Predicting the clinical course in hypertrophic cardiomyopathy using thallium-201 myocardial scintigraphy.

AIMS: This study aimed to evaluate the changes in left ventricular remodelling with time in patients with hypertrophic cardiomyopathy (HCM) using thallium-201 myocardial scintigraphy. METHODS AND RESULTS: Forty-eight patients with HCM participated in the study. The extent score (ES) and a newly devised index termed the 'mean count change' (MCC) were used to evaluate the myocardial perfusion defects. Using the amount of thallium-201 uptake (TU), MCC (%) was calculated using the following formula: (last TU - initial TU)∕initial TU × 100. To confirm the site of the lesion, the left ventricle was divided into five segments: anterior, septal, inferior, lateral, and apex. Cardiovascular complications and deaths were recorded. The mean follow-up period was 8.6 ± 2.0 years. ES increased from 17.4 ± 13.7% to 44.0 ± 22.3% (P < 0.0001). MCC increased from 0% to 12.0 ± 9.0% (P < 0.0001). The apex was the most frequent site of lesion. Twenty-seven patients (56.3%) had experienced left ventricular heart failure (LVHF). Both ES and MCC were greater in patients with LVHF than in those without LVHF. An overlap between the two groups was greater in ES than in MCC. Patients with LVHF had a higher incidence of atrial fibrillation and apoplexy. Nineteen patients (39.6%) died during the study period; 14 died from LVHF, 3 from sudden cardiac death, and 2 from cancer. CONCLUSIONS: Thallium-201 myocardial scintigraphy is useful for detecting the severity of myocardial damage and for confirming the lesion site in patients with HCM. MCC may be superior to ES in the evaluation of these changes with time.

A Comparison of Heart Rate Response between 12 hours Caffeine Abstinence and 24 hours in Adenosine Stress Myocardial Perfusion Imaging.

The aim of this study was to examine whether the heart rate response to adenosine differs after 12 hours [Good control (Good-C)] versus 24 hours [Excellent control (Exc-C)] of caffeine abstinence in adenosine stress thallium-201 (TL) myocardial perfusion imaging (MPI). Patients (n=729) with suspected ischemic heart disease underwent adenosine TL-MPI after 12 (n=226) and 24 (n=503) hours of caffeine abstinence. There was not significant differences between the heart rate of Exc-C and Good-C in 0-2 min after adenosine infusion (0 min 63.7±9.5 versus 63.7±10.0, 1 min 66.4±10.6 versus 65.3±10.5, 2 min 72.3±11.2 versus 70.6±11.4). The heart rate of Exc-C was higher compared to Good-C in 3-6 min after adenosine infusion (3 min 75.6 ±11.7 versus 73.3±11.6 p=0.013, 4 min 79.2±12.9 versus 76.7±12.2 p=0.012, 5 min 79.4±12.6 versus 76.8±12.4 p=0.009, 6 min 79.4±12.5 versus 77.0±12.3 p=0.016). Therefore, the longer caffeine abstinence, namely 24 hours self-restraint, is effective in adenosine TL-MPI.

[Intravenous adenosine and radiopharmaceutical injection in the same line was feasible in adenosine stress myocardial perfusion. imaging].

Adenosine stress myocardial perfusion imaging was performed with an intravenous adenosine and radiopharmaceutical injection in the same line. A syringe containing 720 µg/kg of adenosine in 40 ml of saline was prepared and injected at the constant infusion rate of 400 ml/h. Adenosine was temporarily stopped by the stopcock when 1.5 ml of thallium was injected for 0.5 second from the three-way stopcock with two ways opened. Thereafter, the stopcock was returned to the original position in 0.5 second, and adenosine flow returned to the constant flow rate again. In this method, 0.75% of adenosine total dose was injected at a rate of 3.0 ml/s and adenosine was stopped for 3.6 second. There were no significant differences in either effects and adverse events of adenosine between this method and two intravenous injection line method. Adenosine stress in one venous line method would be an easy method maintaining the dose effect and safety.

Image fusion of coronary tree and regional cardiac function image using multislice computed tomography.

BACKGROUND: Although trials of image fusion, such as positron emission computed tomography and multislice spiral computed tomography (MSCT), have already demonstrated clinical usefulness, fusion of the coronary artery image and functional image by MSCT alone has not been reported yet. Here, a new idea of data analysis is proposed in which both regional cardiac function and the responsible coronary arteries can be assessed by a fused image. METHODS AND RESULTS: The study group comprised 5 patients with coronary artery disease. At the first procedure, 3 dimensional (D) volume rendering coronary artery (3D-CTA) was extracted. At the second procedure, the systolic regional wall thickening was calculated and the color 3D functional surface map of systolic wall thickening (3D-SWT) was generated. At the final procedure, 3D-SWT was superimposed on the left ventricular surface with 3D-CTA using a transparency. In all 5 patients, image fusion of the coronary tree and cardiac function was correctly generated. Image fusion can be displayed as clear 3D images, offering better orientation to help assess both the coronary artery and regional function. CONCLUSIONS: Image fusion of coronary computed tomography angiography and the functional map by MSCT is potentially a new method of assessing both the coronary artery and cardiac function.

Regional cerebral blood flow change in a case of Alzheimer's disease with musical hallucinations.

We examined alteration of regional cerebral blood flow (rCBF) in a case of Alzheimer's disease (AD) patient with musical hallucination. To detect regions related to musical hallucination, single-photon emission computed tomography (SPECT) imaging of the patient and nine sex, age, and cognitive function-matched AD patients without delusions and hallucinations were compared using statistical parametric mapping 99 (SPM99). In comparison with controls, the patient had increased rCBF in left temporal regions and left angular gyrus. This profile could be relevant to the neuroanatomical basis of musical hallucinations.

Thallium-201 scintigraphy in bone and soft-tissue tumors: a comparison of dynamic, early and delayed scans.

OBJECTIVE: It has been reported that delayed scan of thallium-201 (201Tl) scintigraphy is useful for differentiating malignant tumors from benign lesions and for evaluating treatment response. However, physiological muscle uptake which usually increases in delayed scans, often makes it difficult to evaluate 201Tl uptake and its washout in bone and soft-tissue tumors. The purpose of this study was to evaluate whether the delayed scan is necessary and whether a dynamic scan is useful in the evaluation of bone and soft-tissue tumors. METHODS: We studied 175 cases of bone and soft-tissue tumors (malignant 45, benign 130). Dynamic scans were acquired every 5 seconds for 10 minutes after 201Tl injection, and time activity curves (TACs) were generated by adaptive smoothing methods. Early and delayed scans were acquired at 10-15 minutes and 2 hours after injection. 201Tl images were visually interpreted and the radioactivity count ratio (T/N) of tumors to normal tissues and washout rate [WR = (early T/N - delayed T/N)/early T/N] were defined. RESULTS: When there were no 201Tl uptake in dynamic (n = 67) and early scans (n = 68), no tumor uptake was also appreciated in delayed scans, and all but two cases of negative scans were benign. In 107 lesions, although there were significant differences in T/Ns between malignant and benign lesions both on early scans (2.84 +/- 1.45 vs. 2.05 +/- 1.13, p < 0.05) and delayed scans (2.17 +/- 1.03 vs. 1.58 +/- 0.64, p < 0.05), there was a substantial overlap. The T/Ns decreased in delayed scans (i.e., WR > 0) in 100 of 107 cases due to increase of surrounding muscle uptake, and there was no difference in WR between malignant tumors and benign lesions (0.21 +/- 0.14 vs. 0.19 +/- 0.14). CONCLUSIONS: For evaluating bone and soft-tissue tumors, delayed scan had little clinical usefulness and it may be time consuming. Dynamic scan would be useful for demonstrating the differences between tumor blood flow and 201Tl uptake in tumors.

Effect of beta-blocker therapy on myocardial perfusion defects in thallium-201 scintigraphy in patients with dilated cardiomyopathy.

BACKGROUND: The beneficial effects of beta-blocker therapy in patients with heart failure have been confirmed. However, the effects of beta-blockers on myocardial perfusion defects are unclear. The aim of this study was to evaluate the effect of beta-blockers on myocardial perfusion defects estimated by thallium-201 myocardial scintigraphy in patients with dilated cardiomyopathy (DCM) and to investigate the relationships between beta-blocker treatment and myocardial damage and cardiac function. METHODS: 201Tl and echocardiography were performed in 37 patients before and after 6 months of beta-blocker therapy. Extent score (ES) by 201Tl was used to quantitate myocardial perfusion defects before and after treatment. RESULTS: ES was significantly decreased by beta-blocker therapy. According to the change in ES, DCM patients were classified into three groups, patients who improved, patients showing no change and patients who deteriorated. In the improvement and no-change groups, beta-blocker therapy induced a reduction in left ventricular dimensions and an associated increase in ejection fraction. However, in the deterioration group, left ventricular dimensions and ejection fraction were unchanged. There was a significant relationship between the change in left ventricular dimension at end-diastole and the change in ES. CONCLUSIONS: beta-Blocker therapy could attenuate myocardial perfusion defects in some patients with DCM. The improvement in left ventricular function associated with beta-blocker therapy may be related to the attenuation in myocardial perfusion defects.

Assessment of reperfused acute myocardial infarction with two-phase contrast-enhanced helical CT: prediction of left ventricular function and wall thickness.

PURPOSE: To investigate whether two-phase contrast material-enhanced computed tomographic (CT) findings serve as predictors of changes in left ventricular (LV) function and wall thickness (WT) after acute myocardial infarction (MI) and successful angioplasty. MATERIALS AND METHODS: Ethics committee approval and informed consent were obtained. In 58 patients (51 men and seven women; mean age, 62 years +/- 12 [standard deviation]) who had experienced an acute MI and undergone successful angioplasty, two-phase (acquisitions at 45 seconds and 7 minutes) contrast-enhanced CT was performed in the acute (mean interval between treatment and CT, 37 hours +/- 4) and intermediate (mean interval, 28 days +/- 4) periods and for long-term (mean interval, 12 months +/- 4) follow-up. CT images were reviewed for an early perfusion defect (ED) at 45 seconds and for late enhancement (LE) and a residual perfusion defect (RD) at 7 minutes. Myocardial enhancement patterns and WT were assessed, and LV ejection fraction (LVEF) and percentage decrease in WT were calculated. The patient group was subdivided into three groups according to enhancement pattern: Group 1 included patients with LE but no ED or RD; group 2, patients with ED and LE but no RD; and group 3, patients with ED, LE, and RD. Fisher exact testing was used to measure categorical response. Paired and unpaired t tests were used for comparison between two groups (points); Tukey-Kramer multiple comparison and repeated-measures analysis of variance were used for comparisons between the three groups. P < .05 was considered to indicate a significant difference. RESULTS: In group 3 (n = 36), WT in infarcted area was significantly reduced at the intermediate and long-term CT examinations (P < .001). At the intermediate and long-term examinations, percentage decrease in WT was greater in group 2 (n = 10) than in group 1 (n = 12) (P < .05 for intermediate and P < .001 for long-term examination) and was greatest in group 3 (P < .001 for both examinations). LVEF was poorest in group 3 and best in group 1. CONCLUSION: Two-phase contrast-enhanced CT proved useful in predicting LV functional recovery and WT in patients who had experienced acute MI and undergone successful angioplasty.

Myocardial microvascular abnormalities observed by intravenous myocardial contrast echocardiography in patients with hypertrophic cardiomyopathy.

We tested the hypothesis that myocardial microvascular abnormalities occur and are influenced by clinical features in 30 patients with hypertrophic cardiomyopathy (HC) using intravenous myocardial contrast echocardiography. Patients with HC were subdivided into 3 groups: nonobstructive HC (n = 12), obstructive HC (n = 10), or HC with systolic dysfunction and heart failure (n = 8). In patients with nonobstructive HC and obstructive HC, subendocardial peak myocardial contrast intensity at the mid-septal area was significantly decreased and the transmyocardial difference of peak myocardial contrast intensity between subendocardial and periendocardial regions at the mid-septal area was significantly related to regional wall thickness. Reduced peak myocardial contrast intensities at the mid-septal subendocardial and periendocardial regions were observed in patients with HC and heart failure. Our study indicates that subendocardial microvascular abnormalities during end-systole may be associated with severity of regional myocardial hypertrophy in patients with nonobstructive HC and obstructive HC. In addition, progressive microvascular damage may occur in patients with HC and heart failure.

Usefulness of brain SPECT to evaluate brain tolerance and hemodynamic changes during temporary balloon occlusion test and after permanent carotid occlusion.

UNLABELLED: The purpose of this study was to evaluate the usefulness of SPECT during temporary carotid balloon occlusion testing and to evaluate the changes in regional cerebral blood flow (CBF) and regional cerebral perfusion reserve (CPR) after permanent carotid occlusion. METHODS: Temporary balloon occlusion testing was performed on 40 patients (24 head and neck tumors, 16 aneurysms). During the balloon occlusion (total time, 30 min), (99m)Tc-ethylcysteinate dimer (ECD) was injected intravenously about 5 min before balloon deflation, followed by SPECT data acquisition. SPECT images were visually evaluated, and the severity of hypoperfusion on the occluded side was classified using 4 grades (normal, mild, moderate, and severe). The count ratio of the occluded side to the contralateral side (L/N ratio) was also analyzed. In 7 patients who subsequently underwent permanent carotid occlusion, CBF and CPR were quantitatively assessed using (133)Xe inhalation dynamic SPECT at rest and after acetazolamide (ACZ) enhancement (CPR was defined as the percentage increase in CBF after ACZ), and the patients were followed up periodically. RESULTS: SPECT after temporary occlusion showed moderate or severe hypoperfusion in 12 patients, whereas neurologic deterioration was observed in only 4 patients. The L/N ratios were 0.96 +/- 0.03 in normal perfusion (13 patients), 0.93 +/- 0.03 in mild hypoperfusion (15 patients), 0.83 +/- 0.03 in moderate hypoperfusion (10 patients) and 0.66 +/- 0.09 in severe hypoperfusion (2 patients) (P < 0.0001). In the 7 patients who underwent permanent carotid occlusion, CPR decreased after surgery (35% +/- 7% vs. 7% +/- 14%, P < 0.05), even though the resting CBF did not change (54 +/- 8 mL/100 g/min vs. 52 +/- 6 mL/100 g/min, not statistically significant). The steal phenomenon (rCPR < 0%) was observed in 3 patients, 1 of whom experienced transient hemiparesis when blood pressure dropped soon after surgery. On follow-up, the decreased CPR gradually improved and no infarction developed. CONCLUSION: SPECT is useful to detect cerebral hypoperfusion during carotid occlusion. Assessment of CPR is recommended to predict the potential risk of postsurgical complications and to follow up patients after permanent carotid occlusion.

Use of thallium-201 myocardial scintigraphy for the prediction of the response to beta-blocker therapy in patients with dilated cardiomyopathy.

This study was performed to evaluate whether thallium-201 myocardial scintigraphy (Tl-201) and iodine-123-metaiodobenzylguanidine (MIBG) myocardial scintigraphy could predict the usefulness of beta-blocker therapy in patients with dilated cardiomyopathy (DCM). Tl-201 and MIBG were performed in 47 patients before beta-blocker therapy. Patients were classified into group A, if their cardiac function improved, and group B, whose function remained unchanged. Two types of extent score (ES) by Tl-201 were proposed to quantitate myocardial damage, mean-2SD (ES-2) and mean-3SD (ES-3). The ES difference between ES-2 and ES-3 was calculated, and according to ES and ES difference, DCM cases were classified into 3 groups: mild-defect type (mild-type), moderate-defect type (moderate-type) and severe-defect type (severe-type). The heart-to-mediastinum (H/M) MIBG uptake ratio was evaluated, and the percent washout ratio of myocardial MIBG was obtained from these data. Group A comprised 18 mild-type, 14 moderate-type and 1 severe-type cases, and group B comprised 5 mild-type, 4 moderate-type and 5 severe-type cases. A significant relation was observed between the defect type on Tl-201 and the response to beta-blocker therapy (p=0.0090). Both H/M MIBG uptake ratios and washout ratio were not significantly different in the 2 groups. Tl-201 may be useful for predicting the response to beta-blocker therapy in patients with DCM.