Comparative effectiveness of standard vs. AI-assisted PET/CT reading workflow for pre-treatment lymphoma staging: a multi-institutional reader study evaluation

2024 Frood, Willaime, Miles, Chambers, Al-Chalabi, Ali, Hougham, Brooks, Petrides, Naylor, Ward, Sulkin, Chaytor, Strouhal, Patel and Scarsbrook.Background: Fluorine-18 fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) is widely used for staging high-grade lymphoma, with the time to evaluate such studies varying depending on the complexity of the case. Integrating artificial intelligence (AI) within the reporting workflow has the potential to improve quality and efficiency. The aims of the present study were to evaluate the influence of an integrated research prototype segmentation tool implemented within diagnostic PET/CT reading software on the speed and quality of reporting with variable levels of experience, and to assess the effect of the AI-assisted workflow on reader confidence and whether this tool influenced reporting behaviour. Methods: Nine blinded reporters (three trainees, three junior consultants and three senior consultants) from three UK centres participated in a two-part reader study. A total of 15 lymphoma staging PET/CT scans were evaluated twice: first, using a standard PET/CT reporting workflow; then, after a 6-week gap, with AI assistance incorporating pre-segmentation of disease sites within the reading software. An even split of PET/CT segmentations with gold standard (GS), false-positive (FP) over-contour or false-negative (FN) under-contour were provided. The read duration was calculated using file logs, while the report quality was independently assessed by two radiologists with >15 years of experience. Confidence in AI assistance and identification of disease was assessed via online questionnaires for each case. Results: There was a significant decrease in time between non-AI and AI-assisted reads (median 15.0 vs. 13.3 min, p < 0.001). Sub-analysis confirmed this was true for both junior (14.5 vs. 12.7 min, p = 0.03) and senior consultants (15.1 vs. 12.2 min, p = 0.03) but not for trainees (18.1 vs. 18.0 min, p = 0.2). There was no significant difference between report quality between reads. AI assistance provided a significant increase in confidence of disease identification (p < 0.001). This held true when splitting the data into FN, GS and FP. In 19/88 cases, participants did not identify either FP (31.8%) or FN (11.4%) segmentations. This was significantly greater for trainees (13/30, 43.3%) than for junior (3/28, 10.7%, p = 0.05) and senior consultants (3/30, 10.0%, p = 0.05). Conclusions: The study findings indicate that an AI-assisted workflow achieves comparable performance to humans, demonstrating a marginal enhancement in reporting speed. Less experienced readers were more influenced by segmentation errors. An AI-assisted PET/CT reading workflow has the potential to increase reporting efficiency without adversely affecting quality, which could reduce costs and report turnaround times. These preliminary findings need to be confirmed in larger studies

Pulmonary nodules: Assessing the imaging biomarkers of malignancy in a "coffee-break"

Purpose To prospectively assess the repeatability of CT texture features and semi-automated volume measurements extracted from pulmonary nodules (PNs) at low-dose multi–detector row computed tomography (CT). The secondary objective was to investigate the influence of two methods of inspiratory control on the repeatability of CTTA and volumetry. Introduction Although nodule volumetry is a recognized biomarker of malignancy in pulmonary nodules (PNs), caution is needed in its interpretation because of variables such as cardiac motion, respiratory volume variation and inter-scan variability of up to 25%. The alternative technique of CT texture as a potential independent biomarker of malignancy has been suggested, but interscan variability and respiratory volume variation has not been assessed. Materials and methods 40 patients (20 with an indeterminate PN and 20 with pulmonary metastases) underwent two Low Dose CT scans (LDCT) within a 60-minute period (the “Coffee-break”). Patients were randomized to two inspiratory control groups: normal breath hold, and controlled lung volume. 20 texture features were extracted from each automatic contoured region surrounding the PN. The variability and limits of repeatability of texture measurements within individual nodules was assessed. Results The mean difference in volume between the two scans was 6.3%, SD: 29.9%. The 20 textural features displayed 95% CI below ±17.8%, and were less variable than nodule volume (95% CI ±28.9%). All features had high repeatability, calculated by the concordance correlation coefficient, (0.84 ≤ CCC ≤ 0.99). All measurements were more repeatable for the controlled lung volume group than the normal breath-hold group. Conclusion CTTA repeatability was comparable to automatic volumetric measurements, and appears to be improved using controlled volume breath holding.</p

Pulmonary nodules: assessing the repeatability of imaging biomarkers of malignancy

The BTS Pulmonary Nodule Guidelines recommend the use of nodule volumetry as a biomarker of malignancy in pulmonary nodules (PNs). However, studies have shown that there is significant inter-scan variability of such volume measurements, which can vary by up to 25% (Gietema et al 2007). CT Texture analysis (CTTA) has also been shown to be a potential imaging biomarker of malignancy but requires further validation

Pulmonary nodules: assessing the repeatability of imaging biomarkers of malignancy

The BTS Pulmonary Nodule Guidelines recommend the use of nodule volumetry as a biomarker of malignancy in pulmonary nodules (PNs). However, studies have shown that there is significant inter-scan variability of such volume measurements, which can vary by up to 25% (Gietema et al 2007). CT Texture analysis (CTTA) has also been shown to be a potential imaging biomarker of malignancy but requires further validation

Pulmonary nodules: Assessing the imaging biomarkers of malignancy in a "coffee-break"

Purpose To prospectively assess the repeatability of CT texture features and semi-automated volume measurements extracted from pulmonary nodules (PNs) at low-dose multi–detector row computed tomography (CT). The secondary objective was to investigate the influence of two methods of inspiratory control on the repeatability of CTTA and volumetry. Introduction Although nodule volumetry is a recognized biomarker of malignancy in pulmonary nodules (PNs), caution is needed in its interpretation because of variables such as cardiac motion, respiratory volume variation and inter-scan variability of up to 25%. The alternative technique of CT texture as a potential independent biomarker of malignancy has been suggested, but interscan variability and respiratory volume variation has not been assessed. Materials and methods 40 patients (20 with an indeterminate PN and 20 with pulmonary metastases) underwent two Low Dose CT scans (LDCT) within a 60-minute period (the “Coffee-break”). Patients were randomized to two inspiratory control groups: normal breath hold, and controlled lung volume. 20 texture features were extracted from each automatic contoured region surrounding the PN. The variability and limits of repeatability of texture measurements within individual nodules was assessed. Results The mean difference in volume between the two scans was 6.3%, SD: 29.9%. The 20 textural features displayed 95% CI below ±17.8%, and were less variable than nodule volume (95% CI ±28.9%). All features had high repeatability, calculated by the concordance correlation coefficient, (0.84 ≤ CCC ≤ 0.99). All measurements were more repeatable for the controlled lung volume group than the normal breath-hold group. Conclusion CTTA repeatability was comparable to automatic volumetric measurements, and appears to be improved using controlled volume breath holding.</p

A comparison of the imaging features of early stage primary lung cancer in patients treated with surgery, SABR and microwave ablation

Stereotactic Ablative Radiotherapy (SABR) and percutaneous microwave ablation (PMWA) are now being performed in patients deemed “medically inoperable” with non-small cell lung cancer (NSCLC). The majority of these patients are treated without ground truth histology, relying on imaging to establish the diagnosis. The purpose of this study was to investigate whether there were differences in the visible imaging features including CT Texture Analysis (CTTA) between patients referred for surgery, SABR and PMWA, which might suggest differences in underlying diagnosis

A comparison of the imaging features of early stage primary lung cancer in patients treated with surgery, SABR and microwave ablation

Stereotactic Ablative Radiotherapy (SABR) and percutaneous microwave ablation (PMWA) are now being performed in patients deemed “medically inoperable” with non-small cell lung cancer (NSCLC). The majority of these patients are treated without ground truth histology, relying on imaging to establish the diagnosis. The purpose of this study was to investigate whether there were differences in the visible imaging features including CT Texture Analysis (CTTA) between patients referred for surgery, SABR and PMWA, which might suggest differences in underlying diagnosis