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.

Feasibility of Quantitative Tissue Characterization Using Novel Parameters Extracted From Photoacoustic Power Spectrum Considering Multiple Absorbers.

Frequency domain analysis of radio frequency signal is performed to differentiate between different tissue categories in terms of spectral parameters. However, due to complex relationship between the absorber size and spectral parameters, they cannot be used for quantitative tissue characterization. In an earlier study, we showed that using linear relationship between absorber size and two new spectral parameters namely number of lobes and average lobe width, absorber size can be successfully recovered from photoacoustic signal generated by single absorber. As actual biological tissue contains multiple absorbers, in this study we extended the application of these two new spectral parameters for computing absorber size from signals generated by multiple PA absorbers. We revisited our analytical model to establish two new linear relationships between the absorber radius and number of lobes as well as average lobe width considering multiple absorbers with bandlimited acquisition. A simulation study was performed to validate these linear relationships. A retrospective ex vivo study, in which the spectral parameters were computed using multiwavelength photoacoustic signals, was performed with freshly exercised thyroid specimens from 38 actual human patients undergoing thyroidectomy after having a diagnosis of suspected thyroid lesions. From statistical analysis it is shown that both the parameters were significantly different between malignant and non-malignant thyroid and malignant and normal thyroid tissue. Performance of the supervised classification with the computed spectral parameters showed that the extracted parameters could be successfully used to differentiate malignant thyroid tissue from normal thyroid tissue with reasonable degree of accuracy.

Imaging in scrotal trauma: a European Society of Urogenital Radiology Scrotal and Penile Imaging Working Group (ESUR-SPIWG) position statement.

Imaging plays a crucial role in the evaluation of scrotal trauma. Among the imaging modalities, greyscale ultrasound and Colour Doppler ultrasound (CDUS) are the primary techniques with the selective utilisation of advanced techniques such as contrast-enhanced ultrasound (CEUS) and elastography. Despite ultrasound being the mainstay of imaging scrotal trauma, its diagnostic performance is not fully established. Considering these difficulties and their impact on clinical practice, the Scrotal and Penile Imaging Working Group of the European Society of Urogenital Radiology (ESUR-SPIWG) established an expert task force to review the current literature and consolidate their expertise on examination standards and imaging appearances of various entities in scrotal trauma. This paper provides the position statements agreed on by the task force with the aim of providing guidance for the use of imaging especially multiparametric US in scrotal trauma.Key Points• Greyscale and Colour Doppler ultrasound are the mainstay of imaging in patients with scrotal trauma.• Contrast-enhanced ultrasound and elastography are the advanced techniques useful as a problem-solving modality in equivocal cases.• This paper summarises the position statements of the ESUR-SPIWG on the appropriate utilisation of multiparametric ultrasound and other imaging modalities in the evaluation of scrotal trauma.

Computation of Photoacoustic Absorber Size from Deconvolved Photoacoustic Signal Using Estimated System Impulse Response.

Photoacoustic signal recorded by photoacoustic imaging system can be modeled as convolution of initial photoacoustic response by the photoacoustic absorber with the system impulse response. Our goal was to compute the size of photoacoustic absorber using the initial photoacoustic response, deconvolved from the recorded photoacoustic data. For deconvolution, we proposed to use the impulse response of the photoacoustic system, estimated using discrete wavelet transform based homomorphic filtering. The proposed method was implemented on experimentally acquired photoacoustic data generated by different phantoms and also verified by a simulation study involving photoacoustic targets, identical to the phantoms in experimental study. The photoacoustic system impulse response, which was estimated using the acquired photoacoustic signal corresponding to a lead pencil, was used to extract initial photoacoustic response corresponding to a mustard seed of 0.65 mm radius. The recovered radius values of the mustard seed, corresponding to the experimental and simulation studies were 0.6 mm and 0.7 mm.

Senescent Phenotype Induced by p90RSK-NRF2 Signaling Sensitizes Monocytes and Macrophages to Oxidative Stress in HIV-Positive Individuals.

BACKGROUND: The incidence of cardiovascular disease is higher in HIV-positive (HIV+) patients than it is in the average population, and combination antiretroviral therapy (cART) is a recognized risk factor for cardiovascular disease. However, the molecular mechanisms that link cART and cardiovascular disease are currently unknown. Our study explores the role of the activation of p90RSK, a reactive oxygen species-sensitive kinase, in engendering senescent phenotype in macrophages and accelerating atherogenesis in patients undergoing cART. METHODS: Peripheral whole blood from cART-treated HIV+ individuals and nontreated HIV-negative individuals was treated with H2O2 (200 µmol/L) for 4 minutes, and p90RSK activity in CD14+ monocytes was measured. Plaque formation in the carotids was also analyzed in these individuals. Macrophage senescence was determined by evaluating their efferocytotic ability, antioxidation-related molecule expression, telomere length, and inflammatory gene expression. The involvement of p90RSK-NRF2 signaling in cART-induced senescence was assessed by p90RSK-specific inhibitor (FMK-MEA) or dominant-negative p90RSK (DN-p90RSK) and NRF2 activator (NRF2A). Further, the severity of atherosclerosis was determined in myeloid cell-specific wild-type and DN-p90RSK transgenic mice. RESULTS: Monocytes from HIV+ patients exhibited higher levels of p90RSK activity and were also more sensitive to reactive oxygen species than monocytes from HIV-negative individuals. A multiple linear regression analysis involving cART, Reynolds cardiovascular risk score, and basal p90RSK activity revealed that cART and basal p90RSK activity were the 2 significant determinants of plaque formation. Many of the antiretroviral drugs individually activated p90RSK, which simultaneously triggered all components of the macrophage senescent phenotype. cART inhibited antioxidant response element reporter activity via ERK5 S496 phosphorylation. NRF2A reversed the H2O2-induced overactivation of p90RSK in cART-treated macrophages by countering the induction of senescent phenotype. Last, the data obtained from our gain- or loss-of-function mice conclusively showed the crucial role of p90RSK in inducing senescent phenotype in macrophages and atherogenesis. CONCLUSIONS: cART increased monocyte/macrophage sensitivity to reactive oxygen species- in HIV+ individuals by suppressing NRF2-ARE activity via p90RSK-mediated ERK5 S496 phosphorylation, which coordinately elicited senescent phenotypes and proinflammatory responses. As such, our report underscores the importance of p90RSK regulation in monocytes/macrophages as a viable biomarker and therapeutic target for preventing cardiovascular disease, especially in HIV+ patients treated with cART.

Ultrasound evaluation of varicoceles: guidelines and recommendations of the European Society of Urogenital Radiology Scrotal and Penile Imaging Working Group (ESUR-SPIWG) for detection, classification, and grading.

Varicoceles are relatively common particularly in asymptomatic men and are even more prevalent in subfertile men, representing the most common potentially correctable cause of male infertility. Ultrasound (US) is the imaging modality of choice for varicocele evaluation, but there is no widely accepted consensus on examination technique, diagnostic criteria, or classification. In view of this uncertainty, the guideline writing group (WG) of the European Society of Urogenital Radiology (ESUR) Scrotal and Penile Imaging Working Group (ESUR-SPIWG) undertook a literature review and assessment of the quality of relevant evidence. The group then produced evidence-based recommendations for varicocele US examination, interpretation, and classification by consensus agreement. The results are presented in the form of 15 clinical questions with a brief summary of the relevant evidence and the authorised recommendations from the SPIWG. This paper provides a short summary of the evidence evaluation and the complete recommendations.Key Points• Varicocele is a common clinical problem; it is highly prevalent amongst subfertile men and the most common potentially correctable cause of male infertility. • Ultrasound is the imaging modality of choice for varicocele assessment, but there is no generally agreed consensus on the US examination technique or the criteria that should be used for diagnosis, grading, and classification. • This paper summarises the recommendations of the ESUR-SPIWG for standardising the US assessment of varicoceles. This includes examination technique, image interpretation, classification, and reporting.

MRI of the scrotum: Recommendations of the ESUR Scrotal and Penile Imaging Working Group.

OBJECTIVES: The Scrotal and Penile Imaging Working Group (SPI-WG) appointed by the board of the European Society of Urogenital Radiology (ESUR) has produced recommendations for magnetic resonance imaging (MRI) of the scrotum. METHODS: The SPI-WG searched for original and review articles published before September 2016 using the Pubmed and Medline databases. Keywords used were 'magnetic resonance imaging', 'testis or testicle or testicular', 'scrotum', 'intratesticular', 'paratesticular', 'extratesticular' 'diffusion-weighted', 'dynamic MRI'. Consensus was obtained among the members of the subcommittee. The expert panel proposed recommendations using Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence. RESULTS: The recommended MRI protocol should include T1-, T2-weighted imaging, diffusion-weighted imaging and dynamic contrast-enhanced MRI. Scrotal MRI can be clinically applied for lesion characterisation (primary), including both intratesticular and paratesticular masses, differentiation between germ-cell and non-germ-cell neoplasms (evolving), characterisation of the histological type of testicular germ cell neoplasms (TGCNs, in selected cases), local staging of TGCNs (primary), acute scrotum (in selected cases), trauma (in selected cases) and undescended testes (primary). CONCLUSIONS: The ESUR SPI-WG produced this consensus paper in which the existing literature on MRI of the scrotum is reviewed. The recommendations for the optimal imaging technique and clinical indications are presented. KEY POINTS: • This report presents recommendations for magnetic resonance imaging (MRI) of the scrotum. • Imaging acquisition protocols and clinical indications are provided. • MRI is becoming established as a worthwhile second-line diagnostic tool for scrotal pathology.

Introduction to Imaging of Penile Prostheses: A Primer for the Radiologist.

OBJECTIVE: The purpose of this article is to provide radiologists with an introduction to the imaging appearances of various types of penile prostheses and discuss imaging pitfalls. CONCLUSION: Two major types of penile prostheses currently are in use: malleable penile prostheses and inflatable penile prostheses. Sonography is useful in the assessment of the pelvic reservoir and scrotal pump. MRI helps in the complete evaluation of all the prosthetic components, making it a "one-stop shop" imaging technique.

Comprehensive Multimodality Imaging Review of Complications of Penile Prostheses.

OBJECTIVE: The objective of our article is to review the role of imaging in the diagnosis of various complications of a penile prosthesis (PP). CONCLUSION: Complications of a PP can be categorized into three groups: first, malpositioning, which includes buckling, floppy glans, erosion, migration, and crossover; second, mechanical failure, which includes fracture, aneurysm, and leakage; and, third, infection. Radiography, sonography, CT, and MRI are useful in the detection of these complications and complement each other, with MRI being the most useful imaging modality among them.

Value of Multiparametric US in the Assessment of Intratesticular Lesions.

Purpose To evaluate the diagnostic accuracy of multiparametric ultrasonography (US) consisting of gray-scale US, color Doppler US, strain elastography, and contrast agent-enhanced US in the assessment of intratesticular lesions. Materials and Methods Institutional review board approval was obtained for this retrospective study. From January 2012 to December 2015, 55 focal testicular lesions that were indeterminate on gray-scale US scans were further characterized with color Doppler US, strain elastography, and contrast-enhanced US. Strain elastography was performed to assess tissue elasticity, and hard lesions were defined as malignant. Color Doppler US and contrast-enhanced US were performed to determine the absence or presence of vascularization. Avascular lesions were defined as benign. Histopathologic results or follow-up examinations served as reference standards. Correct classification rate, sensitivity, specificity, and likelihood ratio were calculated. Results Of 55 testicular lesions, 43 (78.2%) were benign and 12 (21.8%) were malignant. Single-modality sensitivities and specificities were 66.7% and 88.4% for color Doppler US, 100% and 76.7% for contrast-enhanced US, and 100% and 72.1% for strain elastography, respectively. Among 12 malignant lesions, color Doppler US failed to demonstrate vascularization in four (33.3%) lesions, which were positive for cancer at contrast-enhanced US. By combining strain elastography and contrast-enhanced US, a sensitivity of 100% and specificity of 93.0% were achieved in differentiating benign and malignant focal testicular lesions. Positive likelihood ratio was 5.7 for color Doppler US, 4.3 for contrast-enhanced US, 3.6 for strain elastography, 14.3 for strain elastography combined with color Doppler US, and 14.3 for strain elastography combined with contrast-enhanced US. Conclusion Multiparametric US allows for a reliable differentiation of benign and malignant intratesticular lesions and can potentially be useful in deciding whether orchiectomy can be replaced with follow-up or less invasive organ-sparing strategies. © RSNA, 2017.

Frequency Domain Analysis of Multiwavelength Photoacoustic Signals for Differentiating Among Malignant, Benign, and Normal Thyroids in an Ex Vivo Study With Human Thyroids.

OBJECTIVES: This study investigated the capability of spectral parameters, extracted by frequency domain analysis of photoacoustic signals, to differentiate among malignant, benign, and normal thyroid tissue. METHODS: We acquired multiwavelength photoacoustic images of freshly excised thyroid specimens collected from 50 patients who underwent thyroidectomy after having a diagnosis of suspected thyroid lesions. A thyroid cytopathologist marked histologic slides of each tissue specimen. These marked slides were used as ground truth to identify the regions of interest (ROIs) corresponding to malignant, benign, and normal thyroid tissue. Three spectral parameters: namely, slope, midband fit, and intercept, were extracted from photoacoustic signals corresponding to different ROIs. RESULTS: Spectral parameters were extracted from a total of total of 65 ROIs. According to the ground truth, 12 of 65 ROIs belonged to malignant thyroids; 28 of 65 ROIs belonged to benign thyroids; and 25 of 65 ROIs belonged to normal thyroids. Besides slope, the other 2 spectral parameters and grayscale photoacoustic image pixel values were found to be significantly different (P < .05) between malignant and normal thyroids. Between benign and normal thyroids, all 3 spectral parameters and photoacoustic pixel values were significantly different (P < .05). CONCLUSIONS: Preliminary results of our ex vivo human thyroid study show that the spectral parameters extracted from radiofrequency photoacoustic signals as well as the pixel values of 2-dimensional photoacoustic images can be used for differentiating among malignant, benign, and normal thyroid tissue.

Incidentally detected non-palpable testicular tumours in adults at scrotal ultrasound: impact of radiological findings on management Radiologic review and recommendations of the ESUR scrotal imaging subcommittee.

OBJECTIVES: The increasing detection of small testicular lesions by ultrasound (US) in adults can lead to unnecessary orchiectomies. This article describes their nature, reviews the available literature on this subject and illustrates some classical lesions. We also suggest recommendations to help characterization and management. METHODS: The ESUR scrotal imaging subcommittee searched for original and review articles published before May 2015 using the Pubmed and Medline databases. Key words used were 'testicular ultrasound', 'contrast-enhanced sonography', 'sonoelastography', 'magnetic resonance imaging', 'testis-sparing surgery', 'testis imaging', 'Leydig cell tumour', 'testicular cyst'. Consensus was obtained amongst the members of the subcommittee, urologist and medical oncologist. RESULTS: Simple cysts are frequent and benign, and do not require follow up or surgery. Incidentally discovered small solid testicular lesions detected are benign in up to 80 %, with Leydig cell tumours being the most frequent. However, the presence of microliths, macrocalcifications and hypoechoic areas surrounding the nodule are findings suggestive of malignant disease. CONCLUSION: Asymptomatic small testicular lesions found on ultrasound are mainly benign, but findings such as microliths or hypoechoic regions surrounding the nodules may indicate malignancy. Colour Doppler US remains the basic examination for characterization. The role of newer imaging modalities in characterization is evolving. KEY POINTS: • Characterization of testicular lesions is primarily based on US examination. • The role of MRI, sonoelastography, contrast-enhanced ultrasound is evolving. • Most small non-palpable testicular lesions seen on ultrasound are benign simple cysts. • Leydig cell tumours are the most frequent benign lesions. • Associated findings like microliths or hypoechoic regions may indicate malignancy.

Evaluation of Frequency Domain Analysis of a Multiwavelength Photoacoustic Signal for Differentiating Malignant From Benign and Normal Prostates: Ex Vivo Study With Human Prostates.

OBJECTIVES: The purpose of this study was to investigate the feasibility of differentiating malignant prostate from benign prostatic hyperplasia (BPH) and normal prostate tissue by performing frequency domain analysis of photoacoustic images acquired at 2 different wavelengths. METHODS: We performed multiwavelength photoacoustic imaging on freshly excised human prostate specimens taken from a total of 30 patients undergoing prostatectomy for biopsy-confirmed prostate cancer. Histologic slides marked by a genitourinary pathologist were used as ground truth to define regions of interest (ROIs) in the photoacoustic images. Primarily, 3 different prostate tissue categories, namely malignant, BPH, and normal, were considered, while a fourth category named nonmalignant was formed by combining the ROIs corresponding to BPH and normal tissue together. We extracted 3 spectral parameters, namely slope, midband fit, and intercept, from power spectra of the radiofrequency photoacoustic signals corresponding to the 3 primary tissue categories. RESULTS: We analyzed data from 53 ROIs selected from the photoacoustic images of 30 patients. According to the histopathologic analysis, 19 ROIs were malignant, 8 were BPH, and 26 were normal. All the 3 spectral parameters and C-scan grayscale photoacoustic image pixel values were found to be significantly different (P < .01) between malignant and nonmalignant prostate as well as malignant and normal prostate. CONCLUSIONS: Preliminary results of our ex vivo human prostate study suggest that spectral parameters obtained by performing frequency domain analysis of photoacoustic signals can be used to differentiate between malignant and nonmalignant prostate.

Testicular microlithiasis imaging and follow-up: guidelines of the ESUR scrotal imaging subcommittee.

OBJECTIVES: The subcommittee on scrotal imaging, appointed by the board of the European Society of Urogenital Radiology (ESUR), have produced guidelines on imaging and follow-up in testicular microlithiasis (TML). METHODS: The authors and a superintendent university librarian independently performed a computer-assisted literature search of medical databases: MEDLINE and EMBASE. A further parallel literature search was made for the genetic conditions Klinefelter's syndrome and McCune-Albright syndrome. RESULTS: Proposed guidelines are: follow-up is not advised in patients with isolated TML in the absence of risk factors (see Key Points below); annual ultrasound (US) is advised for patients with risk factors, up to the age of 55; if TML is found with a testicular mass, urgent referral to a specialist centre is advised. CONCLUSION: Consensus opinion of the scrotal subcommittee of the ESUR is that the presence of TML alone in the absence of other risk factors is not an indication for regular scrotal US, further US screening or biopsy. US is recommended in the follow-up of patients at risk, where risk factors other than microlithiasis are present. Risk factors are discussed and the literature and recommended guidelines are presented in this article. KEY POINTS: • Follow up advised only in patients with TML and additional risk factors. • Annual US advised for patients with risk factors up to age 55. • If TML is found with testicular mass, urgent specialist referral advised. • Risk factors - personal/ family history of GCT, maldescent, orchidopexy, testicular atrophy.

Grayscale and color Doppler features of testicular lymphoma.

Pooled data from 16 radiology centers were retrospectively analyzed to seek patients with pathologically proven testicular lymphoma and grayscale and color Doppler images available for review. Forty-three cases were found: 36 (84%) primary and 7 (16%) secondary testicular lymphoma. With unilateral primary lymphoma, involvement was unifocal (n = 10), multifocal (n = 11), or diffuse (n = 11). Synchronous bilateral involvement occurred in 6 patients. Color Doppler sonography showed normal testicular vessels within the tumor in 31 of 43 lymphomas (72%). Testicular lymphoma infiltrates through the tubules, preserving the normal vascular architecture of the testis. Depiction of normal testicular vessels crossing the lesion is a useful adjunctive diagnostic criterion.

Visualization of the diaphragm muscle with ultrasound improves diagnostic accuracy of phrenic nerve conduction studies.

INTRODUCTION: Evaluation of phrenic neuropathy (PN) with phrenic nerve conduction studies (PNCS) is associated with false negatives. Visualization of diaphragmatic muscle twitch with diaphragm ultrasound (DUS) when performing PNCS may help to solve this problem. METHODS: We performed bilateral, simultaneous DUS-PNCS in 10 healthy adults and 12 patients with PN. The amplitude of the diaphragm compound muscle action potential (CMAP) (on PNCS) and twitch (on DUS) was calculated. RESULTS: Control subjects had <38% side-to-side asymmetry in twitch amplitude (on DUS) and 53% asymmetry in phrenic CMAP (on PCNS). In the 12 patients with PN, 12 phrenic neuropathies were detected. Three of these patients had either significant side-to-side asymmetry or absolute reduction in diaphragm movement that was not detected with PNCS. There were no cases in which the PNCS showed an abnormality but the DUS did not. CONCLUSIONS: The addition of DUS to PNCS enhances diagnostic accuracy in PN.

Imaging of traumatic injuries to the scrotum and penis.

OBJECTIVE: The purpose of this article is to review scrotal and penile anatomy, the role of ultrasound in evaluating scrotal and penile trauma, and the vast spectrum of sonographic manifestations of scrotal and penile trauma. CONCLUSION: Scrotal and penile trauma is an uncommon type of trauma injury. However, knowledge of scrotal and penile anatomy and the appropriate imaging findings associated with acute traumatic injuries is important in establishing the correct diagnosis. Sonography is considered the first choice of imaging modalities in establishing a diagnosis and triaging patients into surgical and nonsurgical treatment.

Preliminary results of ex vivo multispectral photoacoustic imaging in the management of thyroid cancer.

OBJECTIVE: The purpose of this study was to validate whether ex vivo multispectral photoacoustic imaging can be used to differentiate malignant tissue, benign nodules, and normal human thyroid tissue. SUBJECTS AND METHODS: Fifty patients undergoing thyroidectomy because of thyroid lesions participated in this study. Multispectral photoacoustic imaging was performed on surgically excised thyroid tissue, and chromophore images that represented optical absorption of deoxyhemoglobin, oxyhemoglobin, lipid, and water were reconstructed. After the imaging procedure, the pathologist marked malignant tissue, benign nodules, and normal regions on histopathologic slides, and digital images of the marked histopathologic slides were obtained. The histopathologic images were coregistered with chromophore images. Areas corresponding to malignant tissue, benign nodules, and normal tissue were defined on the chromophore images. Pixel values within each area were averaged to determine the mean intensities of deoxyhemoglobin, oxyhemoglobin, lipid, and water. RESULTS: There was a statistically significant difference between malignant and benign nodules with respect to mean intensity of deoxyhemoglobin (p = 0.014). There was a difference between malignant and normal tissue in mean intensity of deoxyhemoglobin (p = 0.003), lipid (p = 0.001), and water (p < 0.0001). A difference between benign nodules and normal tissue was found in mean intensity of oxyhemoglobin (p < 0.0001), lipid (p < 0.0001), and water (p < 0.0001). The sensitivity, specificity, and positive and negative predictive values of the system tested in differentiating malignant from nonmalignant thyroid tissue were 69.2%, 96.9%, 81.8%, and 93.9%. CONCLUSION: The preliminary results of this ex vivo human thyroid study suggest that multispectral photoacoustic imaging can be used to differentiate malignant and benign nodules and normal human thyroid tissue.

Penile Evaluation: An Illustrated Review.

ABSTRACT: High-frequency ultrasound is the imaging modality of choice for evaluating penile pathology because of its easy access, low cost, and patient tolerance ( The Penis, Diagnostic Ultrasound, second edtion . Boca Raton: CRC Press; 2007:957-978). This pictorial review will illustrate the sonographic features of emergent and nonemergent penile conditions such as penile fracture, spongial tear, urethral injury, various types of priapism, erectile dysfunction, penile abscess, and Mondor disease.

Testicular torsion: an avascular testis at color Doppler ultrasound is not enough to prove the diagnosis.

INTRODUCTION: A Doppler ultrasound (US) of the scrotum is commonly used to improve the diagnostic confidence for testicular torsion in an emergency setting. However, the sensitivity of this investigation to identify torsion varies largely. This is due, in part, to a lack of guidelines on how-to perform the US and therefore training is necessary. EVIDENCE ACQUISITION: The Scrotal and Penile Imaging Working Group of the European Society of Urogenital Radiology (ESUR-SPIWG) and the Section of Urological Imaging of the European Association of Urology (ESUI) established a joint panel of experts to standardize Doppler US investigation of patients with testicular torsion. The panel reviewed the available literature, identified accumulated knowledge and limitations, and released recommendations on how-to perform Doppler US in patients with acute scrotal pain. EVIDENCE SYNTHESIS: Diagnosis of testicular torsion is based on clinical evaluation and investigation of the cord, the testis, and the paratesticular structures. A preliminary clinical evaluation, including history and palpation, is necessary. Grey scale US, color Doppler US and spectral analysis must be performed by a sonologist with at least level 2 competence. Modern equipment with adequate grey-scale and Doppler capabilities are required. CONCLUSIONS: Standardization of Doppler US in suspicious testicular torsion is presented, with the aim to obtain comparable results among different centres, prevent unnecessary operations, and improve patient management.