The influence of SPECT reconstruction algorithms on image quality and diagnostic accuracy in phantom measurements and 99mTc-sestamibi parathyroid scintigraphy
Nuclear medicine communications
& Keywords Objective: To determine the influence and clinical consequences of different tomographic reconstruction algorithms on image quality and diagnostic accuracy of low count statistics single photon emission computed tomography (SPECT). Methods: Phantom scans were used to assess image quality (% recovered contrast, relative noise level, spatial resolution). Diagnostic accuracy was assessed in parathyroid SPECT of 60 patients with primary hyperparathyroidism. Phantom and patient SPECT
... patient SPECT scans were reconstructed by two different algorithms (ReSPECT and HOSEM). Two blinded nuclear medicine physicians interpreted the patient scans in random order, without knowledge of any clinical data. Subjective image quality and certainty of diagnosis were scored. Results : Significantly lower relative noise levels (0.08 versus 0.13, p=0.042) and higher image spatial resolution (6.6 mm versus 17.1 mm full width at half maximum in the transaxial plane) were found in the phantom studies for ReSPECT as compared to HOSEM, respectively. In the clinical scans mean TBR (target to background ratio) was higher for ReSPECT (4.53 versus 2.97, p<0.001). There was no significant difference in region-based sensitivity (73% versus 68%, p=0.538) or specificity (93% versus 92%, p=0.815) for ReSPECT and HOSEM, respectively. Subjective image quality was higher for ReSPECT, as well as certainty of interpretation (p<0.001). Page 4 of 25 Conclusion: There is significant difference in image quality between commercially available algorithms for tomographic reconstruction of SPECT scans, which appears to have an impact on diagnostic accuracy and interpreter certainty. Therefore, we believe that systematic comparison of different SPECT reconstruction algorithms should be conducted to ensure a reproducible high image quality in clinical SPECT.