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Abstracts Saturday, May 5, 2001
Journal of Nuclear Cardiology January/February 2001
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Non-invasive detection of pulmonary artery involvement in Takayasu's arteritis using pulmonary ventilation/perfusion imaging.
Role of gated myocardial perfusion SPECT in systemic sclerosis compared with electrocardiography and 1-123 meta-iodobenzylguanidine (MIBG) scintigraphy.
P Yang, RF Shi, XJ Liu, YZ Liu, Y Q Tian, ZX He. Department of Nuclear Medicine Fu Wai Hospital, CAMS & PUMC Beijing China. Background: Clinical diagnosis o f pulmonary artery involvement in patients with Takayasu's arteritis but no respiratory symptoms is often difficult. Few studies have reported the usefulness o f radionoclide imaging. This study therefore evaluated the value o f pulmonary ventilation/perfusion imaging for the detection o f pulmonary artery involvement. Methods: Twenty-one patients (20 women, 1 men, aged fi'om 16 to 65 years) with a diagnosis of Takayasu's arteritis underwent a pulmonary ventilation/perfusion imaging. All patients had no respiratory symptoms. Perfusion imaging was performed following an intravenous injection of Tc-99m-MAA (5 mCi), ventilation imaging was performed 24-72 hours if perfusion imaging was abnormal. Results: Perfusion imaging was normal in 7 patients (33%), and abnormal in 14 patients (67%). Segmental perfusion defects involved at least 3 pulmonary segments in all patients. Ventilafion/perfusion mismatch was present in all patients with perfusion defects. Conclusion: In patients with Takayasu's arteritis, pulmonary artery involvement is frequent, and can be noninvasively detected by pulmonary ventilation/perfusion imaging.
K Nakajima, J Taki, T Hignchi, M Kawano, S Sato 1 K Takehara 1, N Tonami. Nuclear Medicine Kanazawa University Hospital Kanazawa, tDcrmatology Kanazawa University Hospital Kanazawa Japan. Purpose: Cardiac involvement is one of the most important prognostic factors in systemic sclerosis (SSc). Although myocardial pcrfusion scintigraphy has been performed in patients with SSc, the roles of gated single-photon emission computed tomography (SPECT) and 1-123 MIBG study have not been validated. We compared Tc-99m MIBI, 1-123 MIBG and ECG findings with the types and severity of SSc. Methods: The study group consisted of 32 patients with SSc (17 with limited-type SSc [I-SSc], 11 with diffuse-type SSc [d-SSc], 4 with complications of polymypsitis, dermatomyositis or sarcoidosis [c-SSc]) and 17 control subjects . The severity of disease was semi-quantified by total skin score based on modified Rodnan's criteria. Tc-99m MIBI study was performed by stress-rest protocol in all patients, and gated SPECT was acquired at rest using a 3-detector SPECT system with 16 frames/cardiac cycle. QGS software was used for quantification. Ejection fraction (EF) and dV/dt parameters including diastolic function were calculated by 4-th order Fourier fitting of the left veutricular volume curve. 1-123 MIBG planar and SPECT studies were performed in 19 of 33 patients, 20 minutes and 4 hours after intravenous injection. MIBG heart/mediastinum (H/M) average count ratio and regional defects were analyzed. Exercise electrocardiography (EGG) and 24-hour Holler ECG were recorded to estimate ischemia and incidence of arrhythmia. Renal and pulmonary involvement was also examined. Results: Regarding stressinduced ischeima, fixed defect and EF by MIBI SPECT, no significant difference was observed among groups. Decreased resting EF was observed in 2 patients with d-SSc and 1 with c-SSc. Diastolic function evaluated by I/3 mean filling rate and time to peak filling rate was abnormal in 29% ofl-SSc, 45% of d-SSc, 75% of c-SSc and 0% of control patients (p-0.ll04). The STT change or arthythmia was observed by Holter/exercise EGG in 18% of I-SSc, 27% ofd-SSc, 50% of c-SSc and 0% of control patients (p-0.ll5). The MIBG defect and early and delayed H/M ratios showed no significant difference among groups, although slight difference in MIBG washout rate was observed between normal and SSc groups (p=ll.ll9}. Conclusion: High incidence of gated SPECT abnormality, particularly diastolic dysfunction, was noted in SSc groups, and was related to the severity of SSc. Gated perfusion SPECT may be utilized as an important diagnostic tool to detect early myocardial involvement in SSc patients in addition to ECG, while MIBG scan was of limited value.
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Accuracy of the heated hand procedure in [F-18I-FDG PET imaging during euglycaemic hyperinsulinemic clamping.
Global and regional pre-and post-synaptic sympathetic function in sudden cardiac death survivors.
AP van der Weerdt, LJ Klein, CA Visser, AA Lammertsma 1, FC Visser. Cardiology Univ. Hosp. Vrije Univ. AmsterdamlpET Centre Univ. Hosp. VriJe Univ. Amsterdam Netherlands.
J Caldwell, JM Link 1, JR Strarton 2, Z Li 3. Cardiology VA Medical Center Seattle, IRadiology University of Washington Seattle, 2Medicine University of Washington Seattle, 3Bioengineering University of Washington Seattle United States of America.
Sampling of arterialized venous blood (AVB) is often used as an alternative to arterial blood (ART) sampling in cardiac [F-18]-FDG PET studies for determination o f the metabolic rate o f glucose (MRGIu). However, this method has not yet been validated for measurement o f plasma IF-18]-FDG activity during an euglycaemic hyperinsulinemic clamp (EHC). Thirty-six patients with ischemic heart disease were studied. All underwent dynamic [F-18]-FDG PET-scanning with ART sampling during EHC. Twenty-four patients underwent additional sampling of AVB and twelve sampling o f venous blood (VB). Samples o f ART and AVB or VB were simultaneously withdrawn at five time-points for measurement o f whole blood and plasma [F-18]-FDG activity and plasma glucose. Ratios were calculated between venous and arterial [F-18]-FDG activity and plasma glucose. During EHC, VB significantly underestimated [F-18]-FDG plasma activity and glucose concentrations. Sampling o f A V B provided more reliable values o f [F-18]-FDG plasma-activity during EHC. However, early activity was underestimated while activity after 20 minutes was overestimated (see Figure). A small difference (5%) in plasma glucose concentration was observed. We conclude that AVB sampling is not identical to ART sampling. Not only the underestimation o f plasma glucose, but also the overestimation of IF-18]FDG will result in underestimation o f MRGIu with AVB sampling. This limits the use o f A V B in [F-18]-FDG studies when EHC is performed.
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Global and/or regional mismatch between pre- and post sympathetic function in survivors of Sudden Cardiac Death (SCD) might generate foci for arrhythmias that result in recurrent episodes of SCD. In a pilot study to test this hypothesis, within a 4 hour period with no patient movement, we performed PET imaging of [C-1 l]-meta-bydroxyephcdrine ( m i l D ) which reflects norepinephrine uptake and [C-I1]-CGP 12177 (CGP) to measure beta-adrenergic receptor density (Bmax) in 9 normal (NL) subjects, in 3 SCD survivors with coronary disease (CAD) and 2 pts with CAD and depressed LV function without SCD. Ages varied from 55-79. No subject was receiving a beta-blocker. Heart rate was higher in the CAD pts (76±12) compared to NL (64±5). Otherwise, them were no significant hcmodynamic differences. LV ejection fraction was 62±12 in the NL subjects, 50~6 in the SCD group and 20~12 in the CAD group. Average global mHED retention fraction, RF, (Schwaiger method) was 0.19±0.02, 0.13±0.07, and 0.09±0.02 for the NL, SCD and CAD groups. Average global Bmax (Dclforge method) was 9. l±4.7, 10.8±5, and 8.3=t:6.2 for the NL, SCD, and CAD groups. Global pre- and post-synaptin mismatch (MM), expressed as the Bmax:RF ratio was calculated for each patient and averaged and was 49±26, 124a:112, and 102=[-90 in the 3 groups respectively. ROI's encompassing the anterior, lateral, inferior, and septal walls from base to apex were examined for Bmax and RF and MM. The results for MM are shown in the table. These pilot data suggest that there are significant differences in prc-syrmptic function between SCD survivors and NL subjects and CAD pts and NL subjects. There was no difference in RF or Bmax between SCD and CAD pts but the number of subjects is still too small. Further imaging studies in additional SCD and CAD pts are required to test the significance of our hypothesis. Region Anterior Lateral Inferior Septal
NL 46±26 47±23 53±27 49±28
SCD 87± 63 161±62 202±210 101 ±85
Regional Pre-:Post-Synaptic Mismatch
CAD 62±42 140i 145 220~250 86±67