Human ; Radionuclide Imaging ; Nuclear Medicine

BACKGROUND: Coronary microcirculation impairment with sequential decrease in cardiac function is reflected by abnormal left ventricular ejection fraction reserve (LVEFR),which precedes diagnostic evidence of myocardial insult. However, prognostic utility of LVEFR is less, if not least explored. The aim of this study was to evaluate the clinical utility of LVEFR in predicting major cardiac events (MACE) among patients with and suspected coronary artery disease (CAD).
MATERIALS AND METHODS: A retrospective cohort study of 245 patients who underwent stress thallium-201 myocardial perfusion scan (MPS) was conducted. The patients were categorized as having normal or abnormal perfusion scan. Each group was subdivided into normal and abnormal LVEFR groups. All subjects were followed up for any major adverse cardiac events 36 months after MPS through review of hospital records.
RESULTS: There was an overall increase in the likelihood of cardiac events with abnormal LVEFR (i.e., odds ratio of 2.99,p=<0.01). Majority of subjects with abnormal MPS also had abnormal LVEFR showing a significantly lower mean LVEFR (1.17± 7.30 vs. 3.02 ± 7.36p =<0.01).
CONCLUSION: Abnormal LVEFR can be used as an independent predictor of cardiac events which can be observed in subjects with normal and abnormal perfusion scans alike.

Human ; Male ; Female ; Middle Aged ; Adult ; Coronary Artery Disease ; Thallium ; Omega-chloroacetophenone ; Microcirculation ; Stroke Volume ; Heart ; Thallium Radioisotopes ; Myocardium ; Perfusion Imaging

BACKGROUND: Coronary microcirculation impairment with sequential decrease in cardiac function is reflected by abnormal left ventricular ejection fraction reserve (LVEFR),which precedes diagnostic evidence of myocardial insult. However, prognostic utility of LVEFR is less, if not least explored. The aim of this study was to evaluate the clinical utility of LVEFR in predicting major cardiac events (MACE) among patients with and suspected coronary artery disease (CAD).
MATERIALS AND METHODS: A retrospective cohort study of 245 patients who underwent stress thallium-201 myocardial perfusion scan (MPS) was conducted. The patients were categorized as having normal or abnormal perfusion scan. Each group was subdivided into normal and abnormal LVEFR groups. All subjects were followed up for any major adverse cardiac events 36 months after MPS through review of hospital records.
RESULTS: There was an overall increase in the likelihood of cardiac events with abnormal LVEFR (i.e., odds ratio of 2.99,p=<0.01). Majority of subjects with abnormal MPS also had abnormal LVEFR showing a significantly lower mean LVEFR (1.17± 7.30 vs. 3.02 ± 7.36p =<0.01).
CONCLUSION: Abnormal LVEFR can be used as an independent predictor of cardiac events which can be observed in subjects with normal and abnormal perfusion scans alike.

Human ; Male ; Female ; Middle Aged ; Adult ; Coronary Artery Disease ; Thallium ; Omega-chloroacetophenone ; Microcirculation ; Stroke Volume ; Heart ; Thallium Radioisotopes ; Myocardium ; Perfusion Imaging

This paper presents a clinical situation in which a Technetium 99m sestamibi myocardial perfusion scintigraphy (MPS) with dipyridamole was used as part of the preoperative evaluation in a 15 year old female with Tetralogy of Fallot. MPS revealed no evident inducible myocardial ischemia, depressed LV wall function and RVH but with good RV function. There are many different techniques for imaging and studying patients with Tetralogy of Fallot (TOF). Echocardiography, ventriculography and invasive angiography remain the mainstay in its evaluation. However, the presence of coronary anomalies in these patients is very common and has negative effect on myocardial perfusion, either preoperatively or postoperatively. Hence, MPS plays an essential role in providing complete assessment in this group of patients.

Human ; Female ; Adolescent ; Angiography ; Cerebral Ventriculography ; Dipyridamole ; Echocardiography ; Heart Defects, Congenital ; Myocardial Ischemia ; Perfusion Imaging ; Technetium Tc 99m Sestamibi ; Tetralogy Of Fallot ; Tomography, X-ray Computed ; ; ; ;

Congenital lobar emphysema (CLE) is a life-threatening but potentially reversible lung abnormality of unknown etiology that can present a diagnostic dilemma. Imaging procedures are helpful for early diagnosis. This paper aims to present the scintigraphic features of CLE in a two-year-old male in correlation with other diagnostic modalities. Lung perfusion scintigraphy revealed globally diminished perfusion to the left lung. High Resolution Computed Tomography (HRCT) of the chest showed intrinsic narrowing of the distal left mainstem bronchus. CT scan of the Pulmonary Arteries (CTPA) showed a small left main pulmonary artery. Lung perfusion scintigraphy in CLE is characterized by markedly attenuated vascularity of the involved lobe with consequent decreased perfusion, and increased to normal perfusion in the unaffected lobe. It plays a vital role in the early diagnosis and management of pediatric pulmonary diseases presenting with a diagnostic dilemma, particularly in cases where it can preclude more invasive diagnostic procedures.

Human ; Male ; Child Preschool ; Bronchi ; Child ; Early Diagnosis ; Lung ; Perfusion Imaging ; Pulmonary Artery ; Pulmonary Emphysema ; Tomography, X-ray Computed

Paget's disease, also known as osteitis deformans, is characterized by rapid bone remodeling and the formation of bone that is structurally abnormal. Men are affected twice as often as women. The disease is uncommon in persons of African and Asian descent. The majority of patients with Paget's disease are usually asymptomatic, although the most frequent symptom is pain. This paper aims to present a rare case of Paget's disease in a local setting and to present the scintigraphic features of Paget's disease in correlation with other diagnostic modalities. This is a case of a 69-year-old female with a history of low back pain and difficulty in walking of one month duration. CT scan showed sclerotic changes in the right pelvic bone probably degenerative or infectious in nature, however, neoplastic process is not totally ruled out. Bone scan showed an osteoblastic lesion in the right hemipelvis. Considerations include Paget's disease and metastasis (in the presence of a primary neoplastic lesion). The alkaline phosphatase was elevated. An open bone biopsy of the right pelvis was done. Histopathologic report showed prominent cement lines with numerous large osteoclasts. This was signed-out as Paget's disease of the bone. Paget's disease is rare in the Philippines. Our case illustrated a common clinical feature of the disease seen in an elderly patient presenting with bone pain, elevated alkaline phosphatase value, and associated with cortical thickening and sclerosis of the right pelvis on radiolograph and osteoblastic lesion on bone scan.

Human ; Male ; Female ; Aged ; Alkaline Phosphatase ; Biopsy ; Bone Remodeling ; Low Back Pain ; Osteitis Deformans ; Osteoclasts ; Pelvic Bones ; Pelvis ; Philippines ; Sclerosis ; Tomography, X-ray Computed ; Walking

BACKGROUND: Blunting of coronary flow reserve (CFR) may precede overt ischemia. The study aimed to correlate CFR with perfusion findings and risk factors for coronary artery disease (CAD).
METHODS: Fifty-four consecutive patients underwent dipyridamole-rest technetium-99m sestamibi single photon emission computed tomography (SPECT) on two separate days. CFR was computed as the quotient of myocardial blood flow (MBF= global tissue perfusion divided by arterial input function) at stress and at rest.
RESULTS: CFR was significantly lower in patients with abnormal perfusion vs normals (p=0.005). Reduced CFR was noted in 83% of patients with normal SPECT. Lower CFR was seen in hypertensive patients with left ventricular hypertrophy (LVH) compared to those without LVH (p=0.029); likewise in DM vs no DM (p=0.121). Independent predictors of reduced CFR were age and extent of ischemia.
CONCLUSION: Abnormal perfusion is associated with reduced CFR. In those with normal perfusion, there is a high prevalence of reduced CFR, which may be attributed to the presence of risk factors for CAD and LVH.

Human ; Male ; Female ; Arteries ; Coronary Artery Disease ; Dipyridamole ; Hypertrophy, Left Ventricular ; Risk Factors ; Technetium Tc 99m Sestamibi ; Tomography, Emission-computed, Single-photon

Patients with LV dysfunction are known to have a high risk for future coronary events. This study aimed to determine the incremental prognostic value of perfusion defects in patients with scintigraphic evidence of LV dysfunction. Patients showing either transient ischemic dilatation or Tl-201 lung:heart ratio of >0.5 on exercise or dipyridamole SPECT Tl- 201 myocardial perfusion scan were included in the study. Perfusion defects were scored semiquantitatively using a 17 -segment, 5-point scale (0 = normal, 4 = absent uptake). The extent and severity of defects were quantified using number of abnormal segments (NAS) and the summed stress score (SSS). Defect reversibility was quantified using the summed difference score (SDS) between stress and rest defects. Patients were followed up for the development of coronary events over a period of 12 - 30 months. There were 6 cardiac deaths and 7 myocardial infarctions in the 65 patients included in the study (20% overall event rate). ROC curve analysis of the scores revealed the following suggested cut-off values for predicting cardiac event: NAS ~ 7 (85% sensitivity, 56% specificity), SSS ~ 19 (77% sensitivity, 67% specificity) and SDS ~ 7 (31 % sensitivity, 60% specificity). ,Event rate was significantly higher above the cut-off value in SSS «19 = 9%, >19 = 32%,p = 0.04). With NAS, the event rate was higher above the cut-off value, with the difference approaching significance (NAS 7 = 26%, P = 0.06). There was no statistically significant difference in the event rate with high or low SDS (SDS 7 = 16%, P = 0.32). The odds ratios for NAS and SSS (5.8,4.9, respectively) were higher compared with SDS (0.56). The extent and severity of stress perfusion defects provided incremental prognostic information in patients with LV dysfunction. Our data suggest that the degree of defect reversibility showed no prognostic value in this subset of patients.

Human ; Male ; Female ; Aged ; Middle Aged ; Adult ; Dilatation ; Dipyridamole ; Myocardial Infarction ; Tomography, Emission-computed, Single-photon ; Myocardial Perfusion Imaging ; Thallium ; Radionuclide Imaging ; Diagnosis ; Cardiac Imaging Techniques

Left ventricular mass (LV mass) is an independent prognostic indicator of cardiovascular complications, and its regression due to therapy translates to positive clinical outcomes. Good correlation of LV mass between qualitative ECG-gated SPECT (OGS) and echocardiography has been reported, and this study aims to verify if such relationship applies in the local setting. Forty-five consecutive patients with normal myocardial perfusion SPECT and recent plain echocardiograms done in the same institution were retrospectively analyzed. Results show a significant correlation (y = 0.296x + 75.962, r = 0.491, p = 0.001) between the LV mass of the two imaging modalities, which was also observed in the TI-201  group (y= 0.256x + 80.325, r_=_0.442, p = 0.006), but not in the Tc-99m sestamibi group (y= 0.402x + 63.456, r_=_0.443, p = 0.272). The mean LV mass by OGS (122.0 ± 26.9) is significantly smaller compared with the mean LV mass by echo cardiography (155.5 ± 44.6), and the difference between the two procedures (mean ± SD: 39.7 ± 32.6, p<0.001) are significantly different among all subiects, and in the TI-201 and Tc-99m sestamibi groups. In conclusion, the LV mass generated by OGS correlates with echocardiographic estimations, but are statistically different, with OGS significantly underestimating the echo cardiographic values. Age, sex and BMI do not influence the LV mass discrepancy between the two imaging modalities, but the presence of soft tissue attenuation artifacts tend to decrease the LV mass generated by OGS, contributing to further LV mass disparity.

Human ; Male ; Female ; Aged ; Middle Aged ; Artifacts ; Body Mass Index ; Echocardiography ; Electrocardiography ; Heart Diseases ; Retrospective Studies ; Technetium Tc 99m Sestamibi ; Tomography, Emission-computed, Single-photon

BACKGROUND/OBJECTIVE: Direct measurement of gland uptake function is done by determining radioactive iodine uptake (RAID) values. Scintigraphic parameters in 99mTc0-4 thyroid scan have been shown to be moderately correlated with FT4 levels. This study aims to correlate these scintigrahic parameters with RAIU values and determine the cutoff that will predict increased gland uptake function.
METHODOLOGY: Patients referred for thyroid scan and RAI uptake at the Philippine Heart Center were included in the study. RAW. values were correlated with thyroid salivary gland ratio, thyroid to background ratio, thyroid count and acquision time. These values were obtained by drawing appropriate regions of interest in the thyroid, salivary gland and the background.
RESULTS: The four parameters were strongly correlated with RAI uptake values. The cut-off for the thyroid salivary gland ratio, thyroid to background ratio, total thyroid count and acquisition time that best predicts increased gland uptake were > 9.3, > 9.8, > 108134 counts, and < 203 seconds, respectively.
CONCLUSION: The four scrim/graphic parameters can be used in determining the activity of the gland using thyroid imaging alone in the absence of RA1U values.

Human ; Male ; Female ; Aged ; Middle Aged ; Adult ; Thyroid Gland ; Iodine ; Salivary Glands ; Viscera