Scrotal disorders: evaluation of testicular enhancement patterns at dynamic contrast-enhanced subtraction MR imaging

Functional Imaging of Testicular Torsion

This article discusses the current clinical role and scope of functional radionuclide imaging using testicular perfusion scintigraphy with 99mTc-pertechnetate in patients presenting with an acute hemiscrotum for an early and reliable diagnosis of testicular torsion. The technique of testicular perfusion scintigraphy is described, and the characteristic findings are detailed with examples. The imaging characteristics of the various phases of testicular torsion and its differentiation from epididymitis and/or epididymo-orchitis and the other related conditions presenting as an acute hemiscrotum are detailed. In some cases, further evaluation by SPECT imaging increases the clarity and accuracy of diagnosis and, on occasion, hybrid SPECT/CT in selected complicated cases improves the diagnostic yield of the perfusion scintigraphy. Ultrasonographic and color Doppler findings are described concurrently with the scintigraphic findings. The several case examples presented demonstrate the additional clinical benefit of complementing functional and structural imaging for improving the sensitivity, specificity and accuracy of testicular imaging in the diagnosis.

Dynamic contrast-enhanced MRI in the assessment of testicular perfusion in infertile men with clinical varicocele

BACKGROUND

Varicocele represents the most common correctable cause of male infertility. The presence of non-invasive imaging parameters providing evidence as to which patients with varicocele are at risk for infertility would be important.

PURPOSE

To explore the role of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) using semi-quantitative parameters in the assessment of testicular perfusion in infertile men with clinical varicocele.

MATERIAL AND METHODS

The study cohort included 11 infertile men with clinical varicocele and six controls, with prior paternity. Subtraction DCE-MRI was performed after gadolinium administration, using a three-dimensional fast field-echo sequence. Time-signal intensity curves were created and semi-quantitative parameters were calculated. The independent samples t-test was used to compare basic T1 perfusion parameters between infertile testes with clinical varicocele and normal testes. Logistic regression analysis was performed to assess the most significant predictor of the diagnosis of clinical varicocele.

RESULTS

Both testes with clinical varicocele and normal testes enhanced moderately and homogeneously, with a linear increase of enhancement throughout the examination. Higher mean values of maximum enhancement (P = 0.026), maximum relative enhancement (P = 0.024), and wash-in rate (P = 0.013) were detected in the testes of infertile men with clinical varicocele, compared to the normal population. The wash-in rate proved the most significant predictor of the diagnosis of clinical varicocele (P = 0.013).

CONCLUSION

DCE-MRI may provide a valuable insight into the testicular perfusion of infertile men with clinical varicocele. The wash-in rate proved a strong and independent predictor of the diagnosis of clinical varicocele.

An Overview of the Role of Multiparametric MRI in the Investigation of Testicular Tumors

Simple Summary

Although conventional ultrasonography remains the primary imaging modality for the assessment of testicular tumors, multiparametric MRI of the scrotum, which combines morphologic and functional data, serves as a powerful adjunct. Based on the recommendations issued by the Scrotal and Penile Imaging Working Group of the European Society of Urogenital Radiology, scrotal MRI is strongly recommended after equivocal US findings. In cases of testicular masses, the main clinical indications are as follows: lesion characterization when sonographic findings are non-diagnostic, discrimination between germ-cell and non-germ-cell testicular tumors, local staging of testicular tumors in patients who are candidates for testis-sparing surgery, and preoperative histological characterization of testicular germ-cell tumors in selected cases. This article aims to provide an overview of the role of multiparametric MRI in the investigation of testicular tumors.

Abstract

Conventional ultrasonography represents the mainstay of testis imaging. In cases in which ultrasonography is inconclusive, scrotal MRI using a multiparametric protocol may be used as a useful problem-solving tool. MRI of the scrotum is primarily recommended for differentiating between benign and malignant testicular masses when sonographic findings are ambiguous. This technique is also accurate in the preoperative local staging of testicular tumors and, therefore, is recommended in patients scheduled for testis-sparing surgery. In addition, MRI may provide valuable information regarding the histological characterization of testicular germ-cell tumors, in selected cases. Scrotal MRI may also help in the differentiation between testicular germ-cell neoplasms and non-germ-cell neoplasms. Axial T1-weighted imaging, axial and coronal T2-weighted imaging, axial diffusion-weighted imaging, and coronal subtracted dynamic contrast-enhanced imaging are the minimum requirements for scrotal MRI. A variety of MRI techniques—including diffusion tensor imaging, magnetization transfer imaging, proton MR spectroscopy, volumetric apparent diffusion coefficient histogram analysis, and MRI-based radiomics—are being investigated for testicular mass characterization, providing valuable supplementary diagnostic information. In the present review, we aim to discuss clinical indications for scrotal MRI in cases of testicular tumors, along with MRI findings of common testicular malignancies.

Leydig Cell Tumors of the Testis: An Update of the Imaging Characteristics of a Not So Rare Lesion

Simple Summary

Stromal tumors of the testis are rare. However, among this group, Leydig cell tumors (LCT) are the most frequent, and recent studies suggest that LCTs account for up to 22% of small testicular nodules. It is now accepted that small LCTs can benefit from testis-sparing surgery or in some selected cases radiological surveillance. Since percutaneous testicular biopsy is still not recommended, the diagnosis of LCT rests on multimodal imaging techniques. Therefore, it is essential for the radiologist and the urologist to know the main imaging features of LCTs in ultrasound and MRI.

Abstract

Pre-operative testicular tumor characterization is a challenge for radiologists and urologists. New data concerning imaging approaches or immunochemistry markers improve the management of patients presenting with a testicular tumor, sometimes avoiding radical orchiectomy. In the past 20 years, imaging modalities, especially ultrasound (US) and magnetic resonance imaging (MRI), improved, allowing for great progress in lesion characterization. Leydig cell tumors (LCT) are rare testicular tumors developing from the stromal tissue, with relatively scarce literature, as most of the studies focus on the much more frequent germ cell tumors. However, with the increase in testicular sonography numbers, the incidence of LCT appears much higher than expected, with some studies reporting up to 22% of small testicular nodules. Multimodal ultrasound using Doppler, Elastography, or injection of contrast media can provide crucial arguments to differentiate LCT from germ cell tumors. Multiparametric MRI is a second intention exam, but it allows for extraction of quantifiable data to assess the diagnosis of LCT. The aims of this article are to review the latest data regarding LCT imaging features, using multimodal ultrasound and multiparametric MRI, and to focus on the peculiar aspect of the testis of patients with Klinefelter’s syndrome. The possibility of an LCT should be raised in front of a small hypoechoic tumor with a marked corbelling hypervascularization in an otherwise normal testicular pulp. Ultrasonographic modules, such as ultrasensitive Doppler, contrast-enhanced ultrasonography, or elastography, can be used to reinforce the suspicion of LCT. MRI provides objective data regarding vascularization and enhancement kinetics.

The utility of diffusion-weighted imaging and ADC values in the characterization of mumps orchitis and seminoma

BACKGROUND

Diffusion-weighted imaging (DWI) can quantitatively reflect the diffusion characteristics of tissues, providing a theoretical basis for qualitative diagnosis and quantitative analysis of a disease.

PURPOSE

To characterize testicular lesions that present as a hypointense signal on magnetic resonance imaging (MRI) T2-weighted images using DWI.

MATERIAL AND METHODS

Study participants were divided into three groups. Group A were healthy controls (n = 35), group B included patients with mumps orchitis (n = 20), and group C included patients with seminoma (n = 15). DWI sequences used b-values of 0, 1000, and 2000 s/mm². Apparent diffusion coefficient (ADC) values between 1000 and 2000 s/mm² were calculated by MRI postprocessing software. The Kruskal-Wallis test and receiver operating characteristic analysis were performed to evaluate how well ADC values distinguished between mumps orchitis and seminoma.

RESULTS

Normal testicular tissue showed a hyperintense signal on DWI and hypointensity on the ADC map: mean ADC value was 0.77 (0.69-0.85) ± 0.08 ×10^-3 mm²/s. Mumps orchitis and seminoma showed slight hyperintensity on DWI: mean ADC values were 0.85 (0.71-0.99) ± 0.15 ×10^-3 mm²/s and 0.43 (0.39-0.47) ± 0.04 × 10^-3 mm²/s, respectively. There were statistically significant differences in mean ADC values between normal testicular tissue and seminoma and between mumps orchitis and seminoma. The cutoff ADC value for differentiating seminoma from mumps orchitis was 0.54 × 10^-3 mm²/s. The sensitivity, specificity, and Youden Index for diagnosing seminoma were 99%, 31%, and 30%, respectively.

CONCLUSION

High b-value DWI has potential utility for differentiating mumps orchitis from seminoma in the clinical setting.

Identifying the deceiver: the non-neoplastic mimickers of genital system neoplasms

Tumors of the genital system are common and imaging is of crucial importance for their detection and diagnosis. Several non-neoplastic diseases may mimic these tumors and differential diagnosis may be difficult in certain cases. Misdiagnosing non-neoplastic diseases as tumor may prompt unnecessary medical treatment or surgical interventions. In this article, we aimed to present the imaging characteristics of non-neoplastic diseases of the male and female genital systems that may mimic neoplastic processes. Increasing awareness of the imaging specialists to these entities may have a severe positive impact on the management of these patients.

When to ask for an MRI of the scrotum

Background

Multiparametric MRI (mpMRI) of the scrotum has been established as a useful second‐line diagnostic tool for the investigation of scrotal diseases. Recently, recommendations on clinical indications for scrotal MRI were issued by the Scrotal and Penile Imaging Working Group of the European Society of Urogenital Radiology.

Objective

To update current research on when to ask for an MRI of the scrotum.

Methods

PubMed database was searched for original articles and reviews published during 2010–2021.

Results

Eighty‐three articles fulfilled the search criteria. Scrotal MRI is mainly recommended after inconclusive US findings or inconsistent with the clinical examination and should be asked in the following cases: differentiation between intratesticular and paratesticular lesions (in rare cases of uncertain US findings), characterization of paratesticular and intratesticular lesions (when US findings are indeterminate), discrimination between germ cell and sex cord‐stromal testicular tumors, local staging of testicular malignancies (in patients planned for testis‐sparing surgery), differentiation between seminomas and non‐seminomatous tumors (when immediate chemotherapy is planned and orchiectomy is delayed), assessment of acute scrotum and scrotal trauma (rarely needed, in cases of non‐diagnostic US findings) and detection and localization of undescended testes (in cases of inconlusive US findings). Although preliminary data show promising results in the evaluation of male infertility, no established role for mpMRI still exists.

Conclusion

Multiparametric MRI of the scrotum, by assessing morphologic and functional data represents a valuable problem‐solving tool, helping to improve our understanding on the nature of scrotal pathology and the process of spermatogenesis. The technique may improve patient care and reduce the number of unnecessary surgical procedures.

Diagnostic performance of multi-parametric MRI to differentiate benign sex cord stromal tumors from malignant (non-stromal and stromal) testicular neoplasms

PURPOSE

Testicular stromal tumors are uncommon, although mostly benign. The purpose of this study is to assess the role of multi-parametric MRI in differentiating benign testicular stromal tumors from malignant testicular neoplasms (non-stromal and stromal).

METHODS

A single-center retrospective study comparing benign stromal tumors (STs) to malignant testicular neoplasms (MTNs) was conducted. MR imaging assessment included tumor size, T2- and T1-weighted signal intensity, T2- and T1-weighted texture pattern, diffusion restriction, presence of hemorrhage and/or necrosis, and measurement of apparent diffusion coefficient and dynamic contrast enhancement (DCE). Inter-observer agreement was assessed using Cohen's kappa and Bland-Altman and data were compared using independent t-tests or χ². Receiver operating characteristic curve analysis was used to test models incorporating various imaging features.

RESULTS

Radical orchiectomy and histopathology revealed 20 testicular neoplasms: seven STs (35%) and thirteen MTNs (65%). MTNs were significantly larger in size than STs (5.1 ± 2.36 cm vs. 1.27 ± 0.56 cm; p-value < 0.001). STs demonstrated more hypointense T2W signal (85.7% vs. 46.2%; p-value < 0.09), less T2W heterogeneous texture (14.3% vs. 61.5%; p-value < 0.04), and less diffusion restriction (16.7% vs. 83.3%; p-value < 0.01) in comparison to MTNs. STs demonstrated mainly homogenous post-contrast enhancement pattern (71.4% vs. 7.7%; p-value < 0.004), while MTNs showed primarily heterogeneous enhancement pattern (77% vs. 14.3%; p-value < 0.02). STs revealed greater corrected venous phase enhancement (STs: 0.59 ± 0.29; MTNs: 0.25 ± 0.25; p-value < 0.03). STs showed higher ADC values, though the difference was not statistically significant (p-value < 0.25). A model combining T2W, DWI, and DCE features showed the best overall diagnostic accuracy with area under ROC curve of 0.99 and confidence interval ranging from 0.94 to 1.

CONCLUSION

Multi-parametric MRI can potentially differentiate benign stromal tumors from malignant testicular neoplasms, which can help to avoid radical orchiectomy. However, future studies using larger sample sizes are needed to validate our results.

Use of diffusion-weighted imaging in the noninvasive diagnostic of obstructed biliary ducts

OBJECTIVE

This study sought to evaluate the role of diffusion-weighted imaging (DWI) in differentiation between obstructed and unobstructed bile ducts in patients undergoing magnetic resonance imaging (MRI).

METHODS

Eighty-four patients, 40 males and 44 females (mean age: 56.4 ± 15.1 years), undergoing MRI with DWI (0-50-500-700) were evaluated and divided into two groups: 58 with abnormal laboratory tests (obstructed group) and 26 with normal laboratory values (unobstructed group). Laboratory tests were total bilirubin, alkaline phosphatase, and gamma-glutamyltransferase. Median ADC values were calculated and correlated with laboratory tests and degree of bile-duct dilatation (absent, moderate, or severe). The persistence of signal on DWI (b500 and b700) in the biliary tract was evaluated. Bilirubin values were tested for correlation with bile-duct ADC values and persistence of b700 signal. For statistical analysis, Student t test, chi-square test and Wilcoxon-Mann-Whitney test were used. ADC maps were plotted for three levels of the biliary tree, and a receiver operating characteristic (ROC) curve was calculated.

RESULTS

In the obstructed group, 15 patients had severe dilatation, 24 had moderate dilatation, and 19 had no appreciable dilatation; 38 patients had persistent signal on b700 images. In the unobstructed group, 23 patients had no dilatation and 3 had moderate dilatation; 4 patients had persistent signal on b700 images. Correlation was found between degree of bile-duct dilatation, bilirubin levels, persistence of b700 signal, and ADC map values. The calculated ADC map cutoff value (353 10^-6 mm²/s) was able to differentiate the obstructed and unobstructed groups with 92.3% sensitivity, 81% specificity, and 91.9% accuracy.

CONCLUSIONS

DWI is able to distinguish patients with obstructed versus unobstructed bile ducts, regardless of the degree of dilatation, correlating with clinical and laboratory findings.

MRI of testicular malignancies

Although testicular carcinoma represents approximately only 1% of solid neoplasms in men, it is the most common malignancy between young men. The two main histologic categories are testicular germ cell tumors (TGCTs), including seminomas and nonseminomas, accounting for 90-95% of testicular neoplasms and sex cord-stromal tumors. Scrotal MRI, including a multiparametric protocol, has been proposed as a valuable supplemental imaging technique in the investigation of testicular pathology. Recently, the Scrotal and Penile Imaging Working Group appointed by the board of the European Society of Urogenital Radiology has produced recommendations on when to perform scrotal MRI. Regarding intratesticular masses, MRI of the scrotum may be used for their characterization, when US findings are indeterminate and for local staging of TGCTs, when organ-sparing surgery is planned. Differentiation between seminomas and nonseminomas is possible based on MRI features, when clinically needed. Scrotal MRI may also help in differentiating between TGCTs and nongerm cell tumors. Functional information based on diffusion-weighted imaging and dynamic contrast-enhanced MRI data improve testicular mass lesion characterization. Preliminary observations on diffusion tensor imaging, magnetization transfer imaging, and proton MR spectroscopy bring about new data in the understanding of testicular microstructure and pathophysiology.

Sonographically indeterminate scrotal masses: how MRI helps in characterization

Magnetic resonance imaging (MRI) of the scrotum represents a useful supplemental imaging technique in the characterization of scrotal masses, particularly recommended in cases of nondiagnostic ultrasonographic findings. An accurate characterization of the benign nature of scrotal masses, including both intratesticular and paratesticular ones may improve patient management and decrease the number of unnecessary radical surgical procedures. Alternative treatment strategies, including follow-up, lesion biopsy, tumor enucleation, or organ sparing surgery may be recommended. The aim of this pictorial review is to present how MRI helps in the characterization of sonographically indeterminate scrotal masses and to emphasize the key MRI features of benign scrotal masses.

Management of testicular Leydig cell tumor: A case report

RATIONALE

Testicular Leydig cell tumor (LCT) is a rare neoplasm. It commonly presents as a painless testicular mass with or without endocrine changes. Histological and immunohistochemical examination play important roles in differentiating LCT from testicular germ cell tumors.

PATIENT CONCERNS

We highlight the imaging phenotype, as well as the pathological findings of a case of LCT in a 62-year-old male.

DIAGNOSES

Preoperative noncontrast CT scan of the abdomen revealed a 7.0 × 6.4 × 5.3 cm oval mass with heterogeneous density, located in the right testis. Pelvic noncontrast MRI showed a heterogeneous mass on T1-weighted and T2-weighted images. The solid part of the tumor exhibited high signal on the diffusion-weighted imaging, and an obvious enhancement on the contrast-enhanced MR imaging. Ultrasonography examination demonstrated a large mixed echogenic space occupying lesion involving the whole right testis with multiple cystic areas and increased vascularity. This patient underwent radical orchiectomy. The pathologic diagnosis was LCT.

INTERVENTIONS

This patient underwent operative resection of the tumor. Due to the negative resection margins and absence of distant metastases, the patient did not receive additional radiotherapy or chemotherapy.

OUTCOMES

Four months after the surgery, the follow-up CT-scan did not reveal any local recurrence and distant metastases.

LESSONS

This case improves our ability to detect and diagnose LCT by summarizing its imaging characteristics as well as reviewing the literature. Additionally, we described the state-of-the-art management of the management of this rare tumor.

Normal testes asymmetry evaluated by apparent diffusion coefficient and magnetization transfer ratio

Background In humans, the left testis generally hangs lower than the right and the right is larger than the left. Magnetic resonance imaging (MRI) represents an important adjuvant modality in the investigation of testicular diseases. Purpose To assess if normal testes asymmetry is related to apparent diffusion coefficient (ADC) and magnetization transfer ratio (MTR). Material and Methods The normal testes from 106 men were included. Testicular volume (TV) was calculated by using the ellipsoid formula: length × width × height × 0.52. Diffusion-weighted imaging was performed using a SS EPI diffusion pulse sequence and b-values of 0 and 900 s/mm^-2. Magnetization transfer imaging was obtained using a 3D GRE sequence both with and without an off-resonance radiofrequency pulse. MTR maps were obtained by the following formula: (SIo-SIm) / (SIo) × 100%, where SIo and SIm represent the signal intensity in the baseline image and that in the corresponding image acquired with an off-resonance MT pulse, respectively. The mean and standard deviation of testicular volume (TV), ADC, and MTR of both testes was calculated and compared using a paired sample t-test. Results The mean TV (mL) was greater ( P = 0.006) for the right testis (16.77 ± 4.84) compared to the left (15.97 ± 4.45). ADC of the right testis (1.09 ± 0.12 × 10 ^- 3mm²s^-1) was not different ( P = 0.064) from that of the left testis (1.07 ± 0.12 × 10^-3mm²s^-1). Differences ( P = 0.032) were observed between MTR of the right (46.6 ± 2.1%) and left testis (46.0 ± 2.2%). Conclusion The reported differences in paired testes size was confirmed, introducing a possible relationship with structural and functional asymmetry of normal testes, based on MTR.

Potential role of imaging in assessing harmful effects on spermatogenesis in adult testes with varicocele

Varicocele is characterized by an abnormal dilatation and retrograde blood flow in the spermatic veins. Varicocele is the leading correctable cause of male infertility. Although it is highly prevalent in infertile men, it is also observed in individuals with normal fertility. Determining which men are negatively affected by varicocele would enable clinicians to better select those men who will benefit from treatment. To assess the functional status of the testes in men with varicocele, color Doppler sonographic parameters were evaluated. Testicular arterial blood flow was significantly reduced in men with varicocele, reflecting an impairment of spermatogenesis. An improvement in the testicular blood supply was found after varicocelectomy on spectral Doppler analysis. Testicular contrast harmonic imaging and elastography might improve our knowledge about the influence of varicocele on intratesticular microcirculation and tissue stiffness, respectively, providing possible information on the early damage of testicular structure by varicocele. Magnetic resonance imaging (MRI), with measurement of apparent diffusion coefficient has been used to assess the degree of testicular dysfunction and to evaluate the effectiveness of varicocele repair. Large prospective studies are needed to validate the possible role of functional sonography and MRI in the assessment of early defects of spermatogenesis in testes with varicocele.

Review of paratesticular pathology: findings on ultrasound and MRI

The paratesticular scrotal contents consist of the spermatic cord, epididymis, and fascia, which originate from the embryologic descent of the testis through the abdominal wall. Historically, the primary diagnostic modality has been high-resolution ultrasound. Magnetic resonance imaging (MRI) is an alternative imaging option. Both contrast MRI and diffusion weighted imaging can assist in differentiating between benign and malignant lesions. Unlike the testis which most disease processes are malignant, a wide spectrum of benign disease processes affects the paratesticular region either in isolation or as part of a contiguous disease process from adjacent organs. The familiarity with the epidemiology, pathogenesis, and imaging features can aid the radiologic diagnoses and guide appropriate clinical management. In this article, we review the ultrasound and MR characteristics of various paratesticular pathologies.

Role of diffusion weighted magnetic resonance imaging in a rat model of testicular torsion

OBJECTIVE

The purpose of this study was to investigate the usefulness of diffusion-weighted imaging (DWI) in the detection of different degrees of testicular torsion (TT) at the 8th hour and testicular salvageability at the 24th hour of torsion.

METHODS

31 rats were randomly classified into 4 groups. In Group 1 (sham-control group), the left testicle was kept outside and replaced. Left testicles were kept outside and twisted 360° in Group 2, 720° in Group 3 and 1080° in Group 4. Later, DWI was performed at 8th and 24th hours. After DWI, bilateral radical orchiectomy and histopathological examination were performed. Apparent diffusion coefficient (ADC) maps were obtained with b-factors of 0 and 800 s mm^-2. Comparisons of ADC values and damage in testicles were performed with Kruskal-Wallis test.

RESULTS

Sensitivity of DWI in the diagnosis of TT was 12.5% for 360° torsion, 100% for 720° torsion and 1080° torsion at the 8th hour of torsion. Mean ADC values of the left testicles increased significantly at the 24th hour of torsion in Groups 3 and 4. All testicles in Groups 3 and 4 were observed to be irrecoverable on histopathological examination.

CONCLUSION

Increased ADC values in the affected testicle may represent irreversible tissue damage. So, immediate surgery is not required at this stage, which may reduce morbidity and mortality caused by immediate surgery and anaesthesia. Advances in knowledge: TT can be diagnosed easily by DWI without administrating any contrast material. DWI findings in the affected testicle may represent testicular salvageability.

Role of Strain Elastography in the Evaluation of Testicular Torsion: An Experimental Study

OBJECTIVES

To evaluate the utility of real-time strain elastography in experimentally induced testicular torsion at different degrees and torsion hours.

METHODS

Thirty-one Wistar albino rats were divided into 4 torsion groups by twisting left testes (group I, sham operated; group II, 360°; group III, 720°; and group IV, 1080°). Elastography was applied at the 8th and 24th hours of torsion. Elasticity patterns (pattern 1, soft testis; pattern 2, moderately soft testis; pattern 3, predominantly hard testis; and pattern 4, almost entirely hard testis) and strain ratios were recorded. Histopathologic evaluation was done at the 24th hour. Interobserver agreement was analyzed.

RESULTS

Changes in elastographic patterns and strain ratios among groups II, III, and IV were statistically significant at both hours as determined by both radiologists (P < .01). Elastographic patterns changed from 2 to 3 in groups II and III to 4 in group III between the 8th and 24th hours (P < .05), but in group IV, patterns were reversed, and pattern 1 was observed at both hours. Pathologically severe necrosis (grade 4) was seen in left testes in group IV. In the other groups, pathologic grading in the left testes was as follows: mostly grade 1 in groups I and II and mostly grade 2 in group III. Elastography showed that right testes were affected in group IV, with significant differences in elastographic patterns and strain ratios (P < .01). Interobserver agreement for elastographic patterns in right testes was substantial at the 8th hour (κ = 0.72) and otherwise excellent (κ = 0.81-0.85). Concordance of strain ratios between observers was excellent for right and left testes at the 8th and 24th hours (intraclass correlation coefficients, 0.990 at the 8th hour and 0.987 at the 24th hour).

CONCLUSIONS

Our results show that real-time strain elastography can be a complementary method in the evaluation of testicular tissue in testicular torsion and can guide surgeons in their surgical approach.

Magnetic resonance imaging findings of cellular angiofibroma of the tunica vaginalis of the testis: a case report

Background

Cellular angiofibroma represents a rare mesenchymal tumor typically involving the inguinoscrotal area in middle-aged men. Although the origin of this benign tumor is unknown, it is histologically classified as an angiomyxoid tumor. Cellular angiofibroma is characterized by a diversity of pathological and imaging features. An accurate preoperative diagnosis is challenging. Magnetic resonance imaging examination of the scrotum has been reported as a valuable adjunct modality in the investigation of scrotal pathology. The technique by providing both structural and functional information is useful in the differentiation between extratesticular and intratesticular diseases and in the preoperative characterization of the histologic nature of various scrotal lesions. There are few reports in the English literature addressing the magnetic resonance imaging findings of cellular angiofibroma of the scrotum and no reports on functional magnetic resonance imaging data. Here we present the first case of a cellular angiofibroma arising from the tunica vaginalis of the testis and we discuss the value of a multiparametric magnetic resonance protocol, including diffusion-weighted imaging, magnetization transfer imaging and dynamic contrast-enhanced magnetic resonance imaging in the preoperative diagnosis of this rare neoplasm.

Case presentation

A 47-year Greek man presented with a painless left scrotal swelling, which had gradually enlarged during the last 6 months. Magnetic resonance imaging of his scrotum displayed a left paratesticular mass, in close proximity to the tunica vaginalis, with heterogeneous high signal intensity on T2-weighted images and no areas of restricted diffusion. The tumor was hypointense on magnetization transfer images, suggestive for the presence of macromolecules. On dynamic contrast-enhanced magnetic resonance imaging the mass showed intense heterogeneous enhancement with a type II curve. Magnetic resonance imaging findings were strongly suggestive of a benign paratesticular tumor, which was confirmed on pathology following lesion excision.

Conclusions

Magnetic resonance imaging of the scrotum by combining conventional and functional magnetic resonance data provides useful diagnostic information in the preoperative characterization of scrotal masses. A possible diagnosis of a benign paratesticular tumor based on magnetic resonance imaging features may improve patient care and decrease the number of unnecessary radical surgical explorations.

Value of dynamic, contrast-enhanced MRI & intraoperative ultrasound for management of a nonpalpable, incidental, testicular Leydig-cell tumor

We report a case of a small, intratesticular, incidentally identified, nonpalpable Leydig-cell tumor in which preoperative, dynamic, contrast-enhanced MRI was essential in characterizing the lesion as a neoplasm. Sonographic evaluation failed to demonstrate internal color Doppler flow, resulting in a differential diagnosis that included debris-filled cyst. At surgical resection, intraoperative ultrasound was essential to locate the mass and confirm complete removal. This case highlights the value of dynamic, contrast-enhanced MRI and intraoperative ultrasound for the management of incidental intratesticular lesions with indeterminate sonographic and Doppler characterization. Radiologists and urologists should be familiar with this approach to the incidental, sonographically indeterminate, nonpalpable intratesticular lesion identified on scrotal ultrasound.

MR Spectra of Normal Adult Testes and Variations with Age: Preliminary Observations

OBJECTIVES

The aim was to determine the proton MR (1H-MR) spectra of normal adult testes and variations with age.

METHODS

Forty-one MR spectra of normal testes, including 16 testes from men aged 20-39 years (group I) and 25 testes from men aged 40-69 years (group II), were analyzed. A single-voxel point-resolved spectroscopy sequence (PRESS), with TR/TE: 2000/25 ms was used. The volume of interest was placed to include the majority of normal testicular parenchyma. Association between normalized metabolite concentrations, defined as ratios of the calculated metabolite concentrations relative to creatine concentration, and age was assessed.

RESULTS

Quantified metabolites of the spectra were choline (Cho), creatine (Cr), myo-inositol (mI), scyllo-inositol, taurine, lactate, GLx compound, glucose, lipids, and macromolecules resonating at 0.9 ppm (LM09), around 20 ppm (LM20), and at 13 ppm (LM13). Most prominent peaks were Cho, Cr, mI, and lipids. A weak negative correlation between mI and age (P = 0.015) was observed. Higher normalized concentrations of Cho (P = 0.03), mI (P = 0.08), and LM13 (P = 0.05) were found in group I than in group II.

CONCLUSIONS

1H-MR spectra of a normal adult testis showed several metabolite peaks. A decrease of levels of Cho, mI, and LM13 was observed with advancing age.

KEY POINTS

• Single-voxel PRESS MRS of a normal testis is feasible. • 1H-MR spectra of a normal testis showed several metabolite peaks. • Most prominent peaks were Cho, Cr, mI, and lipids. • A decrease of Cho, mI, and LM13 was seen with advancing age.

MR imaging of scrotum

Magnetic resonance (MR) imaging of the scrotum has been used as a valuable supplemental diagnostic modality in evaluating scrotal pathology, mostly recommended in cases of inconclusive sonographic findings. Because of the advantages of the technique, MR imaging of the scrotum may provide valuable information in the detection and characterization of various scrotal diseases. The technique may accurately differentiate intratesticular from extratesticular mass lesions and provide important information in the preoperative characterization of the histologic nature of scrotal masses. An accurate estimation of the local extent of testicular carcinomas in patients for whom testis-sparing surgery is planned is possible.

Dynamic contrast-enhanced subtraction MRI for characterizing intratesticular mass lesions

OBJECTIVE

The objective of our study was to analyze the enhancement patterns of various intratesticular mass lesions at dynamic contrast-enhanced subtraction MRI and assess the value of the technique in distinguishing between benign and malignant lesions.

MATERIALS AND METHODS

We retrospectively evaluated the records and images of 44 consecutive men (11 benign and 16 malignant intratesticular lesions) who presented to the department of urology with a variety of clinical symptoms and were referred for imaging. Dynamic contrast-enhanced subtraction MRI was performed using a 3D fast-field echo sequence after the administration of paramagnetic contrast medium. Patients were divided into three groups according to the final diagnosis: benign intratesticular lesions, malignant intratesticular lesions, and normal testes. The patterns of contrast enhancement of both the normal testes and the intratesticular lesions were evaluated. Time-signal intensity plots were created and classified according to shape: Type I presented a linear increase of contrast enhancement throughout the examination, type II showed an initial upstroke followed by either a plateau or a gradual increase in the late contrast-enhanced phase, and type III presented an initial upstroke followed by gradual washout of the contrast medium. The relative percentages of peak height, maximum time, and mean slope were also calculated.

RESULTS

Normal testes enhanced homogeneously with a type I curve. Most benign intratesticular lesions showed inhomogeneous or homogeneous contrast enhancement and a type II curve. Testicular carcinomas showed heterogeneous contrast enhancement with a type III curve. The relative percentages of maximum time to peak proved the most important discriminating factor in differentiating malignant from benign intratesticular masses (p < 0.001).

CONCLUSION

Dynamic contrast-enhanced MRI may be used to distinguish between benign and malignant intratesticular mass lesions.

Segmental testicular infarction: sonographic findings and pathologic correlation

Segmental testicular infarction can mimic testicular carcinoma on sonography and can lead to unnecessary orchiectomy. This case series describes and correlates sonographic and histologic findings of 7 pathologically proven segmental testicular infarction cases. Segmental testicular infarction should be suspected on sonography when a geographic lesion with low or mixed echogenicity has absent or near-absent flow in a patient with scrotal pain. A hyperechoic rim and peripheral hyperemia correspond to interstitial hemorrhage and inflammatory changes. As an infarct evolves, it becomes more discrete and hypoechoic as ghost outlines replace seminiferous tubules. Follow-up or contrast-enhanced magnetic resonance imaging or sonography can increase diagnostic confidence in suspected cases and prevent unnecessary orchiectomy.

Imaging of the scrotum

Ultrasonography is currently the imaging modality of choice when assessing scrotal lesions. Ultrasound findings are sometimes inconclusive, in which case magnetic resonance (MR) imaging might yield additional important information. This article reviews ultrasound and MR imaging features of various intratesticular and extratesticular lesions including acute and nonacute conditions of the scrotum. Nonneoplastic lesions that can mimic scrotal malignancy are discussed. Normal anatomy and imaging techniques are also presented.

The acute pediatric scrotum: presentation, differential diagnosis and management

Both pediatric and adult urologists frequently evaluate pediatric patients with an acute scrotum. We present a detailed review on the acute pediatric scrotum highlighting the clinical presentation, differential diagnosis and management of this common clinical condition. It is important to highlight that a testicular torsion is the most important differential diagnosis and the main priority in each case is to diagnosis and treat a potential testicular torsion is of the essence. The aim of our extensive review is to update/review the appropriate evaluation and management of the acute scrotum and to guide the clinician in distinguishing testicular torsion from the other conditions that commonly mimic this surgical emergency. This review is useful for trainees in UK and Europe who plan to take the FRCS (Urol) examination.

Unilateral testicular seminoma with simultaneous contralateral torsion: a case report

Introduction

Testicular germ cell tumors are the most common malignancies in men. Testicular torsion is also a scrotal phenomenon seen in adolescence and adulthood. The co-occurrence of these two scrotal disorders is extremely rare.

Case presentation

A 28-year-old East Asian man presented at our hospital with painless bilateral scrotal swelling. Both scrotal ultrasonography and computed tomography findings showed bilateral testicular tumors, and magnetic resonance imaging demonstrated a lack of enhancement in his right testis, indicating a hemorrhagic infarction and a left testicular tumor. After a bilateral orchiectomy, the intraoperative and histopathological findings revealed a left seminoma with a complicating contralateral testicular torsion that had developed with hemorrhagic infarction.

Conclusion

Testicular germ cell tumor with contralateral torsion is extremely rare. We could differentiate this case from bilateral testicular tumors appropriately using magnetic resonance imaging, and suggest that magnetic resonance imaging examination may be necessary to diagnose bilateral testicular masses.

The acute scrotum in childhood and adolescence

BACKGROUND

The acute scrotum in childhood or adolescence is a medical emergency. Inadequate evaluation and delays in diagnosis and treatment can result in irreversible harm, up to and including loss of a testis. Various diseases can produce this clinical picture. The testis is ischemic in only about 20% of cases.

METHODS

This review is based on a selective literature search, the existing clinical guideline, and the authors' experience.

RESULTS

The clinical approach to the acute scrotum must begin with a standardized, rapidly performed diagnostic evaluation. Dopper ultrasonography currently plays a central role. Its main use is to demonstrate the central arterial blood supply and venous drainage of the testis. The resistance index of the testicular vessels should also be determined.

CONCLUSION

Physical examination and properly performed Doppler ultrasonography enable adequate evaluation of the acute scrotum in childhood and adolescence. In the rare cases of diagnostic uncertainty, immediate surgical exposure of the testis remains the treatment of choice.

Real-time sonoelastography for the evaluation of testicular lesions

PURPOSE

To evaluate the feasibility of using real-time sonoelastography (RTE) for the differentiation and characterization of testicular lesions.

MATERIALS AND METHODS

Institutional review board approval was obtained for this retrospective study, and the requirement to obtain informed consent was waived. Fifty patients (mean age, 42 years; age range, 18-81 years) with testicular lesions detected with gray-scale ultrasonography (US) and color and/or power Doppler US were evaluated with RTE between December 2004 and August 2010 to assess tissue elasticity of the testes. Stiff or "hard" lesions were suspected of being malignant. Testicular lesions with normal or decreased tissue stiffness ("soft" lesions) were considered benign. Findings from surgery and histopathologic examination were used as the reference standard in 34 cases, and findings from clinical and US follow-up were used as the reference standard in 16 cases. Sensitivity, specificity, negative predictive value, positive predictive value, and diagnostic accuracy were calculated.

RESULTS

Thirty-four of the 50 lesions (68%) were testicular tumors and 16 (32%) were of nontumorous origin. RTE showed the presence of hard lesions in all cases of testicular tumors and three cases of nontumorous lesions. Four lesions with an uncertain diagnosis when tested with gray-scale US and color and/or power Doppler US alone were soft at RTE and showed nontumorous character at follow-up. RTE showed a sensitivity of 100%, a specificity of 81%, a negative predictive value of 100%, a positive predictive value of 92%, and an accuracy of 94% in the diagnosis of testicular tumors.

CONCLUSION

RTE demonstrated all testicular tumors as lesions with increased tissue stiffness. Because of its higher specificity, RTE can provide additional information in cases with indeterminate US findings.

Can radical orchiectomy be avoided for paratesticular adenomatoid tumor?

Paratesticular tumors are rare tumors that are difficult to diagnose preoperatively and therefore, many patients are subjected to inguinal orchiectomy. However, radical orchiectomy can be avoided as the diagnosis of paratesticular tumor can be made on the basis of clinical suspicion, findings of tumor markers and radiological tests.

Magnetic Resonance Imaging of Acute Scrotum

Background and Aims:

The aim of the pilot study was to evaluate the feasibility of dynamic contrast enhanced (CE)-magnetic resonance imaging (MRI) in the detection of testicular ischemia and its ability to differentiate testicle torsion from other causes of acute scrotum.

Material and Methods:

Seventeen boys or young men with an acute scrotum were included in the prospective study during the time period from October 2001 to December 2005. The median age of the patients was 16,4 (7–44) years. The duration of the symptoms preceding the MRI study varied from six hours to 30 days. The study protocol included physical examination by a surgeon, laboratory tests and Doppler ultrasound (DUS) and finally testicles were imaged by using a 1,5 T MRI scanner; T1-weighted and diffusion weighted images were produced. The gadolinium uptake, reported as the region of interest (ROI) perfusion values and presented as curves, was compared between the affected and contralateral testicle. In testicles with normal blood circulation the ROI values increased during the imaging time. Nine patients were operated on, because the spermatic cord torsion could not be excluded by clinical or DUS findings.

Results and Conclusions:

All the normal testicles gave increasing ROI values meanwhile all three testicles with torsion gave constantly low values referring to no perfusion. Other causes of acute scrotum, such as epididymitis and torsion of testicular appendage seemed to be related with normal perfusion. Dynamic CE-MRI seems to show reliably ischemia of testicle and thus it may be helpful in selecting patients with acute scrotum for urgent operation.

Role of contrast enhanced ultrasound in acute scrotal diseases

OBJECTIVE

To evaluate the efficacy of contrast-enhanced ultrasound (CEUS) in patients with acute scrotal pain not defined at ultrasound (US) with colour Doppler .

METHODS

CEUS was carried out in 50 patients with acute scrotal pain or scrotal trauma showing testicular lesion of undefined nature at US. The accuracy of US and CEUS findings versus definitive diagnosis (surgery or follow-up) was calculated.

RESULTS

Twenty-three patients had a final diagnosis of testicular tumour, three abscess, eight focal infarction, seven trauma, three testicular torsion, one haematoma. Five patients were negative. Thirty-five patients were operated (23 testicular tumours, six trauma, three testicular torsion, one abscess, one focal infarction, and one haematoma) and 15 underwent medical treatment or were discharged. US provided a definitive diagnosis in 34/50 as compared to the 48/50 patients diagnosed at CEUS. Sensitivity and specificity were 76% and 45% for US and 96% and 100% for CEUS respectively.

CONCLUSIONS

CEUS was more accurate in the final diagnosis compared to US, potentially reducing the need for further imaging. In particular CEUS can be proposed in emergency in cases where US diagnosis remains inconclusive, namely in infarction, and trauma, when testicular torsion cannot be ruled out, and in identifying testicular mass.

Imaging of the acute scrotum: is there a place for contrast-enhanced ultrasonography?

PURPOSE

To present and evaluate the findings of contrast-enhanced ultrasonography (CEUS) in typical cases of acute painful scrotum.

MATERIALS AND METHODS

Nineteen patients aged from 19 to 61 years old were included in the study. All patients underwent grey-scale and color Doppler ultrasonography (US) of the scrotum, followed by imaging after i.v. administration of 2.4 mL of a second generation ultrasound contrast agent (microbubbles of sulphur hexafluoride). ? dedicated, contrast-sensitive technique was used (Contrast Tissue Imaging - CnTI). The diagnosis was confirmed surgically in 6 cases while in the remaining 8 cases it was based on the combination of clinical, imaging and laboratory findings.

RESULTS

The final diagnosis was testicular torsion (n = 4), epididymitis (n = 2, one of the cases complicated by abscess), testicular abscess (n = 1), scrotal abscess (n = 1), testicular trauma of varying severity (n = 6). Five out of 19 cases were true negatives: neither clinical examination nor laboratory tests revealed any pathology. CEUS showed complete lack of enhancement in all cases of torsion, permitting a rapid and definitive diagnosis. In the cases of infection complicated by abscesses, CEUS delineated the lesions much better than the combination of B-mode/Color Doppler US. The severely traumatized testicles showed minimal, inhomogeneous or patchy enhancement, while cases of minor trauma showed no significant enhancement defects. Hematomas were presented as non-enhancing lesions.

CONCLUSION

Generally, there was no advantage over Doppler US as has been previously shown. However, CEUS can be used supplementary to traditional Doppler US in the investigation of blunt testicular trauma especially when there is uncertainty in diagnosis after appropriate clinical and radiographic evaluations occurs. Further studies are required to clearly define the indications of this method.

MR imaging of scrotal tumors and pseudotumors

Magnetic resonance (MR) imaging is an important imaging technique in the evaluation of scrotal masses, providing a useful adjunct to ultrasonography (US). Although US is the modality of choice for initial evaluation of scrotal pathologic conditions because of its wide availability, low cost, and high sensitivity for detection of testicular and paratesticular disease processes, US findings may occasionally be inconclusive. MR imaging may provide additional information in these cases, often affecting patient management. This article reviews and illustrates the MR imaging features of solid extratesticular and intratesticular benign and malignant scrotal tumors, as well as nonneoplastic lesions that can mimic neoplasia. Normal scrotal MR anatomic features and optimal MR imaging technique are also presented.

Adenomatoid tumor of testis

Adenomatoid tumors are responsible for 30% of all paratesticular masses. These are usually asymptomatic, slow growing masses. They are benign tumors comprising of cords and tubules of cuboidal to columnar cells with vacuolated cytoplasm and fibrous stroma. They are considered to be of mesothelial origin supported by histochemical studies and genetic analysis of Wilms tumor 1 gene expression. Excision biopsy is both diagnostic and therapeutic procedure. The main clinical consideration is accurate diagnosis preventing unnecessary orchiectomy. Diagnostic studies include serum tumor markers (negative alpha fetoprotein, beta HCG, LDH) ultrasonography (hypoechoic and homogenous appearance) and frozen section.

Diagnostic performance of three-dimensional ultrasound extended imaging at scrotal mass lesions

OBJECTIVES

High resolution two-dimensional ultrasound (2D US) difficulty in evaluation of some scrotal mass lesions is not frequent. The aim of the present study was to prospectively evaluate the diagnostic performance of three-dimensional ultrasound extended imaging (3D XI) in characterization of those lesions.

METHODS

The study protocol had the approval of the University's review board all participants' informed consents were obtained. The study included 28 selected patients (12 testicular and 16 para-testicular mass lesions) examined by 2D US and 3D XI applications including computed multi-slice view (MSV) and multi-resolution enhanced images (XI MR). Results were correlated with histopathological findings.

RESULTS

Two-dimensional ultrasound did not adequately characterize 28 patients out of 329 (8.5%). 3D XI interrogation was an easy procedure and distinctive of the pathological findings in 27 patients out of 28 (96.4%). The performance of XI MR with respect to characterization provided additional diagnostic information over MSV.

CONCLUSIONS

The performance of 3D XI with respect to testicular mass characterization proved better than static 2D US. Subsequently, the results of this study suggest that the routine use of 2D US in diagnosis of scrotal mass lesions should preferably be upgraded to 3D XI methods.

MR imaging of testicular torsion: features of testicular hemorrhagic necrosis and clinical outcomes

PURPOSE

To determine whether emergency subtraction dynamic contrast-enhanced MR imaging (DCE-MRI) in combination with T2- and T2*-weighted imaging of the testis is useful in the evaluation of patients with testicular torsion.

MATERIALS AND METHODS

Fourteen patients with surgically proven testicular torsion were examined using preoperative emergency MRI, including T2-weighted, T2*-weighted, and DCE-MRI. The affected testis was examined histologically in eight patients who underwent orchiectomy, and by postoperative follow-up MRI in six patients who underwent orchiopexy. The diagnostic criteria for testicular torsion and detection of hemorrhagic necrosis in the affected testis in emergency MRI were decreased or no perfusion in DCE-MRI and a spotty and/or streaky pattern of low or very low signal intensity in T2- and T2*-weighted images. The intraoperative findings and clinical outcomes were also compared.

RESULTS

The histological findings and follow-up MR images revealed total or partial necrosis of the affected testis in 10 of the 14 patients. In the diagnosis of complete torsion, the sensitivities were 100% for DCE-MRI and 75% for T2- and T2*-weighted imaging. In the detection of testicular necrosis, T2- and T2*-weighted imaging showed the highest accuracy (100%), followed by 12-hour time from onset (93%), intraoperative findings (79%), and DCE-MRI (71%).

CONCLUSION

Emergency MRI can help diagnose testicular torsion and detect testicular necrosis when DCE-MRI is used in combination with T2- and T2*-weighted images.