technetium-tc-99m-tetrofosmin and Necrosis

Treatment induced necrosis is a relatively frequent finding in patients treated for high-grade glioma. Differentiation by imaging modalities between glioma recurrence and treatment induced necrosis is not always straightforward. This is a comparative study of diffusion tensor imaging (DTI), dynamic susceptibility contrast MRI and (99m)Tc-Tetrofosmin brain single-photon emission computed tomography (SPECT) for differentiation of recurrent glioma from treatment induced necrosis.. A prospective study was made of 30 patients treated for high-grade glioma who had suspected recurrent tumor on follow-up MRI. All had been treated by surgical resection of the tumor followed by standard postoperative radiotherapy with chemotherapy. No residual tumor had been found on brain imaging immediately after the initial treatment. All the patients were studied with dynamic susceptibility contrast brain MRI and, within a week, (99m)Tc-Tetrofosmin brain SPECT.. Both (99m)Tc-Tetrofosmin brain SPECT and dynamic susceptibility contrast MRI could discriminate between tumor recurrence and treatment induced necrosis with 100% sensitivity and 100% specificity. An apparent diffusion coefficient (ADC) ratio cut-off value of 1.27 could differentiate recurrence from treatment induced necrosis with 65% sensitivity and 100% specificity and a fractional anisotropy (FA) ratio cut-off value of 0.47 could differentiate recurrence from treatment induced necrosis with 57% sensitivity and 100% specificity. A significant correlation was demonstrated between (99m)Tc-Tetrofosmin uptake ratio and rCBV (P=0.003).. Dynamic susceptibility contrast MRI and brain SPECT with (99m)Tc-Tetrofosmin had the same accuracy and may be used to detect recurrent tumor following treatment for glioma. DTI also showed promise for the detection of recurrent tumor, but was inferior to both dynamic susceptibility contrast MRI and brain SPECT.

Topics: Brain; Brain Neoplasms; Chemoradiotherapy; Contrast Media; Diagnosis, Differential; Diffusion Tensor Imaging; Female; Glioma; Humans; Male; Middle Aged; Necrosis; Neoplasm Recurrence, Local; Organophosphorus Compounds; Organotechnetium Compounds; Radiation Injuries; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

To assess the significance of a paradoxical pattern (PP) (greater tracer uptake during stress than at rest) on gated myocardial perfusion SPECT in myocardial regions with myocardial necrosis.. A review of 1,764 consecutive stress-rest myocardial perfusion SPECT studies in patients with prior myocardial infarction (MI) was conducted. Of these, 117 patients (6.6%) with a PP corresponding to a region with myocardial necrosis were identified. An assessment of perfusion, contractility, wall thickening, scintigraphic criteria for viability, and the characteristics of the culprit artery in regions with a PP was performed.. Of the 160 regions with necrosis, 125 (75%) had a PP: 67 in the anterior region and 58 in the inferior-lateral region. In the PP group, the average tracer activity of defects during stress was significantly higher than at rest (P < .0001). Ninety-three (86.6%) out of 110 PP segments without scintigraphic criteria of viability at rest met viability criteria on stress imaging. The artery supplying regions with a PP was patent in 88% of cases. In the remaining patients it was occluded, although collateral circulation was always present.. In scintigraphic segments corresponding to regions with infarction and PP, a mixture of viable and well perfused myocardium was observed. In most cases, the vessel that supplied the region with PP was either patent, or when the artery was occluded, there was evident collateral circulation.

Topics: Aged; Cardiac-Gated Imaging Techniques; Comorbidity; Female; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Perfusion Imaging; Necrosis; Organophosphorus Compounds; Organotechnetium Compounds; Prevalence; Radiopharmaceuticals; Reproducibility of Results; Risk Assessment; Risk Factors; Sensitivity and Specificity; Spain; Tomography, Emission-Computed, Single-Photon

Topics: Brain Neoplasms; Clinical Trials as Topic; Glioma; Humans; Necrosis; Neoplasm Recurrence, Local; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radionuclide Imaging; Reproducibility of Results; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

To compare the myocardial kinetics of three (99m)technetium-labeled monocationic tracers [methoxy-isobutylisonitrile (MIBI), tetrofosmin, and Q12] in a model of ischemia-reperfusion (IR) to determine their abilities to assess myocardial viability.. Isolated perfused rat hearts (n = 30) were studied in control and IR groups for each tracer. IR hearts were treated with 120 min global no-flow followed by 5 min reflow, then 60 min tracer uptake/clearance. Tracer kinetics were monitored using a scintillation detector.. This model produced significant myocardial injury, without significant differences in the percentage of injured myocardium by triphenyltetrazolium chloride (TTC) staining and creatine kinase (CK) assay. Transmission electron microscopy analysis also confirmed necrosis with abundant mitochondrial damage in the IR hearts. All three IR groups exhibited significantly less mean (+/-standard error of the mean) tracer retention than matched controls (MIBI 73.4 +/- 4.9% vs. 96.9 +/- 1.76%, tetrofosmin 38.7 +/- 4.6% vs. 82.2 +/- 3.5%, and Q12 23.0 +/- 2.5% vs. 43.8 +/- 1.8%, respectively; P < 0.05). Tetrofosmin IR hearts exhibited 54 +/- 9% of control myocardial retention, which was significantly less than either MIBI (86 +/- 5%, P < 0.05) or Q12 (63 +/- 6%, P < 0.05); thus, tetrofosmin provided the best differentiation between nonviable and normal myocardium. Furthermore, tetrofosmin end activity (%id/g) in controls was significantly higher than Q12 (4.09 +/- 0.04 vs. 1.71 +/- 0.06, respectively, P < 0.05), and tetrofosmin end activity (%id/g) in IR hearts was significantly higher than Q12 (2.19 +/- 0.37 vs. 1.06 +/- 0.12, respectively, P < 0.05). The correlation between end activity and viable myocardium determined by TTC staining was r = 0.66 (P < 0.05) for MIBI, r = 0.94 (P < 0.05) for tetrofosmin, and r = 0.91 (P < 0.05) for Q12. The correlation between myocardial end activity and myocardial CK leak was r = -0.62 (P < 0.05) for MIBI, r = -0.87 (P < 0.05) for tetrofosmin, and r = -0.89 (P < 0.05) for Q12.. Nonviable myocardium can be distinguished from normal myocardium by the retention kinetics of all three monocationic tracers studied. Tetrofosmin and Q12 end activities demonstrate the best correlation with infarct size. However, tetrofosmin kinetics may combine the greatest differentiation between nonviable and normal myocardium, while still retaining adequate activity for imaging.

Topics: Animals; Creatine Kinase; Furans; Heart; In Vitro Techniques; Kinetics; Male; Mitochondria, Heart; Myocardial Infarction; Myocardial Reperfusion Injury; Myocardium; Necrosis; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Rats; Rats, Sprague-Dawley; Technetium Tc 99m Sestamibi; Tetrazolium Salts

Topics: Brain; Brain Neoplasms; Diagnosis, Differential; Humans; Magnetic Resonance Imaging; Necrosis; Neoplasm Metastasis; Organophosphorus Compounds; Organotechnetium Compounds; Positron-Emission Tomography; Radiation Injuries; Radiopharmaceuticals; Recurrence; Tomography, Emission-Computed, Single-Photon

Contrast magnetic resonance (CMR) can identify myocardial necrosis after gadolinium administration as a hyperenhanced (HE) area. Yet there are no software tools that can effectively quantify such an area. The aim of this study is to develop a robust and effective algorithmic method for defining the extent of myocardial necrosis evidenced through CMR.. Fifteen patients with previous myocardial infarction underwent nitrate Tetrofosmin G-SPECT and CMR. A software tool was developed, allowing semiautomatic detection of endocardial and epicardial borders and the automatic detection of HE regions. The accuracy of the proposed quantitative method of analysis has been tested with G-SPECT analysis that it is less than an ideal method for assessing myocardial viability, but at present is accepted and widely used in the clinical arena.. Segmental (SEHE) and global extension of HE were evaluated. HE was present in 161 of the 255 analyzed segments. Of the 161 HE segments, the mean SEHE was 36 +/- 30%. The operator independence (intraobserver: r = 0.97, p < 0.0001, interobserver: r = 0.95, p < 0.0001) was good and significant, with noticeable time savings with respect to manual analysis. There was strong and inverse correlation between SEHE and scintigraphic regional uptake reduction (r = -0.66, p < 0.0001), and also a positive correlation between SEHE and SPECT defect extension (r = 0.75, p < 0.0001). When assessing the global extent of necrosis, the correlation between the two techniques was strong (r = 0.79, p = 0.0004).. The proposed method of quantifying myocardial necrosis by CMR is highly reliable, reproducible, and operator-independent for quantifying.

Topics: Algorithms; Contrast Media; Gadolinium DTPA; Humans; Image Enhancement; Image Processing, Computer-Assisted; Magnetic Resonance Imaging, Cine; Middle Aged; Myocardium; Necrosis; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

There are no published data in the literature on the scintigraphic perfusion pattern in patients with myocardial infarction (MI) and normal coronary arteries (NCA).. To evaluate myocardial perfusion imaging in a series of patients with MI and NCA.. Twenty-seven patients who had developed a MI and had NCA were studied. As a control group we included 27 patients with a recent MI and coronary artery disease (CAD). All patients underwent stress/rest tetrofosmin myocardial perfusion SPECT within 6 months from MI.. In patients with NCA tetrofosmin stress images revealed 41 hypoperfused segments in 17 patients (63%). On rest images, 13 segments remained unchanged, 4 showed partial reperfusion, 10 normalized and 14 worsened. Additionally, there were 18 new hypoperfused segments in nine patients. Therefore, perfusion worsened at rest in 18 patients (67%) (32 segments). Overall, at rest there were 49 hypoperfused segments in 22 patients (81%). In patients with CAD, stress images revealed 71 hypoperfused segments. On rest images, 39 segments remained unchanged, 16 showed partial reperfusion and 12 normalized. Four segments worsened at rest and only four patients (15%) showed new perfusion defects at rest.. Myocardial perfusion with tetrofosmin might appear considerably worse at rest than at stress in patients with MI and NCA. Specifically, a reverse perfusion pattern in the infarct area is a frequent finding and is likely to be due to residual tissue viability. We postulate that in these patients the hyperemic response to exercise may mask resting underperfusion areas.

Topics: Adult; Aged; Case-Control Studies; Coronary Angiography; Coronary Circulation; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Infarction; Necrosis; Observer Variation; Organophosphorus Compounds; Organotechnetium Compounds; Tomography, Emission-Computed, Single-Photon

Despite low specificity routine mammography is the method of choice to screen women for breast cancer. In addition high frequency ultrasonography (US) or magnetic resonance imaging (MRI) can improve breast cancer diagnosis. However there is a lack of conventional imaging to improve the high rate of false positive results that make biopsy or surgery necessary.. The purpose of our study was to evaluate prospectively the sensitivity, specificity, PPV and NPV of scintimammography with a new cationic complex Tc-99m-tetrofosmin.. Fourtyeight patients in whom mammography and/or high resolution ultrasonography (10 MHz) revealed suspicious breast lesions were studied with Tc-99m-tetrofosmin scintimammography. In thirtyfour of them biopsy and/or surgery was performed for histological evaluation. After intravenous injection of 555 MBq Tc-99m-tetrofosmin dynamic images over three minutes (1 frame/10 sec.) planar images in anterior and lateral projections (5 min. p.i.) and SPECT imaging including 3-D-reconstruction (20 min. p.i.) were performed. Scintimammography was evaluated as negative, equivocal (+), probably (+2) or definitely (+3) positive. Scintimammography with Tc-99m-tetrofosmin was negative in 18 patients (17 t.p., 1 f.n.) and positive in 16 patients (10 t.p., 6 f.p.). The false negative scintimammography was observed in a patient with infiltrating ductal carcinoma pT1, the false positive results in a patient with fibrocystic disease; all of the five fibroadenomas were also "false" positive. Sensitivity of Tc-99m-tetrofosmin scintimammography in this prospective study was 91%, specificity 74%, PPV 63% and NPV 94%. Scintimammographic results in patients with suspicious breast lesion show, that Tc-99m-tetrofosmin accumulates in breast cancer as well as in fibroadenoma. However the high NPV of 94% excludes breast cancer in suspicious mammographic lesions in a very high degree and therefore reduces the need of biopsy and/or surgery in most of these patients. Our first results show that scintimammography with Tc-99m-tetrofosmin might play a role as further diagnostic step before surgery for women in whom mammography and/or ultrasonography show suspicious lesions.

Topics: Adult; Aged; Breast; Breast Diseases; Breast Neoplasms; Carcinoma, Ductal, Breast; Female; Fibrocystic Breast Disease; Humans; Mammography; Middle Aged; Necrosis; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Tomography, Emission-Computed, Single-Photon; Ultrasonography, Mammary