Comparison of high efficiency CZT SPECT MPI to coronary angiography

Background  

The recently introduced cadmium zinc telluride (CZT) SPECT cameras have the potential to reduce radiation exposure to patients and shorten imaging time. So far, there has been only one small study comparing the results of high efficiency CZT SPECT myocardial perfusion imaging (MPI) to invasive coronary angiography.     

Novel attenuation correction of SPECT images using scatter photopeak window data for the detection of coronary artery disease

Background

Attenuation correction using segmentation with scatter and photopeak window data (SSPAC) may enable evaluation of the attenuation map in a patient-specific manner without the need for additional radiation exposure and more acquisition time. We examined the feasibility of SSPAC and compared the sensitivity, specificity, and accuracy of this new correction method with that of conventional non-corrected myocardial perfusion single-photon emission computed tomography (SPECT) among patients with suspected or diagnosed coronary artery disease.

Methods and Results

One hundred sixty-one patients who underwent both ^99mTc-tetrofosmin stress/rest SPECT examination and invasive coronary angiography were enrolled in the study. Data from the SSPAC-corrected and non-corrected methods were analyzed quantitatively using summed stress scores. Attenuation maps were obtained successfully for 150 (93%) of the patients. The SSPAC-corrected and non-corrected methods accurately predicted coronary artery disease defined as >50% luminal stenosis verified by coronary artery angiography and/or prior myocardial infarction, for 91% and 77% patients, respectively (P < .05). For diagnosis of coronary artery disease, SSPAC improved sensitivity in the left anterior descending artery territory and specificity in the right coronary artery territory.

Conclusions

Attenuation correction with SSPAC may be a feasible method of correction for myocardial perfusion SPECT and in some cases may provide better accuracy for diagnosing coronary artery disease.     

CT冠状动脉成像在冠心病诊断中的应用

目的:研究CT冠状动脉成像在冠心病早期诊断冠状动脉狭窄定性定量判读的作用。方法:对34例临床未发生急性冠脉综合征的冠心病患者,先后进行冠状动脉造影、128排双源CT冠状动脉成像。以冠状动脉造影为"金标准",计算CT冠状动脉成像敏感性、特异性、阳性预测值、阴性预测值。结果:①与冠状动脉造影相比,CT冠状动脉成像的敏感性为68%,特异性为97%,阳性预测值为89%,阴性预测值为90%。②CT冠状动脉成像有65个血管段图像质量差,约占12%,造成图像质量差的原因主要为钙化,心跳、呼吸伪影,少部分为管腔显示不良。结论:冠心病早期诊断中,CT冠状动脉成像可用作冠状动脉造影前筛选,CT冠状动脉成像阴性的患者不必行冠状动脉造影检查;CT冠状动脉成像阳性的患者,可行冠状动脉造影进一步确认病变。     

Improved detection of left main coronary artery disease with attenuation-corrected SPECT

BACKGROUND: Myocardial perfusion imaging has demonstrated a limited sensitivity as a means of accurately identifying left main (LM) coronary disease. Because regional quantitative perfusion biases are eliminated with attenuation corrected (AC) single photon emission computed tomography (SPECT), as compared with uncorrected (NC) SPECT, we hypothesized that AC SPECT would demonstrate increased diagnostic accuracy for the detection of significant LM coronary stenosis. METHODS AND RESULTS: We studied 28 patients (23 men, 5 women; mean age, 66+/-9 years) with significant LM stenoses (> or =50%) and 34 control patients (27 men, 7 women; mean age, 65+/-11 years) with 2-vessel coronary disease. Rest thallium-201 and stress technetium 99m sestamibi SPECT imaging with and without AC were performed, as described earlier. Both AC and NC images were analyzed visually and quantitatively in comparison with corresponding normal databases. A greater sensitivity for detection of an LM defect pattern (64% vs. 7%, P = .0009) with equivalent specificity (94% vs. 100%, P = not significant) was demonstrated by means of visual analysis of AC SPECT images. More disease was demonstrated in a greater number of territories with AC SPECT images than with NC images (2.14+/-0.97 for AC images vs. 1.43+/-0.84 for NC images, P = .0001). Similar improvement in the detection of LM disease was shown by means of automated quantitative analysis (57% for AC SPECT vs 14% for NC SPECT, P = .0005), again with no loss in specificity. CONCLUSIONS: AC SPECT with the University of Michigan method in consecutive patients with LM stenoses and a select control population with severity matched multivessel coronary disease significantly improved the diagnostic accuracy of myocardial perfusion imaging for the identification of LM coronary disease, compared with uncorrected SPECT.     

Comparison of 99mTc-hexakis 2-methoxy-2-isobutyl isonitrile and 201Tl SPECT imaging for evaluation of coronary artery disease

To evaluate clinical value of 99mTc-hexakis 2-methoxy-2-isobutyl isonitrile (MIBI) imaging for assessing coronary artery disease (CAD), 99mTc-MIBI SPECT imaging at post-exercise and at rest was compared with 201Tl SPECT imaging at post-exercise and 3 hours redistribution in 27 patients suspected with CAD. The sensitivities for detecting CAD patients were 94% (17/18) by both studies. The specificities were 71% (5/7) by 99mTc-MIBI and 57% (4/7) by 201Tl (p = NS). The sensitivities for detecting stenosed coronary arteries (greater than or equal to 75% stenosis) were also similar between 99mTc-MIBI (78%) and 201Tl (74%) (p = NS). The similar specificity values were obtained by 99mTc-MIBI (84%) and by 201Tl (82%) (p = NS). The patterns of abnormality (normal, ischemia and scar) were similar between 99mTc-MIBI and 201Tl images in 22 of the 25 cases (88%) and 117 of the 125 segments (94%). However, these patterns were occasionally different particularly in patients who received PTCA or CABG. Thus, 99mTc-MIBI SPECT imaging seems to be as accurate as 201Tl SPECT imaging for the detecting and evaluating CAD.     

Diagnostic accuracy of high-resolution attenuation-corrected Anger-camera SPECT in the detection of coronary artery disease

Background

There is limited data on diagnostic accuracy of recently introduced high-resolution Anger (HRA) SPECT incorporating attenuation correction (AC), noise reduction, and resolution recovery algorithms. We therefore studied 54 consecutive patients (excluding those with prior MI or cardiomyopathy) who had HRA-AC SPECT and coronary angiography (CA) ≤ 30 days and no change in symptoms.

Methods

The HRA-AC studies were acquired in 128 × 128 matrix (3.2 mm pixel) format with simultaneous Gd-153 line-source AC. Measured variables were image quality, interpretive certainty, sensitivity and specificity for any CAD, sensitivity for single- and multivessel CAD, and the influence of gender, body mass index (BMI), and stress modality.

Results

The mean age of the patients was 66 ± 11 years with a BMI of 32 ± 7 kg·m^?2. Mean interpretive certainty score was 2.7 on a 3-point scale and mean image quality score was 3.3 on a 4-point scale. Stress perfusion defects were detected in 34 of 38 patients with obstructive CAD [sensitivity 89%, 95% confidence interval (CI) 76%-95%]. The specificity was 75% (CI 51%-90%) and overall diagnostic accuracy was 85% (CI 73%-92%). Accuracy did not differ for females vs males, for BMI ≤30 vs >30, or for pharmacologic vs exercise SPECT. Sensitivity for single-vessel disease was 88% (CI 69%-96%) and for multivessel disease was 93% (CI 69%-99%).

Conclusion

New Anger technology incorporating innovative improvements results in high image quality with excellent interpretive certainty and high diagnostic accuracy.     

Automated SPECT analysis compared with expert visual scoring for the detection of FFR-defined coronary artery disease

Purpose

Traditionally, interpretation of myocardial perfusion imaging (MPI) is based on visual assessment. Computer-based automated analysis might be a simple alternative obviating the need for extensive reading experience. Therefore, the aim of the present study was to compare the diagnostic performance of automated analysis with that of expert visual reading for the detection of obstructive coronary artery disease (CAD).

Methods

206 Patients (64% men, age 58.2?±?8.7 years) with suspected CAD were included prospectively. All patients underwent ^99mTc-tetrofosmin single-photon emission computed tomography (SPECT) and invasive coronary angiography with fractional flow reserve (FFR) measurements. Non-corrected (NC) and attenuation-corrected (AC) SPECT images were analyzed both visually as well as automatically by commercially available SPECT software. Automated analysis comprised a segmental summed stress score (SSS), summed difference score (SDS), stress total perfusion deficit (S-TPD), and ischemic total perfusion deficit (I-TPD), representing the extent and severity of hypoperfused myocardium. Subsequently, software was optimized with an institutional normal database and thresholds. Diagnostic performances of automated and visual analysis were compared taking FFR as a reference.

Results

Sensitivity did not differ significantly between visual reading and most automated scoring parameters, except for SDS, which was significantly higher than visual assessment (p?<?0.001). Specificity, however, was significantly higher for visual reading than for any of the automated scores (p?<?0.001 for all). Diagnostic accuracy was significantly higher for visual scoring (77.2%) than for all NC images scores (p?<?0.05), but not compared with SSS AC and S-TPD AC (69.8% and 71.2%, p?=?0.063 and p?=?0.134). After optimization of the automated software, diagnostic accuracies were similar for visual (73.8%) and automated analysis. Among the automated parameters, S-TPD AC showed the highest accuracy (73.5%).

Conclusion

Automated analysis of myocardial perfusion SPECT can be as accurate as visual interpretation by an expert reader in detecting significant CAD defined by FFR.

     

99Tcm-MIBI心肌显像检测“罪犯”血管

目的 探讨^99Tc^m-甲氧基异丁基异腈（MIBI）心肌显像在检测“罪犯”血管中的价值。方法 选择冠状动脉造影证实有多支血管病变并成功进行经皮冠状动脉腔内成形术（PTCA）等血流重建治疗的冠心病患者46例，PTCA术前进行运动、静息、静脉滴注硝酸甘油介入^99Tc^m-MIBI心肌显像，明确缺血与存活心肌量最多的部位，以对应支配该部位的病变血管确定为“罪犯”血管。以术后疗效为标准，验证其准确性。结果 46例中，冠状动脉造影发现病变血管107支，心肌显像确定“罪犯”血管46支。临床对确定的“罪犯”血管进行相应的血流重建治疗，随访均有良好疗效。结论 运动、静息、静脉滴注硝酸甘油介入^99Tc^m-MIBI心肌显像检测“罪犯”血管准确可靠，实用可行。     

多层螺旋CT无创性冠状动脉造影图像质量分析及冠状动脉病变评价

目的分析多层螺旋CT无创性冠状动脉造影图像质量的主要影响因素,以正确评价冠状动脉病变。方法64例患者行多层螺旋CT冠状动脉造影检查,用回顾性心电门控选择最佳相位窗,并分别以容积再现（VR）、最大密度投影（MIP）、曲面重建（CPR）等后处理技术将冠状动脉分为15个节段进行分析。结果显示血管直径大于2mm的冠状动脉节段共960个,能满足影像学评价的节段共884个（92．08％）;不能满足影像学评价的节段共76个（7．92％）;64例中的58例（90．63％）冠状动脉CTA图像质量均为2级或1级,其余6例（9．37％）冠状动脉CTA图像质量为3级,共发现冠状动脉存在中、重度狭窄者44例（占68．75％）,其中单支病变28例,双支病变16例;另发现冠状动脉存在轻度狭窄者16例（占25．00％）,其中单支病变8例,双支病变8例;冠状动脉未见明确狭窄者4例（6．25％）。结论高质量的MSCT无创性冠状动脉造影对冠状动脉病变有较高的诊断价值。     

Comparison between dipyridamole and adenosine as pharmacologic coronary vasodilators in detection of coronary artery disease with thallium 201 imaging

Background

Both dipyridamole and adenosine are widely used as pharmacologic stressors with ²⁰¹Tl imaging for detection of coronary artery disease. The purpose of this study was to compare dipyridamole and adenosine ²⁰¹Tl imaging directly in patients with angiographically proved coronary artery disease.

Methods and Results

Fifty-four patients were submitted to two planar ²⁰¹Tl studies: one with dipyridamole and the other with adenosine. The interval between the two studies varied from 2 to 7 days and the order was assigned randomly. Three standard planar views were obtained 10 minutes and 4 hours after the injection of 3.0 mCi ²⁰¹Tl. Administration of dipyridamole was as follows: 0.142 mg/kg/min during 4 minutes, followed by a slight exercise and ²⁰¹Tl injection. The infusion of adenosine was as follows: 0.140 mg/kg/min during 6 minutes with injection of ²⁰¹Tl after the third minute of infusion. Patients were asked to give their preference considering the number type, severity, and duration of side effects on a scale from 0 (worst) to 5 (best). Reading was done by two experienced observers. The heart was divided into three segments per view. The change in systolic blood pressure was-12±11 mm Hg for adenosine and-5±10 mm Hg for dipyridamole (p<0.001), and the change in heart rate was 18±10 beats/min for adenosine and 8±7 beats/min for dipyridamole (p<0.001). With regions of interest, ischemic/normal wall ratios were determined: 0.78 ± 0.06 for adenosine and 0.83±0.08 for dipyridamole (p<0.001). Adenosine detected 295 normal, 170 ischemic, and 21 scar segments, whereas dipyridamole detected 326, 135, and 25 segments, respectively. Patients preferred adenosine (4.3±1.0 for adenosine vs 3.8±1.5 for dipyridamole; p<0.04) mainly because of the short duration of side effects.

Conclusion

This study shows that the use of adenosine with ²⁰¹Tl imaging may have some advantages over dipyridamole.     

Gated stress-only 99mTc myocardial perfusion SPECT imaging accurately assesses coronary artery disease

In today's cost containment environment it is important to consider changes to standard protocols which would reduce cost, particularly if there is no significant loss of diagnostic accuracy. The aim of the present study was to assess the usefulness of a gated stress-only Tc sestamibi protocol in comparison to conventional gated dual isotope rest-stress myocardial perfusion single photon emission computed tomography (SPECT) in the detection and localization of coronary artery disease (CAD). Sixty-five consecutive patients (65+/-10 years, 22 women) who had undergone conventional gated perfusion SPECT were chosen retrospectively. Fifty-three of these 65 patients had previous coronary arteriography, 45 with at least one stenosis, eight without stenosis, and 12 of these 65 patients had <5% likelihood of CAD. Three readers interpreted the gated stress-only and dual isotope studies in separate sessions blinded to (1). their previous readings, (2). the interpretation by others, and (3). the angiographic results. Readers used a five-point scale to score their visual and quantitative assessment of perfusion, function and compromised vascular territory. Their average score was used for determination of the accuracy by using receiver operating characteristic (ROC) analysis of the techniques. The areas under ROC curves were determined for the detection of CAD and localization of vascular territories. Fifty-four of these patients had 97 significant stress induced perfusion defects as determined by the CEqual quantitative program. The agreement between protocols for the assessment of reversibility in these 97 defects was analysed. There were no statistically significant differences between dual isotope rest/stress and gated stress-only studies for the detection and localization of CAD. The area under the dual isotope rest/stress ROC curve was 0.78+/-0.07 compared to the area under the gated stress-only ROC curve of 0.80+/-0.06, resulting in P=0.30. For the combined vessels comparison of the area under the dual isotope rest/stress ROC curve was 0.73+/-0.04 versus the area under the gated stress-only ROC curve of 0.74+/-0.04, resulting in P=0.27. Similar non-significant differences were obtained when comparing the area under the dual isotope versus gated stress-only ROC curves for the left anterior descending vascular territory (LAD, 0.61+/-0.08 vs 0.660.08, P=0.14), the left circumflex vascular territory (LCX, 0.82+/-0.07 vs 0.81+/-0.06, P =0.47) or the right coronary vascular territory (RCA, 0.80+/-0.06 vs 0.78+/-0.06, P=0.28). The analysis of the reversibility of stress induced perfusion defects yielded a global agreement between protocols of 93% (kappa=0.42). The differences were due to the expert readers, using the gated stress-only protocol, misinterpreting some patients with attenuation artefacts, subendocardial infarction and functional stunning. These results show that the lower cost gated stress-only myocardial Tc myocardial perfusion SPECT studies are comparable to the conventional dual isotope studies when the clinical question is the detection and localization of coronary artery disease. Nevertheless, we also showed that this approach is limited when attempting to interpret the reversibility of stress induced perfusion defects in patients who exhibit attenuation artefacts, subendocardial infarction and functional stunning.     

Automatic detection of coronary artery disease in myocardial perfusion SPECT using image registration and voxel to voxel statistical comparisons

The purpose of this study was to compare the performance of automatic detection of coronary artery disease (CAD) with that of expert observers. A male and female normal image template was constructed from normal stress technetium-99m single photon emission computed tomography (SPECT) studies. Mean and standard deviation images for each sex were created by registering normal studies to a standard shape and position. The test group consisted of 104 patients who had been routinely referred for SPECT and angiography. The gold standard for CAD was defined by angiography. The test group studies were registered to the respective templates and the Z-score was calculated for each voxel. Voxels with a Z-score greater than 5 indicated the presence of CAD. The performance of this method and that of three observers were compared by continuous receiver operating characteristic (CROC) analysis. The overall sensitivity and specificity for automatic detection were 73% and 92%, respectively. The area (Az) under the CROC curve (+/-1 SE) for automatic detection of CAD was 0.88+/-0.06. There was no statistically significant difference between the performances of the three observers in terms of Az and that of automatic detection (P> or =0.25, univariate Z-score test). The use of this automated statistical mapping approach shows a performance comparable with experienced observers, but avoids inter-observer and intra-observer variability.     

Correct spatial normalization of myocardial perfusion SPECT improves detection of multivessel coronary artery disease

BACKGROUND: This study sought to improve the detection of multivessel coronary artery disease (CAD) with the use of rest and exercise single photon emission computed tomography (SPECT) perfusion scintigraphy by developing a processing scheme, which provides proper regional normalization of the images for interpretation. When SPECT perfusion images are interpreted, one area of myocardium serves as "normal." We hypothesized that if this "normal" region changes location from rest to stress, the stress images must be adjusted for proper interpretation. By taking into account the level of tracer activity in this "normal" area on the resting images, we could more accurately identify patients with multivessel CAD.Methods and results Dual-isotope rest (thallium 201) and exercise dobutamine or adenosine stress (technetium 99m sestamibi) perfusion SPECT studies were examined in 258 patients with 2- or 3-vessel CAD on coronary arteriography performed within 6 months of each other (mean interval, 19 days). If a shift in regional location of the "normal" segment from rest to stress was present, the images were (1) interpreted in the usual fashion for the number of vessels with ischemia (PRE-NORM) and (2) reinterpreted after quantitative normalization (ie, adjusting the display window until the intensity of the "normal" segment was matched at rest and stress [POST-NORM]). Interpretation was performed with blinding to arteriographic results. An angiographic stenosis was defined as luminal diameter stenosis greater than 50%. Three control groups comprising (1) single-vessel CAD (n = 119), (2) no significant angiographic CAD (n = 118), and (3) a normalcy group of low pre- and post-test probability of CAD (n = 44) were also studied to determine the incidence of false-positive results induced by the renormalization technique. A shift in the "normal" segment occurred in 81 studies of 258 patients (31%), 80 of which were read as abnormal PRE-NORM (sensitivity, 99%); however, for their 216 stenosed vessels, only 143 were detected PRE-NORM (vessel sensitivity, 66%; accuracy, 65%). The mean POST-NORM change in the display was 11%. POST-NORM, all 82 patients' studies were interpreted as abnormal (sensitivity, 100%), and 196 of 216 vascular territories were abnormal (vessel sensitivity, 91%; accuracy, 83%; both P <.0001 vs PRE-NORM). In the single-vessel disease, no significant disease, and normalcy groups, 19 of 119, 15 of 118, and 11 of 44 patients, respectively, demonstrated a shift in the peak pixel location. However, there were no significant changes in single-vessel sensitivity, angiographic specificity, or normalcy in these patients. CONCLUSIONS: With multivessel CAD, the "normal" region on SPECT often changes in location from rest to stress, potentially masking the extent and severity of multivessel ischemia. Renormalization of the images to match their resting level before image interpretation allows diagnosis of contralateral ischemia and strikingly improves the detection of multivessel CAD, without a substantive loss in specificity.     

SPECT and PET in the evaluation of coronary artery disease.

Cardiac positron emission tomography (PET) is an accurate method for assessing myocardial perfusion and metabolism in the evaluation of coronary heart disease. PET allows more accurate detection of myocardial ischemia than single photon emission tomography (SPECT). In addition, PET has higher spatial resolution and allows attenuation correction and the quantification of various physiologic parameters. PET with 2-(fluorine-18) fluoro-2-deoxy-D-glucose is considered the standard of reference for predicting improvement in regional or global left ventricular function after revascularization by identifying hibernating viable myocardium that shows diminished perfusion and preserved metabolism. Other less commonly used clinical applications of cardiac PET include assessment of myocardial oxygen consumption and fatty acid metabolism. The use of PET in myocardial imaging is expected to increase in the near future with the regional distribution of positron-emitting radiotracers and the emergence of relatively low-cost PET systems.     

Motion-frozen myocardial perfusion SPECT improves detection of coronary artery disease in obese patients.

In this study, we compared the diagnostic performance of the standard SPECT with motion-frozen (MF) myocardial perfusion SPECT (MPS) in obese patients. METHODS: A total of 90 consecutive obese patients (body mass index, 30.1-46.8, average, 34.3 +/- 3.6; age, 63 +/- 12 y; 30% women) underwent standard supine rest (201)Tl/stress (99m)Tc dual-isotope gated MPS and cardiac catheterization within 3 mo. MF images were obtained by nonlinear warping of cardiac phases to the end-diastolic position. Total perfusion deficit (TPD) was obtained for summed (S-TPD) and motion-frozen (MF-TPD) datasets with sex-specific standard and MF normal limits. RESULTS: The area under the receiver-operating-characteristic (ROC) curve for detection of coronary artery disease (CAD) by MF-TPD was significantly larger than that for S-TPD (0.93 +/- 0.25 vs. 0.88 +/- 0.32, P < 0.05). MF-TPD had higher specificity (77% vs. 55%, P < 0.05) and accuracy (89% vs. 80%, P < 0.05) than did S-TPD. CONCLUSION: MF processing of MPS improves CAD detection in obese patients.     

Thallium-201 washout in coronary artery disease using SPECT — a comparison with coronary angiography

In this study, tomographic ²⁰¹Tl washout analysis and coronary angiography were compared in 100 subjects. Seventeen subjects with healthy coronary arteries were used as reference material, on the basis of which the reference ranges for both the total washout of the heart muscle and the regional washout were determined. With angiography as the standard, this material yielded the following sensitivity values for total myocardial washout: 80% for three vessel proximal disease (n=30), 64% for peripheral three vessel disease (n=14), 66% for two vessel disease (n=29) and 71% for single vessel disease (n=17). Specificity in the reference group was 94%. Sensitivity values for regional washout were 83%, 93%, 59% and 71%, respectively. Stress ECG gave about 10% lower sensitivities. As far as sensitivity is concerned, however, visual assesment of tomographic images proved to be the best single method. In three patients, washout analysis was necessary to reveal evenly distributed ischemia and in seven cases it was essential in order to confirm an uncertain diagnosis; in other words, washout analysis had diagnostic value in 10 of the 100 patients.     

Comparison of dual to single contrast bolus magnetic resonance myocardial perfusion imaging for detection of significant coronary artery disease

Purpose:

To investigate the incremental diagnostic value of dual‐bolus over single‐contrast‐bolus first pass magnetic resonance myocardial perfusion imaging (MR‐MPI) for detection of significant coronary artery disease (CAD).

Materials and Methods:

Patients (n = 49) with suspected CAD underwent first pass adenosine stress and rest MR‐MPI and invasive coronary angiography (CA). Gadolinium diethylenetriamine pentaacetic acid (Gd‐DTPA) was injected with a prebolus (1 mL) and a large bolus (0.1 mmol/kg). For the single‐bolus technique, the arterial input function (AIF) was obtained from the large‐contrast bolus. For the dual‐bolus technique, the AIF was reconstructed from the prebolus. Absolute myocardial perfusion was calculated by Fermi‐model constrained deconvolution. Receiver operating characteristic (ROC) analysis was used to investigate diagnostic accuracy of MR myocardial perfusion imaging for detection of significant CAD on CA at vessel‐based analysis.

Results:

The area under the curve (AUC) of the minimal stress perfusion value for the detection of significant CAD using the single‐bolus and dual‐bolus technique was 0.85 ± 0.04 (95% confidence interval [CI], 0.77–0.93) and 0.77 ± 0.05 (95% CI, 0.67–0.86), respectively.

Conclusion:

In this study the dual‐bolus technique had no incremental diagnostic value over single‐bolus technique for detection of significant CAD with the used contrast concentrations. J. Magn. Reson. Imaging 2010;32:88–93. © 2010 Wiley‐Liss, Inc.     

Prognosis of stress-only SPECT myocardial perfusion imaging with prone imaging

Background

Stress-only single-photon emission computed tomography myocardial perfusion imaging (SO SPECT MPI) is associated with similarly benign prognosis as stress-rest SPECT MPI. However, previous studies have used attenuation correction rather than prone imaging to increase the rate of SO studies.

Objectives

To assess the prognosis of SO SPECT MPI performed with prone imaging.

Methods

We performed a retrospective cohort analysis of all patients who underwent a Tc-99m gated SPECT MPI over a 58-month period.

Results

Two thousand four hundred and sixty five patients were followed up. Of them, 1114 (45.2%) patients had a SO supine test, 388 (15.7%) underwent a SO supine and prone test, and the remaining 963 (39.1%) patients underwent a full stress-rest SPECT MPI. There was a similar annual mortality rate between the SO supine/prone group (1.3%), the SO supine (1.5%), and the stress-rest (1.5%) group (P = 0.47). Patients in the stress-rest group were significantly more likely to suffer from myocardial infarction (MI) as compared to the other two groups with an annual rate of 0.7% as compared to 0.4% (P = 0.049).

Conclusions

Normal supine-prone SO SPECT MPI is associated with a similarly benign prognosis as stress-rest SPECT MPI. The adjunction of prone imaging to the stress supine significantly increases the rate of SO SPECT MPI