Aneurysmal 99m Tc-HMPAO Uptake in Brain Death.

ABSTRACT: A 41-year-old man was admitted to hospital due to sudden loss of consciousness. A regional brain perfusion SPECT/low-dose CT showed abnormal 99m Tc-HMPAO uptake in the right hemisphere frontotemporally without any other supratentorial or infratentorial radiotracer uptake. A neuropathological examination disclosed a middle cerebral artery aneurysm. Presumably, vessel wall fibrosis prevented collapse. Multiple transmural dissections of the fibrotic aneurysmal wall were the source of the subarachnoid hemorrhage. This interesting image shows that radiotracer accumulation in cerebral artery aneurysms can be a diagnostic pitfall in brain death scintigraphy assessment.

Spinal fusion for single-level SPECT/CT positive lumbar degenerative disc disease: the SPINUS I study.

INTRODUCTION AND PURPOSE: With current imaging modalities and diagnostic tests, identifying pain generators in patients with non-specific chronic low back pain (CLBP) is difficult. There is growing evidence of the effectiveness of SPECT/CT examination in diagnosing the source of pain in the spine. The study aims to investigate the effect of posterior interbody fusion on a single-level SPECT/CT positive lumbar degenerative disc disease (DDD). MATERIAL AND METHODS: This is a prospective study of patients with chronic low back pain (CLBP) operated on for a single-level SPECT/CT positive DDD. Primary outcomes were changes in visual analogue scale (VAS) scores and the Oswestry Disability Index (ODI). Secondary outcomes were complications, return to work, satisfaction and willingness to re-undergo surgery. RESULTS: During a 3-year period, 38 patients underwent single-level fusion surgery. The mean preoperative VAS score of 8.4 (± 1.1) decreased to 3.2 (± 2.5, p < 0.001) and the mean preoperative ODI of 51.5 (± 7.3) improved to 20.7 (± 14.68, p < 0.001) at a 2-year follow-up. A minimum clinically important difference (30% reduction in VAS and ODI) was achieved in 84.2% of patients. Some 71% of patients were satisfied with the surgery results and 89.4% would undergo surgery again. There were four complications, and two patients underwent revision surgery. Some 82.9% of patients returned to work. CONCLUSION: Fusion for one-level SPECT/CT positive lumbar DDD resulted in substantial clinical improvement and satisfaction with surgical treatment. Therefore, SPECT/CT imaging could be useful in assessing patients with CLBP, especially those with unclear MRI findings. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04876586.

Effects of Spinal Cord Stimulation on Cardiac Sympathetic Nerve Activity in Patients with Heart Failure.

BACKGROUND: Spinal cord stimulation (SCS) reduces sympathetic activity in animal models of heart failure with reduced ejection fraction (HF) but limited data exist of SCS in patients with HF. The aim of the present study was to test the primary hypothesis that SCS reduces cardiac sympathetic nerve activity in HF patients. Secondary hypotheses were that SCS improves left ventricular function and dimension, exercise capacity, and clinical variables relevant to HF. METHODS: HF patients with a SCS device previously participating in the DEFEAT-HF trial were included in this crossover study with 6-week intervention periods (SCS-ON and SCS-OFF). SCS (50 Hz, 210-µs pulse duration, aiming at T2-T4 segments) was delivered for 12 hours daily. Indices of myocardial sympathetic neuronal function (heart-to-mediastinum ratio, HMR) and activity (washout rate, WR) were assessed using 123 I-metaiodobenzylguanidine (MIBG) scintigraphy. Echocardiography, exercise testing, and clinical data collection were also performed. RESULTS: We included 13 patients (65.3 ± 8.0 years, nine males) and MIBG scintigraphy data were available in 10. HMR was not different comparing SCS-ON (1.37 ± 0.16) and SCS-OFF (1.41 ± 0.21, P = 0.46). WR was also unchanged comparing SCS-ON (41.5 ± 5.3) and SCS-OFF (39.1 ± 5.8, P = 0.30). Similarly, average New York Heart Association class (2.4 ± 0.5 vs 2.3 ± 0.6, P = 0.34), quality of life score (24 ± 16 vs 24 ± 16, P = 0.94), and left ventricular dimension and function as well as exercise capacity were all unchanged comparing SCS-ON and SCS-OFF. CONCLUSION: In patients with HF, SCS (12 hours daily, targeting the T2-T4 segments of the spinal cord) does not appear to influence cardiac sympathetic neuronal activity or function as assessed by MIBG scintigraphy.

Assessment of left ventricular diastolic function by radionuclide ventriculography in patients with chronic heart failure and reduced ejection fraction.

STUDY OBJECTIVE: To compare parameters of diastolic function as assessed by radionuclide ventriculography (RNVG) and Doppler echocardiography (ECHO) in the patients with chronic heart failure and reduced ejection fraction (HF REF). PATIENTS AND METHODS: RNVG and ECHO were performed on the same day in 40 patients with systolic chronic HF, NYHA II and III, with LV EF < 50 % and sinus rhythm, followed at tertiary HF clinic. Diastolic function was assessed by RNVG using parameters: PFR (peak filling rate [% SV/sec]), TFR - time to peak filling rate (ms), and by ECHO using pulse Doppler parameters: the peak Doppler velocities of early (E) and late diastolic flow (A), the E/A ratio, the calculated mean of the early (E´) diastolic velocity of septal and lateral mitral annulus measured by tissue Doppler imaging, and the E/E´ ratio. RESULTS: The mean PFR was 421.7 (median 371.0) % SV/sec and TPF was 198.7 ms (median 169.5), the mean E/A ratio was 1.21 (median 0.85) and the E/E´ ratio was 9.0 (median 8.40). TPF correlated significantly (inverse correlation) with the E/A ratio (r = -0.34, p = 0.030), and not significantly with E´ (r = -0.27, p = 0.082), the PFR/age ratio correlated with the E/E´ ratio (r = -0.31, p = 0.05). CONCLUSION: Significant correlations of parame-ters of diastolic function as assessed by radionuclide and Doppler studies were identified in the HF REF patients.

Pulse wave as an alternate signal for data synchronization during gated myocardial perfusion SPECT imaging.

PURPOSE: Proper identification of the cardiac cycle is essential for gated SPECT myocardial perfusion imaging. We have developed an alternate method of ECG for gating, that is, using the peripheral pulse wave (PW) as the triggering signal for gated SPECT acquisition. The aim of this study is to compare the use of this method of gating with the standard ECG trigger. METHODS: We tested the PW triggering by comparing it with the ECG trigger. We evaluated 33 patients (25 males, 8 females), average age of 61 years (39-80) referred for stress myocardial perfusion imaging. Data from all patients were acquired twice and were processed by CEqual and QGS software. We compared the left ventricular ejection fraction (LVEF), end-diastolic and end-systolic volumes (EDV, ESV). Paired t test and Pearson correlation coefficient were used for comparison. RESULTS: The mean LVEF, EDV, and ESV calculated with the ECG trigger were 0.52, 120, and 64, respectively, those with the pulse-wave trigger were 0.48, 126, and 71, respectively. Mean paired difference for LVEF was -0.034 (P<0.001), for EDV 5.9 (P=0.012), and for ESV 7.9 (P<0.001). Pearson correlation coefficient for LVEF was 0.955, for EDV 0.987, and for ESV 0.991 (P<0.001 for all correlations). CONCLUSION: Triggering of gated-data acquisition by the PW is feasible. Quantitative parameters of cardiac function correlate highly with those obtained from the ECG trigger and the absolute differences are not clinically significant across a wide range of values.

99mTc-besilesomab (Scintimun) in peripheral osteomyelitis: comparison with 99mTc-labelled white blood cells.

PURPOSE: The diagnosis of osteomyelitis is a challenge for diagnostic imaging. Nuclear medicine procedures including white blood cell imaging have been successfully used for the identification of bone infections. This multinational, phase III clinical study in 22 European centres was undertaken to compare anti-granulocyte imaging using the murine IgG antibody besilesomab (Scintimun) with (99m)Tc-labelled white blood cells in patients with peripheral osteomyelitis. METHODS: A total of 119 patients with suspected osteomyelitis of the peripheral skeleton received (99m)Tc-besilesomab and (99m)Tc-hexamethylpropyleneamine oxime (HMPAO)-labelled white blood cells (WBCs) in random order 2-4 days apart. Planar images were acquired at 4 and 24 h after injection. All scintigraphic images were interpreted in an off-site blinded read by three experienced physicians specialized in nuclear medicine, followed by a fourth blinded reader for adjudication. In addition, clinical follow-up information was collected and a final diagnosis was provided by the investigators and an independent truth panel. Safety data including levels of human anti-mouse antibodies (HAMA) and vital signs were recorded. RESULTS: The agreement in diagnosis across all three readers between Scintimun and (99m)Tc-HMPAO-labelled WBCs was 0.83 (lower limit of the 95% confidence interval 0.8). Using the final diagnosis of the local investigator as a reference, Scintimun had higher sensitivity than (99m)Tc-HMPAO-labelled WBCs (74.8 vs 59.0%) at slightly lower specificity (71.8 vs 79.5%, respectively). All parameters related to patient safety (laboratory data, vital signs) did not provide evidence of an elevated risk associated with the use of Scintimun except for two cases of transient hypotension. HAMA were detected in 16 of 116 patients after scan (13.8%). CONCLUSION: Scintimun imaging is accurate, efficacious and safe in the diagnosis of peripheral bone infections and provides comparable information to (99m)Tc-HMPAO-labelled WBCs.

Predictors of improvement of unrepaired moderate ischemic mitral regurgitation in patients undergoing elective isolated coronary artery bypass graft surgery.

BACKGROUND: The persistence of moderate ischemic mitral regurgitation (IMR) after isolated coronary artery bypass graft surgery is an important independent predictor of long-term mortality. The aim of the present study was to identify predictors of postoperative improvement in moderate IMR in patients with ischemic heart disease undergoing elective isolated coronary artery bypass graft surgery. METHODS AND RESULTS: The study population consisted of 135 patients with ischemic heart disease (age, 65+/-9 years; 81% male) and moderate IMR undergoing isolated coronary artery bypass graft surgery. Fourteen patients died before the 12-month follow-up echocardiography and were excluded. At the 12-month follow-up, 57 patients showed no or mild IMR (improvement group), whereas 64 patients failed to improve (failure group). Before coronary artery bypass graft surgery, the improvement group had significantly more viable myocardium and less dyssynchrony between papillary muscles than the failure group (P<0.001). All other preoperative parameters were similar in both groups. Large extent (> or =5 segments) of viable myocardium (odds ratio, 1.45; 95% confidence interval, 1.22 to 1.89; P<0.001) and absence (<60 ms) of dyssynchrony (odds ratio, 1.49; 95% confidence interval, 1.29 to 1.72; P<0.001) were independently associated with improvement in IMR. The majority (93%) of patients with viable myocardium and an absence of dyssynchrony showed an improvement in IMR. In contrast, only 34% and 18% of patients with dyssynchrony and nonviable myocardium, respectively, showed an improvement in IMR, whereas 32% and 49%, respectively, of these patients showed worsening of IMR (P<0.001). CONCLUSIONS: Reliable improvement in moderate IMR by isolated coronary artery bypass graft surgery was observed only in patients with concomitant presence of viable myocardium and absence of dyssynchrony between papillary muscles.

Severe left ventricular dyssynchrony is associated with poor prognosis in patients with moderate systolic heart failure undergoing coronary artery bypass grafting.

OBJECTIVES: The objective of the present study was to assess the relationship between the presence of left ventricular (LV) dyssynchrony and clinical outcome in patients with moderate systolic heart failure undergoing coronary artery bypass graft (CABG) surgery. BACKGROUND: The presence of LV dyssynchrony is associated with poor prognosis in patients with LV dysfunction. METHODS: The study consisted of 215 consecutive patients with ischemic cardiomyopathy and dyspnea (age 65 +/- 9 years, 81% male) undergoing CABG. Dyssynchrony was calculated by tissue Doppler imaging from regional time intervals in basal LV segments before and 1 month after CABG. Myocardial viability was assessed using single-photon emission computed tomography (SPECT) before CABG. RESULTS: Twenty-five patients (11.6%) died within 30 days (in-hospital mortality) of CABG. The presence of pre-CABG dyssynchrony > or =119 ms had the highest predictive accuracy for in-hospital mortality, with a sensitivity of 84% and a specificity of 71%. During the median follow-up period of 359 days (interquartile range 219 to 561), an additional 19 patients (10.3%) died and 34 patients (18.5%) were hospitalized for worsening heart failure. At Cox regression analysis, post-CABG dyssynchrony > or =72 ms and > or =5 viable segments were identified as independent predictors of clinical events, with a hazard ratio (HR) of 5.02, 95% confidence interval (CI) 2.57 to 10.02 (p < 0.001), and an HR of 0.63, 95% CI 0.55 to 0.75 (p < 0.001), respectively. Patients without post-CABG dyssynchrony and with viable myocardium had excellent prognosis compared with patients with severe post-CABG dyssynchrony and nonviable myocardium (event rate 3% vs. 64%; p < 0.001). CONCLUSIONS: The presence of severe LV dyssynchrony is associated with poor clinical outcomes despite revascularization. These results advocate a routine assessment of both LV dyssynchrony and viability to predict outcome in systolic heart failure patients undergoing CABG surgery.

Myocardial positive pre-ejection velocity accurately detects presence of viable myocardium, predicts recovery of left ventricular function and bears a prognostic value after surgical revascularization.

AIMS: To assess the accuracy of tissue Doppler imaging-derived myocardial positive pre-ejection velocity (+Vic) in detecting myocardial viability defined by dobutamine stress echocardiography (DSE), fluorine-18 fluorodeoxyglucose positron emission tomography (PET), and contrast-enhanced magnetic resonance imaging (MRI), and in predicting recovery of left ventricular (LV) function after coronary artery bypass grafting (CABG) in patients with chronic ischaemic LV dysfunction. METHODS AND RESULTS: +Vic in dysfunctional segments was recorded in 54 patients treated medically and 65 patients undergoing CABG [age 67 +/- 9 year; LV ejection fraction (EF) 30 +/- 6%]. A good agreement was observed between +Vic and detection of viable myocardium at DSE, PET, and MRI (kappa = 0.76). The presence of +Vic in greater than or equal to five dysfunctional segments had the highest sensitivity (93%) and specificity (60%) to identify patients (n = 28) with > or =10% increase in LV EF between baseline and 6-month echocardiogram. During follow-up (median 333 days, interquartile range 209-490 days), 13 cardiac events (6 deaths, 7 hospitalizations) occurred in 24 patients with small extent of viable myocardium (< 5 + Vic), whereas only four hospitalizations in 39 patients with > or =5 + Vic (54% vs. 10%; P < 0.001). CONCLUSION: The extent of +Vic in dysfunctional segments accurately predicts extent of viable myocardium and bears a clinical prognostic value in patients with ischaemic LV dysfunction considered for CABG.

Increase in utilization of myocardial perfusion imaging in the Czech Republic: activity and practice of nuclear cardiology, 2003.

BACKGROUND: The second survey of nuclear cardiology in the Czech Republic was conducted to ascertain whether the activity had increased since the first survey in 2001; we also intended to identify new trends in clinical practice. MATERIALS AND METHODS: All 46 departments of nuclear medicine in the Czech Republic completed a questionnaire concerning nuclear cardiology activity in 2002-2003 and current clinical and technical practices. RESULTS: There were 66 SPET cameras in 2003 in comparison with 54 SPET cameras in 2001. Of the 46 centres, 39 (85%) provided nuclear cardiology service. The total number of cardiac studies was 19,261 in 2003 (i.e. 1.9 studies/1,000 population; myocardial perfusion imaging (MPI) studies accounted for 91.3% of total nuclear cardiology. In 2001-2003, the utilization rate of MPI increased annually by 10%, 13% and 21% respectively. Twenty-six departments (67%) reported that the number of MPI had increased. The utilization of gated SPET method showed a very positive trend; as only 39% of all MPI studies were acquired using ECG-gating in 2001, but in 2003, there was an increase to 61%. We observed no increase in utilization of attenuation correction (3 centres in 2003 in comparison with 5 centres in 2001). Despite new PET capacity in the Czech Republic, the total number of FDG cardiology studies was somewhat lower in 2003 than in 2001 (155 compared with 163 studies). CONCLUSIONS: Our data documented substantial growth in the number of MPI examinations in 2001-2003. However, Czech Republic nuclear cardiology activity still remained below the European average (2.2 studies/1,000 population in 1994); a further increase in MPI activity is necessary to adequately support the needs of cardiac patients.

Activity and practice of nuclear cardiology in the Czech Republic, 2001.

Radionuclide myocardial perfusion imaging (MPI) has been on the rise in Europe and the USA. Details on nuclear cardiology in the Czech Republic are not available as yet, as it is impossible to obtain comprehensive data from official registers owing to different methods of reporting and data evaluation. A questionnaire concerning nuclear cardiology activity and practice in 2001 was sent to all nuclear medicine departments in the Czech Republic. All 48 departments completed the questionnaire. In 2001, 50 planar and 54 tomographic (SPET) scintillation cameras were used. The average age of the SPET cameras was 5 years (13% of SPET cameras were >8 years old). Out of the 48 centres, 39 (81%) provided a nuclear cardiology service; the total number of cardiological studies was 15,740 in 2001 (1.5 studies/1,000 population/year). The most frequently employed method was MPI (81.7%), the frequency of which had increased by 10% compared with 2000; 26 of the 39 (67%) departments reported that MPI activity was increasing. Nevertheless, the Czech Republic nuclear cardiology activity remained below the European average (2.2/1,000 population in 1994) and, particularly, below activity in the USA (15/1,000 in 1997). The activity was rather unevenly spread. Whereas two centres with >1,000 studies/year accounted for 20% of the total MPI studies, 16 of 39 (41%) departments exhibited low activity (<200 studies/year) and accounted for only 15% of the total MPI studies. The use of SPET increased from 91% in 2000 to 94% in 2001 (only three institutes performed planar examinations). The most widely used tracer was (99m)Tc-MIBI (60% of total MPI), followed by (201)Tl (21%) and (99m)Tc-tetrofosmin (19%). ECG-gated SPET was employed by 20/39 (51%) centres, of which 11 (28%) performed it as a standard examination; 39% of the total MPI studies included this technique. Thirteen percent (5/39) of the departments used attenuation correction, and 69% (27/39) of the departments used a prone projection. Equilibrium radionuclide ventriculography, with 2,317 examinations (14.7%), ranked second among all nuclear cardiology methods, followed by first-pass angiocardiography (406 studies, 2.6%) and (18)F-FDG (163 studies, 1%).

Increased prognostic value of combined myocardial perfusion SPECT imaging and the quantification of lung Tl-201 uptake.

PURPOSE: The authors wanted to identify those patients assessed by exercise SPECT in whom the quantification of lung Tl-201 uptake helps to evaluate disease prognosis. METHODS: One hundred forty-nine patients (114 men, 35 women; 74 after myocardial infarction [MI]; mean age, 54 +/- 9 years) underwent exercise Tl-201 SPECT. The SPECT patterns were divided into normal (n = 45), fixed defects (n = 29), and inducible ischemia (n = 75). Anterior planar imaging was performed before SPECT acquisition to calculate the lung-to-heart ratio (L:H). RESULTS: During an average follow-up of 20 +/- 9 months, eight patients had died of cardiac causes and 13 patients experienced nonfatal MIs. Among the 45 patients with normal perfusion, no cardiac event was observed and the L:H ratio was not helpful for risk stratification. In 29 patients with fixed defects, four cardiac deaths occurred (all in patients with L:H ratios >0.5; annual event rate, 21.1% for L:H ratios >0.5 compared with 0% for L:H ratios <0.5; chi-square = 4.07, P < 0.05). Among the 75 patients with ischemia, 4 died and 13 had nonfatal MIs (annual event rate, 15.4% for L:H ratios >0.5 compared with 13% for L:H ratios <0.5; P = NS). CONCLUSIONS: These findings suggest a benign prognosis in patients with normal SPECT (regardless of the L:H ratio). Conversely, all patients with ischemia are at high risk for future cardiac events. Quantification of the Tl-201 lung uptake seems to be valuable in evaluations of disease prognosis, especially in patients with fixed defects.