Tumor-Induced Parkinsonism Due to a Large Meningioma Diagnosed by 99m Tc-TRODAT-1 SPECT/CT.

ABSTRACT: A 67-year-old woman complained of rest and postural tremors in her left upper extremity, associated with bradykinesia and gait disorder since 2 years ago, with no significant response to antiparkinsonism drugs. Dopamine transporter SPECT/CT revealed a remarkable area of 99m Tc-TRODAT-1 uptake in a huge tumoral lesion in the right frontotemporal region, compressing and dislocating the right striatum with evidence of significant midline shift. The patient underwent surgical resection with a diagnosis of meningioma on preoperative MRI and postoperative histology report, experiencing a marked recovery in symptoms after 1 month.

Comparing the role of 99m Tc-HYNIC-PSMA-11 and 99m Tc-MDP scintigraphy for the initial staging of intermediate to high-risk prostate cancer.

BACKGROUND: Although bone scintigraphy and abdominopelvic computed tomography (CT)/MRI have been the mainstay of initial staging in the intermediate to high-risk prostate cancer (PC) patients, prostate-specific membrane antigen (PSMA) PET/CT imaging provides promising additional value in the initial N/M staging of these patients in recent years. 99m Tc-PSMA scan is a new alternative to PSMA PET tracers with little evidence regarding its diagnostic value in the initial staging of PC. METHODS: This prospective study included 40 patients with newly diagnosed PC with initial intermediate or high-risk features [prostate-specific antigen (PSA) > 10 ng/dl, Gleason score ≥7 or stage cT2b and more]. All patients underwent both 99m Tc-methylene diphosphonate (MDP) bone scan and 99m Tc-HYNIC-PSMA-11 scan with maximum interval of 2 weeks. Abdominopelvic CT and MRI were also performed in this timeframe. Then, the results of these methods were compared with the final diagnosis data. RESULTS: Among the 40 included patients, 28 patients had finally been diagnosed as localized PC and 12 patients showed lymph node or metastatic involvement. The sensitivity, specificity and accuracy of 99m Tc-HYNIC-PSMA-11 vs. 99m Tc-MDP were 83.3% vs. 50.0%, 100% vs. 82.1% and 95% vs. 72.5%, respectively. However, when combined with the results of abdominopelvic CT/MRI the sensitivity reached 100% for both and the specificity raised to 100% and 96.4% for 99m Tc-HYNIC-PSMA-11 and 99m Tc-MDP, respectively. CONCLUSION: 99m Tc-HYNIC-PSMA-11 performs well in the initial staging of intermediate to high-risk PC and especially in low source areas without PET/CT it can be used as the first-line method of metastatic evaluation instead of bone scintigraphy. However, the combination and correlation of cross-sectional imaging is essential to gain the optimal diagnostic value.

Incidental Detection of Papillary Thyroid Carcinoma in Tc-99 m PSMA Imaging in a Case with Negative FNA Result.

Prostate-specific membrane antigen (PSMA) is a type II transmembrane glycoprotein and is expressed in multiple solid malignant neoplasms. We presented a case of a prostate cancer patient who went through Tc-99 m PSMA SPECT, and multifocal increased radiotracer uptake in the thyroid gland was demonstrated. Despite negative FNA results for malignancy, post-operative histopathologic examination illustrated papillary thyroid carcinoma.

Characterization of left ventricular diastolic parameters of gated-single-photon emission computed tomography myocardial perfusion imaging in patients with diabetes and normal myocardial perfusion and systolic function.

BACKGROUND: Diabetic cardiomyopathy is defined as an independent entity with a specified pathological progression from diastolic dysfunction with preserved ejection fraction to overt heart failure. Myocardial perfusion imaging (MPI) with gated-single-photon emission computed tomography (G-SPECT) has been introduced as a feasible tool to evaluate left ventricular (LV) diastolic function. The aim of this study was to investigate the characteristics of diastolic parameters derived from G-SPECT MPI in diabetic patients compared to patients at very low risk of coronary artery disease (CAD) and with no other CAD risk factors. METHODS: This cross-sectional study was performed on patients referred to the nuclear medicine department for G-SPECT MPI. Demographic and clinical data, as well as medical history, were extracted from a digital registry system including 4447 patients. Then, two matched groups of patients with only diabetes as cardiac risk factor ( n = 126) and those without any identifiable CAD risk factors ( n = 126) were selected. Diastolic parameters of MPI, including peak filling rate, time to peak filling rate, mean filling rate at the first third of diastole and second peak filling rate, were derived using quantitative software for eligible cases. RESULTS: The mean age of the diabetic and nondiabetic groups was 57.1 ± 14.9 and 56.7 ± 10.6 years, respectively ( P = 0.823). Comparison of quantitative SPECT MPI parameters between the two groups showed a statistically significant difference only in total perfusion deficit scores, whereas none of the functional parameters, including diastolic and dyssynchrony indices and the shape index, were significantly different. There were also no significant differences in diastolic function parameters between diabetes and nondiabetes patients in the age and gender subgroups. CONCLUSION: Based on the G-SPECT MPI findings, there is a comparable prevalence of diastolic dysfunction in patients with only diabetes as a cardiovascular risk factor and low-risk patients with no cardiovascular risk factors in the setting of normal myocardial perfusion and systolic function.

Correlation of response to subthalamic deep brain stimulation in Parkinson's disease patients with striatal dopamine transporter density on 99mtc-TRODAT-1 SPECT.

BACKGROUND: Deep brain stimulation (DBS) is a surgical approach with electrical stimulation of certain parts of the brain, which reduce Parkinson's disease (PD) symptoms. Since the loss of dopaminergic neurons in the substantia nigra is the main pathophysiology of PD, we aimed to evaluate the association of response to DBS with preoperative dopamine transporter density (DAT) and its postoperative changes in PD patients who underwent the bilateral implantation of the electrodes in the subthalamic nucleus (STN). METHOD: A prospective evaluation of Parkinson's disease patients who underwent STN-DBS for 2 years was done. 99mTc-TRODAT-1 single-photon emission computed tomography (SPECT) scan and assessment of PD using unified Parkinson's disease rating scale (UPDRS) III were performed in both pre- and post-operation states. The correlation of response to DBS after 6 months was assessed with baseline findings and postoperative changes of 99mTc-TRODAT-1 SPECT parameters. RESULTS: Compared to the preoperative state, UPDRS III scores and Levodopa equivalent daily dose (LEDD) were significantly decreased after DBS. However, in 17 patients who underwent both pre-and post-operative 99mTc-TRODAT-1 SPECT, no significant change was seen in any quantitative parameters, including right and left striatal-binding ratio (SBR) as well as striatal asymmetry index (SAI). No significant correlation was also found between the percent of UPDRS III change after DBS and values of preoperative SBRs. The percentage of LEDD reduction also showed no significant correlation with the preoperative state of 99 m-TRODAT-1 SPECT. CONCLUSION: Our results showed that the mechanism of DBS action is not accompanied by short-term compensation of DAT in basal ganglia in severely advanced PD.

Myocardial Perfusion SPECT Imaging Radiomic Features and Machine Learning Algorithms for Cardiac Contractile Pattern Recognition.

A U-shaped contraction pattern was shown to be associated with a better Cardiac resynchronization therapy (CRT) response. The main goal of this study is to automatically recognize left ventricular contractile patterns using machine learning algorithms trained on conventional quantitative features (ConQuaFea) and radiomic features extracted from Gated single-photon emission computed tomography myocardial perfusion imaging (GSPECT MPI). Among 98 patients with standard resting GSPECT MPI included in this study, 29 received CRT therapy and 69 did not (also had CRT inclusion criteria but did not receive treatment yet at the time of data collection, or refused treatment). A total of 69 non-CRT patients were employed for training, and the 29 were employed for testing. The models were built utilizing features from three distinct feature sets (ConQuaFea, radiomics, and ConQuaFea + radiomics (combined)), which were chosen using Recursive feature elimination (RFE) feature selection (FS), and then trained using seven different machine learning (ML) classifiers. In addition, CRT outcome prediction was assessed by different treatment inclusion criteria as the study's final phase. The MLP classifier had the highest performance among ConQuaFea models (AUC, SEN, SPE = 0.80, 0.85, 0.76). RF achieved the best performance in terms of AUC, SEN, and SPE with values of 0.65, 0.62, and 0.68, respectively, among radiomic models. GB and RF approaches achieved the best AUC, SEN, and SPE values of 0.78, 0.92, and 0.63 and 0.74, 0.93, and 0.56, respectively, among the combined models. A promising outcome was obtained when using radiomic and ConQuaFea from GSPECT MPI to detect left ventricular contractile patterns by machine learning.

Evaluating the correlation of serum leptin levels with evidence of coronary artery disease on myocardial perfusion single-photon emission computed tomography in suspected coronary artery disease patients.

BACKGROUND: Cardiovascular disease is currently the most common cause of death worldwide. Several risk factors have been identified for cardiovascular diseases, including hypertension, hyperlipidemia and diabetes. Leptin is a peptide hormone that acts as a proinflammatory cytokine and has a variety of effects in hemostasis and metabolism such as lipid metabolism, production of glucocorticoid, angiogenesis, etc. The aim of this study was to determine the relationship between the concentrations of leptin with evidence of coronary artery disease in the myocardial perfusion scan. METHOD: A one year retrospective cross-sectional study was conducted on patients who are suspected of coronary artery disease that referred to the nuclear medicine department for performing myocardial perfusion scan. The patients were classified based on the results of the myocardial perfusion scan. Serum leptin was measured with ELISA assay. The correlation of serum leptin with these parameters and also with different groups of age, sex and coronary artery disease risk factors was also compared. RESULTS: The mean serum level of leptin was 290.44 ng/ml (82.9-1600 ng/ml). There is no meaningful relation between serum leptin and coronary artery disease risk factors, age and sex; also, none of the quantitative myocardial perfusion scan parameters have a significant correlation with serum leptin. CONCLUSION: Based on our findings, there was no significant correlation between myocardial perfusion scan parameters and leptin levels. Serum leptin and different groups of age, sex and coronary artery risk factors were not correlated as well.

The role of contrast-enhanced and non-contrast-enhanced MRI in the follow-up of multiple sclerosis.

BACKGROUND: Magnetic resonance imaging (MRI) is widely used in patients with multiple sclerosis (MS) for different indications. However, frequent administration of gadolinium in these patients can have some potential complications. So, a more limited approach reducing the use of gadolinium should be considered. PURPOSE: To evaluate the additional benefits of contrast-enhanced MRI over non-contrast-enhanced MRI in routine follow-up of patients with MS. MATERIAL AND METHODS: This is a retrospective cohort study including patients with MS who underwent both contrast-enhanced and non-contrast-enhanced MRI for two time-points with an interval of at least six months. Non-contrast-enhanced images were compared for each patient and interpreted as non-progressive or progressive disease. Then, rate and type of enhancing lesions were analyzed and compared between the groups. All images were reviewed and compared visually by two radiologists. RESULTS: A total of 462 patients (392 women; mean age = 36 years) were included. Of these patients, 352 were in the non-progressive group and 112 were in progressive group. Comparison of baseline and follow-up contrast-enhanced MRIs revealed that 13 (3.7%) patients in the non-progressive group and 58 (51.8%) patients in progressive group developed enhancing lesions (P < 0.001). All 58 patients in the progressive group developed new enhancing lesions, whereas all those in the non-progressive group revealed persistent or reactivated enhancing lesions without evidence of new lesions. CONCLUSION: According to the very low incidence rate of new enhancing lesions in patients with non-progressive disease on follow-up non-contrast-enhanced MRI, routine administration of contrast in follow-up studies is not suggested.

Brain TRODAT-SPECT Versus MRI Morphometry in Distinguishing Early Mild Parkinson's Disease from Other Extrapyramidal Syndromes.

BACKGROUND AND PURPOSE: The clinical differentiation of Parkinson's disease (PD) from other extrapyramidal syndromes has made a challenge in neurology. This study aimed to compare the specificity and sensitivity of brain MRI volumetry and dopamine transporter scans in differentiating PD from other extrapyramidal syndromes in the early stages of the disease. METHODS: This study included 34 patients younger than 70 years old with less than 3 years of extrapyramidal symptoms. Demographic and clinical history of the patients, including age, sex, and disease duration, was gathered. Disease severity was assessed using Unified Parkinson's Disease Rating Scale III (UPDRS III). For all patients, 99m Tc-TRODAT single-photon emission computed tomography (SPECT) and MRI volumetry were performed. Patients were followed up for 1 year and examined for final diagnosis. RESULTS: According to the quantitative 99m Tc-TRODAT analysis, all of the specific binding ratio (SBR) parameters, including right, left, and bilateral SBRs, were significantly higher in the non-Parkinsonian patients. Also, the results indicated a high diagnostic accuracy for both quantitative 99m Tc-TRODAT analysis (about 88% for SBR parameters) and MRI volumetry (71% for bilateral olfactory bulbs volume) in diagnosing PD. Regarding the diagnosis of PD, there were no significant differences between quantitative scan results and olfactory bulb volumetry according to the area under the receiver operating characteristic curves. CONCLUSION: 99m Tc-TRODAT has a higher accuracy in differentiation of early PD from non-Parkinsonian conditions, particularly essential tremor. Olfactory bulbs volumetry by using MRI can also serve as a potential alternative method in this regard.

Application of Brain Perfusion SPECT in the Evaluation of Response to Zolpidem Therapy in Consciousness Disorder Due to Traumatic Brain Injury.

BACKGROUND: Traumatic brain injury (TBI) is a critical health problem with various comorbidities and socioeconomic consequences. Tending to increase in recent decades, TBI results in more cases of consciousness disorders including vegetative state (VS)/minimally conscious state (MCS). However, no definite or effective treatment still exists for these conditions. The aim of this article is to study the effects of zolpidem in patients with VS caused by TBI by using brain perfusion single-photon emission computed tomography (SPECT). MATERIALS AND METHODS: This was a prospective clinical trial on a cohort of patients with VS. We evaluated the TBI database to find VS/MCS patients, between the ages of 20 and 65 years. We received written consent from their family members prior to enrollment and compared their clinical status and brain perfusion SPECT prior and after 2 weeks of zolpidem therapy. RESULTS: Among the 12 patients included in this study, six patients changed to MCS after 2 weeks. Comparison of their motor score, revealed a statistically significant difference (2.08 vs. 3.75, P = 0.007, respectively). None of the quantitative or qualitative brain perfusion parameters showed any differences after zolpidem therapy. However, the perfusion pattern, with focal or multifocal cortical defects, was significantly more prevalent in the responder group (five patients vs. one patient, P = 0.015). CONCLUSION: Zolpidem therapy may improve consciousness levels and motor function in a considerable portion of VS patients with TBI. This study showed that the presence of focal brain perfusion defect can predict response to zolpidem.

Plasma leptin level is positively associated with blood pressure measures independent of gender and BMI.

Background: Since the introduction of leptin, many studies suggest an important role for this hormone in obesity-related hypertension. However, in non-obese patients, there are controversial results regarding the possible role of leptin in essential hypertension especially in both sexes and different groups of body mass index (BMI). We aimed to evaluate the association of leptin and hypertension in both female and male gender.Materials and Methods: This cross-sectional study was conducted, recruiting 80 essential hypertensive patients and 80 healthy normotensive volunteers using convenience sampling method. Subjects without history of diabetes mellitus, hyperlipidemia, smoking, thyroid disease and insulin or corticosteroid use were included in two groups of normotensive and hypertensive subjects who were matched for age, sex and BMI. Systolic and diastolic blood pressure (SBP and DBP), weight and height were measured for all subjects and a blood sample was obtained for measurement of leptin, fasting blood sugar and lipid profiles.Results: Leptin was significantly higher in hypertensive patients as compared to normotensive subjects in all study population and both male and female subgroups (p < 0.001). Statistically significant correlation was also found between leptin and both SBP and DBP in above-mentioned subgroups. In comparison of controlled and uncontrolled hypertensive patients, leptin was significantly higher in uncontrolled hypertensive patients (p < 0.001).Conclusion: Comparing two groups of hypertensive and normotensive subjects, leptin is found to be positively correlated with hypertension in both genders. Leptin level also tends to be higher in uncontrolled hypertensive patients which may indicate a possible role for leptin in mechanism of uncontrolled hypertension.

The effect of chewing-gum on dose rate of salivary gland in differentiated thyroid carcinoma patients treated with radioiodine.

BACKGROUND: Although, different methods have been suggested on reducing salivary gland radiation after radioiodine administration, an effective preventive or therapeutic measure is still debated. To the best of our knowledge this is the second study that aimed to evaluate the effect of chewing-gum as a sialagogue on the radioiodine content of salivary gland, and radioiodine-induced symptoms of salivary gland dysfunction. METHODS: Twenty-two patients who were referred to radioiodine therapy were randomized into chewing-gum (group A) and control (group B) groups. Anterior and posterior planar images including both head and neck were obtained 2, 6, 12, 24 and 48 hours after the administration of radioiodine in all patients and round regions of interest (ROI) were drawn for both left and right parotid glands with a rectangular ROI in the region of cerebrum as the background. All patients were followed once, 6 months after radioiodine administration via a phone call for subjective evaluation of symptoms related to salivary gland damage. RESULTS: There was no significant difference between the two groups regarding the mean age, gender and initial iodine activity. The geometric mean of background-corrected count per administrated dose and acquisition time was calculated for bilateral parotid glands. This normalized parotid count showed a significant reduction in net parotid count in both groups during the first 48 hours after the radioiodine administration. However, no significant difference was found between the groups according to the amount and pattern of dose reduction in this time period. CONCLUSIONS: This study revealed that chewing-gum had no significant effect on the radioiodine content of parotid glands during the first 48 hours after radioiodine administration. Also, no significant difference was found in the incidence of relevant symptoms after 6 months comparing both groups.

Comparison of Quantitative Perfusion and Function Parameters of Gated-SPECT Myocardial Perfusion Imaging in Patients With Concordant and Discordant Left Bundle-Branch Block.

BACKGROUND: Patients with left bundle-branch block (LBBB) can be classified to discordant LBBB (dLBBB) and concordant LBBB (cLBBB) according to T-wave orientation in lateral leads. This classification indicates different functional left ventricular (LV) parameters with worse prognosis in dLBBB patients. However, there are no data regarding the impact of this classification on perfusion status of the left ventricle. The aim of this study is to evaluate and compare the SPECT myocardial perfusion imaging (MPI) findings of LV perfusion and function between dLBBB and cLBBB patients. METHODS: All patients who were referred for SPECT MPI during an 11 months' period were evaluated. Patients with evidence of LBBB on standard baseline 12-lead ECG were included, and their demographic, medical history, and imaging data were recorded. Quantitative perfusion and function parameters of LV included summed stress score, summed rest score, summed difference score, total perfusion deficit (TPD) at both phases with delta TPD, ejection fraction, end-diastolic volume, end-systolic volume, summed motion score, summed thickening score, phase SD, and phase histogram bandwidth. All baseline ECGs were further assessed by a cardiologist to categorize patients as the cLBBB or dLBBB group according to concordance of the T wave with QRS complex in lateral leads. RESULTS: Finally, 97 patients with 46 cLBBB and 51 dLBBB cases were included. Baseline characteristics and cardiovascular risk factors including diabetes mellitus, hypertension, hyperlipidemia, history of coronary artery disease (CAD), family history of CAD, and smoking were not significantly different between the 2 groups. However, summed stress score (12.2 vs 6.7), summed difference score (4.0 vs 2.6), stress TPD (11.0 vs 6.4), and delta TPD (4.8 vs 3.9) were significantly higher in dLBBB patients. In addition, functional parameters were also significantly worse in dLBBB patients with lower ejection fraction and higher end-diastolic volume, end-systolic volume, summed motion score, and summed thickening score in these patients. Mean phase SD and phase histogram bandwidth were also significantly higher in dLBBB patients. CONCLUSIONS: This study revealed that LBBB patients with discordant T wave in lateral leads have significantly higher ischemic scores and worse functional parameters with more dyssynchrony in gated SPECT MPI.

Role of Hepatobiliary Scintigraphy in the Diagnosis of Gallbladder Agenesis; A Case Report and Brief Review of Literature.

Gallbladder agenesis (GA) is a rare congenital anomaly. Only 50% of the cases with GA are symptomatic, presenting mostly in the 4th or 5th decade of life. The clinical presentation of GA and imaging findings are non-specific and often misinterpreted as other diseases such as ectopic gall bladder. This can lead to unnecessary surgery when the final diagnosis is usually made. Although GA can cause an identical pattern to acute cholecystitis in hepatobiliary scintigraphy, in certain clinical settings, scintigraphy can be helpful as a confirmatory study, especially to rule out the possibility of ectopic gall bladder. In our case, the combination of imaging findings including ultrasonography, computed tomography, and hepatobiliary scintigraphy led to accurate diagnosis avoiding further surgeries.

Pilocarpine effect on dose rate of salivary gland in differentiated thyroid carcinoma patients treated with radioiodine.

OBJECTIVE: Although different methods have been suggested on reducing salivary gland radiation after radioiodine administration, an effective preventive or therapeutic measure is still up for debate. The aim of this study was to evaluate the effect of pilocarpine, as a sialagogue drug on the radioiodine content of the salivary gland, and radioiodine-induced symptoms of salivary gland dysfunction. PATIENTS AND METHODS: Patients who were referred for radioiodine therapy were randomized into pilocarpine and placebo groups. The patients as well as the nurse who administered the tablets, and the specialist who analyzed the images, were all unaware of the patients' group. Anterior and posterior planar images including that of both the head and neck were obtained 2, 6, 12, 24, and 48 h after the administration of radioiodine in all patients, and round regions of interest were drawn for both left and right parotid glands, with a rectangular region of interest in the region of the cerebrum as background. All patients were interrogated once, 6 months after radioiodine administration, by a phone call for subjective evaluation of symptoms related to salivary gland damage. RESULTS: There was no significant difference between the two groups with regard to the mean age, sex, and initial iodine activity. The geometric mean of background-corrected count per administered dose and acquisition time was calculated for the bilateral parotid glands. This normalized parotid count showed a significant reduction in net parotid count in both groups during the first 48 h after radioiodine administration. However, no significant difference was found between the groups according to the amount and pattern of dose reduction in this time period. CONCLUSION: This study revealed that pilocarpine had no significant effect on the radioiodine content of parotid glands during the first 48 h after radioiodine administration. No significant difference was found in the incidence of symptoms between the two groups treated with placebo and pilocarpine.

Impact of the Amount of Liquid Intake on the Dose Rate of Patients Treated with Radioiodine.

PURPOSE: Despite therapeutic effects of radioiodine in patients with differentiated thyroid cancer, there are some disadvantages due to harmful radiation to other tissues. According to the current guidelines, patients are recommended to drink lots of water and frequent voiding to reduce the amount of 131I in the body. This study was designed to assess the impact of the amount of liquid intake on reduction of the measured dose rate of radioiodine-treated patients. MATERIALS AND METHODS: A total of 42 patients with differentiated thyroid cancer without metastasis who had undergone total thyroidectomy and had been treated with radioiodine were selected. The patients were divided into two groups according to the amount of their fluid intake which was measured during the first 48 h after 131I administration. In all patients, the dose rate was measured immediately and 48 h after iodine administration. RESULTS: Each group included 21 patients. Dose rate ratio (the ratio of the second dose rate to the first dose rate) and dose rate difference ratio (the ratio of the difference between the two measured dose rates to the first dose rate) were calculated for each patient. Despite the significant difference in the amount of the liquid drunk, no statistically significant difference was seen between the different groups in parameters of dose-rate ratio and dose-rate difference ratio. CONCLUSION: Higher fluid intake (>60 ml/h in our study) alone would not effectively reduce the patient's radiation dose rate at least not more than a well-hydrated state. It seems that other interfering factors in the thyroidectomized patients may also have some impacts on this physiologic process.

Unusual Displacement of Urinary Bladder by a Dilated Rectosigmoid Colon on Bone Scintigraphy.

A 7-year-old boy with chief complaint of chronic pelvic pain was referred to our nuclear medicine department for bone scintigraphy. The images showed a focus of radiotracer activity in the right side of pelvic cavity, which is further confirmed as urinary bladder by single-photon emission computed tomography (SPECT) and delayed images. Because of high possibility of mass effect in pelvic cavity, pelvic magnetic resonance imaging (MRI) was performed, and it revealed an unusual dilatation of rectosigmoid colon with no evidence of pelvic mass.

The Effect of Antiseptic on 99mTc-DMSA Scans.

Approximately 30 years ago, it has been suggested that chlorhexidine, which is used as antiseptic, can produce Tc colloid complex during Tc-dimercaptosuccinic acid (DMSA) preparation. However, in all cases of liver and spleen uptake in Tc-DMSA scan, it should still be kept in mind because of the introduction of new antiseptic brands with different formulation under various names. Our case is just a sample of this effect, which resulted from application of a new brand of antiseptic by technologists in our center that unintentionally led to low-quality Tc-DMSA scans for a period, and after restrict control of all other confounding factors in the preparation of kit, it was just resolved by changing antiseptic to ethanol.

Comparison of Gated SPECT Myocardial Perfusion Imaging with Echocardiography for the Measurement of Left Ventricular Volumes and Ejection Fraction in Patients With Severe Heart Failure.

BACKGROUND: Gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is known as a feasible tool for the measurement of left ventricular ejection fraction (EF) and volumes, which are of great importance in the management and follow-up of patients with coronary artery diseases. However, considering the technical shortcomings of SPECT in the presence of perfusion defect, the accuracy of this method in heart failure patients is still controversial. OBJECTIVES: The aim of the present study was to compare the results from gated SPECT MPI with those from echocardiography in heart failure patients to compare echocardiographically-derived left ventricular dimension and function data to those from gated SPECT MPI in heart failure patients. PATIENTS AND METHODS: Forty-one patients with severely reduced left ventricular systolic function (EF ≤ 35%) who were referred for gated SPECT MPI were prospectively enrolled. Quantification of EF, end-diastolic volume (EDV), and end-systolic volume (ESV) was performed by using quantitative gated spect (QGS) (QGS, version 0.4, May 2009) and emory cardiac toolbox (ECTb) (ECTb, revision 1.0, copyright 2007) software packages. EF, EDV, and ESV were also measured with two-dimensional echocardiography within 3 days after MPI. RESULTS: A good correlation was found between echocardiographically-derived EF, EDV, and ESV and the values derived using QGS (r = 0.67, r = 0.78, and r = 0.80 for EF, EDV, and ESV, respectively; P < 0.001) and ECTb (r = 0.68, 0.79, and r = 0.80 for EF, EDV, and ESV, respectively; P < 0.001). However, Bland-Altman plots indicated significantly different mean values for EF, 11.4 and 20.9 using QGS and ECTb, respectively, as compared with echocardiography. ECTb-derived EDV was also significantly higher than the EDV measured with echocardiography and QGS. The highest correlation between echocardiography and gated SPECT MPI was found for mean values of ESV different. CONCLUSIONS: Gated SPECT MPI has a good correlation with echocardiography for the measurement of left ventricular EF, EDV, and ESV in patients with severe heart failure. However, the absolute values of these functional parameters from echocardiography and gated SPECT MPI measured with different software packages should not be used interchangeably.

Importance of Heparin Provocation and SPECT/CT in Detecting Obscure Gastrointestinal Bleeding on 99mTc-RBC Scintigraphy: A Case Report.

We presented a pediatric case with a history of intermittent melena for 3 years because of angiodyplasia of small intestine. The results of frequent upper gastrointestinal endoscopies and colonoscopies as well as both Tc-red blood cell (RBC) and Meckel's scintigraphies for several times were negative in detection of bleeding site. However, Tc-RBC scintigraphy with single-photon emission computed tomography (SPECT)/computed tomography (CT) after heparin augmentation detected a site of bleeding in the distal ileum which later was confirmed during surgery with final diagnosis of angiodysplasia.It could be stated that heparin provocation of bleeding before Tc-RBC scintigraphy accompanied by fused SPECT/CT images should be kept in mind for management of intestinal bleeding especially in difficult cases.