Wertigkeit von Ultraschall und Magnetresonanztomographie (MRT) bei der Erstdiagnose von Hodentumoren

Conventional ultrasound remains the standard of care in the diagnosis of testicular
tumors. It has shown good sensitivity and specificity in this indication and is also
universally available and inexpensive to use. Accuracy can be further improved by
adding ultrasound contrast agents or elastography. In parts, small lesions cannot be
definitively assessed by ultrasound. The importance of magnetic resonance imaging
(MRI) in the diagnosis of equivocal testicular lesions remains unclear. The use of
contrast medium and different phases is expected to provide additional diagnostic
information. Normal testicular tissue as well as benign and malignant testicular lesions
show variable contrast enhancement on MRI. Diffusion-weighted imaging (DWI) can
further increase the accuracy of MRI. However, evidence-based standardized MRI
protocols for the investigation of equivocal testicular lesions are still lacking. An own
retrospective multicenter study [1] showed a sensitivity of 85.7% and a specificity of
72.8% for MRI in the diagnosis of equivocal testicular lesions. However, it was shown
that the radiologist could not make a final decision concerning the dignity in up to
20%. In such cases, surgical exposure and histological confirmation remain the only
option. In addition, benign lesions are significantly smaller than malignant lesions. It
is also known from the literature that palpable lesions are mostly malignant, whereas
smaller lesions discovered incidentally tend to be benign. Both MRI and ultrasound are
good at estimating the size of malignant tumors, and this may facilitate the planning
of testis-sparing surgery.