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.

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.

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.

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.

Real-time sonoelastography for the evaluation of testicular lesions.

PURPOSE: To evaluate the feasibility of using real-time sonoelastography (RTE) for the differentiation and characterization of testicular lesions. MATERIALS AND METHODS: Institutional review board approval was obtained for this retrospective study, and the requirement to obtain informed consent was waived. Fifty patients (mean age, 42 years; age range, 18-81 years) with testicular lesions detected with gray-scale ultrasonography (US) and color and/or power Doppler US were evaluated with RTE between December 2004 and August 2010 to assess tissue elasticity of the testes. Stiff or "hard" lesions were suspected of being malignant. Testicular lesions with normal or decreased tissue stiffness ("soft" lesions) were considered benign. Findings from surgery and histopathologic examination were used as the reference standard in 34 cases, and findings from clinical and US follow-up were used as the reference standard in 16 cases. Sensitivity, specificity, negative predictive value, positive predictive value, and diagnostic accuracy were calculated. RESULTS: Thirty-four of the 50 lesions (68%) were testicular tumors and 16 (32%) were of nontumorous origin. RTE showed the presence of hard lesions in all cases of testicular tumors and three cases of nontumorous lesions. Four lesions with an uncertain diagnosis when tested with gray-scale US and color and/or power Doppler US alone were soft at RTE and showed nontumorous character at follow-up. RTE showed a sensitivity of 100%, a specificity of 81%, a negative predictive value of 100%, a positive predictive value of 92%, and an accuracy of 94% in the diagnosis of testicular tumors. CONCLUSION: RTE demonstrated all testicular tumors as lesions with increased tissue stiffness. Because of its higher specificity, RTE can provide additional information in cases with indeterminate US findings.

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.

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.

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.

Iatrogenic Ureteral Injury as a Complication of Posterior or Lateral Lumbar Spine Surgery: A Systematic Review of the Literature.

OBJECTIVE: Iatrogenic ureteral injury associated with lumbar spine surgery is an uncommon but devastating complication with associated medicolegal implications. METHODS: We performed a systematic review of the English language literature published between 1954 and 2019, accessed through 4 popular databases. We found 44 articles (28 case reports, 9 case-based reviews, 4 case series, 1 original article, 1 case illustration, and 1 pictorial) containing 46 cases of ureteral injuries after posterior or lateral lumbar spine surgery. RESULTS: Except for 5 cases with insufficient data, 24 of the remaining 41 patients were female and 17 were male, with ages ranging from 16 years to 83 years. Excluding 4 cases without enough information, initial diagnoses of lumbar disc herniation (n = 33) or lumbar spinal stenosis (n = 4), spondylolisthesis (n = 3), degenerative disc disease (n = 1), and failed back surgery syndrome (n = 1) were reported from 18 countries; 54% of patients were from the United States, Japan, or Turkey. The interval from spinal surgery to restorative surgery ranged from <24 hours to 1 month to 1 year; in 48% of patients, it was >1 week, and 90% of patients recovered completely. Initial surgery was combined with vascular injury in 15% of patients. CONCLUSIONS: Ureteral injury associated with lumbar spine surgery is overreported in developed or developing countries. It should be considered in the differential diagnosis of any patient who presents with symptoms of acute abdomen after lumbar spine surgery, and patients who underwent restorative surgery had a good prognosis.

Metastatic pheochromocytoma to the pancreas diagnosed by endoscopic ultrasound-guided fine needle aspiration: A case report and review of literature.

Pancreatic pheochromocytomas are rare and typically diagnosed by local resection. We present the first reported case of metastatic pheochromocytoma to the pancreas diagnosed by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) and cytology. A 67-year-old female presented with 2 to 3 months of abdominal pain. A CT scan showed a large mass in the head of the pancreas engulfing the superior mesentery artery and vein, along with a large mass in the left adrenal gland. An EUS-FNA was performed on the pancreatic mass with a 22-gauge needle, yielding an adequate sample. Papanicolaou stain, Diff-Quik, and cell block showed loosely cohesive clustered tumor cells and singly dispersed pleomorphic naked tumor nuclei with anisonucleosis and cytoplasmic vacuolization. Tumor cells stained positive for synaptophysin, chromogranin A, and CD56 and negative for CK AE1/3 and CK AE1/3-CAM5.2 cytokeratin cocktail. Because of cytokeratin negativity, diffusely positive neuroendocrine markers, and the presence of an adrenal mass, a metastatic malignant pheochromocytoma was suspected. Additional testing showed elevations in plasma metanephrines and normetanephrines, urine metanephrine-to-creatinine and normetanephrine-to-creatinine ratios, and serum chromogranin A. An iodine123 -metaiodobenzylguanidine (MIBG) scan was obtained, which showed significantly increased MIBG uptake in the left adrenal lesion. A diagnosis of metastatic malignant pheochromocytoma was made. Surgical oncology was consulted, who recommended against resection of the adrenal mass in favor of outpatient management. Metastatic pheochromocytoma to the pancreas are rare tumors that may yield diagnostic material by EUS-FNA with a 22-gauge needle.

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.

ACR Appropriateness Criteria® Hematuria.

Hematuria is a common reason for patients to be referred for imaging of the urinary tract. All patients diagnosed with hematuria should undergo a thorough history and physical examination, urinalysis, and serologic testing prior to any initial imaging. Ultrasound, CT, and MRI are the most common imaging modalities used to evaluate hematuria. This document discusses the following clinical scenarios for hematuria: initial imaging of microhematuria without risk factors or history of recent vigorous exercise, or presence of infection, or viral illness, or present or recent menstruation; initial imaging of microhematuria in patients with known risk factors and no history of recent vigorous exercise, or presence of infection, or viral illness, or present or recent menstruation or renal parenchymal disease; initial imaging of microhematuria in the pregnant patient and initial imaging of gross hematuria. Follow-up of normal or abnormal findings is beyond the scope of this review. 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.

Metastatic versus primary oncocytic papillary adenocarcinoma of the endometrium: a report of a case and review of the literature.

We report a case of an oncocytic papillary adenocarcinoma of the endometrium in an 89-year-old female with vaginal bleeding. Imaging studies revealed lesions in the uterus, kidneys, pancreas, gluteus, and an enlarged portacaval lymph node. Diagnostic workup included an endometrial biopsy which showed malignant, oncocytic cells in a predominantly papillary pattern. These cells stained positive for epithelial markers (pan-cytokeratin, CK7, epithelial membrane antigen) and weakly for estrogen receptor. The cells were negative for cytokeratin 903, CAM 5.2, progesterone receptor, CD10, RCC Marker, CA-125, c-kit, and vimentin. Consultation with experts in Gynecologic and Genitourinary pathology returned a diagnosis of "adenocarcinoma compatible with metastatic renal cell carcinoma"--an intriguing possibility worthy of further exploration. To our knowledge, there are no reports in the literature of metastatic oncocytic papillary renal cell carcinoma to the endometrium. The clinical and pathologic features of oncocytic papillary endometrial lesions, including primary and metastatic processes, are reviewed.

Multitechnique evaluation of renal hydatid disease.

OBJECTIVE: Hydatid involvement of the kidney accounts for only 2-4% of all cases of hydatid disease. The purpose of this article is to review the imaging features of hydatid disease of the kidney and thus show the role of radiography, excretory urography, sonography, CT, and MRI in the diagnosis of hydatidosis. CONCLUSION: The radiologist should be familiar with the imaging findings of hydatid disease because early diagnosis is important for more appropriate treatment.

Multiview spatial compounding using lens-based photoacoustic imaging system.

Recently, an acoustic lens has been proposed for volumetric focusing as an alternative to conventional reconstruction algorithms in Photoacoustic (PA) Imaging. Acoustic lens can significantly reduce computational complexity and facilitate the implementation of real-time and cost-effective systems. However, due to the fixed focal length of the lens, the Point Spread Function (PSF) of the imaging system varies spatially. Furthermore, the PSF is asymmetric, with the lateral resolution being lower than the axial resolution. For many medical applications, such as in vivo thyroid, breast and small animal imaging, multiple views of the target tissue at varying angles are possible. This can be exploited to reduce the asymmetry and spatial variation of system the PSF with simple spatial compounding. In this article, we present a formulation and experimental evaluation of this technique. PSF improvement in terms of resolution and Signal to Noise Ratio (SNR) with the proposed spatial compounding is evaluated through simulation. Overall image quality improvement is demonstrated with experiments on phantom and ex vivo tissue. When multiple views are not possible, an alternative residual refocusing algorithm is proposed. The performances of these two methods, both separately and in conjunction, are compared and their practical implications are discussed.

ACR Appropriateness Criteria® Post-Treatment Follow-up and Active Surveillance of Clinically Localized Renal Cell Cancer.

Renal cell carcinoma (RCC) accounts for most malignant renal tumors and is considered the most lethal of all urologic cancers. For follow-up of patients with treated or untreated RCC and those with neoplasms suspected to represent RCC, radiologic imaging is the most useful component of surveillance, as most relapses and cases of disease progression are identified when patients are asymptomatic. Understanding the strengths and limitations of the various imaging modalities for the detection of disease, recurrence, or progression is important when planning follow-up regimens. This publication addresses the appropriate imaging examinations for asymptomatic patients who have been treated for RCC with radical or partial nephrectomy, or ablative therapies. It also discusses the appropriate imaging examinations for asymptomatic patients with localized biopsy-proven or suspected RCC undergoing active surveillance. 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.

Utility of CT whirl sign in guiding management of small-bowel obstruction.

OBJECTIVE: The purpose of this study was to examine the relation between the CT whirl sign and outcome among patients with a clinical and radiologic diagnosis of small-bowel obstruction (SBO). MATERIALS AND METHODS: The cases of 453 patients who underwent abdominal CT because of clinical suspicion of SBO were reviewed retrospectively. Patients with a radiologic diagnosis of SBO were included. Management with surgery or medical therapy was correlated with the presence of the whirl sign and other radiologic findings. Statistical calculations were performed to determine the value of the whirl sign in predicting the type of management needed for SBO. RESULTS: According to CT criteria, 194 patients received a diagnosis of SBO and were included in the study. The whirl sign was identified on the CT scans of 40 of the 194 patients. Thirty-two of the 40 patients had SBO necessitating surgery, for a positive predictive value of 80%; 133 of 154 patients did not need surgery, for a negative predictive value of 86%. Fifty-three of 194 patients either underwent surgery or died of SBO during conservative therapy. The whirl sign was present on the CT scans of 32 of the 53 patients, for a sensitivity of 60%. One hundred thirty-three of 141 patients did not need surgery and did not have a whirl sign, for a specificity of 94%. The odds ratio for the whirl sign in predicting the presence of SBO necessitating surgery was 25.3 (95% CI, 10.3-62.3). CONCLUSION: A patient with the whirl sign on CT is 25.3 times as likely as a patient without the sign to have SBO necessitating surgery. The results suggest an important role of the whirl sign in assessment of treatment options for patients with clinical and radiologic signs of SBO.