Prostate MRI cancer detection rate by deep learning-assisted image quality categorization: gas-induced susceptibility...

To evaluate the impact of gas-induced artifacts in diffusion-weighted imaging (DWI) on prostate MRI cancer detection rate (CDR).

This three-center retrospective study included 34,697 MRI examinations between 2017 and 2022. Seven radiologists categorized the degree of gas-induced artifacts of 1595 DWI series into optimal, mild, moderate, and severe. Then, a deep learning model categorizing artifact severity was developed to help identify series with gas-induced artifacts. After excluding series used for training the model, the model was applied to 12,594 DWI series, which were performed for patients without documented prostate cancer. Of these, radiologists reviewed the bottom 300 series predicted as poor image quality and recategorized them if necessary. Case-control matching was performed to compare CDR. Examinations categorized by radiologists as mild-severe were used as target groups, while those categorized as optimal by either radiologists or the model were used to construct matched control groups. CDR was defined as the number of examinations assigned PI-RADS ≥ 3 with pathologically proven clinically significant cancer divided by the total number of examinations. The degree of CDR reduction was evaluated using the chi-squared test.

The target groups included 632 examinations (66.0 ± 9.5 years). The CDR in the target and matched control groups, respectively, for each artifact grade were as follows: severe (n = 141) vs optimal (n = 705), 0.24 vs 0.26, p = 0.58; moderate (n = 161) vs optimal (n = 966), 0.25 vs 0.24, p = 0.84; mild (n = 330) vs optimal (n = 1320), 0.25 vs 0.22, p = 0.17.

No evidence was found that gas-induced DWI artifacts reduce the CDR of prostate MRI.

The CDR of prostate MRI was not significantly reduced by susceptibility artifacts from rectal gas, which will be one consideration in rectal preparation protocols.

Gas-induced susceptibility artifact is a common issue in prostate MRI. The CDR decreased as the degree of artifacts increased. But there was no significant reduction even in severe artifact cases.