Lesion Confidence Research Articles

The lexicon of PET/CT reports in prostate patients: Evaluating confidence.

232 Background: Pet/CT scans are increasingly used to evaluate prostate cancer patients with biochemical failure following surgery or radiation therapy for localized prostate cancer. We assessed the language used in report impressions to characterize the reader's confidence for lesions in various anatomic sites. Methods: Between 2015 and 2021, 419 fluciclovine PET/CT scan reports were identified in our institutional outcomes database. Thirteen phrases routinely used in the report impression section by radiologists at least once to characterize a lesion of interest were identified. The phrases were categorized in the following confidence categories: Definitive (positive, negative), Likely (consistent with, most likely, favors, probable), and Unsure (suspicious for, concerning for, non-specific, conspicuous, compatible with, borderline, unknown). The final analysis set included 353 reports where the prescan PSA value was known within the prior 90 days of the scan. Descriptive statistics, stratified by prescan PSA value, were used to characterize this language for the following anatomic regions: bone, regional lymph nodes, prostate fossa, prostate gland/seminal vesicles, other soft tissue. Results: Overall, definitive language was used between 34.6% to 87.1% of the time, depending on the anatomic context (table). The intact prostate was the least likely site to use definitive language (34.6%), whereas bone was most likely (87.1%). Intact prostates in post-radiation patients had the most uncertainty to the persistence of disease (42.3% unsure, 23.1% likely). The highest degree of definitive certainty occurred in impressions of persons with PSA <0.5 (89.2%), whereas the least definitive certainty was in patients with PSA >1 (66.2%). Overall, definitive, likely and unsure findings were reported in 68.6, 9.7%, and 21.7% of scans. Conclusions: Fluciclovine PET/CT scans routinely result in equivocal findings, which vary by anatomic site of interest and prescan PSA level. The language utilized in these reports has not been standardized. Future work aims to create a clear confidence level lexicon standard to assist radiologists and providers in reporting standardization.[Table: see text]

Noise Texture Deviation: A Measure for Quantifying Artifacts in Computed Tomography Images With Iterative Reconstructions.

The aims of this study were to introduce the measure noise texture deviation as quantitative parameter for evaluating iterative reconstruction (IR)-specific artifacts in computed tomography (CT) images and to test whether IR-specific artifacts, quantified through this measure, are reduced in advanced modeled IR (ADMIRE) as compared with sinogram-affirmed IR (SAFIRE) images of the liver ex vivo and in patients with hypodense liver lesions. In the ex vivo study part, an abdominal phantom was used. In the institutional review board-approved in vivo study part, 40 consecutive patients (mean age, 63 years) with hypodense liver lesions undergoing abdominal CT in the portal-venous phase were included. Images were reconstructed with filtered back projection, with the second-generation IR algorithm SAFIRE and with the third-generation IR algorithm ADMIRE. Noise power spectra and noise texture deviation were calculated in the phantom; image noise was measured in the phantom and in patients. Two blinded readers evaluated all image data regarding IR-specific artifacts (plastic-like, blotchy appearance); patient data were evaluated regarding conspicuity and confidence for detecting hypodense liver lesions. Image noise was significantly reduced at increasing IR levels (P < 0.001) with both algorithms, with no significant differences between corresponding strength levels of SAFIRE and ADMIRE (all, P > 0.05). Noise power spectra were similar at corresponding strength levels of SAFIRE and ADMIRE (all, P > 0.05). Noise texture deviation in ADMIRE was reduced compared with corresponding strength levels of SAFIRE (all, P < 0.001) and strongly correlated with subjective IR-specific artifacts (r = 0.88, P < 0.001). Iterative reconstruction-specific artifacts were significantly reduced in ADMIRE compared with that in SAFIRE images at strength levels 3 or greater, both ex vivo and in vivo (all, P < 0.001). There were no significant differences in the readers' ratings of lesion conspicuity and lesion confidence in detecting hypodense liver lesions between SAFIRE and ADMIRE (P > 0.05). Only lesion conspicuity was superior with SAFIRE and ADMIRE compared with filtered back projection (all, P < 0.001). Noise texture deviation is a quantitative measure reflecting IR-specific artifacts and is reduced in CT images with ADMIRE compared with SAFIRE.