Can MRI with diffusion-weighted imaging reliably detect cryptorchidism? A systematic review and diagnostic accuracy meta-analysis.

PURPOSE: Non-palpable undescended testes require accurate localisation, but the role of magnetic resonance imaging (MRI) combined with diffusion-weighted imaging (DWI) remains uncertain. We evaluated the diagnostic accuracy of MRI-DWI for detecting clinically non-palpable undescended testes.

METHODS

This PROSPERO (CRD420261411862) registered review searched PubMed, Embase, Web of Science, and CENTRAL to June 6, 2026. Eligible diagnostic-accuracy studies assessed MRI-DWI against diagnostic laparoscopy or operative exploration. Two reviewers extracted 2 × 2 data, and assessed QUADAS-2 risk of bias. Sensitivity and specificity were pooled using bivariate random-effects models, with hierarchical summary receiver operating characteristic (HSROC) analysis, likelihood ratios, diagnostic odds ratios, and Fagan nomograms used to summarise diagnostic performance.

RESULTS

Fifteen studies were included. In seven testis-level studies (340 testes), pooled sensitivity and specificity were 92.6% (95% CI 88.4-95.3%) and 94.3% (85.6-97.9%) and the HSROC area under the curve (AUC) was 0.957. In eight patient-level studies (1782 patients), pooled sensitivity and specificity were 86.7% (77.1-92.7%) and 85.8% (68.8-94.3%) and the HSROC AUC was 0.917. Positive MRI-DWI increased post-test probability on the Fagan nomogram, but a negative result left a residual probability of 21%. Heterogeneity was minimal at the testis level but substantial at the patient level analysis. Deeks' test suggested small-study effects only in the testis-level analysis.

CONCLUSIONS

MRI-DWI shows good-to-excellent accuracy and can support localization, operative planning, and counselling. However, a negative MRI-DWI result does not safely exclude the presence of a viable or otherwise at-risk undescended testis and leaves a clinically meaningful residual probability of disease. Therefore, negative imaging should not be used to omit operative exploration. MRI-DWI should be regarded as an adjunctive localisation tool rather than a replacement for diagnostic laparoscopy, which remains necessary for definitive evaluation.