US of the Penis: Beyond Erectile Dysfunction.

High-frequency US, with a linear transducer and gray-scale, color, and spectral Doppler US techniques, is the primary imaging modality for evaluation of the penis. It can allow delineation of anatomy and assessment of dynamic blood flow; it is easily available and noninvasive or minimally invasive; it is cost effective; and it is well tolerated by patients. US assessment after pharmacologic induction of erection is an additional tool in assessing patients with suspected vasculogenic impotence, and also in selected patients with penile trauma and suspected Peyronie disease. Penile injuries, life-threatening infections, and vascular conditions such as priapism warrant rapid diagnosis to prevent long-term morbidities due to clinical misdiagnosis or delayed treatment. US can facilitate a timely diagnosis in these emergency conditions, even at the point of care such as the emergency department, which can facilitate timely treatment. In addition, color and spectral Doppler US are valuable applications in the follow-up of patients treated with endovascular revascularization procedures for vasculogenic erectile dysfunction. Image optimization and attention to meticulous techniques including Doppler US is vital to improve diagnostic accuracy. Radiologists should be familiar with the detailed US anatomy, pathophysiologic characteristics, scanning techniques, potential pitfalls, and US manifestations of a wide spectrum of vascular and nonvascular penile conditions to suggest an accurate diagnosis and direct further management. The authors review a range of common and uncommon abnormalities of the penis, highlight their key US features, discuss differential diagnosis considerations, and briefly review management. ©RSNA, 2024 Supplemental material is available for this article.

Polyarteritis Nodosa.

Online supplemental material is available for this article.

Preparing IR for COVID-19: The Singapore Experience.

This paper describes country-wide special measures undertaken for interventional radiology staff during the current coronavirus disease 2019 (COVID-19) pandemic. Although each interventional radiology service around the world faces unique challenges, the principles outlined in this article will be useful when designing or strengthening individual practices and integrating them within wider hospital and national measures. Moving beyond the current outbreak, these measures will be useful for any future infectious diseases which are likely to arise.

Diagnostic Ultrasound Services During the Coronavirus Disease (COVID-19) Pandemic.

OBJECTIVE. Nosocomial transmission of coronavirus disease (COVID-19) to frontline health care workers is well known, and health care workers may inadvertently become vectors for onward transmission. Ultrasound (US) service providers are at significant risk because scanning usually requires prolonged close patient contact. The bulky US equipment may also facilitate fomite transmission of disease. With increasing use of point-of-care and portable diagnostic US services, the risk is substantial. CONCLUSION. Our experience and protocols may help service providers with their own effective response against COVID-19.

Case 265: Lemmel Syndrome or Biliary Obstruction Due to a Periampullary Duodenal Diverticulum.

History A 70-year-old man presented to the emergency department with fever, chills, rigors, and upper abdominal discomfort. Physical examination revealed jaundice and mild right upper quadrant tenderness. Laboratory tests revealed an increased C-reactive protein level of 133 mg/L (normal range, 0.2-0.9 mg/L), a white blood cell count of 11.69 ×109/L (normal range, 4-10 ×109/L), and an obstructive pattern on liver function tests, with a total bilirubin level of 3.5 mg/dL (59.9 µmol/L) (normal range, 0.4-1.9 mg/dL [6.8-32.5 µmol/L]), an alkaline phosphatase level of 716 U/L (11.9 µkat/L) (normal range, 39-99 U/L [0.65-1.65 µkat/L]), and an aspartate aminotransferase level of 88 U/L (1.47 µkat/L) (normal range, 12-42 U/L [0.20-0.70 µkat/L]). Serum amylase level was within normal limits at 84 U/L (1.40 µkat/L) (normal range, 38-149 U/L [0.63-2.48 µkat/L]). A clinical diagnosis of hepatobiliary sepsis due to ascending cholangitis was made. Relevant medical history included gastric carcinoma treated with a Billroth II surgical procedure 17 years earlier that was performed in conjunction with cholecystectomy. In addition, there were episodes of ascending cholangitis 6-12 months prior to the current admission that were managed conservatively with antibiotics at another institution. Blood cultures were positive for Klebsiella oxytoca. Administration of intravenous antibiotics was started, and CT examination of the abdomen was performed. Because a previous Billroth II procedure had been performed, the patient underwent percutaneous transhepatic cholangiography.

Case 265.

History A 70-year-old man presented to the emergency department with fever, chills, rigors, and upper abdominal discomfort. Physical examination revealed jaundice and mild right upper quadrant tenderness. Laboratory tests revealed an increased C-reactive protein level of 133 mg/L (normal range, 0.2-0.9 mg/L), a white blood cell count of 11.69 ×109/L (normal range, 4-10 ×109/L), and an obstructive pattern on liver function tests, with a total bilirubin level of 3.5 mg/dL (59.9 µmol/L) (normal range, 0.4-1.9 mg/dL [6.8-32.5 µmol/L]), an alkaline phosphatase level of 716 U/L (11.9 µkat/L) (normal range, 39-99 U/L [0.65-1.65 µkat/L]), and an aspartate aminotransferase level of 88 U/L (1.47 µkat/L) (normal range, 12-42 U/L [0.20-0.70 µkat/L]). Serum amylase level was within normal limits at 84 U/L (1.40 µkat/L) (normal range, 38-149 U/L [0.63-2.48 µkat/L]). A clinical diagnosis of hepatobiliary sepsis due to ascending cholangitis was made. Relevant medical history included gastric carcinoma treated with a Billroth II surgical procedure 17 years earlier that was performed in conjunction with cholecystectomy. In addition, there were episodes of ascending cholangitis 6-12 months prior to the current admission that were managed conservatively with antibiotics at another institution. Blood cultures were positive for Klebsiella oxytoca. Administration of intravenous antibiotics was started, and CT examination of the abdomen was performed ( Fig 1 ). Because a previous Billroth II procedure had been performed, the patient underwent percutaneous transhepatic cholangiography ( Fig 2 ). Figure 1a: (a) Arterial phase axial CT image at the level of the pancreatic head. (b) Portal venous phase coronal reformatted CT image shows the upper abdomen. Figure 1b: (a) Arterial phase axial CT image at the level of the pancreatic head. (b) Portal venous phase coronal reformatted CT image shows the upper abdomen. Figure 2: Fluoroscopic image obtained with percutaneous transhepatic cholangiography during the most recent admission.

Diagnosis and Management of Complications from Percutaneous Biliary Tract Interventions.

Complications related to percutaneous biliary tract interventions (PBTIs) can range from access site discomfort to life-threatening vascular complications. These complications are relatively uncommon, and most of them are self-limiting. However, major complications for which an increased level of patient care and/or a prolonged hospital stay are required and that may lead to death-albeit rarely-can occur. Some of the most common complications related to PBTI include pain, infection, bile leakage, and catheter blockage. These conditions can be easily recognized by using the patient's clinical history and laboratory examination results. However, the more uncommon complications, such as life-threatening hemobilia, acute pancreatitis, and catheter and stent fractures, may have nonspecific clinical manifestations, and the underlying pathologic condition may be found only when it is being sought specifically. It is important that diagnostic and interventional radiologists be aware of the wide spectrum of PBTI-related complications, as early recognition and treatment may prevent catastrophic situations. In addition, knowledge of the different treatment options is essential for guidance in interventional radiology procedures such as transarterial control of hemobilia, imaging-guided direct percutaneous embolization of pseudoaneurysms, and percutaneous treatment of catheter- and stent-related complications such as fractures. The authors review a wide spectrum of complications associated with PBTI and the percutaneous management of these conditions. They also highlight valuable lessons learned from morbidity and mortality rounds at a high-volume tertiary care center. ©RSNA, 2017.

Vascular complications related to image-guided percutaneous thermal ablation of hepatic tumors

Percutaneous thermal ablation of hepatic tumors is accepted as a safe, reliable, and cost-effective therapeutic option for treating hepatocellular carcinoma and hepatic metastases. However, operators should be familiar with the myriad of vascular and non-vascular complications that can occur post-ablation and that are described in the literature. This review will focus on the various vascular complications related to percutaneous thermal ablation of hepatic tumors and discuss strategies to avoid and manage these complications.

Concordance of the ACR TI-RADS Classification With Bethesda Scoring and Histopathology Risk Stratification of Thyroid Nodules.

Importance: Although most thyroid nodules are benign, 10% to 15% of them harbor cancer. Thyroid ultrasonography is useful for risk stratification of nodules, and American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) classification provides recommendations for fine-needle aspiration cytology (FNAC) based on objective ultrasonographic features of these nodules. Objective: To validate the concordance of ACR TI-RADS classification with Bethesda classification and histopathology. Design, Setting, and Participants: This retrospective cohort study was performed to evaluate the concordance of ACR TI-RADS classification with Bethesda classification and histopathology and was conducted in Singapore General Hospital Outpatient Otolaryngology clinic in March 2021 to May 2021. Data analysis was performed in May 2021. Main Outcomes and Measures: Results were deemed concordant when ACR TI-RADS recommendations aligned with Bethesda scores. Conversely, results were classified as nonconcordant with Bethesda scores and/or histopathology results when nodules that were recommended for FNAC yielded benign results or nodules that were not recommended for FNAC yielded malignant results. Results: A total of 446 patients (370 women [83%]; mean [range] age, 60 [24-89] years) who underwent ultrasonography of the thyroid and ultrasonography-guided thyroid FNACs were identified. A total of 492 of 630 nodules (78.1%) were benign on FNAC (Bethesda II). Score 3 ACR TI-RADS nodules yielded the highest negative predictive values: 94.6% (95% CI, 92.9%-95.9%; P < .001) compared with Bethesda scoring and 100.0% (95% CI, 15.8%-100.0%; P = .003) compared with histopathology. Score 4 or 5 ACR TI-RADS nodules yielded positive predictive values of 2.8% and 16.2%, respectively, compared with Bethesda scoring and 6.1% and 66.7%, respectively, compared with histopathology. Small (<1.5 cm) ACR TI-RADS nodules of scores of 4 and 5 that were not recommended for FNAC yielded a malignant risk of 5.7% and 25.0% on Bethesda 5 and 6, respectively. On surgical excision, 5 of 46 (10.9%) ACR TI-RADS 4 nodules and 15 of 21 (71.4%) of ACR TI-RADS 5 nodules were confirmed to be malignant. Among nodules initially not recommended for FNAC, histopathology-proven cancer was found in 4 of 13 (30.7%) and 3 of 6 (50.0%) of nodules, respectively. Conclusions and Relevance: These findings suggest that ACR TI-RADS score 3 nodules have a low risk of cancer and should be considered for FNAC only if nodules are 2.5 cm or larger. Patients with small (<1.5 cm) ACR TI-RADS 4 and 5 nodules should be appropriately counseled for FNAC to exclude cancer.

Imaging features of therapeutic drug-induced musculoskeletal abnormalities.

Increasing use of a wide variety of therapeutic drugs with known musculoskeletal side-effect profiles necessitates a rigorous understanding and approach when evaluating imaging features suggestive of drug-induced musculoskeletal abnormalities. The etiology of such abnormalities is diverse, and the clinical and imaging manifestations may be nonspecific. The recognition of adverse effects depends, first, on the physician's vigilant review of clinical information for relevant drug history and indicative signs, and second, on the radiologist's ability to detect musculoskeletal changes consistent with known potential effects of specific drugs. Musculoskeletal abnormalities induced by therapeutic drugs may be broadly categorized as embryopathic, juvenile, or postmaturation. Embryopathic skeletal abnormalities result from the teratogenic effects of drugs administered to pregnant women (eg, thalidomide, anticonvulsants). Other therapeutic agents characteristically lead to abnormalities during postnatal skeletal maturation (eg, high-dose vitamins or prostaglandin) either because they are used exclusively in children or because they have idiosyncratic effects on immature musculoskeletal structures. Many drugs (eg, statins) may have musculoskeletal side effects that, although independent of the stage of skeletal maturation, are most often seen in adults or elderly people because they are commonly prescribed for people in these age groups. Drug-induced musculoskeletal abnormalities may be further characterized according to the predominant skeletal manifestations as osteomalacic, proliferative, or osteoporotic and according to the involvement of soft tissues as musculotendinous or chondral.

A Tale of Two Organ Systems: Imaging Review of Diseases Affecting the Thoracic and Neurological Systems. Part 2.

In an era of rapidly expanding knowledge and sub-specialization, it is becoming increasingly common to focus on one organ system. However, the human body is intimately linked, and disease processes affecting one region of the body not uncommonly affect the other organ systems as well. Understanding diseases from a macroscopic perspective, rather than a narrow vantage point, enables efficient and accurate diagnosis. This tenet holds true for diseases affecting both the thoracic and neurologic systems; in isolation, the radiologic appearance of disease in one organ system may be nonspecific, but viewing the pathophysiologic process in both organ systems may markedly narrow the differential considerations, and potentially lead to a definitive diagnosis. In this article, we discuss a variety of disease entities known to affect both the thoracic and neurological systems, either manifesting simultaneously or at different periods of time. Some of these conditions may show neither thoracic nor neurological manifestations. These diseases have been systematically classified into infectious, immune-mediated/ inflammatory, vascular, syndromic/ hereditary and neoplastic disorders. The underlying pathophysiological mechanisms linking both regions and radiologic appearances in both organ systems are discussed. When appropriate, brief clinical and diagnostic information is provided. Ultimately, accurate diagnosis will lead to expedited triage and prompt institution of potentially life-saving treatment for these groups of complex disorders.

A Tale of Two Organ Systems: Imaging review of diseases affecting the thoracic and neurological systems. Part 1.

In an era of rapidly expanding knowledge and sub-specialization, it is becoming increasingly common to focus on one organ system. However, the human body is intimately linked, and disease processes affecting one region of the body not uncommonly affect the other organ systems as well. Understanding diseases from a macroscopic perspective, rather than a narrow vantage point, enables efficient and accurate diagnosis. This tenet holds true for diseases affecting both the thoracic and neurological systems; in isolation, the radiologic appearance of disease in one organ system may be nonspecific, but viewing the pathophysiologic process in both organ systems may markedly narrow the differential considerations, and potentially lead to a definitive diagnosis. In this article, we discuss a variety of disease entities known to affect both the thoracic and neurological systems, either manifesting simultaneously or at different periods of time. Some of these conditions may show neither thoracic nor neurological manifestations. These diseases have been systematically classified into infectious, immune-mediated / inflammatory, vascular, syndromic / hereditary and neoplastic disorders. The underlying pathophysiological mechanisms linking both regions and radiologic appearances in both organ systems are discussed. When appropriate, brief clinical and diagnostic information is provided. Ultimately, accurate diagnosis will lead to expedited triage and prompt institution of potentially life-saving treatment for these groups of complex disorders.

Cost-Effectiveness of Drug-Coated Balloon Angioplasty Versus Conventional Balloon Angioplasty for Treating Below-the-Knee Arteries in Chronic Limb-Threatening Ischemia: The SINGA-PACLI Trial.

PURPOSE: Drug-coated balloon angioplasty (DCBA) has been studied as a potentially superior option compared to conventional percutaneous transluminal angioplasty (PTA) in treating below-the-knee (BTK) arteries in chronic limb-threatening ischemia (CLTI). The aim of this study is to examine the cost-effectiveness of DCBA versus PTA in BTK arteries based on a randomized controlled trial. MATERIAL AND METHODS: A prospective economic study was embedded in a randomized controlled trial of 138 patients with CLTI. Resource use and health outcomes were assessed at baseline, and at 3, 6 and 12 months post-intervention. Costs were calculated from a societal perspective and health outcomes measured using quality-adjusted life years with probabilistic sensitivity analysis performed to account for subject heterogeneity. RESULTS: Compared with participants randomized to receive PTA, participants randomized to DCBA gained an average baseline-adjusted quality-adjusted life years (QALYs) of .012 while average total costs were USD$1854 higher; this translates to an incremental cost-effectiveness ratio (ICER) of US$154,500 additional cost per QALY gained. However, the estimate of ICER had substantial variance with only 48% of bootstrap ICERs meeting a benchmark threshold of US$57,705 (the average gross domestic product (GDP) per capita of Singapore). CONCLUSION: The use of DCBA in BTK arteries in CLTI patients was not cost-effective compared with PTA. LEVEL OF EVIDENCE: 2, Randomized trial.

Recurrent Stenoses in Arteriovenous Fistula (AVF) for Dialysis Access: cuttIng ballooN angioplaSTy combined wITh paclitaxel drUg-coaTed balloon angioplasty, an observatIONal study (INSTITUTION Study).

PURPOSE: To study the safety and efficacy of cutting balloon angioplasty (CBA) followed by paclitaxel drug-coated balloon (PCB) angioplasty for recurrent venous lesions in arteriovenous fistulas (AVFs). MATERIALS AND METHODS: We conducted a prospective single-arm cohort study of CBA followed by PCB angioplasty for recurrent AVF stenoses between September 2017 and April 2019. In total, 44 participants were recruited. Target lesions were included if they had recurred within 12 months post-angioplasty, were > = 0.5 cm upstream from the arteriovenous anastomosis, and did not involve the central veins. Up to two non-target lesions per circuit/participant with the same definition were allowed. Lesions were considered separate when there was an intervening 2-cm segment of normal vessel. Technical success was defined as complete lesion effacement on angioplasty. End-points of target and circuit patency were evaluated clinically at 3, 6, and 12 months post-procedure. RESULT: Technical success was 96% (42/44): Two participants were excluded from analysis due to the need for high-pressure balloon angioplasty as the target lesions did not efface with CBA. The median follow-up duration was 337.5 days. Mean stenosis pre- and post-angioplasty was 69.0% (51.6-84.8) and 20.8% (0-44.8), respectively. The target lesion primary, primary assisted and circuit patency for the entire study population (n = 42) were 61.6 ± 7.8%, 92.7 ± 4.0%, and 54.7 ± 7.9%, respectively, at 12 months. For participants without non-target lesions (n = 22), the rates were 77.3 ± 8.9%, 90.9 ± 6.1%, and 60.7 ± 11.0%, respectively, at 12 months. CONCLUSION: CBA followed by PCB angioplasty appears safe and feasible for treatment of recurrent venous lesions in dysfunctional AVFs.

Usual and unusual causes of splaying of the carotid artery bifurcation: the Lyre sign--a pictorial review.

The 'Lyre' sign describes the characteristic splaying of the carotid artery bifurcation due to a carotid body tumour (paraganglioma) on conventional carotid angiography. In this pictorial review, we describe and illustrate two cases demonstrating the equivalent Lyre sign on multi-detector computed tomography (MDCT) and ultrasound resulting from carotid body tumour and extra-cranial internal carotid artery pseudoaneurysm. Both of these pathologies can manifest acutely and warrant accurate diagnosis to prevent potential catastrophic consequences. We also emphasise the added value of MDCT in making a definitive diagnosis and discuss other differential considerations splaying the carotid bifurcation.

Pictorial review: computed tomography features of cardiovascular emergencies and associated imminent decompensation.

Multi-detector computed tomography (MDCT) scanner is available in most hospitals and is increasingly being used as the first line imaging in trauma and suspected cardiovascular emergencies, such as acute coronary syndrome, pulmonary artery thrombo-embolism, abdominal aortic aneurysm and acute haemorrhage (Ryan et al. Clin Radiol 60:599-607, 2005). A significant number of these patients are haemodynamically unstable and can rapidly progress into shock and death. Recognition of computed tomography (CT) signs of imminent cardiovascular decompensation will alert the clinical radiologist to the presence of shock. In this review, the imaging findings of cardiovascular emergencies in both acute traumatic and non-traumatic settings with associated signs of imminent decompensation will be described and illustrated.

Use of the term "superficial femoral vein" in ultrasound.

PURPOSE: To determine the frequency of use of the term "superficial femoral vein" (SFV) in the radiologic reports from a sample of sonographic investigations for suspected deep vein thrombosis and to assess the potential for clinical error in their interpretation. METHODS: Retrospective review of 425 consecutive reports from medical patients attending the Imaging Department over a 6-month period for the presence of the term "superficial femoral vein" and for the presence of thrombus. A questionnaire was sent to a sample of referring clinicians to assess their understanding of the anatomy of the deep venous system of the leg and indications for anticoagulant treatment. RESULTS: Of the 425 sonographic investigations reviewed, 90 (21.2%) used the term "superficial femoral vein," and 12 (13.3%) were positive for SFV thrombus. Among 87 clinicians, 74.7% believed the SFV to be part of the superficial venous system and that its thrombosis did not require anticoagulant treatment, although anticoagulation is now indicated in selected cases of superficial venous thrombosis. CONCLUSION: Seventy-five percent of clinicians do not recognize the SFV as being part of the deep venous system and that its thrombosis requires anticoagulant treatment. In this study, 13% of SFV examined were positive for thrombus, and four patients (4.4%) had an isolated SFV thrombus that could have been left untreated due to this misunderstanding. Use of the term "superficial femoral vein" is prone to misinterpretation by clinicians and potentially hazardous to patients. It should be replaced by "common femoral vein" and "femoral vein" in reports.