Deep-learning-based reconstruction of T2-weighted magnetic resonance imaging of the prostate accelerated by compressed sensing provides improved image quality at half the acquisition time.

Background: Deep-learning-based reconstruction (DLR) improves the quality of magnetic resonance (MR) images which allows faster acquisitions. The aim of this study was to compare the image quality of standard and accelerated T2 weighted turbo-spin-echo (TSE) images of the prostate reconstructed with and without DLR and to find associations between perceived image quality and calculated image characteristics. Methods: In a cohort of 47 prospectively enrolled consecutive patients referred for bi-parametric prostate magnetic resonance imaging (MRI), two T2-TSE acquisitions in the transverse plane were acquired on a 3T scanner-a standard T2-TSE sequence and a short sequence accelerated by a factor of two using compressed sensing (CS). The images were reconstructed with and without DLR in super-resolution mode. The image quality was rated in six domains. Signal-to-noise ratio (SNR), and image sharpness were measured. Results: The mean acquisition time was 281±23 s for the standard and 140±12 s for the short acquisition (P<0.0001). DLR images had higher sharpness compared to non-DLR (P<0.001). Short and short-DLR had lower SNR than the standard and standard-DLR (P<0.001). The perceived image quality of short-DLR was rated better in all categories compared to the standard sequence (P<0.001 to P=0.004). All domains of subjective evaluation were correlated with measured image sharpness (P<0.001). Conclusions: T2-TSE acquisition of the prostate accelerated using CS combined with DLR reconstruction provides images with increased sharpness that have a superior quality as perceived by human readers compared to standard T2-TSE. The perceived image quality is correlated with measured image contrast.

Quantification and significance of extraprostatic findings on prostate MRI: a retrospective analysis and three-tier classification.

OBJECTIVES: To quantify extraprostatic findings (EPFs) on prostate MRI, estimate the proportion of reported and unreported EPFs, assess their clinical importance, and propose standardized reporting of EPFs. MATERIALS AND METHODS: Prostate 3-T MRI studies, reports, and clinical data from 623 patients (age 67.9 ± 8.2 years) were retrospectively analyzed and re-evaluated for the presence of EPFs and their clinical significance: E1-no finding or findings that have no clinical significance; E2-potentially significant findings; and E3-significant findings. RESULTS: Secondary reading identified 1236 EPFs in 593 patients (1.98 ± 1.13 EPFs per patient, no EPFs in 30 patients), from which 468 (37.8%) were mentioned in the original report. The most common findings included diverticulosis (44% of patients), hydrocele (34%), inguinal fat hernia (16%), and bladder wall trabecular hypertrophy (15%). There were 80 (6.5%) E2 EPFs and 30 (2.4%) E3 EPFs. From E3 EPFs, 10 (33%) were not originally reported. A workup was suggested in 35 (52%) of the 67 originally reported E2 and E3 findings with follow-up and performed in 20 (30%). Fourteen (21%) EPFs in 11 patients influenced their management. Four experienced radiologists originally reported 1.8 to 2.5 findings per patient (p < 0.0001). CONCLUSIONS: EPFs on prostate MRI are frequent, but only 2.4% are clinically significant (E3), and 33% of these are not reported. Only 30% of E2 and E3 findings are further explored, and 21% influence patient management. We suggest that an "E" category should be attached to the PI-RADS system to identify the presence of EPFs that require further workup. CRITICAL RELEVANCE STATEMENT: Extraprostatic findings on prostate MRI are frequent, but only 2.4% are clinically significant (E3), and 33% of these are not reported. We advocate standardized reporting of extraprostatic findings indicating their clinical significance. KEY POINTS: • Extraprostatic findings on prostate MRI are frequent with an average of two findings per patient. • 2.4% of extraprostatic findings are significant, and 33% of these are not reported. • There is a significant variability among experienced radiologists in reporting extraprostatic findings.

Gadoxetate disodium, a modern hepatospecific MRI contrast agent: Indirect signs for gadolinium deposition in the brain structures with signal intensity increase after intravenous application.

BACKGROUND: Gadolinium brain deposits after intravenous application of gadolinium-based contrast agents (GBCA) have been recently reported. AIM: We focused selectively on gadoxetate disodium, a hepatospecific linear GBCA. There are currently only a few studies in peer-reviewed literature focused selectively on gadoxetate disodium with conflicting results. MATERIALS AND METHODS: Twenty patients (mean age 55.5 ± 14.0 years) after previous repeated administrations of gadoxetate disodium (mean 2.6 ± 1.5) for liver diagnostic process were included. All patients had normal renal and liver functions, an intact blood-brain barrier, and did not receive any other GBCA. They underwent 26 brain magnetic resonance imaging (MRI) with T1WI axial scans for signal intensity (SI) evaluation. The SI changes were measured in globus pallidus (GP), dentate nucleus (DN), pons (Po), and thalamus (Th) and SI ratios (DN/Po, GP/Po, GP/Th, Th/Po) were calculated. The control group consisted of 10 healthy volunteers (mean age 54.8 ± 12.1 years) with no prior GBCA applications. STATISTICAL ANALYSIS: Robust linear regression was used to test the effect of number of applications on the SI ratios. RESULTS: The significant effect of number of gadoxetate previous applications on DN/Po SI ratio was found. On an average, the DN/Po ratio increased by 0.36 percentage points [P = 0.042, 95% CI (0.03, 0.69)]. Other SI ratios were not significantly affected. CONCLUSIONS: Repeated administrations of hepatospecific gadoxetate disodium leads to a statistically significant increase in the SI values in DN in patients with normal renal and liver functions, and with an intact blood-brain barrier, probably due to gadolinium deposition.