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

OBJECTIVES: Impairment of coronary flow reserve (CFR) precedes preclinical atherosclerosis. However, data are lacking regarding its prognostic utility using SPECT imaging. Thus, this study aimed to determine the clinical utility of CFR by sestamibi imaging in predicting future cardiac events in patients with normal and abnormal myocardial perfusion scan (MPS).

METHODS: This was a prospective cohort study of 54 consecutive adult patients with suspected coronary artery disease referred to Nuclear Medicine Division, Philippine Heart Center for dipyridamole technetium-99m sestamibi SPECT MPS from August 2012 to September 2013. Patients with normal (summed stress score, SSS <3) and abnormal (SSS> 4) perfusion scans were further subdivided based on their CFR whether normal (CFR> 2) or abnormal (CFR < 2). Using a validated 2-day protocol, estimated CFR was computed from the ratio of dipyridamole myocardial blood flow (MBE) to resting MBF. MBF was obtained by dividing the global myocardial counts with the arterial input function. Global myocardial counts were derived from the average of the mean counts/pixel of two representative short-axis tomograms at the mediobasal and medioapical views. For the arterial input function, first-pass analysis of the pulmonary artery was performed to generate the time-activity curve (TAC). The mean counts/pixel of the area under the curve represented the input junction. Patients were monitored for major adverse cardiac events (MACE) through phone contact by patient and by review of hospital and physician's record six months after scintigraphy (mean follow-up 9+3 months). Major cardiac events include cardiac death, acute coronary syndrome, unstable angina, and revascularization.

RESULTS: A prospective cohort of 54 consecutive patients with no known CAD, were enrolled in the study. Abnormal MPI revealed significantly lower CFR (1.64 + 0.47 vs. 1.19 + 0.36, p=0.005). The annual cardiac event rate increased in the presence of reduced CFR in spite of a normal MPI (from 0% to 6.9%), and was even higher when both MPI and CFR were abnormal (from 0% to 34.7%). In Kaplan-Meier analysis, patients with abnormal perfusion revealed-significantly higher incidence of cardiac events compared with normal perfusion (chi-square 4.93, p=0.027). There was a trend towards increased incidence of cardiac events in patients with abnormal CFR; however, this did not reach statistical significance (chi-square 0.61, p=0.434).

CONCLUSION: A low CFR was associated with an increased incidence of MACE, particularly in the presence of abnormal perfusion findings.

Human ; Male ; Female ; Adult ; Technetium Tc 99m Sestamibi ; Dipyridamole ; Acute Coronary Syndrome ; Kaplan-meier Estimate ; Heart ; Angina, Unstable ; Myocardium

BACKGROUND: Serum thyroglobulin assays and I-131 imaging and routinely employed for the detection of remaining functioning thyroid tissue after surgery and radioiodine therapy. However, the sensitivity of I-131 is suboptimal resulting in cases of positive thyroglobulin test but negative I-131 imaging, potentially creating a dilemma in subsequent therapeutic management. Other radiopharmaceuticals, such as TI-201 may offer better sensitivity, although it is not clear whether this contributes to the decision-making for subsequent I-131therapy. This prospective cohort study aimed to determine if Tl-201 imaging identified thyroid tissues that will take up therapeutic I-131, and to help define its clinical utility.
METHODS: Fourteen consecutive patients who underwent surgery for well-differentiated thyroid cancer, had I-131 therapy at least eight months previously, and with elevated thyroglobulin (>10 ng/mL) but negative pre-therapy (111 MBq) I-131 whole body scan (WBS), were enrolled in the study. WBS was done using 56.74 MBq of Tl-201. All patients had repeat I-131 ablation (3.7-7.4GBq) one to two months after Tl-201 imaging. Post-therapy WBS was done four to seven days after.
RESULTS: All 14 patients had papillary thyroid carcinoma. Ten patients had a positive Tl-201 scan. Of the 14 subjects, only two had a positive post-therapy I-131 WBS, both whom had a positive Tl-201 scan. Thallium-201 scanning showed a fairly high sensitivity (71%) in demonstrating thyroid remnants or metastases using a thyroglobulin level of >10 ng/mL as standard. However, a positivel Tl-201 scan only has a predictive value of 20% for subsequent uptake of therapeutic I-131 as shown in the post-therapy scan.
CONCLUSION: Thallium-201 uptake correlates poorly with therapeutic I-131 uptake in thyroglobulin-positive, but I-131 scan-negative, differentiated thyroid cancer patients. Results of this study suggest that the presence of thyroid remnants and metastases on Tl-201 imaging is inappropriate as a basis for subsequent I-131 therapy.

Human ; Male ; Female ; Middle Aged ; Adult ; Thyroglobulin ; Thyroid Cancer, Papillary ; Radiopharmaceuticals ; Iodine Radioisotopes ; Thallium ; Thyroid Neoplasms ; Carcinoma ; Neoplasms, Second Primary ; Thallium Radioisotopes

INTRODUCTION: Patients with well-differentiated thyroid carcinoma (WDTC) may require more than one session of radioactive iodine therapy (RAIT). This study was conducted to determine if post-therapy whole body scintigraphy (PTWBS) can identify patients who will require repeat RAIT due to persistent disease.

METHOD: The records of patients with WDTC who were referred to the Philippine General Hospital for RAIT from 2005-2007 were reviewed in this retrospective cohort study. PTWBS results (number of remnants, area of remnants, and presence of metastasis) of patients who had repeat RAIT (based on laboratory and clinical evidence of persistent disease) were compared with those of patients who did not have repeat RAIT. Multiple logistic regression analysis was done.

RESULTS: Forty-five of 99 patients in the study [45%, 95% Confidence Interval (CI): 35 had repeat RAIT. Thirty-six of 38 patients (95%) with metastases on PTWBS required repeat RAIT, while only 9 of 61 patients (15%) with no scan evidence of metastases required subsequent therapy. Controlling for age group (age), the odds ratio was 102 (95% CI: 20 . Positive and negative predictive values were 95 and 85% respectively. The same results were obtained using metastases alone as a predictor. Twenty-six patients had extra-cervical metastases by PTWBS and all required repeat RAIT. The number and aggregate size of thyroid remnants by PTWBS, however, were not found to be predictive of the need for repeat therapy.

CONCLUSION: The presence of functioning metastases seen on PTWBS was highly predictive of the need for repeat RAIT.

Human ; Male ; Female ; Middle Aged ; Adult ; Hospitals, General ; Philippines ; Whole Body Imaging ; Thyroid Neoplasms ; Carcinoma ; Radionuclide Imaging ; Iodine

Congenital cystic adenomatoid malformation is a rare bronchopulmonary malformation resulting from an arrest in lung development between 4th and 7th week of fetal life. It typically presents as respiratory distress in the neonatal period and recurrent pulmonary infections in adults; and is sometimes associated with other congenital abnormalities [especially CCAM Type II]. Chest roentgenograms and CT scan are the usual modalities of choice in its initial evaluation and histopathology done post-operatively establishes the diagnosis. Ventilation-Perfusion [VQ] scintigraphy is of paramount importance in the routine assessment of CCAM patients but is often disregarded. This paper presents the incremental value of doing a lung perfusion scintigraphy and aims to emphasize the significance of performing a VQ scan in such cases.
Human ; Female ; Adult ; RADIONUCLIDE IMAGING ; SCINTIGRAPHY ; DIAGNOSTIC IMAGING ; CYSTIC ADENOMATOID MALFORMATION OF LUNG, CONGENITAL ; CONGENITAL CYSTIC ADENOMATOID MALFORMATION OF LUNG ; LUNG DISEASES ; TOMOGRAPHY SCANNERS, X-RAY COMPUTED

The study aims to determine the relationship of body mass index (BMI) and related anthropometric measurements on the image quality of Tl-201 and Tc-99m sestamibi myocardial perfusion scans (MPS). A total of 163 scans were analyzed. A blinded experienced physician performed visual analysis on the scans image quality on two different occasions. Quantitative parameter used was the heart-to-lung ratio (HLR). Regression analysis was done to determine the association of HLR with BMI and myocardial tracer uptake, ROC curves were generated to establish BMI and HLR cut-off points. Increasing BMI was associated with visually poorer images in the Tl-201 MPS group (p 0.003) but not for the Tc-99m MPS group (p 0.065). It was also associated with decrease HLR and myocardial tracer upatake for both tracers (p <0.001). ROC curves revealed BMI cut-off points of 28 (Tl-201 p 0.000; Tc99m sestamibi p 0.004) for both procedures; HR cut-off values of 3.0 for Tl-201 )p 0.295) and 2.5 for Tc-99m sestamibi (p 0.875). the image quality of Tl-201 scans begins to deteriorate at a BMI of 28 and HLR of 3.0 with myocardial count density reduction (less than or equal to 6000 counts) translating to visually poorer images. On the other hand , image quality of Tc-99m sestamibi scans also tend to deteriorate similarly at a BMI of 28. However, in contrast to Tl-201, the lower HLR cut-off of 2.5 suggests a relatively higher myocardial count density (greater than or equal to 9000 counts) rendering the image quality to be still satisfactory for subjective assessment.
Human ; Male ; Female ; Middle Aged ; Adult ; Young Adult ; Adolescent ; Child ; MYOCARDIAL PERFUSION IMAGING ; MYOCARDIAL SCINTIGRAPHY ; DIAGNOSIS ; DIAGNOSTIC TECHNIQUES AND PROCEDURES ; DIAGNOSTIC IMAGING ; CARDIAC IMAGING TECHNIQUES ; BODY MASS INDEX

The aim of this study is to determine the diagnostic accuracy of antithyroglobulin antibodies in predicting recurrent differentiated thyroid carcinoma. We searched PubMed (1990-2010) and Google Scholar (1990-2010). Citation searches, manual searches and screening of references of f included studies were done. Diagnostic studies that utilized antithyroglobulin antibodies as a predictor of recurrent differentiated thyroid carcinoma. The authors searched citations that correlated with the criteria using a data collection form generated in Review Manager 5 (REVMAN 5). The methodological quality was then assessed using Quality Assessment of Studies of Diagnostic Accuracy (QUADAS). Hierarchical summary receiver operating characteristic (HSROC) mete-analytical tool was used to estimate summary receiver operating characteristic (ROC) curves. Eight studies with 2116 participants with 182 patients with recurrent differentiated thyroid carcinoma were included. Pooled sensitivity and specifically were 63% and 79% respectively. SROC shows an overall are under the curve (AUC) of 0.712. Antithyroglobulin antibody has ability to predict recurrent differentiated thyroid carcinoma.
THYROID NEOPLASMS ; NEOPLASMS ; NEOPLASMS BY SITE ; ENDOCRINE GLAND NEOPLASMS

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 ; ; ; ;