Elastography and diffusion-weighted MRI in patients with testicular microlithiasis, normal testicular tissue, and testicular cancer: an observational study

Abstract

Background Ultrasound elastography is increasingly available in clinical practice. Recent studies showed higher velocity stiffness in testicular tumors compared to normal testicles. Purpose To evaluate ultrasound elastography in combination with the apparent diffusion coefficient measurements in diffusion weighted (DW) magnetic resonance imaging (MRI) in testicles. DW can be a useful tool in evaluating testicular malignancies. However, the relationship between velocity stiffness and MRI diffusion is not well established. Material and Methods We prospectively included 132 patients with testicular microlithiasis (n = 53), or normal testicular tissue (n = 53), or suspected for testicular cancer (n = 26). All 132 patients underwent ultrasonography including shear wave elastography and MRI diffusion coefficient examination of the scrotum. Results No clinically relevant difference in velocity stiffness was found between normal and testicles with microlithiasis. There was a significant difference in stiffness between patients with testicular microlithiasis (0.78 m/s), normal testicular tissue (0.77 m/s), and patients with testicular cancer (1.95 m/s) ( P ≤ 0.001). Similarly, there was a statistically significant difference in MRI diffusion values between patients with testicular microlithiasis (0.978 × 10mms), normal testicular tissue (0.929 × 10mms), and testicular cancers (0.743 × 10mms) ( P < 0.01). Conclusion Patients with testicular microlithiasis had no malignant characteristics measured with shear wave elastography or MRI diffusion. MRI diffusion and elastography may be useful to preoperatively differentiate benign from malignant testicular lesions.

Causal contributors to tissue stiffness and clinical relevance in urology

“…Aging, neoplasia, and metabolic diseases can lead to fibrosis and an increase of tissue stiffness 5 . Thus, tissue stiffness is a clinically relevant parameter for diagnosis and prognosis purposes, as we have here shown that alteration of this mechanical parameter is coupled with the progression of diseases and malignancies associated with kidney cancer and fibrosis 143 , PCa 177 , 178 , bladder cancer 167 , testicular cancer 189 , and infertility related diseases 190 – 192 . Biochemical, topographical, and mechanical modification of the ECM occurs both at the primary and metastatic site 19 , 21 , 26 , but there is also an important cellular contribution to the altered tissue stiffness by means of cell density, contractility, and traction 82 , 93 .…”

“…The stiffness of testicular cancer can be more than double the stiffness of normal testis, suggesting that increased stiffness could be used as a testicular malignancy marker, and detectable by ultrasound elastography 188 , 189 . In testicular microlithiasis, a modest increase of tissue stiffness compared to normal testicles was measured by SWE 188 , but no malignant characteristics are measured by SWE or MRI diffusion in this condition (stiffness values reported in Table 2 ) 189 . Thus, benign testicular lesions can be differentiated from malignant ones both by MRI diffusion and elastography.…”

When to ask for an MRI of the scrotum

“…The literature search found a total of 1106 articles (tumors, n = 584; acute scrotum, n = 193; undescended testes, n = 178; and infertility, n = 151). Ultimately, 83 articles were deemed relevant and used as the literature basis of this review (tumors, n = 50; acute scrotum, n = 6; undescended testes, n = 7; and infertility, n = 20) 6–9,13,24–33,35,43,48–110 . The flow chart of the selection process is shown in Figure 1.…”

“…24 DWI by assessing the microscopic diffusion movements of water molecules in testicular tissue, greatly improves the diagnostic efficiency of MRI in the detection and characterization of intratesticular lesions. 50,51,[55][56][57]63,72 Testicular malignancies often present with restricted diffusion and a lower apparent diffusion coefficient (ADC) value, when compared to normal testis and benign intratesticular lesions (Figure 4). A cut-off ADC of 0.99 × 10 −3 mm 2 /s has been reported reliable for the characterization of intratesticular lesions, with a sensitivity of 93.3%, specificity of 90%, PPV of 87.5%, and NPV of 94.7%.…”

Role of multiparametric ultrasound in testicular focal lesions and diffuse pathology evaluation, with particular regard to elastography: Review of literature

“…Pedersen et al also discovered a correlation between SWE and MRI-DWI values, meaning that within stiff lesions a higher impediment to water molecules diffusion is present. 53 Marcon et al found that stiffness of focal testicular lesions is increased in comparison with normal parenchyma both at SWE and VTIQ, with the values of the latter being higher than the ones of the former, because of technical differences between the two methods. 55 Some authors made further research trying to discriminate benign from malignant lesions using SE; they had good feedbacks although controversial.…”