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.

Prostate Cancer-PET Imaging Update.

Prostate cancer is the most common non-dermatologic cancer in men, and one of the leading causes of cancer-related mortality. The incidence of prostate cancer increases precipitously after the age of 65 and demonstrates variable aggressiveness, depending on its grade and stage at diagnosis. Despite recent advancements in prostate cancer treatment, recurrence is seen in 25% of patients. Advancements in prostate cancer Positron Emission Tomography (PET) molecular imaging and recent United States Food and Drug Administration (FDA) approvals have led to several new options for evaluating prostate cancer. This manuscript will review the commonly used molecular imaging agents, with an emphasis on Fluorine-18 fluciclovine (Axumin) and PSMA-ligand agents, including their protocols, imaging interpretation, and pitfalls.

Contrast-Enhanced Ultrasound as a Problem-Solving Modality: Tips and Tricks.

ABSTRACT: Contrast-enhanced ultrasound (CEUS) continues to be an ever-growing tool in radiation-free imaging. While it has been widely used in cardiac imaging, CEUS has only recently become an Food and Drug Administration-approved and viable modality for evaluation of abdominal structures. Ultrasound contrast agents are nontoxic, microbubble-based vascular agents and can be used to reliably assess enhancement patterns of various lesions in real time. In particular, it's non nephrotoxic nature makes CEUS a particularly important tool in renal failure patients requiring serial follow-up. This review provides a comprehensive discussion on the utility of CEUS agents, imaging techniques, comparison with traditional cross-sectional imaging modalities, and its application in diagnosing kidney and liver lesions. This pictorial review is illustrated with cases of renal and hepatic lesions that the practicing radiologist should become familiar with as CEUS becomes increasingly popular.

Thoracic Outlet Syndrome-An Uncommon Cause of Acute Upper-Limb Ischemia.

ABSTRACT: Acute upper-limb ischemia is usually secondary to thromboembolic occlusion. The heart is the usual source of emboli in the majority of patients. In a small percentage of cases, the thromboembolic process may start in a proximal large-sized artery, such as the subclavian artery, resulting in thromboembolic occlusion of the upper extremity's small peripheral arteries. In patients with acute upper-limb ischemia, a systematic color flow Doppler ultrasound of the upper extremity arteries may reveal thoracic outlet syndrome as the underlying cause. This pictorial review presents a systemic color flow Doppler approach to evaluate upper extremity arteries in patients with thoracic outlet syndrome presenting as acute ischemia.

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.

Predicting pelvic congestion syndrome: Concomitant pelvic pain diagnoses do not affect venography or embolization outcomes.

OBJECTIVES: Pelvic congestion syndrome (PCS) is a challenging diagnosis to make secondary to nonspecific presenting symptoms and imaging findings. This retrospective review aims to discern predictive factors which can guide the decision to perform catheter-based venography and prognosticate outcomes. MATERIAL AND METHODS: A retrospective analysis of patients who underwent catheter venography for PCS between January 2014 and December 2019 was performed. Multiple factors, including patient demographics, clinical history, pre-procedural imaging, venographic findings, and treatment outcomes 180 days post-procedure, were included in the analysis. Venographic findings were used to separate patients into two groups (positive or negative), with these factors compared across groups. Regression analysis controlled for the confounding effects of age and body mass index (BMI). Treated subjects were separated based on outcome (partial, no response, complete response, or technical failure), and comparisons were performed. RESULTS: Eighty patients were included in the initial analysis. Two patients were excluded due to prior embolization or portal hypertension. Seventy-eight patients were included in the final analysis. Sixty-two patients had positive findings, and 16 had no venographic findings to suggest PCS. A history of prior pregnancy was a significant predictor of positive venographic results (odds ratio = 5.99, P = 0.007). BMI was significantly lower in those with positive venographic results (P = 0.047). Presence of concomitant diagnoses did not affect venographic findings or treatment outcomes. No factors predicted treatment outcomes. Five of the treated patients had subsequent successful pregnancies. CONCLUSION: A lower BMI supports the decision to perform venography for suspected PCS. In addition, patients who carried concomitant potentially confounding diagnoses for chronic pelvic pain were found to have similar rates of venographic findings suggesting PCS, as well as similar treatment outcomes.

ACR Appropriateness Criteria® Adrenal Mass Evaluation: 2021 Update.

The appropriate evaluation of adrenal masses is strongly dependent on the clinical circumstances in which it is discovered. Adrenal incidentalomas are masses that are discovered on imaging studies that have been obtained for purposes other than adrenal disease. Although the vast majority of adrenal incidentalomas are benign, further radiological and biochemical evaluation of these lesions is important to arrive at a specific diagnosis. Patients with a history of malignancy or symptoms of excess hormone require different imaging evaluations than patients with incidentalomas. This document reviews imaging approaches to adrenal masses and the various modalities utilized in evaluation of adrenal lesions. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Sonographic Evaluation of Pelvic Venous Disorders.

ABSTRACT: Pelvic venous disorders are a group of interrelated conditions characterized by venous incompetence. These conditions often manifest with nonspecific symptoms that overlap with many gynecological, gastrointestinal, and urologic diseases. Clinical diagnosis can be difficult, and imaging can play a vital role in differentiating etiology. Sonographic evaluation is often the first step in evaluating these symptoms. Special attention to possible underlying pelvic venous disorders can reveal characteristic findings, support diagnosis, and guide treatment. Here we review pelvic congestion syndrome, nutcracker syndrome, May-Thurner syndrome, and other venous disorders, with a specific focus on sonographic findings and considerations.

Role of color flow Doppler ultrasound in the evaluation of acute scrotal pain.

Color flow Doppler ultrasound is a critical tool in the assessment of the scrotum. Ultrasound is the first-line imaging modality and can rapidly differentiate between surgical and nonsurgical conditions, allowing for appropriate and prompt patient management. We review the role of color flow Doppler in the evaluation of acute scrotal pain, highlighting some of the most commonly seen pathologies such as epididymo-orchitis and testicular torsion.

ACR Appropriateness Criteria® Renal Failure.

Renal failure can be divided into acute kidney injury and chronic kidney disease. Both are common and result in increased patient morbidity and mortality. The etiology is multifactorial and differentiation of acute kidney injury from chronic kidney disease includes clinical evaluation, laboratory tests, and imaging. The main role of imaging is to detect treatable causes of renal failure such as ureteral obstruction or renovascular disease and to evaluate renal size and morphology. Ultrasound is the modality of choice for initial imaging, with duplex Doppler reserved for suspected renal artery stenosis or thrombosis. CT and MRI may be appropriate, particularly for urinary tract obstruction. However, the use of iodinated and gadolinium-based contrast should be evaluated critically depending on specific patient factors and cost-benefit ratio. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

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.

ACR Appropriateness Criteria® Indeterminate Renal Mass.

Renal masses are increasingly detected in asymptomatic individuals as incidental findings. CT and MRI with intravenous contrast and a dedicated multiphase protocol are the mainstays of evaluation for indeterminate renal masses. A single-phase postcontrast dual-energy CT can be useful when a dedicated multiphase renal protocol CT is not available. Contrast-enhanced ultrasound with microbubble agents is a useful alternative for characterizing renal masses, especially for patients in whom iodinated CT contrast or gadolinium-based MRI contrast is contraindicated. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Idiopathic Granulomatous Mastitis and its Mimics on Magnetic Resonance Imaging: A Pictorial Review of Cases from India.

OBJECTIVES: Idiopathic granulomatous mastitis (IGM) is a rare inflammatory disease of the breast, which is benign but potentially morbid. Mammographic and sonographic findings have been well characterized, but magnetic resonance imaging (MRI) findings have been less thoroughly documented. The objective of this study was to demonstrate characteristic findings for IGM and its mimics via a retrospective review. MATERIAL AND METHODS: Breast MRI examinations performed at Sir Ganga Ram Hospital in New Delhi, India between 2014 and 2019 were retrospectively reviewed to identify cases in which a pattern suggestive of granulomatous mastitis was seen. Cases of known malignancy were excluded. Any available breast pathology results were then obtained, and cases with presumptive or definitive diagnoses were compiled for analysis. RESULTS: Overall, cases identified with characteristic imaging findings and confirmed diagnosis included seven cases of IGM, four cases of invasive ductal carcinoma, two cases of tuberculous mastitis, one case of non- tuberculous infectious mastitis, one case of foreign body mastitis, and one case of eosinophilc mastitis. One case of IGM with masses rather than of non-mass enhancement was also identified. CONCLUSION: In our review, cases with clustered ring enhancement were found to have inflammatory, idiopathic, infectious and malignant etiologies. While, these etiologies can only be reliably differentiated on pathology, familiarity with the pattern and an awareness of the differential may lead to decreased morbidity due to delays in diagnosis.

Compressed sensing for reduced hardware footprint in medical ultrasound.

In this work, a compressed sensing method to reduce hardware complexity of ultrasound imaging systems is proposed and experimentally verified. We provide clinical evaluation of the method with a possible high compression rates (up to 64 RF signals compressed into a single channel on receive) which uses elastic net estimation for decoding stage. This allows a reduction in size and power consumption of the front-end electronics with only a minor loss in image quality. We demonstrate an 8-fold receive channel count reduction with a 3.16 dB and 3.64 dB mean absolute error for gallbladder and kidney images, respectively, as well as 7.4% increase in the contrast-to-noise ratio for kidney images and 0.1% loss in the contrast-to noise ratio for gallbladder images, on average. The proposed method may enable a fully portable ultrasonic device with virtually no loss in image quality as compared to a full size clinical scanner to be constructed.