total of 220 patients were included into the study. Of them, there were 120 patients with breast lesions (100 patients with breast cancer and 20 patients with benign breast tumors) and '00 patients with laryngeal/hypopharyngeal diseases (80 patients with laryngeal/hypopharyngeal cancer and 20 patients with benign laryngeal/hypopharyngeal lesions). Results: no abnormal 199Tl uptake was seen in all patients with benign breast and laryngeal lesions, indicating a 100% specificity of 199Tl SPECT. In breast cancer patients, increased 199Tl uptake in the breast was visualized in 94.8% patients, 99mTc-MIBI in 93.4% patients. Increased 199Tl uptake in axillary lymph nodes was detected in 60% patients and 99mTc-MIBI in 93.1% patients. In patients with laryngeal/hypopharyngeal cancer, sensitivity of SPECT with 199Tl and 99mTc-MIBI were 95%. The 199Tl SPECT sensitivity in identification of regional lymph node metastases in patients with laryngeal/hypopharyngeal cancer was 75% and the 99mTc-MIBI SPECT sensitivity was 17%. Conclusion: the data obtained show that SPECT with 199Tl and 99mTc-MIBI can be used as one of the additional imaging methods in detection of tumors.

Early detection of radiation-induced heart disease using 99mTc-MIBI SPECT gated myocardial perfusion imaging in patients with oesophageal cancer during radiotherapy

Background and purposeThe primary aim of this prospective study was to investigate the value of 99mTc-methoxyisobutylisonitrile (MIBI) single photon emission computed tomography (SPECT) gated myocardial perfusion imaging (GMPI) in the detection of radiation-induced heart disease (RIHD) as early as during radiotherapy (RT) for oesophageal cancer (EC). The second aim was to analyse the correlation between cardiac toxicity and the dose–volume factors. Materials and methodsThe 99mTc-MIBI SPECT GMPI was performed both pre-RT and during RT (40Gray). The results of the SPECT were quantitatively analysed with QGS/QPS software and read by two experienced nuclear medicine physicians. The correlation between the changes in the SPECT parameters and the RT dosimetric data was analysed. ResultsEighteen patients with locally advanced EC were enrolled in the study. Compared with the baseline, the imaging during RT showed not only significant decreases in the wall motion (WM) (1/20 segments), wall thickening (WT) (2/20 segments), end-diastolic perfusion (EDP) (5/20 segments) and end-systolic perfusion (ESP) (8/20 segments) (p<0.05) but also a significant increase in the heart rate (74.63±7.79 vs 81.49±9.90, p=0.036). New myocardial perfusion defects were observed in 8 of the 18 patients. The V37–V40 was significantly higher (p<0.05) in the patients with the new perfusion defects during RT than in the patients who did not exhibit these defects. ConclusionsRadiotherapy for EC induces cardiac damage from an early stage. 99mTc-MIBI SPECT GMPI can detect the occurrence of cardiac impairment during RT. The WM, WT, EDP and ESP may be valuable as early indicators of RIHD. The percentage of the heart volume that receives a high dose is an important factor that is correlated with RIHD.

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.

Adenovirus-mediated expression of human sodium-iodide symporter gene permits in vivo tracking of adipose tissue-derived stem cells in a canine myocardial infarction model

IntroductionIn vivo tracking of the transplanted stem cells is important in pre-clinical research of stem cell therapy for myocardial infarction. We examined the feasibility of adenovirus-mediated sodium iodide symporter (NIS) gene to cell tracking imaging of transplanted stem cells in a canine infarcted myocardium by clinical single photon emission computed tomography (SPECT). MethodsBeagle dogs were injected intramyocardially with NIS-expressing adenovirus-transfected canine stem cells (Ad-hNIS-canine ADSCs) a week after myocardial infarction (MI) development. 99mTc-methoxyisobutylisonitrile (99mTc-MIBI) and 99mTc-pertechnetate (99mTcO4−) SPECT imaging were performed for assessment of infarcted myocardium and viable stem cell tracking. Transthoracic echocardiography was performed to monitor any functional cardiac changes. ResultsLeft ventricular ejection fraction (LVEF) was decreased after LAD ligation. There was no significant difference in EF between the groups with the stem cell or saline injection. 125I uptake was higher in Ad-hNIS-canine ADSCs than in non-transfected ADSCs. Cell proliferation and differentiation were not affected by hNIS-carrying adenovirus transfection. 99mTc-MIBI myocardial SPECT imaging showed decreased radiotracer uptake in the infarcted apex and mid-anterolateral regions. Ad-hNIS-canine ADSCs were identified as a region of focally increased 99mTcO4− uptake at the lateral wall and around the apex of the left ventricle, peaked at 2 days and was observed until day 9. ConclusionsCombination of adenovirus-mediated NIS gene transfection and clinical nuclear imaging modalities enables to trace the fate of transplanted stem cells in infarcted myocardium for translational in vivo cell tracking study for prolonged duration.

Utility of left lateral supine position for myocardial perfusion single-photon emission computed tomography compared with other methods of correcting inferior wall attenuation.

Single-photon emission computed tomography (SPECT) myocardial perfusion imaging is an accepted method for reflecting the pathophysiological significance of lesions detected by coronary angiography. However, it has an inherent drawback in terms of false-positive perfusion defects for the inferior myocardial wall. To overcome this problem, different acquisition techniques have been proposed, including the computed tomographic-based attenuation correction method. In this respect, a new imaging technique, left supine lateral position SPECT myocardial perfusion imaging with technetium-99m methoxyisobutylisonitrile (Tc-99m MIBI), has been proposed to eliminate this problem and its value has been investigated in this report. Sixty-two patients were prospectively and randomly enrolled in this study. They underwent Tc-99m MIBI SPECT in the supine, prone, left lateral, and sitting positions after an adequate stress test on the same day.The presence and extent of defects on stress images were noted in the supine image data set for the 11 myocardial segments, which were then labeled as 1 or 0 if a defect was present or absent, respectively. This evaluation sequence was repeated in all other image data sets. When defects persisted in other scan positions it was regarded as true positive, and when they were resolved they were regarded as false positive. By this means, the percentages of resolving perfusion defects by that imaging position were calculated for each observer per positional pair under comparison. From six interpretations carried out by the nuclear medicine physicians, 6×11×3=198 four-fold tables in 11 segments were analyzed for discrepancies between position pairs. In 31 of 33 discrepant interpretations, defects observed in any of the other positions were resolved in the lateral position. Only in two evaluations of one observer were the discrepancies against lateral positioning for the anterior wall. If the inferior wall was considered alone, it was clearly obvious that lateral positioning was more accurate than the other positions.Intraobserver evaluation showed the methodology to be highly reproducible.The SPECT findings were concordant with coronary angiography results in selected patients. Visual and quantitative evaluations of the variation in inferior wall activity lead us to suggest that SPECT imaging with Tc-99m MIBI be performed in the left lateral position to allow better visualization of the inferior and septal walls in those departments not able to utilize computed tomographic attenuation correction.

Detection of Radiation-Induced Heart Disease by Gated Myocardial Perfusion Imaging in Patients With Esophageal Cancer During RT: Prevention/Screening

As an important treatment for thoracic cancers, radiation therapy (RT) can cause definite cardiotoxicity, even with modern techniques, such as 3D-CRT and IMRT. This prospective study was initiated to assess radiation-induced heart disease (RIHD) during-RT (at 40 Gy) using gated 99mTc-sestamibi (MIBI) single photon emission computed tomography (SPECT) in patients with esophageal cancer. This ongoing study aimed to investigate the value of 99mTc-MIBI SPECT in the detection of RIHD as early as during-RT.

Detection of Radiation-Induced Heart Disease by Gated Myocardial Perfusion Imaging in Patients With Esophageal Cancer During RT

As an important treatment for thoracic cancers, radiation therapy (RT) can cause definite cardiotoxicity, even with modern techniques, such as 3D-CRT and IMRT. This prospective study was initiated to assess radiation-induced heart disease (RIHD) during-RT (at 40Gy) using gated 99mTc-sestamibi (MIBI) single photon emission computed tomography (SPECT) in patients with esophageal cancer. This ongoing study aimed to investigate the value of 99mTc-MIBI SPECT in the detection of RIHD as early as during-RT.

Acute Myocardial Infarct Detection with Dual Energy CT: Correlation with Single Photon Emission Computed Tomography Myocardial Scintigraphy in a Canine Model

Dual-energy CT (DECT) has been used to detect myocardial infarct. However, few comparable studies with histopathological findings as gold standard have been published. To investigate the accuracy of DECT iodine maps for detecting acute myocardial infarction compared with single photon emission computed tomography (SPECT) in a canine model using histopathological findings as the reference standard. A model of myocardial ischemia was created by ligating the left anterior descending (LAD) coronary artery after thoracotomy in six dogs, while another three dogs undergoing thoracotomy without LAD ligature served as a control group. Contrast-enhanced DECT scans of the heart were performed, followed by resting 99mTc-MIBI SPECT myocardial perfusion imaging in all nine dogs before and 3 h after the procedure. Triphenyltetrazolium chloride (TTC) staining was performed and analyzed. In the short axis of the left ventricle, the wall surface was divided into 17 segments, which were assessed for infarcted myocardium on conventional CT from average-weighted data, DECT myocardial iodine maps, conventional CT plus DECT, SPECT, and histopathology. Inter-observer and inter-modality agreement for conventional CT, DECT myocardial iodine maps, and SPECT were calculated. CT value of infracted and non-infracted areas was measured. With the histopathological results as the reference standard, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were 75.0% (30/40), 92.0% (104/113), 76.9% (30/39), 91.2% (104/114), 87.6% (134/153) for conventional CT, 85.0% (34/40), 84.1% (95/113), 65.4% (34/52), 94.1% (95/101), 84.3% (129/153) for DECT myocardial iodine maps; 87.5% (35/40), 92.9% (105/113), 81.4% (35/43), 95.5% (105/110), 91.5% (140/153) for conventional CT plus DECT; 82.5% (33/40), 90.3% (102/113), 75.0% (33/44), and 93.6% (102/109), 88.2% (135/153) for SPECT, respectively. Excellent inter-observer agreement (Kappa value >0.8) and good inter-modality agreement (Kappa value >0.6) for each modality were found. CT values of infarcted myocardium (26 ± 22 HU, 36 ± 33 HU, 34 ± 16 HU) were lower than those of non-infarcted myocardium (115 ± 16 HU, 121 ± 28 HU, 123 ± 11 HU) on images of 140 kVp, 80 kVp, and average-weighted 120 kVp images (all P < 0.05). With histopathology as the reference standard, DECT myocardial iodine maps can detect acute myocardial infarction with diagnostic accuracy comparable to resting SPECT myocardial perfusion imaging in a canine model. DECT plus conventional CT had a potential to improve the detection of acute myocardial infarction.

Perioperative single photon emission computed tomography in predicting survival of malignant glioma patients

Single photon emission computed tomography (SPECT) is widely used in the evaluation of glioma patients and has been demonstrated to correlate with glioma malignancy and proliferation indexes. The aim of this study was to evaluate the association between perioperative technetium-99m-methoxyisobutylisonitrile ((99m)Tc-MIBI) uptake on SPECT scans and survival of malignant glioma patients. A total of 17 patients (11 males and 6 women; mean age, 62.2±8.4 years) with histologically confirmed malignant gliomas (16 glioblastoma multiforme and 1 gliosarcoma) underwent (99m)Tc-MIBI SPECT scans 2.8±1.9 days before surgery and 9.8±1.5 days after surgery. The total intensity index (TII) that corresponds to the area and intensity of tracer uptake was calculated before and after surgery. In addition, the change of TII before versus after surgery (Δ TII) was calculated. The overall survival (OS) was defined as the period between the date of surgery and the date of death. The median overall survival time was 12.4 months, ranging from 1.4 to 88 months; there were nine (45%) 12-month survivors. In univariate analyses using a log-rank test, worse OS was significantly associated with higher preoperative TII (≥12), higher postoperative TII (≥6), lower Δ TII (<50%) and higher number of neurological symptoms prior to surgery (≥4). In multivariate analyses, higher postoperative TII, a greater number of neurological symptoms and female gender were found to be factors with independent prognostic value of OS. Patients who survived more than 12 months following surgery had a significantly lower postoperative TII, higher Δ TII and greater rate of gross total resection compared to patients who survived less than 12 months following surgery. Higher peri-operative tracer uptake and lower decrease of tracer uptake following surgery (suggesting less radical resection) were associated with worse OS of malignant glioma patients. Our results suggest that SPECT may be used to predict survival of malignant glioma patients; however, further studies using larger samples are required.

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.

Myocardial perfusion is preserved in patients with psoriasis without clinically evident cardiovascular disease

Psoriasis is associated with a premature atherosclerosis due to the chronic inflammatory process. To evaluate the effect of disease process on myocardial perfusion, we planned to perform 99mTc-MIBI myocardial perfusion single photon emission computed tomography (SPECT) in patients with psoriasis. The study group consisted of 28 psoriasis patients (17 men, 11 women), aged 18-76 years, and mean age 41.2 +/- 14.1 years. The patients were selected among those who were older than 18 years and longer than 10 years of disease duration with more than two times of systemic treatment. All patients underwent 99mTc-MIBI myocardial perfusion SPECT with the same day protocol. We detected various risk factors including smoking habits in 7, family history of cardiovascular disease in 4, hypertension in 1, hyperlipidemia in 9 patients. We completed myocardial perfusion SPECT for each patient and found normal perfusion pattern in SPECT images. We detected that myocardial perfusion is preserved in the patients with psoriasis. The majority of acute heart attacks are caused by noncritical coronary stenosis and this may be an explanation for increased cardiovascular risk in these patients despite normal coronary perfusion.

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.

99mTc-MIBI imaging of AIDS-related Kaposi's sarcoma in the lungs

Pulmonary Kaposi's sarcoma (KS) occurs in more than 10% of patients with acquired immunodeficiency syndrome (AIDS) and has a high mortality rate. Prompt detection, diagnosis, and treatment reduce patient morbidity and mortality. The objective of this study was to determine the efficacy of 99mTc-hexakis-2-methoxy isobutyl isonitrile (99mTc-MIBI) imaging in detecting pulmonary AIDS-related KS. 99mTc-MIBI imaging was performed on 72 human immunodeficiency virus-seropositive patients with bronchoscopic diagnosis of pulmonary KS (36 patients), pneumonia (22), normal tracheo-bronchial tree (11), lymphoma (2), and bronchogenic carcinoma (1). Lung uptake and lymph node detection in KS were compared on planar and single photon emission computed tomography (SPECT) scans. The lung/myocardium ratios on the 1-h planar images were significantly higher in KS and normal lungs than opportunistic infection. Using the lung/myocardium ratio of 1 as cutoff, the sensitivity, specificity, and accuracy of the 1-h planar images for detecting pulmonary KS were 75, 57.58, and 66.67%, respectively. Abnormal lymph node uptake, pleural/pericardial effusions, and ascites were detected more readily on SPECT. Planar 99mTc-MIBI imaging has moderate sensitivity, specificity, and accuracy for detecting pulmonary KS. SPECT is more effective in detecting abnormal lymph nodes, pleural/pericardial effusions, and ascites. 99mTc-MIBI SPECT followed by planar imaging at 40-60 min can be useful in assessing pulmonary KS.

LETTER TO THE EDITOR

Dear Editor, We read with attention the article “Evaluation of glioma proliferation by 99mTc-Tetrofosmin” by Alexiou et al. (Neuro-Oncology 2008;10:104–105). We have significant experience in the use of single-photon emission computed tomography (SPECT) images in the management of malignant glioma patients.1–3 In our opinion, the published study was too small and underestimated the implications of SPECT images in the management of glioma patients. We would like to clarify this subject by sharing some of our own experiences. Tetrofosmin scintigraphy has characteristics similar to those of technetium-99m–labeled methoxyisobutylisonitrile (99mTc-MIBI) scintigraphy. Moreover, its sensitivity and specificity in distinguishing malignant lesions from benign tumors and in discriminating recurrent glioma from radionecrosis are the same as those of 99mTc-MIBI scintigraphy.2 Moreover, tetrofosmin could be used as a noninvasive marker of glioma proliferative activity, like the sestamibi tracer, but the clinical utility of tetrofosmin needs to be evaluated.4 We point out the following: 99mTc-MIBI SPECT has proved useful in detecting intracranial tumors before therapy, especially neurosurgery, with higher sensitivity and specificity for gliomas than for other cancer histologies (i.e., lymphomas). Moreover, MIBI uptake has been correlated with the grade of malignancy of gliomas.4 99mTc-MIBI brain SPECT may be helpful for evaluating the degree of tumor resection of malignant gliomas.4 99mTc-MIBI brain SPECT may help in establishing the prognosis of glioma patients at the end of radiation therapy, allowing for adaptations in patient care. These new data should be considered in the design of future clinical studies of malignant glioma therapies as a way to quickly assess the therapies’ efficiency.1,3,4 Thank you for sharing these observations with your readers.