Fig 1.
Transabdominal views in the transverse/axial (A) and longitudinal/sagittal (B) planes. Transperineal views in the longitudinal/sagittal (C) and transverse/coronal planes (D). Lines represent “Axial 1” measurements (right to left), dashed lines represent “Axial 2” measurements (anterior-posterior), arrowed lines represent Sagittal measurements.
Fig 2.
Example Transabdominal (TA) and Transperineal (TP) US views.
Axial (A) and sagittal (D) MR images. B, E: TA ultrasound views from the same patient in the axial (B) and sagittal planes (E). C, F: TP ultrasound views in the axial (C) and sagittal planes (F). The sagittal TA US view (E) has shadowing from the pubis bone overlying the prostatic apex, which may affect measurement accuracy, conversely shadowing affects the axial view of TP imaging (C).
Table 1.
US views acquired for deriving prostate volumes.
Table 2.
Patient demographics.
Table 3.
Intraclass correlation coefficient (ICC) agreement between MRI-derived and US-derived prostate volumes.
Fig 3.
TURP defect affects measurements.
Axial (A) and coronal (B) T2-weighted images show TURP defect at the base of the gland, with corresponding transverse transabdominal US image (C). MRI triplanar and segmentation volumes will differ, and sagittal US measurements will vary depending if the gland is measured in the midline position, or more laterally.
Fig 4.
Limited views due to patient body habitus.
MRI Axial T1-weighted image (A) shows depth of prostate; corresponding sagittal T2-weighted image of the prostate (B). C: Transabdominal transverse imaging is limited (calipers outline prostate). D: Transperineal sagittal views more clearly demonstrate the prostate.
Table 4.
Intraclass correlation coefficient (ICC) inter-observer agreement for MRI- and US- derived prostate volumes.
Table 5.
Categorical comparison of MRI and US-derived PSA-density (PSA-D) at different biopsy thresholds of <0.15 ng/mL2, 0.15–0.20 ng/mL2 and >0.20 ng/mL2) and agreement to biopsy or not at PSA-density thresholds of 0.15 ng/mL2 and 0.12 ng/mL2.
Table 6.
Sensitivity, Specificity, Positive predictive value (PPV), Negative predictive value (NPV) between MRI-PSA density and each US PSA density for the decision to biopsy at PSA threshold >0.15 ng/mL2.
Table 7.
Sensitivity, Specificity, Positive predictive value (PPV), Negative predictive value (NPV) between MRI-PSA density and each US PSA density for the decision to biopsy at PSA threshold >0.12 ng/mL2.