Imaging of acute scrotal infections, complications and mimics

Infection of the scrotum and its contents is the most common cause of acute scrotum. Imaging plays an important role in evaluating disease extent, severity and its complications. Sonography is the modality of choice for imaging the acute scrotum. This pictorial review discusses the varied clinical and imaging features of scrotal infections and their complications, with correlative CT, when available.

Point-of-care ultrasonography for the diagnosis and manual detorsion of testicular torsion

Testicular torsion is a urological emergency caused by the loss of testicular tissue due to ischemic damage. Rapid diagnosis and urgent treatment play a crucial role in the management of testicular torsion. Manual detorsion can be performed at the bedside, thereby reducing the duration of ischemia. Recent studies have reported the use of point-of-care ultrasonography for diagnosing testicular torsion; however, no review article has focused on the ultrasonographic findings pertaining to manual detorsion. This review describes the diagnosis of testicular torsion and the ultrasonographic indications for manual detorsion. Spermatic cord twisting or the whirlpool sign, absence of or decreased blood flow within the affected testis, abnormal testicular axis, abnormal echogenicity, and enlargement of the affected testis and epididymis due to ischemia are the sonographic findings associated with testicular torsion. The following findings are considered indications for manual detorsion: direction of testicular torsion, i.e., inner or outer direction (ultrasonographic accuracy of 70%), and the degree of spermatic cord twist. The following sonographic findings are used to determine whether the treatment was successful: presence of the whirlpool sign and the degree and extent of perfusion of the affected testis. Misdiagnosis of the direction of manual detorsion, a high degree of spermatic cord twisting and insufficient detorsion, testicular compartment syndrome, and testicular necrosis were found to result in treatment failure. The success of manual detorsion is determined based on the symptoms and sonographic findings. Subsequent surgical exploration is recommended in all cases, regardless of the success of manual detorsion.

Testicular torsion diagnosis and injury assessment using photoacoustic oxygenation imaging

Testicular torsion (TT) is a medical emergency that requires immediate diagnostic evaluation. Photoacoustic imaging (PAI) has the potential to provide spatially resolved oxygen saturation (sO₂), which can serve as a valuable marker in TT diagnosis. We investigated the potential of PAI as an alternative method for TT diagnosis and testicular injury assessment. We measured sO₂ levels in different degrees of TT models using PAI at various time points. Based on histopathological results, we found that the averaged sO₂ per pixel (sO2®) and reduction of sO2® (rsO₂) in twisted testicles had significant correlations with hypoxic conditions. Both sO2® and rsO₂ exhibited excellent diagnostic abilities in detecting TT and identifying ischemia/hypoxia injury following TT. Furthermore, PAI-measured sO₂ demonstrated favorable diagnostic capabilities in discriminating if the testicle had suffered irreversible injury. In summary, PAI presents a potentially promising novel approach in evaluating TT and warrants further clinical investigation.

High risk and low prevalence diseases: Testicular torsion

INTRODUCTION

Testicular torsion is a serious condition that carries with it a high rate of morbidity.

OBJECTIVE

This review highlights the pearls and pitfalls of testicular torsion, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence.

DISCUSSION

Testicular torsion is a urological emergency that occurs with rotation of the testicle along its supporting ligaments leading to obstruction of vascular flow. A key risk factor is the presence of a bell-clapper deformity. The most common population affected includes children in a bimodal distribution with the most cases occurring in the first year of life and between 12 and 18 years, although cases do occur in adults. Acute, severe, unilateral scrotal pain is the most common presenting symptom. Nausea and vomiting are common, but the presence or absence of a cremasteric reflex is not a reliable indicator of disease. The TWIST score may assist with clinical decision making in patients presenting with acute testicular pain but should not be used in isolation. If torsion is suspected or confirmed, consultation with the urology specialist should not be delayed, as outcomes are time sensitive. Ultrasound can be used for diagnosis, but a normal ultrasound examination cannot exclude the diagnosis. Treatment includes emergent urology consultation for surgical exploration and detorsion, as well as symptomatic therapy in the ED. Manual detorsion can be attempted in the ED while awaiting transfer or consultation.

CONCLUSIONS

An understanding of testicular torsion can assist emergency clinicians in diagnosing and managing this disease.

Detection of Testicular Torsion With Preserved Intratesticular Flow By Point of Care Ultrasound in the Emergency Department: A Case Report

BACKGROUND

Ultrasonography is an effective diagnostic tool for testicular torsion (TT), which is typically characterized by the absence of blood flow in the affected testicle on color Doppler mode. However, there are a few reported cases of TT with symmetrical preserved flow. We report a case of TT with the preserved intratesticular flow on color Doppler ultrasound.

CASE REPORT

A 14-year-old boy was admitted due to sudden-onset right scrotal pain. Point-of-care ultrasound (POCUS) revealed that the right testicle was larger than the left. The intratesticular flow in both testicles was preserved. Radiology-performed ultrasound confirmed the preserved intratesticular flow observed on POCUS, but also demonstrated a whirlpool sign of the right spermatic cord. TT was confirmed surgically. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians should investigate the presence of intratesticular blood flow and the whirlpool sign of the spermatic cord or other ultrasound features suggestive of TT, even if testicular blood flow is preserved. Suspicion of TT from POCUS findings warrants further evaluation to preserve the patient's fertility.

Pearls and Pitfalls of Pediatric Scrotal Imaging

Ultrasonography (US) is the primary imaging modality for the evaluation of pediatric scrotal disease. The ability to obtain exceptional anatomical detail and testicular perfusion information without ionizing radiation makes it the essential tool for evaluating scrotal pain and palpable masses. Challenges arise in both the performance and interpretation of scrotal US in the child. Optimizing imaging parameters and recognizing key differentiating US features help minimize misinterpretations that can lead to poor patient outcomes. Key pearls and pitfalls in pediatric scrotal ultrasound methods and diagnoses are reviewed. Knowledge of what is normal for the various ages of childhood from neonate through adolescence is necessary for accurate US analysis. Imaging evaluation of key causes of the acute painful scrotum including testicular appendage torsion, epididymitis, and testicular torsion are discussed. Sonographic features for the diagnosis of benign and malignant scrotal masses, microlithiasis, and cryptorchidism are reviewed.

Do Not Get It Twisted: Common and Uncommon Manifestations of Testicular Torsion

Color flow and spectral Doppler ultrasound are the backbone of scrotal imaging when evaluating acute scrotal pain. Testicular Torsion is one of the most common causes of acute scrotal pain but can be a challenging diagnosis both clinically and sonographically. This article will review the pertinent Doppler ultrasound findings that can help make the diagnosis of both complete and partial torsion. A review of other causes of testicular ischemia will also be included as these pathologies can mimic Testicular Torsion.

The diagnostic value of ultrasound in pediatric testicular torsion with preserved flow

BACKGROUND

Testicular torsion is the reduction of blood flow to the testis after spermatic cord torsion. For patients, the diagnosis of testicular torsion is controversial and complicated by the fact that ultrasound blood flow signals are not significantly reduced in comparison to the unaffected, healthy, testis, despite persistent symptoms on the affected side. Our study aims to investigate the diagnostic characteristics of high-resolution ultrasonography (US) in pediatric testicular torsion with the preserved flow to increase diagnostic accuracy.

METHODS

Seven pediatric patients aged 49 days to 15 years old, with the preserved blood flow, but surgically diagnosed as testicular torsion, from October 2017 to August 2019, were retrospectively included in the study. The imaging manifestations of high-frequency ultrasonography were evaluated.

RESULTS

All cases had preserved testicular blood flow, but the surgical findings showed various degrees of twist, from 90 to 540 degrees. Preoperative ultrasound showed spermatic cord distortion in all cases, and testicular long axis tilting in four cases (4/7 = 57.1%).

CONCLUSION

In some testicular torsion cases, Color Doppler may show normal or increased blood flow signals in the testis. We should further observe the morphology and position of the testes and epididymides, the echo of the testicular parenchyma, and, especially evaluate the "whirlpool sign" in the spermatic cord, to avoid missing testicular torsion with blood flow signals.

Role of ultrasound in manual detorsion for testicular torsion

PURPOSE

Manual detorsion can be performed for testicular torsion before scrotal exploration. Using sonographic findings, this study investigated the need for additional treatments after manual detorsion for testicular torsion.

METHODS

This study evaluated 13 retrospective cases of testicular torsion subjected to manual detorsion. Manual detorsion was classified as failure or success based on residual spermatic cord twist. The following sonographic findings of the affected testis were compared using the Fisher exact test: whirlpool sign, horizontal or altered lie, and hypoperfusion.

RESULTS

Manual detorsion failed in five patients. There was a significant difference in the incidence of the whirlpool sign between the two groups (present/absent sign in the failure vs. success groups: 4/1 vs. 0/8, p = 0.007). Horizontal or altered lie and hypoperfusion in the affected testis were not significantly different between groups (5/0 vs. 3/4, p = 0.07, one case excluded, and 5/0 vs. 4/4, p = 0.10, respectively).

CONCLUSIONS

Ultrasound findings after manual detorsion, particularly, the whirlpool sign, were useful for planning subsequent treatment such as additional manual detorsion or surgical intervention. The testicular axis and the perfusion of the twisted testis may not recover to normal after successful manual detorsion, but if they recover, this procedure could be judged a success.

Diffusion tensor imaging in evaluating testicular injury after unilateral testicular torsion and detorsion in rat model: A preliminary study

Diffusion tensor imaging (DTI) is a functional magnetic resonance sequence based on the movement of water molecules. This study attempted to investigate the feasibility of DTI in evaluating testicular injury after testicular torsion and detorsion. Seventy-two rats were randomly divided into the sham group, torsion group and detorsion group. The left testis in the sham group was brought out through a scrotal incision for 1 hr, and that of the torsion group was twisted 720^o clockwise for 1 hr and fixed to the scrotum, while the detorsion group was restored after being twisted 720° for 1 hr. Rats were further divided into four subgroups according to the set time, then performed DTI and histology analysis. The mean diffusion of the torsion and detorsion groups increased within 24 hr (p <.01), while it in the detorsion-1-week-group was lower than that in the detorsion-24-hr-group (p <.05). The fraction anisotropy of both experimental groups decreased in the acute phase (p <.01), while that of the detorsion-1-week-group increased (p <.01). Cosentino score in both experimental groups showed an increasing trend (p <.05). Besides, the spermatogenic ability of the detorsion-1-week-group decreased (p <.05). In conclusion, DTI was able to evaluate the injury after testicular torsion and detorsion.

Duration of symptoms is the only predictor of testicular salvage following testicular torsion in children: A case-control study

OBJECTIVE

Testicular torsion (TT) is an emergency requiring a prompt diagnosis and surgery to avoid irreversible changes and a complete loss of testis. The present study aimed to identify potential factors that may be predict a testicular salvage after TT in pediatric patients.

METHODS

Consecutive medical records of all children ≤16 years old with surgically confirmed TT over a period of five years (2011-2016) were collected. Patients were divided into 2 groups according to testicular viability and the type of treatment: Orchidectomy and orchidopexy. The differences between the two groups and potential predictors of testicular salvage were analyzed.

RESULTS

Thirty-one boys with TT met the inclusion criteria and were included in the study. The mean age was 13.6 years (range, 10 days - 15.8 years). Testicular salvage was possible in 18 (58.1%) patients. The duration of symptoms and a lesser degree of torsion indicated a testicular salvage in children and adolescents with testicular torsion, but in multivariate analysis only duration of symptoms (time to surgical detorsion) was significantly associated with the risk of non-salvage. At follow-up, testicular atrophy affected 73.3% of the patients treated with orchidopexy.

CONCLUSION

Duration of symptoms is the only predictor of successful testicular salvage following testicular torsion in children. It is associated with a substantial risk of testicular loss and atrophy.

Testicular Torsion in the Emergency Room: A Review of Detection and Management Strategies

Testicular torsion is a challenging and time-sensitive diagnosis that is encountered frequently in daily practice, especially in the emergency room. A thorough history, the presence of a painful and swollen testis and testicular ultrasonography plays a vital role in the prompt diagnosis of testicular torsion. Prompt diagnosis is essential to prevent complications of testicular torsion which include testicular infarction, necrosis, and sub/infertility. This can be challenging as there are various other conditions that may mimic the presentation of testicular torsion. Since testicular torsion is an extremely time-sensitive diagnosis, it may also be a subject of many medicolegal challenges. This review article serves as a guide for clinicians involved with the diagnosis and management of testicular torsion. We review and discuss detection and management strategies based on their validity, statistical significance, and effectiveness in enabling prompt diagnosis and management of testicular torsion. Medicolegal implications of testicular torsion are also highlighted.

Imaging of the acute scrotum: keys to a rapid diagnosis of acute scrotal disorders

Imaging of the scrotum in the setting of acute symptoms such as pain or swelling is commonly performed emergently to differentiate between patients who require immediate surgery and those that do not. Acute scrotal symptoms are generally caused by infectious, traumatic or vascular etiologies. Rapid diagnosis and initiation of treatment is vital for testicular salvage in cases of acute testicular torsion, testicular rupture, and Fournier gangrene. Epididymitis, epididymo-orchitis, torsed testicular appendage, segmental testicular infarction, scrotal hematomas, testicular neoplasms, and acute idiopathic scrotal edema can have similar clinical presentations, but these conditions do not require immediate surgery. Ultrasound is the well-established first-line imaging modality for the acute scrotum. Contrast-enhanced ultrasound and magnetic resonance imaging can be useful as problem-solving tools when ultrasound studies are inconclusive or equivocal. This review describes normal scrotal anatomy and a wide range acute scrotal disorders, with emphasis on the imaging and clinical features that can minimize the risk of misdiagnosis.

Estimating the time of onset of testicular torsion using ultrasonography in an experimental rat model

Purpose

We aimed to document the time of onset of ultrasonographic and histologic changes in the testes of a rat model following testicular torsion.

Methods

Twenty-five Sprague-Dawley rats were divided into four groups. All animals underwent preoperative Doppler ultrasonography. Groups 1, 2, and 3 underwent unilateral surgical torsion of the testis lasting for 72, 24, and 6 hours, respectively. Group 4 underwent a sham operation. The animals were followed with Doppler ultrasonography at 6, 24, 48, and 72 hours postoperatively. Histologic examinations were performed at the designated final time point for each group.

Results

After torsion, enlargement of the epididymal head and thickening of the spermatic cord over time were noted. Based on the ultrasonographic dimensions, the ratio of the epididymal volume increased with time following torsion (p=0.002). The torsed testes had an average weight gain of 0.27 g at 6 hours compared to the control testes, but an average weight loss of 0.22 g at 72 hours (P=0.006). Changes in testicular echotexture were noted as soon as 6 hours after torsion, but there was no consistent pattern of echotexture change thereafter. Histologically, viable tubules were seen 6 hours after torsion, while extensive hemorrhagic necrosis was found at 72 hours.

Conclusion

In evaluating testicular torsion, the enlargement ratio of the epididymis and thickening of the spermatic cord on Doppler ultrasonography may be useful for determining the urgency of immediate surgery. Changes in testicular echotexture may not be a reliable indicator of the time of onset.

Diagnostic Accuracy of Ultrasound for the Directionality of Testicular Rotation and the Degree of Spermatic Cord Twist in Pediatric Patients With Testicular Torsion

OBJECTIVES

To evaluate the diagnostic accuracy of ultrasound (US) to diagnose the directionality of testicular rotation and the degree of spermatic cord twist in pediatric patients with testicular torsion.

METHODS

A retrospective review of 14 pediatric patients with testicular torsion was conducted. The directionality of testicular rotation was classified as an inner or outer direction (inner, counterclockwise in the left testis [viewed from below] and clockwise in the right testis; and outer, counterclockwise in the right testis and clockwise in the left testis). The Clopper-Pearson method and the Fisher exact, Mann-Whitney U, and Wilcoxon signed rank sum tests were used for the statistical analyses.

RESULTS

The diagnostic accuracy of US in the directionality of testicular rotation and the degree of spermatic cord twist were 78.6% (11 of 14; 95% confidence interval, 49.2%-95.3%) and 36.4% (4 of 11; 95% confidence interval, 10.9%-69.2%), respectively. Outer rotation was seen in 50.0% of the cases. The directionality of testicular rotation and the degree of spermatic cord twist as determined by US were not significantly different between the patients with salvaged testis and those with testicular loss (inner/outer direction, 4/2 versus 4/4; P = .627; mean twist ± SD, 330.0° ± 73.5° versus 337.5° ± 115.4°; P > .999). There was no significant difference in the degree of spermatic cord twist determined by US and surgical results (343.0° ± 97.1° versus 458.2° ± 168.2°; P = .063).

CONCLUSIONS

The accuracy of US in determining the directionality of testicular rotation was relatively high in our small cohort. This information may be useful for pediatric surgeons and urologists when performing early manual reduction for testicular torsion.

Frontiers in pediatric testicular torsion: An integrated review of prevailing trends and management outcomes

Testicular torsion remains the most frequent cause of testicular ischemia, especially in adolescents and young adults. Timely diagnosis and intervention are keys to saving the affected testicle. This review presents current trends in the diagnosis and treatment of torsion, potential pitfalls and consequent outcomes. Additionally, other salient issues surrounding testicular torsion are also discussed, including: pathogenesis of injury, legal ramifications, fertility outcomes, novel management techniques, and recent advances in diagnostic technology.

The ultrasonographic "whirlpool sign" in testicular torsion: valuable tool or waste of valuable time? A systematic review and meta-analysis

PURPOSE

A positive whirlpool sign (WS) is defined as the presence of a spiral-like pattern when the spermatic cord is assessed during ultrasonography (US), using standard, high-resolution ultrasonography (HRUS) and/or color Doppler sonography (CDS), in the presence of testicular torsion. The objective of this review was to assess the validity and accuracy of this sign by performing a comprehensive systematic literature review and meta-analysis.

METHODS

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, a comprehensive literature search was performed (August, 2017), using the following databases: BMJ Best Practice, Cochrane Library, Embase, PubMed, Scopus, and Web of Science. Selected studies were further assessed for relevance and quality using the Oxford 2010 Critical Appraisal Skills Program (CASP).

RESULTS

Of the studies assessed, a total of 723 participants were included, with a mean of 72.3 (SD 71.9) participants. Of the participants, 226 (31.3%) were diagnosed with testicular torsion (TT). Meta-analysis of the studies that provided sufficient data resulted in a pooled sensitivity and specificity of the WS of 0.73 (95% CI, 0.65-0.79) and 0.99 (95% CI, 0.92-0.99), respectively. Removal of all neonates increased the pooled sensitivity to 0.92 (95% CI, 0.70-0.98) while the pooled specificity remained almost unchanged at 0.99 (95% CI, 0.95-1.00). The estimated summary effect of all studies with sufficient data was 4.34 (95% CI, 1.01-7.67; n = 394; p = 0.001). A large degree of heterogeneity was suggested by an I² statistic of 88.27% (95% CI, 68.60-98.68%). Removal of neonatal subjects increased the estimated summary effect to 5.32 (95% CI, 1.59-9.05; n = 375; p = 0.001).

CONCLUSION

The WS, when correctly diagnosed, may be viewed as a very definitive sign for TT in the pediatric and adult populations. However, its role in neonates is limited.

Testicular torsion with preserved flow: key sonographic features and value-added approach to diagnosis

Testicular sonography has contributed greatly to the preoperative diagnosis of testicular torsion in the pediatric patient and is the mainstay for evaluation of acute scrotal pain. Despite its high sensitivity and specificity, both false-negative and false-positive findings occur. Presence of documented Doppler flow within the testis might be a dissuading factor for surgical exploration with resultant testicular loss in the false-negative cases. Our goal is to illustrate key sonographic features in the spectrum of testicular torsion with preserved testicular flow, and to describe how to differentiate testicular torsion from epididymitis in order to avoid the under-diagnosis of testicular torsion. We simplify the anatomy of the bell clapper testis. We also describe our sonographic protocol for testicular torsion and share valuable tips from our approach to challenging cases.

Ultrasonography of pediatric urogenital emergencies: review of classic and new techniques

Urogenital emergencies are fairly common in the pediatric population, and a timely and correct diagnosis is necessary to avoid possible future infertility. In this field, ultrasonography is essential, as it has the advantages of being radiation-free and readily accessible. In particular, a high-frequency transducer allows precise evaluation of the morphology and vascularity of the scrotum, which is on the surface of the body. Beyond conventional techniques, new advanced imaging techniques have been developed, including elastography and contrast-enhanced ultrasonography. However, several pitfalls remain in the diagnosis of urogenital diseases using ultrasonography. Thus, accurate knowledge and sufficient experience with the technique are essential for making a correct diagnosis. This review provides an overview of pediatric urogenital emergency pathologies and recent ultrasonography techniques.

Extratesticular masses in children: taking ultrasound beyond paratesticular rhabdomyosarcoma

Extratesticular cystic and solid scrotal masses are commonly encountered in pediatrics. The most common extratesticular malignancy is paratesticular rhabdomyosarcoma. The remainder of the common pathologies encountered -- appendage torsion, epididymitis and varicoceles -- are mostly benign. These frequently encountered benign lesions are confidently differentiated from paratesticular rhadbomyosarcoma using high-frequency scrotal sonography in combination with clinical features. Less commonly encountered extratesticular masses may not be as easily classified; however, these also have distinguishing features that can enable differentiation from malignancy. This review discusses the sonographic findings, and relevant clinical and pathological manifestations of the more unusual extratesticular masses encountered in two tertiary pediatric institutions during a 10-year period. While these extratesticular pathologies are encountered relatively infrequently, recognition of their manifestations enables appropriate management.