Signal Thresholding Segmentation of Ventricular Volumes in Young Patients with Various Diseases-Can We Trust the
Titus Thut1,2, Emanuela Valsangiacomo Büchel1,2, Julia Geiger2,3
1Pediatric Cardiology, Department of Surgery, Pediatric Heart Center, University Children's Hospital Zurich, 8032 Zurich, Switzerland.
Insights
Manual and 30% threshold cardiac magnetic resonance imaging (CMR) segmentation accurately measure biventricular volumes in young patients. This method shows good agreement with flow measurements and is reproducible for clinical use.
Area of Science:
- Cardiology
- Medical Imaging
- Biomedical Engineering
Background:
- Right and left ventricular volumes are crucial for diagnosing and predicting outcomes in cardiac diseases.
- Accurate measurement of these volumes relies on segmenting myocardial borders in cardiac magnetic resonance (CMR) images.
- Automated methods like signal thresholding require validation for clinical application.
Purpose of the Study:
- To compare manual and automated MassK application biventricular volume measurements using different signal thresholds.
- To evaluate the agreement between volumetric measurements and flow measurements in the aorta and pulmonary artery.
- To assess the reproducibility of volumetric measurements in a young patient cohort.
Main Methods:
- Biventricular volumes (end-diastole and end-systole) were measured manually and with MassK at 30%, 50%, and 70% signal thresholds.
- Stroke volumes and cardiac indices were calculated from volumetric data and phase contrast flow measurements.
- Reproducibility was assessed through interobserver variability in 20 patients; measurements were acquired in 94 patients.
Main Results:
- End-diastolic and end-systolic volumes were largest with manual segmentation and decreased with increasing MassK thresholds.
- Manual and 30% threshold-based stroke volumes and cardiac indices showed the best correlation with flow measurements.
- Low interobserver variability was observed for all manual and MassK-derived volume measurements.
Conclusions:
- Manual and 30% threshold-based biventricular volume segmentation provide the most accurate results compared to flow measurements.
- These methods demonstrate good agreement and reproducibility in a young cardiac referral population.
- Validated automated segmentation can be reliably used in clinical settings for biventricular volume assessment.
Abstract:
In many cardiac diseases, right and left ventricular volumes in systole and diastole are diagnostically and prognostically relevant. Measurements are made by segmentation of the myocardial borders on cardiac magnetic resonance (CMR) images. Automatic detection of myocardial contours is possible by signal thresholding techniques, but must be validated before use in clinical settings. Biventricular volumes were measured in end-diastole (EDVi) and in end-systole (ESVi) both manually and with the MassK application, with signal thresholds at 30%, 50%, and 70%. Stroke volumes (SV) and cardiac indices (CI) were calculated from volumetric measurements and from flow measured in the ascending aorta and the main pulmonary artery, and both methods were compared. Reproducibility of volumetric measurements was tested in 20 patients. Measurements were acquired in 94 patients aged 15 ± 9 years referred for various conditions. EDVi and ESVi of both ventricles were largest with manual segmentation and inversely proportional to the MassK threshold. Manual and k30 SV and CI corresponded best to flow measurements. Interobserver variability was low for all volumes manually and with MassK. In conclusion, manual and 30% threshold-based biventricular volume segmentation agree best with two-dimensional, phantom-corrected phase contrast flow measurements in a young cardiac referral population and are well reproducible.
