EVALUATION OF THE SUBFERTILE MALE: PART 4 - IMAGING STUDIES

In the comprehensive evaluation of male fertility, imaging studies play an important role in identifying structural issues that may impact reproductive health. This is the fourth in our series of blogs on the evaluation of the subfertile male. In this blog, I will cover the key imaging modalities used in assessing the scrotum, prostate, and, in some cases, the upper urinary tract. We’ll discuss when and why these studies are used, their advantages, and the insights they provide. Together with blood tests and semen analysis, imaging studies offer a comprehensive picture of male fertility health and can help identify potential issues needing further treatment or intervention.

Scrotal Imaging

Scrotal imaging is often the first imaging study performed in men with fertility concerns. The scrotum houses the testicles, epididymis, and other structures critical for sperm production and transport, so assessing scrotal anatomy is essential.

• Purpose: Scrotal imaging is used to examine the testicles, epididymis, and surrounding structures for abnormalities such as varicoceles (enlarged veins in the scrotum), hydroceles (fluid-filled sacs around the testicle), cysts, or testicular masses.
• Indications: Scrotal imaging is recommended when there are concerns about structural abnormalities (e.g., palpable masses, testicular pain, or swelling) or when initial semen analysis results indicate potential sperm transport or production issues.
• Preferred Modality: Ultrasound is the first-line choice for scrotal imaging. It provides high-resolution images without radiation, is cost-effective, and is widely accessible. Using spectral Doppler and elastography, testis function can also be evaluated.
• Additional Modalities: MRI may be used in rare cases where ultrasound findings are unclear, or when more detailed imaging is required, especially for assessing the extent of a mass or other specific findings.

Prostate Imaging

The prostate gland plays an important role in male fertility by contributing fluids to semen that help nourish and transport sperm. Imaging of the prostate can reveal structural or functional issues that may affect sperm quality and fertility.

• Purpose: Prostate imaging assesses the size, shape, and structure of the prostate gland. It is particularly useful for identifying benign prostatic hyperplasia (enlargement of the prostate), prostatitis (inflammation), prostatic abscess, cysts, ejaculatory duct obstruction, or other anatomical concerns that might impact fertility.
• Indications: Prostate imaging may be indicated if a man has symptoms suggestive of prostatitis or other prostate issues (e.g., pain, difficulty with urination), especially if semen analysis suggests potential issues with sperm motility or other parameters affected by prostate function.
• Preferred Modality: Transrectal ultrasound (TRUS) is typically the first choice for prostate imaging. TRUS provides detailed images of the prostate and nearby structures with minimal discomfort and no radiation.
• Additional Modalities: In cases where more detailed imaging is required, such as detecting prostate lesions or assessing inflammation, MRI can be used. MRI offers greater detail for soft tissues but is generally reserved for situations where TRUS findings are inconclusive.

Upper Tract Imaging

In certain cases, imaging of the upper urinary tract, including the kidneys and ureters, may be recommended. While less commonly needed in routine fertility evaluation, upper tract imaging can reveal abnormalities that may indirectly impact fertility or indicate congenital or acquired conditions affecting reproductive health.

• Purpose: Upper tract imaging assesses the kidneys, ureters, and bladder. It is typically used to identify structural abnormalities such as congenital blockages, kidney cysts, or obstructions.
• Indications: Upper tract imaging may be warranted if there is a history of recurrent urinary tract infections, kidney disease, bilateral varicocele or a large right varicocele, or anatomical abnormalities detected through physical examination or other tests.
• Preferred Modality: Ultrasound is often the first choice, as it’s non-invasive and provides sufficient detail for many common issues.
• Additional Modalities: If ultrasound findings are unclear or if there is a suspicion of more complex abnormalities, a CT scan or MRI may be used. CT provides excellent detail for structures like the ureters and kidneys but involves radiation, so it is generally reserved for more specific diagnostic needs.

Imaging Modalities: Ultrasound, MRI, and CT

• Ultrasound: Ultrasound is the preferred first-line imaging modality in male fertility evaluation due to its accessibility, non-invasive nature, affordability, and lack of radiation. It provides high-quality images for examining the scrotum, prostate, and even the upper tract in many cases.
• MRI (Magnetic Resonance Imaging): MRI is used for its superior soft-tissue contrast, which is helpful when detailed images are required. MRI is often reserved for cases with complex or inconclusive ultrasound findings.
• CT Scan (Computed Tomography): CT is typically used only when upper tract imaging is required, or when there are concerns about specific structural abnormalities not well-visualized on ultrasound or MRI. However, CT is avoided in routine fertility assessment due to radiation exposure.

Comprehensive Fertility Assessment

When blood testing, semen analysis, and imaging studies are combined, healthcare providers can gain a comprehensive understanding of the male partner’s reproductive health. Blood tests reveal hormone levels and metabolic health, semen analysis assesses the quality and functionality of sperm, and imaging studies identify structural issues that may contribute to subfertility. Together, these assessments provide a thorough view of male fertility, helping doctors develop individualized treatment plans.

In some cases, further evaluation, such as a testis biopsy, may be necessary to reach a definitive diagnosis, especially when blood tests, semen analysis, and imaging are inconclusive.

Causes of Male Infertility and Imaging Approaches

Here is a chart summarizing the imaging diagnostic approaches used to identify various causes of male infertility. This chart highlights how each diagnostic tool contributes to uncovering the various factors that may impact male fertility.

Conclusion

In evaluating male fertility, each component—blood testing, semen analysis, and imaging—plays a crucial role. Imaging studies, particularly through ultrasound, help detect structural issues in the scrotum, prostate, and upper urinary tract that may affect reproductive health. By integrating these assessments, physicians gain a comprehensive view of potential fertility barriers and can recommend targeted, effective treatment strategies. For some patients, additional steps like a testis biopsy may be required to confirm findings and guide treatment. This multi-faceted approach gives patients and providers the best chance of identifying and addressing the underlying causes of subfertility, helping couples on their path to conception.