Publications by authors named "Hisham Tchelepi"

27 Publications

  • Page 1 of 1

Current Ultrasound Technologies and Instrumentation in the Assessment and Monitoring of COVID-19 Positive Patients.

IEEE Trans Ultrason Ferroelectr Freq Control 2020 11 28;67(11):2230-2240. Epub 2020 Aug 28.

Since the emergence of the COVID-19 pandemic in December of 2019, clinicians and scientists all over the world have faced overwhelming new challenges that not only threaten their own communities and countries but also the world at large. These challenges have been enormous and debilitating, as the infrastructure of many countries, including developing ones, had little or no resources to deal with the crisis. Even in developed countries, such as Italy, health systems have been so inundated by cases that health care facilities became oversaturated and could not accommodate the unexpected influx of patients to be tested. Initially, resources were focused on testing to identify those who were infected. When it became clear that the virus mainly attacks the lungs by causing parenchymal changes in the form of multifocal pneumonia of different levels of severity, imaging became paramount in the assessment of disease severity, progression, and even response to treatment. As a result, there was a need to establish protocols for imaging of the lungs in these patients. In North America, the focus was on chest X-ray and computed tomography (CT) as these are widely available and accessible at most health facilities. However, in Europe and China, this was not the case, and a cost-effective and relatively fast imaging modality was needed to scan a large number of sick patients promptly. Hence, ultrasound (US) found its way into the hands of Chinese and European physicians and has since become an important imaging modality in those locations. US is a highly versatile, portable, and inexpensive imaging modality that has application across a broad spectrum of conditions and, in this way, is ideally suited to assess the lungs of COVID-19 patients in the intensive care unit (ICU). This bedside test can be done with little to no movement of the patients from the unit that keeps them in their isolated rooms, thereby limiting further exposure to other health personnel. This article presents a basic introduction to COVID-19 and the use of the US for lung imaging. It further provides a high-level overview of the existing US technologies that are driving development in current and potential future US imaging systems for lung, with a specific emphasis on portable and 3-D systems.
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http://dx.doi.org/10.1109/TUFFC.2020.3020055DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7654715PMC
November 2020

Contrast-Enhanced Ultrasound-Guided Interventions-The New Sheriff in Town?: A Case-Based Review of Problem Solving With Ultrasound Contrast.

Ultrasound Q 2020 Jun;36(2):91-101

Division of Ultrasonography, Keck School of Medicine, University of Southern California, Los Angeles, California.

Ultrasound (US)-guided intervention is a well-established medical procedure and offers advantages such as real-time guidance, portability, reduced cost, shortened procedure time compared with computed tomography, and lack of ionizing radiation. Ultrasound contrast agents (UCAs) are a useful adjunct to US-guided procedures. The addition of microbubble UCAs during US-guided interventions can assist with biopsy planning and lesion selection, aid in identification of target lesions, and direct the biopsy toward viable tissue. Ultrasound contrast agents have been in use outside of the United States for many years and have been used off label at select institutions across the United States before the Food and Drug Administration approval of Lumason (Bracco Diagnostics) for liver lesion evaluation in April 2016. After Food and Drug Administration approval, the use of UCAs has expanded rapidly, and UCAs are being used for a variety of clinical applications. Ultrasound contrast agents have been shown to be safe, and there is no renal toxicity. In this article, we will discuss the indications and techniques for using contrast-enhanced ultrasound during US-guided interventions, and we will present case examples where contrast-enhanced ultrasound added value.
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http://dx.doi.org/10.1097/RUQ.0000000000000455DOI Listing
June 2020

Contrast-Enhanced Ultrasound Appearance of Hypervirulent Klebsiella pneumoniae Liver Abscesses.

J Ultrasound Med 2020 Jul 5;39(7):1447-1452. Epub 2020 Feb 5.

Department of Radiology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.

There has been a paradigm shift with Klebsiella pneumoniae (KP) emerging as the most frequently isolated bacterium in pyogenic liver abscesses in immunocompetent patients. Colonization of this hypervirulent KP strain has led to community-acquired liver abscesses. Septic seeding to distant sites of the body has been recognized and is strongly associated with diabetes. Contrast-enhanced computed tomographic features have been described. Grayscale ultrasound (US) features remain inconclusive, with variable US appearances. Here we describe the contrast-enhanced US features of KP liver abscesses, which correlated with previously described computed tomographic findings. The use of contrast-enhanced US eliminates the need for radiation exposure.
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http://dx.doi.org/10.1002/jum.15235DOI Listing
July 2020

Assessment of Fibrosis in Liver Transplant Recipients: Diagnostic Performance of Shear Wave Elastography (SWE) and Correlation of SWE Findings With Biopsy Results.

AJR Am J Roentgenol 2019 12 1;213(6):W264-W271. Epub 2019 Oct 1.

Department of Radiology, Keck School of Medicine, University of Southern California, 2nd Fl, Imaging, 1500 San Pablo St, Los Angeles, CA 90033.

Liver transplant patients are monitored for rejection and hepatic fibrosis and often undergo liver biopsies. The purpose of the present study is to determine whether noninvasive shear wave elastography (SWE) can quantify fibrosis in liver transplant recipients, with the aim of decreasing and possibly eliminating unnecessary biopsies for patients with suspected or progressive hepatic fibrosis. Between May 1, 2015, and December 31, 2017, our prospective study evaluated 111 adult liver transplant patients (age range, 23-79 years) who underwent 147 ultrasound (US) SWE examinations of the right hepatic lobe followed by biopsies. SWE values were compared with the histologic fibrosis (Metavir) scores of the biopsy samples. SWE threshold values were determined using classification and regression tree analysis by anchoring to the degree of fibrosis. The sensitivity, specificity, positive predictive value, and negative predictive value (with 95% CIs) were calculated on the basis of the threshold value. Overall prediction accuracy was estimated using the AUC value from the ROC curve. From the 147 US SWE examinations and liver biopsies, consistent threshold values were identified for patients with no or minimal fibrosis (Metavir scores of F0 and F1, respectively) compared with significant fibrosis (Metavir scores of F2, F3, or F4). A median SWE value of 1.76 m/s or less denoted no or minimal fibrosis, whereas a value greater than 1.76 m/s denoted significant fibrosis. The sensitivity of US SWE examinations in classifying fibrosis was 0.77 (95% CI, 0.5-0.93). The specificity, positive predictive value, and negative predictive value were 0.79 (95% CI, 0.71-0.86), 0.33 (95% CI, 0.19-0.49), and 0.96 (95% CI, 0.91-0.99), respectively. Liver transplant patients may avoid liver biopsy if US SWE examination shows a median shear wave velocity of 1.76 or less, which corresponds to a Metavir score of F0 or F1, denoting no or minimal fibrosis.
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http://dx.doi.org/10.2214/AJR.19.21160DOI Listing
December 2019

Qualitative and Quantitative Contrast-enhanced Endoscopic Ultrasound Improves Evaluation of Focal Pancreatic Lesions.

Clin Gastroenterol Hepatol 2020 04 6;18(4):917-925.e4. Epub 2019 Sep 6.

Department of Radiology, Radiomics Group, University of Southern California Keck School of Medicine, Los Angeles, California.

Background & Aims: Endoscopic ultrasound (EUS) is a sensitive method to evaluate the pancreas but its diagnostic capability for several diseases is limited. We compared the diagnostic yield of unenhanced EUS with that of contrast-enhanced EUS for focal pancreas lesions and identified and tested quantitative parameters of contrast enhancement.

Methods: We performed a prospective tandem-controlled trial in which 101 patients with focal pancreas lesions (48 with masses, 28 with cysts, and 25 with pancreatitis) underwent conventional EUS followed by contrast EUS using intravenous perflutren microspheres. The diagnosis at each stage was scored and compared with a standard (findings from surgical pathology analysis, cytologic, and/or 6-month clinical follow-up evaluations). Quantitative parameters were generated by time-intensity curve analysis. Solid lesions were divided into derivation and testing cohorts for a crossover validation analysis of the quantitative parameters. The primary outcome was diagnostic yield of unenhanced vs contrast EUS in analysis of focal pancreas lesions.

Results: Contrast increased the diagnostic yield of EUS from 64% (65/101 lesions accurately assessed) to 91% (92/101 lesions accurately assessed); the odds ratio [OR] was 7.8 (95% CI, 2.7-30.2) for accurate analysis of lesions by contrast-enhanced EUS relative to unenhanced EUS. The contrast increased accuracy of analysis of pancreas masses (OR, 6.0; 95% CI, 1.8-31.8), improving assessment of neuroendocrine and other (non-carcinoma) tumors. Contrast increased the diagnostic yield for pancreas cysts to 96% (27/28) compared with 71.4% (20/28) for unenhanced EUS (P = .02), due to improved differentiation of mural nodules vs debris. Time-intensity curve analysis revealed distinct patterns of relative peak enhancement (rPE) and in-slope (rIS) for different lesions following contrast injection: for adenocarcinomas, values were low rPE and low rIS; for neuroendocrine masses, values were high rPE and normal IS; and for chronic pancreatitis foci, values were normal rPE and low rIS. In the validation cohort, these parameters correctly characterized 91% of lesions and improved yield relative to unenhanced EUS (OR, 10; 95% CI, 1.4-34.0).

Conclusions: Contrast-enhanced EUS improves the accuracy of analysis of focal pancreas lesions, compared with unenhanced EUS. Integration of practical quantitative parameters, specifically relative peak enhancement and in-slope, might increase the diagnostic accuracy of contrast EUS. ClinicalTrials.gov no: 02863770.
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http://dx.doi.org/10.1016/j.cgh.2019.08.054DOI Listing
April 2020

"Bright Band Sign" A Grayscale Ultrasound Finding in Hepatic Infarction.

J Ultrasound Med 2019 Sep 21;38(9):2515-2520. Epub 2019 Jan 21.

Department of Radiology, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA.

Hepatic infarction is infrequent due to the dual blood supply of the liver and the compensatory relationship between the hepatic artery and portal vein. Most cases occur in liver transplants due to vascular complications. Grayscale sonography combined with color and spectral wave Doppler can assess for vessel patency and parenchymal abnormalities. Liver infarctions appear as hypoechoic nonvascular regions on conventional and Doppler sonography. Here, we describe a grayscale ultrasound feature within liver infarctions in 2 liver transplants and in 1 native liver due to iatrogenic complication. This feature is similar to those described recently in the literature within splenic infarcts.
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http://dx.doi.org/10.1002/jum.14939DOI Listing
September 2019

Contrast-Enhanced Ultrasound Imaging of Breast Masses: Adjunct Tool to Decrease the Number of False-Positive Biopsy Results.

J Ultrasound Med 2019 Sep 31;38(9):2259-2273. Epub 2018 Dec 31.

Departments of Radiology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.

Objectives: This pilot study evaluated use of contrast-enhanced ultrasound (CEUS) to reduce the number of benign breast masses recommended for biopsy.

Methods: This prospective study included 131 consenting women, from October 2016 to June 2017, with American College of Radiology Breast Imaging Reporting and Data System category 4a, 4b, and 4c masses detected by mammography, conventional ultrasound (US), or both. Contrast-enhanced US examinations (using intravenous injection of perflutren lipid microspheres or sulfur hexafluoride lipid-type A microspheres) were performed before biopsy. Qualitative and quantitative CEUS parameters were compared with reference standard histopathologic results from biopsy of 131 masses.

Results: There were 109 benign, 6 high-risk, and 16 malignant masses, with a median size of 12 mm (range, 4 to 48 mm) on conventional US imaging. Of 131 masses, 93 (71%) enhanced on CEUS imaging, including 73 of 109 (67%) benign, 6 of 6 (100%) high-risk, and 14 of 16 (87.5%) malignant. Thirty-eight lesions did not enhance, including 36 of 109 (33%) benign and 2 of 16 (12.5%) malignant. Prediction models using recursive petitioning revealed that CEUS may reduce 31% (95% confidence interval, 23%, 40%) of benign biopsies for masses that are: nonenhancing with circumscribed margins or enhancing with an oval shape and homogeneous enhancement. Quantitative parameters indicated that benign masses had the longest time to peak (P = .078), highest time-to-peak ratio of mass to background (P = .036), lowest peak intensity (P = .021), and smallest difference in peak intensity between the mass and background (P = .079) compared to high-risk and malignant lesions.

Conclusions: Contrast-enhanced US may be a valuable modality that can be used to predict benign pathologic results of breast masses, thereby reducing the number of biopsies.
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http://dx.doi.org/10.1002/jum.14917DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7735954PMC
September 2019

Retrospective Analysis of Contrast-enhanced Ultrasonography Effectiveness in Reducing Time to Diagnosis and Imaging-related Expenditures at a Single Large United States County Hospital.

Ultrasound Q 2019 Jun;35(2):99-102

Department of Radiology, LAC+USC Medical Center and Keck School of Medicine of the University of Southern California, Los Angeles, CA.

Hepatic and renal lesions detected during ultrasound examinations frequently require subsequent contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) for characterization, delaying time to imaging diagnosis and increasing overall health care expenditures. Contrast-enhanced ultrasonography (CEUS) is a comparatively low-cost diagnostic tool that is underutilized in the evaluation of such indeterminate or suspicious hepatic and renal lesions. A retrospective chart review of CEUS examinations performed in our department demonstrated significantly shorter time to imaging diagnosis with CEUS compared to CT or MRI, largely due to the ability to perform the CEUS examination at the time of initial examination. For example mean time to completion for outpatient examinations was 5.2, 52.3, and 123.5 days for CEUS, CT, and MRI, respectively. The majority (78.4%) of CEUS examinations were completed the same day as the initial examination. Additionally, 66.7% of CEUS examinations were deemed diagnostic, abrogating further workup with CT or MRI in most cases. Annual imaging cost reduction of up to US $117,000 is anticipated in our institution based on projected reductions in follow-up CT and MRI examinations. These results indicate when CEUS was used as a first step to characterize both incidental lesions in patients without known risk factors for malignancy as well as suspicious lesions in patients with risk factors it can greatly reduce time to diagnosis and health care expenditures.
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http://dx.doi.org/10.1097/RUQ.0000000000000375DOI Listing
June 2019

The Value of Needle-Guidance Technology in Ultrasound-Guided Percutaneous Procedures Performed by Radiology Residents: A Comparison of Freehand, In-Plane, Fixed-Angle, and Electromagnetic Needle Tracking Techniques.

J Ultrasound Med 2019 Feb 19;38(2):399-405. Epub 2018 Jul 19.

Department of Radiology, Keck School of Medicine of the University of Southern California, Los Angeles, California USA.

Objectives: Radiology residents typically learn ultrasound-guided procedures by performing supervised procedures on patients who may experience longer procedure times and higher complication rates. The purpose of this study was to determine if existing technologies, such as in-plane, fixed-angle guidance (IPFA) and electromagnetic needle tracking (ENT), can improve resident procedure time and accuracy.

Methods: Radiology residents (18 total) were randomized to 1 of 3 ultrasound-guidance technique groups-freehand, IPFA, or ENT-and instructed to place a needle into 4 liver lesions in a humanoid phantom, each increasing in difficulty. For each lesion, residents were timed from skin puncture to needle placement, and the number of times the needle was pulled back and redirected (pullbacks) was recorded. Primary outcomes were total time and total number of pullbacks for all 4 lesions. Secondary outcomes were individual time and number of pullbacks for each lesion.

Results: Compared to the freehand group, the IPFA and ENT groups demonstrated lower procedural time and number of pullbacks both in total and for each individual lesion. Differences in total time and total number of pullbacks were significant (P < .001), as were differences for lesion 3 (P = .002-.02) and lesion 4 (P < .001). Differences for lesions 1 and 2 were not statistically significant.

Conclusions: Radiology resident procedure time and procedure accuracy (as judged by number of pullbacks) are significantly improved by the use IPFA and ENT guidance technologies.
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http://dx.doi.org/10.1002/jum.14701DOI Listing
February 2019

Ultrasound, Computed Tomography, and Magnetic Resonance Imaging in a Patient With Medullary Cystic Kidney Disease.

Ultrasound Q 2018 Dec;34(4):288-291

Department of Radiology, Keck School of Medicine of the University of Southern California, Los Angeles, CA.

Among the renal cystic diseases that result in end-stage renal disease, an important hereditary cause is medullary cystic kidney disease, which affects adults in an autosomal dominant pattern. It is characterized by progressive renal failure, tubulointerstitial fibrosis, and formation of small cysts in the renal medulla and corticomedullary junction. While the appearance of medullary/corticomedullary cysts may not be pathognomonic for medullary cystic kidney disease, encountering a patient with renal failure and medullary/corticomedullary cysts should prompt further investigation, given the implication of having the disease. Genetic testing can be used to identify potential renal donors as well as identify affected individuals in order to control risk factors for chronic renal disease that may mitigate the progression of the disease process. The treatment of choice is renal transplantation.
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http://dx.doi.org/10.1097/RUQ.0000000000000366DOI Listing
December 2018

Contrast-enhanced ultrasound of benign liver lesions.

Abdom Radiol (NY) 2018 04;43(4):848-860

Department of Radiology, University of Alabama at Birmingham, 619 19th Street South, JTN 338, Birmingham, AL, 35294, USA.

Liver lesions are often incidentally detected on ultrasound examination and may be incompletely characterized, requiring further imaging. Contrast-enhanced ultrasound (CEUS) was recently approved by the Food and Drug Administration in the United States for liver lesion characterization. CEUS has the ability to characterize focal liver lesions and has been shown to be superior to color Doppler and power Doppler ultrasound in the detection of tumor vascularity. Differentiating benign from malignant liver lesions is essential to characterizing liver lesions. The CEUS imaging characteristics of benign liver lesions are reviewed, including hepatic cysts, hemangiomas, focal fat, focal nodular hyperplasia, hepatocellular adenomas, abscesses, and traumatic lesions.
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http://dx.doi.org/10.1007/s00261-017-1402-2DOI Listing
April 2018

Applications of contrast-enhanced ultrasound in the kidney.

Abdom Radiol (NY) 2018 04;43(4):880-898

Department of Radiology, Keck USC School of Medicine, 1500 San Pablo Street, 2nd Floor Imaging, Los Angeles, CA, 90033, USA.

Incidental discovery of renal lesions on cross-sectional imaging studies performed for other indications is not uncommon. With the increased reliance on medical imaging, the number of incidentally detected renal lesions has also grown over time. While simple cysts account for the majority of these lesions, the presence of complex features within a cystic lesion, such as septations and solid components, can present a confusing picture. Solid lesions, too, can be indeterminate, and distinguishing between benign solid masses (like lipid-poor angiomyolipomas and oncocytomas) and renal cell carcinoma affects patient management and can prevent unnecessary interventions. Indeterminate renal lesions are traditionally further characterized by multiphase imaging, such as contrast-enhanced computed tomography and magnetic resonance imaging. Contrast-enhanced ultrasound (CEUS) is a new, relatively inexpensive technique that has become increasingly employed in the diagnostic workup of indeterminate renal lesions. With its lack of nephrotoxicity, the absence of ionizing radiation, and the ability to evaluate the enhancement pattern of renal lesions quickly and in real-time, CEUS has unique advantages over traditional imaging modalities. This article provides an overview of the current clinical applications of CEUS in characterizing renal lesions, both cystic and solid. Additional applications of CEUS in the kidney, including its roles in renal transplant evaluation and guidance for percutaneous biopsy, will also be briefly discussed.
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http://dx.doi.org/10.1007/s00261-017-1307-0DOI Listing
April 2018

Hepatic Kaposi Sarcoma Revisited: An Important but Less Commonly Seen Neoplasm in Patients With Acquired Immunodeficiency Syndrome.

Ultrasound Q 2017 Mar;33(1):109-111

Keck School of Medicine of USC, Los Angeles, CA.

Hepatic Kaposi sarcoma (KS) is the most commonly seen hepatic neoplasm in patients with acquired immunodeficiency syndrome (AIDS), found in 34% of patients in an autopsy series. However, the incidence of hepatic KS has significantly declined since the advent of highly active antiretroviral therapy and is not as commonly seen on imaging. We present a case of hepatic KS in a patient with AIDS, which was initially mistaken for hepatic abscesses on computed tomography. We discuss the computed tomography, grayscale ultrasound, and contrast-enhanced ultrasound appearance of hepatic KS and how to distinguish this hepatic neoplasm from other common hepatic lesions seen in patients with AIDS.
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http://dx.doi.org/10.1097/RUQ.0000000000000267DOI Listing
March 2017

Torsion, infarction, and rupture of a nongravid uterus: a complication of a large ovarian cyst.

Abdom Radiol (NY) 2016 12;41(12):2359-2363

Department of Radiology, Keck School of Medicine, University of Southern California, 1200 N. State St, D&T 3D321, Los Angeles, CA, 90033, USA.

Torsion of a nongravid uterus is rare, as most cases of uterine torsion occur during pregnancy. We report a case of a large ovarian cyst causing uterine torsion, infarction, and rupture. A 57-year-old woman presented with acute-onset abdominal pain and increasing abdominal girth over the past year. Contrast-enhanced computed tomography (CT) demonstrated axial rotation and swirling of the uterus and the mesenteric fat, leading to a preoperative diagnosis of uterine torsion. Laparotomy confirmed that the uterine corpus had undergone a 180-degree axial rotation, and further revealed uterine wall infarction and rupture into the endometrium as well as partial decapitation of the uterus from the cervix. The swirled appearance of the uterus, radiologically similar to the "whirlpool sign" seen in bowel volvulus, is an important CT finding to recognize, especially in view of the risk of irreversible ischemic complications this uncommon entity may inflict on the uterus.
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http://dx.doi.org/10.1007/s00261-016-0789-5DOI Listing
December 2016

Beyond the Bifurcation: There Is More to Cerebrovascular Ultrasound Than Internal Carotid Artery Stenosis!

Ultrasound Q 2016 Sep;32(3):224-40

University of Southern California Keck School of Medicine.

Carotid ultrasonography (US) is most commonly performed to identify potential areas of flow-limiting stenosis in the internal carotid artery. Identification of stenosis and unstable plaque is important because these entities are leading predictors of stroke, the fourth most common cause of death in the United States. However, US can detect other important but less common vascular pathologies if proper techniques and nuances of these entities are understood.In this article, we discuss the US appearance of abnormalities involving the carotid, vertebral, subclavian, and innominate arteries as well as the key clinical components of each diagnosis. These include congenital variants, dissection, stenosis, and vasculopathy. In addition, correlation of US findings with both magnetic resonance imaging and computed tomography more comprehensively demonstrates the complementary nature of these imaging modalities.
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http://dx.doi.org/10.1097/RUQ.0000000000000184DOI Listing
September 2016

Ultrasound Fusion: Role in Interventional Musculoskeletal Radiology.

Ultrasound Q 2015 Sep;31(3):219-20

Department of Radiology, University of Southern California, Keck School of Medicine, Los Angeles, CA.

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http://dx.doi.org/10.1097/RUQ.0000000000000150DOI Listing
September 2015

Subclavian steal following left subclavian artery occlusion during thoracic endovascular aortic repair: Doppler findings and literature review.

J Ultrasound Med 2015 May;34(5):926-9

Department of Radiology, University of Southern California Keck School of Medicine, Los Angeles, California USA.

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http://dx.doi.org/10.7863/ultra.34.5.926DOI Listing
May 2015

Sclerosing angiomatoid nodular transformation of the spleen.

Ultrasound Q 2014 Sep;30(3):241-3

*Department of Radiology, Wake Forest School of Medicine; †Department of Radiology, Wake Forest Baptist Medical Center, Winston-Salem, NC; and ‡Department of Radiology, Keck School of Medicine-University of Southern California, Los Angeles, CA.

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http://dx.doi.org/10.1097/RUQ.0000000000000100DOI Listing
September 2014

Paraganglioma of the urinary bladder.

Ultrasound Q 2014 Sep;30(3):233-5

*Resident Physician (Adraktas), †Assistant Professor of Radiology, Medical Director of Ultrasound, Abdominal Imaging Fellowship Director (Caserta), Wake Forest Baptist Health, Winston-Salem, NC; and ‡Associate Professor of Radiology, Director of Ultrasound (Tchelepi), USC, Keck School of Medicine, Los Angeles, CA.

Extra-adrenal paragangliomas of the urinary bladder are rare. Typically, patients present with symptoms related to catecholamine hypersecretion or mass effect, but these tumors can also be encountered incidentally on imaging studies obtained for a different purpose. It is important to recognize the key imaging features of this entity so that it may be suggested as a possible differential diagnosis in the setting of a newly identified bladder mass.
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http://dx.doi.org/10.1097/RUQ.0000000000000113DOI Listing
September 2014

Malignant transformation of a 5-mm gallbladder polyp over 2 years: a case report and review of current literature.

Ultrasound Q 2015 Mar;31(1):66-8

Department of Radiology, University of Southern California, Keck School of Medicine, Los Angeles, CA.

Gallbladder polyps (GBPs) are incidentally seen in 4% to 7% of adults on abdominal ultrasounds. Most GBPs are benign cholesterol polyps, adenomyomatosis, or inflammatory polyps. Currently, cholecystectomy is widely accepted as appropriate care for polyps 10 mm or larger as they present a higher risk for malignancy. However, the management of small polyps smaller than 10 mm has continued to be a dilemma to clinicians and radiologists. Many authors support a nonoperative approach with imaging follow-up for polyps smaller than 10 mm, as most have been shown to be benign. However, small polyps do have the potential to be neoplastic adenomas and become malignant. In this report, we will describe a case of a tiny GBP that subsequently developed into a 20-mm carcinoma over a period of 2 years.
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http://dx.doi.org/10.1097/RUQ.0000000000000094DOI Listing
March 2015

Color comet-tail artifact: clinical applications.

AJR Am J Roentgenol 2009 Jan;192(1):11-8

Department of Radiology, Wake Forest University School of Medicine, Medical Center Blvd., Meads Hall, 2nd Fl., Winston-Salem, NC 27157-1088, USA.

Objective: This article explores the circumstances under which the color comet-tail artifact occurs and illustrates the clinical value of the artifact.

Conclusion: Subtle abnormalities on gray-scale sonograms often are better appreciated and understood when the color comet-tail artifact is present. This artifact often is helpful in situations in which gray-scale imaging does not provide adequate information for a conclusive diagnosis. Visualization of the color comet-tail artifact can improve diagnostic confidence in a wide spectrum of clinical conditions encountered in sonographic practice.
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http://dx.doi.org/10.2214/AJR.07.3893DOI Listing
January 2009

Traumatic pseudoaneurysm of the occipital artery: case report and review of the literature.

Ear Nose Throat J 2008 Nov;87(11):E7-12

Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.

Only 3 cases of traumatic pseudoaneurysm of the occipital artery have been reported since 1644. We report a fourth case, which occurred in an 85-year-old woman who experienced a blunt trauma during a fall. The pseudoaneurysm resolved without surgical intervention. We also review the literature on traumatic pseudoaneurysms, as well as true aneurysms, of the external carotid system, with emphasis on current diagnostic and therapeutic options.
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November 2008

Sonography of acute pancreatitis: prevalence of findings and pictorial essay.

Ultrasound Q 2005 Jun;21(2):95-104; quiz 150, 153-4

Providence Hood River Memorial Hospital, Hood River, Oregon, USA.

The purpose of this article is to describe the sonographic findings of acute pancreatitis, establish their individual prevalence, and illustrate the sonographic findings in acute pancreatitis. Prevalence of findings was determined by reviewing abdominal sonograms in 48 adult patients, derived from 71 consecutive patients who had been scanned using our standard abdominal protocol, which routinely evaluates the pancreas and peripancreatic regions. The mean anteroposterior measurement of the pancreatic body at the level of the superior mesenteric artery was 21.1 mm +/- 6.4 mm with a range of 12 to 45. Decreased pancreatic echogenicity compared with the liver was noted in 21 patients (44%). A heterogeneous echo pattern was detected in 27 patients (56%). Focal intrapancreatic regions of abnormal echogenicity were seen in 11 of 48 patients (23%). Focal masses were seen in 8 of 48 patients (17%). Hypoechoic peripancreatic areas of inflammation were seen in 29 of 48 patients (60%) and acute peripancreatic fluid collections were seen in 10 of 48 patients (21%). In this study, sonography revealed abnormalities in 45 of 48 patients (91.7%). Diffuse decreased echogenicity, focal contour, and focal echogenicity changes within the pancreas are associated with extrapancreatic disease.
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June 2005

Ultrasound of focal liver masses.

Ultrasound Q 2004 Dec;20(4):155-69

Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.

Detecting and characterizing focal liver lesions is one of the most difficult challenges in imaging today. All standard noninvasive imaging modalities are less sensitive than generally perceived, and characterization is imperfect. Liver sonography's main strengths are its ability to definitively characterize common benign lesions (eg, cysts and hemangiomas), safety, low cost, and its ability to guide biopsy. Sonography's weaknesses include its inability to image the entire liver in many patients and its inferiority to CT as a means of detecting extrahepatic malignant disease. Sonography is less sensitive than CT or MRI in detecting focal lesions. Ultrasound contrast agents will certainly improve liver lesion detection and characterization, but their impact is not yet clear. Typical findings in common focal liver lesions are discussed, and some hints to improve sonographic diagnosis are presented. Increased color Doppler flow should bring the possibility of hepatocellular carcinoma and focal nodular hyperplasia to mind, but Doppler diagnosis is ultimately not highly specific. Sonography, including Doppler analysis, is useful to assess the resectability of malignant masses. Intraoperative ultrasound is the most sensitive imaging modality in detecting focal liver lesions.
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http://dx.doi.org/10.1097/00013644-200412000-00002DOI Listing
December 2004

Sonography of spermatic cord leiomyoma: case report and review of the literature.

J Ultrasound Med 2004 Apr;23(4):569-71

Department of Radiology and Urology, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA.

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http://dx.doi.org/10.7863/jum.2004.23.4.569DOI Listing
April 2004

Sonography of diffuse liver disease.

J Ultrasound Med 2002 Sep;21(9):1023-32; quiz 1033-4

Department of Radiology, Keck School of Medicine, University of Southern California, Los Angeles, USA.

Sonography is often the first imaging procedure performed in the evaluation of individuals with suspected liver disease. Evaluation for biliary dilatation is always performed, because bile duct obstruction can cause abnormal liver test results, raising the suspicion of liver disease. Ultrasound is a useful but imperfect tool in evaluating diffuse liver disease. We discuss the uses and limitations of sonography in evaluating parenchymal liver disease. Sonography can show hepatomegaly, fatty infiltration of the liver, and cirrhosis, all with good but imperfect sensitivity and specificity. Sonography is of limited usefulness in acute hepatitis. Increased parenchymal echogenicity is a reliable criterion for diagnosing fatty liver. Cirrhosis can be diagnosed in the correct clinical setting when the following are present: a nodular liver surface, decreased right lobe-caudate lobe ratio, and indirect evidence of portal hypertension (collateral vessels and splenomegaly). Ultrasound plays an important role in the imaging of conditions and procedures common in patients with diffuse liver disease.
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http://dx.doi.org/10.7863/jum.2002.21.9.1023DOI Listing
September 2002