title: Magnetic resonance imaging of experimental testicular torsion.
abstract: We investigated the feasibility of contrast enhanced (CE)-dynamic magnetic resonance imaging (MRI) for the detection of testicular torsion induced hypoperfusion in an experimental rat model. Adult Sprague-Dawley rats were subjected to unilateral testicular torsion of 360 or 720 degrees. After 1 h, the tail veins of the anaesthetized rats were cannulated and T2 -, diffusion-weighted and T1-weighted CE-dynamic MRI were subsequently performed by a 1.5 T MRI scanner. On apparent diffusion coefficient (ADC) images, the region of interest values of the ischaemic and control testes was compared. From CE-dynamic MR images, the maximal slopes of contrast enhancement were calculated and compared. In testicular torsion of 360 degrees, the maximal slope of contrast enhancement was 0.072%/s vs. 0.47%/s in the contralateral control testis (p < 0.001). A torsion of 720 degrees diminished the slope of contrast enhancement to 0.046%/s vs. 0.37%/s in the contralateral testis (p < 0.001). Diminished blood flow during torsion also followed in decreased ADC values in both 360 degrees (12.4% decrease; p < 0.05) and 720 degrees (10.8% decrease; p < 0.001) of torsion. Torsion of the testis causes ipsilateral hypoperfusion and decreased gadolinium uptake in a rat model that can be easily detected and quantified by CE-dynamic MRI. In diffusion-weighted MRI images, acute hypoperfusion results in a slight decrease of ADC values. Our results suggest that CE-dynamic MRI in combination with diffusion-weighted MRI can be used to detect compromised blood flow due to acute testicular torsion.
authors.affiliation: Department of Urology, Tampere University Hospital, Teiskontie 35, PL 2000, 33521 Tampere, Finland. antti.kaipia@pshp.fi
authors.forename: A
authors.initials: A
authors.lastname: Kaipia
authors.forename: P
authors.initials: P
authors.lastname: Ryymin
authors.forename: E
authors.initials: E
authors.lastname: Mäkelä
authors.forename: M
authors.initials: M
authors.lastname: Aaltonen
authors.forename: V
authors.initials: V
authors.lastname: Kähärä
authors.forename: M
authors.initials: M
authors.lastname: Kangasniemi
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013086:Spermatic Cord Torsion / Q000175:diagnosis; D013733:Testicular Diseases / Q000175:diagnosis*; D013737:Testis / Q000098:blood supply; D014102:Torsion Abnormality / Q000175:diagnosis