Browsing by Subject "ultrasound"
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Item Assessing the performance of ultrasound imaging systems using images from relatively high‐density random spherical void phantoms: A simulation study(Wiley, 2022-02) Holland, Mark R.; Radiology & Imaging Sciences, School of MedicineBackground The development of clinically meaningful, objective, and quantitative methods for assessing the performance of ultrasound imaging systems represents a continuing area of interest. One approach has been to image phantoms with randomly distributed spherical voids. Purpose The objectives of this study were: (1) to explore the potential of using relatively high-volume fraction random spherical void (RSV) phantoms as an approach for quantitatively assessing the performance of ultrasound imaging systems; (2) to identify potential metrics that can be used to provide quantitative assessments of images obtained from relatively high-volume fraction RSV phantoms; and (3) to demonstrate changes in the quantitative metrics that can occur as image features are degraded. Methods A series (10 each) of computer-simulated RSV phantoms with a range of RSV volume fractions (0.05, 0.15, and 0.25) were generated. To determine the number of image planes necessary to provide robust measurements, a series of consecutive planes (ranging from 1 to 150) within each type of simulated phantom were analyzed. The observed circular cross-section radii histogram distributions (representing the intersection of each plane with the local distribution of spherical voids) were compared with the theoretical histogram distribution. Simulated phantom images were produced by adding speckle and degradation of imaging system performance was modeled by averaging 1 to 9 neighboring planes to represent increasing elevation plane thicknesses. Quantification of the performance of the imaging system was determined by measuring the: (1) mean number of circular cross-sections detected per image frame; (2) mean fractional area of circular cross-sections detected per image frame; (3) agreement of observed circular cross-section radii histogram distribution with the theoretical distribution (Chi-square statistic); and (4) contrast and contrast-to-noise ratio as a function of observed circular cross-section radius. Results Results suggest that analyses of a sufficient number of image planes (providing over approximately 3000 total circular cross-sectional areas) provides excellent agreement between the observed and theoretical histogram distributions (mean Chi-square < 0.004). For the 0.15 volume fraction series of simulated RSV phantoms, using 150 image plane analyses, phantom images show decreasing mean number of circle cross-sections detected per frame (31.5 ± 0.3, 28.4 ± 0.3, 28.2 ± 0.3, 26.3 ± 0.3, and 25.3 ± 0.3); decreasing mean fractional area of circle cross-sections per frame (0.157 ± 0.002, 0.133 ± 0.001, 0.133 ± 0.001, 0.111 ± 0.001, and 0.108 ± 0.001); and a decreasing agreement with the theoretical histogram distribution of radii (Chi-square values: 0.070 ± 0.004, 0.140 ± 0.005, 0.149 ± 0.007, 0.379 ± 0.011, and 0.518 ± 0.010) for 1, 3, 5, 7, and 9 plane averages, respectively. Contrast and contrast-to-noise measurements as a function of observed circular cross-section radius also demonstrate marked changes with simulated image degradation. Conclusions Results of this simulation study suggest that analyses of images obtained from relatively high-density RSV phantoms may offer a promising approach for assessing ultrasound imaging systems. The proposed measurements appear to provide reproducible, robust, quantitative metrics that can be compared with corresponding theoretical values to provide quantifiable, objective metrics of imaging system performance.Item Characteristics of testicular tumors in prepubertal children (age 5–12 years)(Elsevier, 2018) Karmazyn, Boaz; Weatherly, David L.; Lehnert, Stephen J.; Cain, Mark; Fan, Rong; Jennings, S. Gregory; Ouyang, Fangqian; Kaefer, Martin; Radiology and Imaging Sciences, School of MedicineIntroduction Testicular tumors in children have two peaks with different types of tumors; in the first 4 years of life a third to half are benign with increased risk of malignancy during puberty. The pathology of testicular tumors between these peaks, at the age of 5–12 years, is not known. We hypothesized that because of the low level of testosterone at this time, the incidence of malignant tumors is very low. Objective To compare malignancy risk of primary testicular tumors in children in the prepubertal period (5–12 years) compared with younger (0–4 years) and pubertal (13–18 years) children. Study design We retrospectively (2002–2016) identified patients <18 years with surgery for primary testicular tumor. Patients with testicular tumor risk were excluded. Ultrasound studies were reviewed for contralateral testis volume, tumor morphology, and tumor maximal diameter, for three age groups: 0–4, 5–12, and 13–18 years. The Freeman-Halton extension of the Fisher exact probability test was adopted for categorical outcomes, and one-way ANOVA for continuous outcomes. Results Fifty-two patients (mean age 11.0 years, range 6 days–18 years) were identified. Malignant tumor prevalence significantly differed ( p < 0.01) among age groups ( Fig ).: 0–4 (72.7%, 8/11), 5–12 (0%, 0/16), and 13–18 years (44.0%, 11/25). The most common tumor types in 5–12 years were epidermoid cyst (31.3%, 5/16) and tumor mimics (37.5%, 6/16). Prevalence of cystic tumors in 5–12 year olds was not significantly different compared with other age groups. Contralateral testicular volume >4 mL (pubertal surge) significantly ( p < 0.01) differed among groups: 0–4 years (0/11), 5–12 years (3/16), and 13–18 years (19/20). In children aged 13–18 years the mean tumor maximal diameter (29.8 ± 4.4 mm) was significantly larger (p < 0.01) compared with children 5–12 years (9.3 ± 5.5 mm) and all malignant tumors had contralateral testicular volume >4 mL. Discussion We found that preadolescent children between the ages of 5 and 12 years have distinctive characteristics compared with the other age groups. Most importantly, no malignant testicular tumors were found in this age group. About a third of the children presented with an incidental testicular mass. The testicular tumors were significantly smaller (9.3 ± 6.7 mm) compared with those in children aged 13–18 years (29.8 ± 4.4 mm). There were limitations because of the retrospective nature of the study. Conclusion We found no malignant testicular tumors in children aged 5–12 years with no risk factors and prior to pubertal surge. Our study suggests use of more conservative treatment in this group of patients.Item Describing Self-confidence in Ultrasound Performance with Increased Exposure(2020-03-06) Shanks, Anthony L.; Schultz, Katherine; Bhamidipalli, Surya; Rouse, Caroline; Scott, NicoleItem Design and rationale of the B-lines lung ultrasound guided emergency department management of acute heart failure (BLUSHED-AHF) pilot trial(Elsevier, 2018) Russell, Frances M.; Ehrman, Robert R.; Ferre, Robinson; Gargani, Luna; Noble, Vicki; Rupp, Jordan; Collins, Sean P.; Hunter, Benton; Lane, Kathleen A.; Levy, Phillip; Li, Xiaochun; O'Connor, Christopher; Pang, Peter S.; Emergency Medicine, School of MedicineBackground Medical treatment for acute heart failure (AHF) has not changed substantially over the last four decades. Emergency department (ED)-based evidence for treatment is limited. Outcomes remain poor, with a 25% mortality or re-admission rate within 30 days post discharge. Targeting pulmonary congestion, which can be objectively assessed using lung ultrasound (LUS), may be associated with improved outcomes. Methods BLUSHED-AHF is a multicenter, randomized, pilot trial designed to test whether a strategy of care that utilizes a LUS-driven treatment protocol outperforms usual care for reducing pulmonary congestion in the ED. We will randomize 130 ED patients with AHF across five sites to, a) a structured treatment strategy guided by LUS vs. b) a structured treatment strategy guided by usual care. LUS-guided care will continue until there are ≤15 B-lines on LUS or 6h post enrollment. The primary outcome is the proportion of patients with B-lines ≤ 15 at the conclusion of 6 h of management. Patients will continue to undergo serial LUS exams during hospitalization, to better understand the time course of pulmonary congestion. Follow up will occur through 90 days, exploring days-alive-and-out-of-hospital between the two arms. The study is registered on ClinicalTrials.gov (NCT03136198). Conclusion If successful, this pilot study will inform future, larger trial design on LUS driven therapy aimed at guiding treatment and improving outcomes in patients with AHF.Item Diagnosis and Follow-up of Incidental Liver Lesions in Children(Wolters Kluwer, 2022-03) Karmazyn, Boaz; Rao, Girish S.; Johnstone, Lindsey S.; Severance, Tyler S.; Ferguson, Michael J.; Marshalleck, Francis E.; Molleston, Jean P.; Radiology and Imaging Sciences, School of MedicineABSTRACT: Incidental liver lesions are identified in children without underlying liver disease or increased risk of hepatic malignancy in childhood. Clinical and imaging evaluation of incidental liver lesions can be complex and may require a multidisciplinary approach. This review aims to summarize the diagnostic process and follow-up of incidental liver lesions based on review of the literature, use of state-of-the-art imaging, and our institutional experience. Age at presentation, gender, alpha fetoprotein levels, tumor size, and imaging characteristics should all be taken into consideration to optimize diagnosis process. Some lesions, such as simple liver cyst, infantile hemangioma, focal nodular hyperplasia (FNH) and focal fatty lesions, have specific imaging characteristics. Recently, contrast-enhanced ultrasound (CEUS) was FDA-approved for the evaluation of pediatric liver lesions. CEUS is most specific in lesions smaller than 3 cm and is most useful in the diagnosis of infantile hemangioma, FNH, and focal fatty lesions. The use of hepatobiliary contrast in MRI increases specificity in the diagnosis of FNH. Recently, lesion characteristics in MRI were found to correlate with subtypes of hepatocellular adenomas and associated risk for hemorrhage and malignant transformation. Biopsy should be considered when there are no specific imaging characteristics of a benign lesion. Surveillance with imaging and AFP should be performed to confirm the stability of lesions when the diagnosis cannot be determined, and when biopsy is not feasible.Item Dissimilar Ultrasound Instruments(2013-01-20) Feigenbaum, HarveyItem Functional and Morphological Changes Associated with Burst Wave Lithotripsy-Treated Pig Kidneys(Mary Ann Liebert Inc., 2022-11-28) Connors, Bret A.; Gardner, Tony; Liu, Ziyue; Lingeman, James E.; Kreider, Wayne; Williams , James C.; Biostatistics and Health Data Science, Richard M. Fairbanks School of Public HealthPurpose: Burst wave lithotripsy (BWL) is a new technique for comminution of urinary stones. This technology is noninvasive, has a low positive pressure magnitude, and is thought to produce minor amounts of renal injury. However, little is known about the functional changes related to BWL treatment. In this study, we sought to determine if clinical BWL exposure produces a functional or morphological change in the kidney. Materials and Methods: Twelve female pigs were prepared for renal clearance assessment and served as either sham time controls (6) or were treated with BWL (6). In the treated group, 1 kidney in each pig was exposed to 18,000 pulses at 10 pulses/s with 20 cycles/pulse. Pressure levels related to each pulse were 12 and −7 MPa. Inulin (glomerular filtration rate, GFR) and para-aminohippuric acid (effective renal plasma flow, eRPF) clearance was measured before and 1 hour after treatment. Lesion size analysis was performed to assess the volume of hemorrhagic tissue injury created by each treatment (% FRV). Results: No visible gross hematuria was observed in any of the collected urine samples of the treated kidneys. BWL exposure also did not lead to a change in GFR or eRPF after treatment, nor did it cause a measurable amount of hemorrhage in the tissue. Conclusion: Using the clinical treatment parameters employed in this study, BWL did not cause an acute change in renal function or a hemorrhagic lesion.Item History of Echocardiography: How to introduce something new in medicine(2013-10-30) Feigenbaum, HarveyEchocardiography as we know it today began at Indiana University School of Medicine in the fall of 1963, exactly 50 years ago. This talk will document how this technology became the world’s leading cardiovascular imaging tool.Item Imaging in Suspected Renal Colic: Systematic Review of the Literature and Multispecialty Consensus(Elsevier, 2019-09-01) Moore, Christopher L.; Carpenter, Christopher R.; Heilbrun, Marta E.; Klauer, Kevin; Krambeck, Amy C.; Moreno, Courtney; Remer, Erick M.; Scales, Charles; Shaw, Melissa M.; Sternberg, Kevan M.; Urology, School of MedicineBackground Renal colic is common, and CT is frequently utilized when the diagnosis of kidney stones is suspected. CT is accurate but exposes patients to ionizing radiation and has not been shown to alter either interventional approaches or hospital admission rates. This multi-organizational transdisciplinary collaboration sought evidence-based, multispecialty consensus on optimal imaging across different clinical scenarios in patients with suspected renal colic in the acute setting. Methods In conjunction with the American College of Emergency Physicians (ACEP) eQual network, we formed a nine-member panel with three physician representatives each from ACEP, the ACR, and the American Urology Association. A systematic literature review was used as the basis for a three-step modified Delphi process to seek consensus on optimal imaging in 29 specific clinical scenarios. Results From an initial search yielding 6,337 records, there were 232 relevant articles of acceptable evidence quality to guide the literature summary. At the completion of the Delphi process consensus, agreement was rated as perfect in 15 (52%), excellent in 8 (28%), good in 3 (10%), and moderate in 3 (10%) of the 29 scenarios. There were no scenarios where at least moderate consensus was not reached. CT was recommended in 7 scenarios (24%), with ultrasound in 9 (31%) and no further imaging needed in 12 (45%). Summary Evidence and multispecialty consensus support ultrasound or no further imaging in specific clinical scenarios, with reduced-radiation dose CT to be employed when CT is needed in patients with suspected renal colic.Item In Vitro Ultrasound Measurements of Powered and Unpowered Total Cavopulmonary Connection(Austin Publishing Group, 2014) Iliff, BP; Kerlo, AEM; Chen, J; Rodefeld, MD; Goergen, CJ; Department of Surgery, IU School of MedicineThree-staged Fontan palliation is performed on children suffering from single ventricle congenital heart disease. The series of surgical procedures reroutes blood from the vena cavae directly to the pulmonary arteries, creating a total cavopulmonary connection (TCPC). A viscous impeller pump (VIP) is currently being developed as a cavopulmonary assist device that can modestly augment cavopulmonary flow, reduce systemic venous pressure, and improve ventricular preload. This study used ultrasound to visualize complex flow patterns in powered and unpowered in vitro mock Fontan circulations. The idealized TCPC was modeled with a silicone mold and blood analog made of water and glycerol that was seeded with 10-μm glass beads. B-mode, color Doppler, and pulsed-wave Doppler images were used to visualize complex flow patterns in the idealized TCPC with (1) no VIP, (2) static VIP, and powered VIP rotation rates of (3) 500 and (4) 2,000 rotations per minute (RPM). Pulsed-wave Doppler data showed higher mean velocities and greater variance in the outlets relative to the larger inlets. The maximum inlet velocity ± SD increased from 10.9 ± 3.53 cm/s with no VIP to 15.9 ± 1.03 when the VIP was rotating at 2,000 RPM. Likewise, the maximum outlet velocity increased from 14.9 ± 11.2 cm/s to 18.9 ± 7.25 cm/s at 2,000 RPM. The faster mean velocities with the VIP rotating suggest that the pump augments cavopulmonary flow. The results of this study suggest that measuring complex flow patterns with ultrasound in vivo could be used clinically to optimize VIP positioning and rotation rate during and after implantation.