Left ventricular ejection fraction determined with the nuclear stethoscope, gamma camera and contrast ventriculography

Left ventricular ejection fractions (EF) were measured with a nuclear stethoscope (NSt, beat-to-beat and ECG gated summation method) and contrast ventriculography (VG) immediately following one another (IFOA) (r X 0.96 and 0.95, respectively, n = 13). NSt and ECG gated gamma camera (MUGA) recordings IFOA were compared (r = 0.97 and 0.96, respectively, n = 23) as were non-IFOA recordings (r = 0.90 and 0.91, respectively, n = 13). Correlation between repeated NSt EF measurements gave: r = 0.91 (n = 22) for both methods. Paired NSt recordings in an invasive test situation (during invasive angiocardiography) and in a noninvasive situation (supine, 30 min of rest) gave for patients with EF less than 50 (mean +/- S.D.): EF invasive = 36 +/- 12, EF noninvasive = 41 +/- 13 (n = 4, p less than 0.05), and for patients with EF greater than or equal to 50: EF invasive = 59 +/- 7, EF noninvasive = 57 +/- 7 (n = 9, N.S.). The mean paired differences (EF noninvasive -EF invasive) in the low (less than 50) and high (greater than or equal to 50) EF range differed significantly: +5.3 versus -1.3, respectively (p less than 0.001). The recordings with the ECG-gated summation method gave similar results. The heart rate (beats min-1) in the noninvasive and invasive situation were (mean +/- S.D.): 68 +/- 11 and 78 +/- 16, respectively (p less than 0.01). We conclude that the patients were in a higher level of stress in the invasive situation. Accordingly ventricles with normal contractility (EF greater than or equal to 50) reacted with a slight increase in EF, and ventricles with compromised function (EF less than 50) reacted with a decrease in EF, compared to the values in the noninvasive situation. Incorporated in a correlation between MUGA and VG are, besides methodologically based differences, test-situation based systematical differences. Consequently the results of MUGA method should be given uncorrected. The results documents the accuracy and reliability of the NSt.     

Use of the esophageal stethoscope in pediatric transports

INTRODUCTION: Monitoring cardiac and respiratory function during helicopter transports can be difficult, so the authors devised a study of the esophageal stethoscope for pediatric patients. SETTING: The study was conducted at Pediflite in Tennessee, which transports between 250 to 300 pediatric patients every year. MATERIALS AND METHODS: A disposable esophageal stethoscope was used as an adjunct to other monitoring systems in intubated patients. Prior to transport, the stethoscope was placed orally by the respiratory therapist and advanced to the point where heart sounds are heard best, at which point breath sounds can also be heard clearly. The device's ear piece easily fit under the crew member's headphones, which block helicopter noise. Three sizes of stethoscope are available: a 6 French for patients 1 day to 4 years old, a 9 French for those 4 to 12 years old, and an 18 French for patients 12 years of age or older. RESULTS: The esophageal stethoscope was used in 55 patients ranging in age from newborn to 18 years. Eighteen of 55 (33%) had multiple trauma or closed head injury, and 14 of 55 (25%) suffered respiratory failure. The esophageal stethoscope proved to be easy to place, had a low risk of complications and allowed continuous access to breath sounds. In addition, the ability to hear heart tones was minimally affected by noise or vibration. CONCLUSION: Due to its ability to continuously monitor breath sounds, endotracheal tube obstruction or displacement can be rapidly detected by the esophageal stethoscope. Also, if there is failure of the cardiopulmonary monitor, heart sounds can be continuously monitored. The esophageal stethoscope is a simple but potentially valuable tool in pediatric and neonatal transports for monitoring respiratory and cardiac status.     

Ultrafast nuclear myocardial perfusion imaging on a new gamma camera with semiconductor detector technique: first clinical validation

Purpose

To assess the diagnostic performance of a novel ultrafast cardiac gamma camera with cadmium-zinc-telluride (CZT) solid-state semiconductor detectors for nuclear myocardial perfusion imaging (MPI).

Methods

The study group comprised 75 consecutive patients (55 men, BMI range 19–45 kg/m²) who underwent a 1-day ^99mTc-tetrofosmin adenosine-stress/rest imaging protocol. Scanning was performed first on a conventional dual-detector SPECT gamma camera (Ventri, GE Healthcare) with a 15-min acquisition time each for stress and rest. All scans were immediately repeated on an ultrafast CZT camera (Discovery 530 NMc, GE Healthcare) with a 3-min scan time for stress and a 2-min scan time for rest. Clinical agreement (normal, ischaemia, scar) between CZT and SPECT was assessed for each patient and for each coronary territory using SPECT MPI as the reference standard. Segmental myocardial tracer uptake values (percent of maximum) using a 20-segment model and left ventricular ejection fraction (EF) values obtained using CZT were compared with those obtained using conventional SPECT by intraclass correlation and by calculating Bland-Altman limits of agreement.

Results

There was excellent clinical agreement between CZT and conventional SPECT on a per-patient basis (96.0%) and on a per-vessel territory basis (96.4%) as shown by a highly significant correlation between segmental tracer uptake values (r=0.901, p<0.001). Similarly, EF values for both scanners were highly correlated (r=0.976, p<0.001) with narrow Bland-Altman limits of agreement (?5.5–10.6%).

Conclusion

The novel CZT camera allows a more than fivefold reduction in scan time and provides clinical information equivalent to conventional standard SPECT MPI.     

A comprehensive,targeted approach to the clinical care of athletes following sport-related concussion

Purpose

The purpose of this paper is to discuss risk and prognostic factors for concussion outcomes, review comprehensive approaches to assessment, and describe a new method for conceptualizing treatment for sport-related concussion using clinical experience.

Methods

Based on the current literature of sport-related concussion and clinical experience, an approach for conceptualizing concussion care using clinical trajectories and targeted treatments was developed.

Results

A comprehensive approach to assessment and targeted treatments for sport-related concussion was developed using specific clinical trajectories.

Conclusion

Sport-related concussions are heterogeneous and require an individualized clinical approach. The use of a comprehensive approach for assessing specific clinical trajectories following a sport-related concussion will help clinicians better conceptualize this injury. Clinicians can then match targeted treatment pathways to specific clinical trajectories to accelerate safe return to play for athletes following a sport-related concussion.

Level of evidence

V.     

Adherence monitoring of rehabilitation exercise with inertial sensors: A clinical validation study

BackgroundRehabilitation has an established role in the management of a wide range of musculoskeletal conditions. Much of this treatment relies on self-directed exercises at home, where adherence of execution is unknown. Demonstrating treatment fidelity is necessary to draw conclusions about the efficacy of rehabilitation interventions in both clinical and research settings. There is a lack of tools and methods to achieve this.Research questionThis study aims to evaluate the feasibility of using a single inertial sensor to recognise and classify shoulder rehabilitation activity using supervised machine learning techniques.MethodsTwenty patients with shoulder pain were monitored performing five rehabilitation exercises routinely prescribed for their condition. Accelerometer, gyroscope and magnetometer data were collected via a device mounted onto an arm sleeve. Non-specific motion data was included in the analysis. Time and frequency domain features were calculated from labelled data segments and ranked in terms of their predictive importance using the ReliefF algorithm. Selected features were used to train four supervised learning algorithms: decision tree, k-nearest neighbour, support vector machine and random forests. Performance of algorithms in accurately classifying exercise activity was evaluated with ten-fold cross-validation and leave-one-subject-out-validation methods.ResultsOptimal predictive accuracies for ten-fold cross-validation (97.2%) and leave-one-subject-out-validation (80.5%) were achieved by support vector machine and random forests algorithms, respectively. Time domain features derived from accelerometer, magnetometer and orientation data streams were shown to have the highest predictive value for classifying rehabilitation activity.SignificanceClassification models performed well in differentiating patient exercise activity from non-specific movement and identifying specific exercise type using inertial sensor data. A clinically useful account of home rehabilitation activity will help guide treatment strategies and facilitate methods to improve patient engagement. Future work should focus on evaluating the performance of such systems in natural and unsupervised settings.     

Quadruple inversion-recovery b-SSFP MRA of the abdomen: Initial clinical validation

The purpose of this study is to assess the image quality and diagnostic accuracy of non-contrast quadruple inversion-recovery balanced-SSFP MRA (QIR MRA) for detection of aortoiliac disease in a clinical population. QIR MRA was performed in 26 patients referred for routine clinical gadolinium-enhanced MRA (Gd-MRA) for known or suspected aortoiliac disease. Non-contrast images were independently evaluated for image quality and degree of stenosis by two radiologists, using consensus Gd-MRA as the reference standard. Hemodynamically significant stenosis (≥50%) was found in 10% (22/226) of all evaluable segments on Gd-MRA. The sensitivity and specificity for stenosis evaluation by QIR MRA for the two readers were 86%/86% and 95%/93% respectively. Negative predictive value and positive predictive value were 98%/98% and 63%/53% respectively. For stenosis evaluation of the aortoiliac region QIR MRA showed good agreement with the reference standard with high negative predictive value and a tendency to overestimate mild disease presumably due to the flow-dependence of the technique. QIR MRA could be a reasonable alternative to Gd-MRA for ruling out stenosis when contrast is contraindicated due to impaired kidney function or in patients who undergo abdominal MRA for screening purposes. Further work is necessary to improve performance and justify routine clinical use.     

核心脏病学的应用进展

核心脏病学在技术上取得了一定的新进展。在冠心病诊断中核心脏病学检查与其他心脏影像学检查方法各有其优、缺点,彼此相互补充、不能替代。核心脏学检查在冠心病的诊断、危险度评估分层和治疗方案的确定提供了一站式的服务。对于特定人群的冠心病筛查,核心脏病学检查具有特殊的价值。     

Suspected pulmonary embolism and deep venous thrombosis: A comprehensive MDCT diagnosis in the acute clinical setting

Both pulmonary arterial and peripheral venous sides of venous thromboembolism (VTE) can now be efficiently and safely investigated by multi-detector CT (MDCT) at the same time by a combined CT angiography/CT venography protocol. In the emergency setting, the use of such a single test for patients suspected of suffering from VTE on a clinical grounds may considerably shorten and simplify diagnostic algorithms. The selection of patients to be submitted to MDCT must follow well-established clinical prediction rules in order to avoid generalized referral to CT on a generic clinical suspicion basis and excessive population exposure to increased ionizing radiation dose, especially in young patients. Clinical and anatomical wide-panoramic capabilities of MDCT allow identification of underlying disease that may explain patients' symptoms in a large number of cases in which VTE is not manifest. The analysis of MDCT additional findings on cardiopulmonary status and total thrombus burden can lead to better prognostic stratification of patients and influence therapeutic options. Some controversial points such as optimal examination parameters, clinical significance of subsegmentary emboli, CT pitfalls and/or possible falsely positive diagnoses, and outcome of untreated patients in which VTE has been excluded by MDCT without additional testing, must of course be taken into careful consideration before the definite role of comprehensive MDCT VTE "one-stop-shop" diagnosis in everyday clinical practice can be ascertained.     

心血管核医学若干临床应用进展

21世纪影像学是将传统影像学与现代影像学结合 ,以形态学为基础 ,发展与脏器功能、代谢、受体、基因显像相结合的分子影像学。其主要从分子生物学与活体化学水平展示疾病发生发展的规律 ,内容有神经受体显像 ,基因显像 ,放射免疫显像(RII) ,以及活体分子生化、代谢显像等 ,从而对疾病的诊断与认识更加全面 ,更加深入。探测仪器方面 ,最显著的一个特点是将形态学影像与脏器的功能、灌注、代谢显像相融合 (fusion) ,实现综合优化诊断。心血管核医学也向心血管分子影像学的方向发展。尽管目前PET CT主要应用于肿瘤学 ,但在未来 3～5年内PET CT或PET MRI在心血管的应用会有令人瞩目的进展[1 3 ] 。一、心脏神经受体显像受体显像是用放射性核素标记某种配体 ,与靶组织中某些高亲和力的受体产生特异性结合 ,通过核素显像显示其密度与分布。到目前为止 ,能够在活体检查心脏神经受体的仅核素受体显像技术[4,5] ,其他的心血管成像技术均不能直接检测心脏的受体功能。用于心脏神经受体研究较多的配体是12 3 I 间碘苄胍 (MIBG)。1.12 3 I MIBG在心力衰竭中的研究。MIBG是抗高血压药物胍乙啶的衍生...     

A clinical application of an automated phantom-film QA procedure for validation of IMRT treatment planning and delivery

To quantify the correlation between planned and delivered intensity-modulated radiation therapy (IMRT) dose distributions, IMRT plans for 37 prostate carcinoma patients were analyzed. IMRT treatment plans were converted into hybrid phantom plans using a commercially available treatment planning system and delivered to a specialized film phantom via a static-tomotherapy technique. The films were analyzed using a commercial film dosimetry system. Hybrid phantom axial dose maps and film images were normalized, registered to one another, and subtracted to calculate the overall relative dose difference throughout the entire film area on a pixel-by-pixel basis. The average percentage of pixels with dose-difference values greater than ± 3% among analyzed hybrid patient plans was 8.6% ± 3%. The average percentage of pixels with dose differences greater than ± 5% was 1.7% ± 1.0%. The number of pixels with more than ± 10% dose differences was negligible. An initial subset of hybrid plans was used to develop a quantitative criterion to verify for positional accuracy based on dosimetric verification of intensity map of IMRT plans for prostate patients in our institution. Plans with less than 5% of the pixels outside the ± 5% dose-difference range were accepted. This method could be implemented for other anatomical sites or treatment planning and delivery systems. © 2003 American Association of Medical Dosimetrists.     

A clinical application of an automated phantom-film QA procedure for validation of IMRT treatment planning and delivery

To quantify the correlation between planned and delivered intensity-modulated radiation therapy (IMRT) dose distributions, IMRT plans for 37 prostate carcinoma patients were analyzed. IMRT treatment plans were converted into hybrid phantom plans using a commercially available treatment planning system and delivered to a specialized film phantom via a static-tomotherapy technique. The films were analyzed using a commercial film dosimetry system. Hybrid phantom axial dose maps and film images were normalized, registered to one another, and subtracted to calculate the overall relative dose difference throughout the entire film area on a pixel-by-pixel basis. The average percentage of pixels with dose-difference values greater than ± 3% among analyzed hybrid patient plans was 8.6% ± 3%. The average percentage of pixels with dose differences greater than ± 5% was 1.7% ± 1.0%. The number of pixels with more than ± 10% dose differences was negligible. An initial subset of hybrid plans was used to develop a quantitative criterion to verify for positional accuracy based on dosimetric verification of intensity map of IMRT plans for prostate patients in our institution. Plans with less than 5% of the pixels outside the ± 5% dose-difference range were accepted. This method could be implemented for other anatomical sites or treatment planning and delivery systems. © 2003 American Association of Medical Dosimetrists.     

The role of nuclear cardiology in clinical decision making

This review suggests that the field of nuclear cardiology is alive, well, and thriving, providing relevant information that aids in everyday clinical decision making for nuclear medicine and referring physicians alike. Despite the competition from other modalities, the clinically appropriate applications of nuclear cardiology techniques are likely to increase. The foundation of this optimism is based on the vast amount of data documenting cost-effective clinical applications for diagnosis, risk stratification, and assessing therapy in both chronic and acute coronary artery disease (CAD), the powerful objective quantitative analysis of perfusion and function provided by the technique, and the increasing general availability of the approach.     

The use of nuclear cardiology in clinical decision making

Extensive data exist to support the role of myocardial perfusion single-photon emission computed tomography (MPS) in risk stratification. Normal MPS studies usually are associated with very low risk, and patient risk increase significantly as a function of MPS results. Ventricular function measurements from gated single-photon emission computed tomography further augment risk stratification, particularly with respect to identifying patients at risk of cardiac death. Ancillary findings are prognostically important, particularly in the setting of normal or near-normal MPS results. Recent data suggest that MPS results can identify which patients will benefit from revascularization versus medical therapy and have expanded the understanding of how stress MPS is helpful in the identification of risk, enhanced the means of identifying risk, and improved its use as a means to identify optimal posttest treatment.