A second‐generation virtual‐pinhole PET device for enhancing contrast recovery and improving lesion detectability of a whole‐body PET/CT scanner
| العنوان: | A second‐generation virtual‐pinhole PET device for enhancing contrast recovery and improving lesion detectability of a whole‐body PET/CT scanner |
|---|---|
| المؤلفون: | Qiang Wang, Ke Li, Kenneth Puterbaugh, Stefan Siegel, Jianyong Jiang, J. Young, Yuan-Chuan Tai, Joseph A. O'Sullivan |
| المصدر: | Med Phys |
| بيانات النشر: | Wiley, 2019. |
| سنة النشر: | 2019 |
| مصطلحات موضوعية: | Scanner, Materials science, medicine.diagnostic_test, Detector, Contrast Media, General Medicine, Torso, Article, Imaging phantom, Lyso, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, medicine.anatomical_structure, Positron emission tomography, Positron Emission Tomography Computed Tomography, 030220 oncology & carcinogenesis, Image Processing, Computer-Assisted, medicine, Whole Body Imaging, Pinhole (optics), Monte Carlo Method, Sensitivity (electronics), Biomedical engineering |
| الوصف: | Purpose We have developed a second-generation virtual-pinhole (VP) positron emission tomography (PET) device that can position a flat-panel PET detector around a patient's body using a robotic arm to enhance the contrast recovery coefficient (CRC) and detectability of lesions in any region-of-interest using a whole-body PET/computed tomography (CT) scanner. Methods We constructed a flat-panel VP-PET device using 32 high-resolution detectors, each containing a 4 × 4 MPPC array and 16 × 16 LYSO crystals of 1.0 × 1.0 × 3.0 mm3 each. The flat-panel detectors can be positioned around a patient's body anywhere in the imaging field-of-view (FOV) of a Siemens Biograph 40 PET/CT scanner by a robotic arm. New hardware, firmware and software have been developed to support the additional detector signals without compromising a scanner's native functions. We stepped a 22 Na point source across the axial FOV of the scanner to measure the sensitivity profile of the VP-PET device. We also recorded the coincidence events measured by the scanner detectors and by the VP-PET detectors when imaging phantoms of different sizes. To assess the improvement in the CRC of small lesions, we imaged an elliptical torso phantom measuring 316 × 228 × 162 mm3 that contains spherical tumors with diameters ranging from 3.3 to 11.4 mm with and without the VP-PET device. Images were reconstructed using a list mode Maximum-Likelihood Estimation-Maximization algorithm implemented on multiple graphics processing units (GPUs) to support the unconventional geometries enabled by a VP-PET system. The mean and standard deviation of the CRC were calculated for tumors of different sizes. Monte Carlo simulation was also conducted to image clusters of lesions in a torso phantom using a PET/CT scanner alone or the same scanner equipped with VP-PET devices. Receiver operating characteristic (ROC) curves were analyzed for three system configurations to evaluate the improvement in lesion detectability by the VP-PET device over the native PET/CT scanner. Results The repeatability in positioning the flat-panel detectors using a robotic arm is better than 0.15 mm in all three directions. Experimental results show that the average CRC of 3.3, 4.3, and 6.0 mm diameter tumors was 0.82%, 2.90%, and 5.25%, respectively, when measured by the native scanner. The corresponding CRC was 2.73%, 6.21% and 10.13% when imaged by the VP-PET insert device with the flat-panel detector under the torso phantom. These values may be further improved to 4.31%, 9.65% and 18.01% by a future dual-panel VP-PET insert device if DOI detectors are employed to triple its detector efficiency. Monte Carlo simulation results show that the tumor detectability can be improved by a VP-PET device that has a single flat-panel detector. The improvement is greater if the VP-PET device employs a dual-panel design. Conclusions We have developed a prototype flat-panel VP-PET device and integrated it with a clinical PET/CT scanner. It significantly enhances the contrast of lesions, especially for those that are borderline detectable by the native scanner, within regions-of-interest specified by users. Simulation demonstrated the enhancement in lesion detectability with the VP-PET device. This technology may become a cost-effective solution for organ-specific imaging tasks. |
| تدمد: | 2473-4209 0094-2405 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::aece3d569e02c32d3c231de9d0e69ba1Test https://doi.org/10.1002/mp.13724Test |
| حقوق: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....aece3d569e02c32d3c231de9d0e69ba1 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 24734209 00942405 |
|---|