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Limthongkul W.,University of Chicago | Karaikovic E.E.,University of Chicago | Savage J.W.,Northwestern University | Markovic A.,Northshore University Healthsystems
Spine Journal | Year: 2010

Background context: During the last decade, vertebral augmentation techniques with cement (kyphoplasty and vertebroplasty) have revealed that 75% to 100% of individuals with osteoporotic vertebral compression fractures have good to moderate pain relief postoperatively, as well as adequate restoration of the vertebral body height. The volume of cement injected into a vertebra varied in different reports. To our knowledge, there are no studies that report on the physiological distribution of thoracic and lumbar vertebrae body volumes. Purpose: The purpose of this study was to quantitatively evaluate thoracic and lumbar vertebral body volumes. Study design/setting: Forty computed tomography (CT) scans of the thoracic and lumbar spines were used to measure a volume of each vertebral body. Methods: Forty CT scans with standard 2.5-mm bone window cuts of the thoracic and lumbar vertebrae (20 men and 20 women) were analyzed to measure the volumetric capacity of vertebral bodies using a BrainLAB Software (iPlan RT image 4.0) program. The software was tested for validity and reliability in two pilot studies. Mean and standard deviations for each vertebral body volume were calculated and recorded. The vertebral body working distance and the so-called "safe zone" were also measured to determine a size of a balloon to be used in kyphoplasty. Results: Vertebral body volume increased gradually from T1 to L4 with the exception of L5, which measured to be smaller than L4. The mean thoracic vertebrae volume was 15.0 cm3 (ranged in the absolute values from 5.2 to 39.5 cm3), and the mean lumbar vertebrae volume was 35 cm3 (ranged in the absolute values from 19.7 to 61.5 cm3). Men had larger volume vertebral bodies only in the lumbar spine compared with women. The average vertebral body working distances from T1 to T4 was 23.4±2.7 mm, from T5 to T9 was 30.3±3.6 mm, and from T10 to L5 was 35.5±3.9 mm. Conclusions: Knowing the physiological variability of vertebral body volumes may help prevent complications as a result of underaugmentation or overaugmentation with excessive amount of cement during kyphoplasty or vertebroplasty in osteoporotic compression fractures. We recommend using 10 mm balloons from T1 to T4, 15 mm balloons from T5 to T9, and 20 mm balloons from T10 to L5 for kyphoplasty. © 2010 Elsevier Inc. All rights reserved. Source


Thompson T.M.,University of Illinois at Chicago | Leikin J.B.,Northshore University Healthsystems | Leikin J.B.,University of Chicago
Journal of Medical Toxicology | Year: 2015

We previously reported the financial data for the first 5 years of one of the author’s medical toxicology practice. The practice has matured; changes have been made. The practice is increasing its focus on office-based encounters and reducing hospital-based acute care encounters. We report the reimbursement rates and other financial metrics of the current practice. Financial records from October 2009 through September 2013 were reviewed. This is a period of 4 fiscal years and represents the currently available financial data. Charges, payments, and reimbursement rates were recorded according to the type and setting of the medical toxicology encounter: forensic consultations, outpatient clinic encounters, nonpsychiatric inpatient consultations, emergency department (ED) consultations, and inpatient psychiatric consultations. All patients were seen regardless of ability to pay or insurance status. The number of billed Current Procedural Terminology (CPT) codes for office-based encounters increased over the study period; the number of billed CPT codes for inpatient and ED consultations reduced. Office-based encounters demonstrate a higher reimbursement rate and higher payments. In the fiscal year (FY) of 2012, office-based revenue exceeded hospital-based acute care revenue by over $140,000 despite a higher number of billed CPT encounters in acute care settings, and outpatient payments were 2.39 times higher than inpatient, inpatient psychiatry, observation unit, and ED payments combined. The average payment per CPT code was higher for outpatient clinic encounters than inpatient encounters for each fiscal year studied. There was an overall reduction in CPT billing volume between FY 2010 and FY 2013. Despite this, there was an increase in total practice revenue. There was no change in payor mix, practice logistics, or billing/collection service company. In this medical toxicology practice, office-based encounters demonstrate higher reimbursement rates and overall payments compared to inpatient and ED consultations. While consistent with our previous studies, these differences have been accentuated. This study demonstrates the results of changes to the practice—reduced inpatient/ED consultations and increased outpatient encounters. These practice changes resulted in higher overall revenue despite a lower patient volume. In this analysis, the office-based practice of medical toxicology has higher reimbursement rates, nearly 2.5 times higher, when compared to hospital-based acute care consultations. © 2014, American College of Medical Toxicology. Source


Chen J.L.,Northshore University Healthsystems
International Journal of Pediatric Otorhinolaryngology | Year: 2015

Introduction: There is evidence for temporary hearing loss in neonates immediately after birth because of residual liquid derived from amniotic fluid in the ME cavity.This study examines whether a referred newborn hearing screen (NBHS) with subsequent testing confirming normal hearing can be attributed to persistence of middle ear effusion and predict poor Eustachian tube function manifested as recurrent otitis media or otitis media with effusion in the first year of life. The aims of the present study are to investigate the following: (1) whether infants who fail a neonatal hearing screen and subsequently pass are more likely to experience recurrent otitis media or otitis media with effusion, (2) whether these infants are more likely to obtain tympanostomy tubes. Methods: This retrospective cohort study examined newborns who referred their NBHS and were subsequently noted to have normal hearing and a control group comprised of newborns who passed their NBHS. Univariate and multivariate analysis was performed on the data collected as well as generation mean cumulative function plots. Results: The baseline characteristics of the case and control groups are not statistically significant with regards to gender, number of otitis media (OM), delivery mode, or the need for tubes in the follow up period. Within the refer group, those with bilateral refers were twice as likely to have otitis media than those with a unilateral refer (p=. 0.012). The logistic regression model for odds of subsequent otitis media was not statistically significant for bilateral or unilateral refer though the logistic regression model for odds of tubes demonstrated a statistically significant increased risk in bilateral refer patients. With time to event analysis, it was seen that bilateral refer patients are more likely to have OM than control and unilateral refer patients. Conclusion: There is no difference in the incidence of subsequent OM between those infants who passed the NBHS versus those who initially referred and then passed subsequent audiology examination. However there was a difference in the number of otitis media between those infants who referred bilaterally versus those who referred unilaterally. © 2015 Elsevier Ireland Ltd. Source


Lo R.,University of Chicago | Donaldson C.,Northshore University Healthsystems
Ultrasound Quarterly | Year: 2013

INTRODUCTION: Color Doppler ultrasound (CDUS) is currently preferred to screen for renal artery stenosis (RAS); however, a wide range of sensitivities and specificities have been reported. We wanted to identify potential factors contributing to this wide range and to improve CDUS screening for RAS. We noted RAS was overcalled when the peak systolic velocity (PSV) was found in the mid-main renal artery, and we sought to determine whether this was a consistent source of error. METHODS: We reviewed the medical records of patients at Northshore University Healthsystems with a positive RAS examination by CDUS from 2009 to 2012, defined as a PSV greater than 200 cm/s and/or a renal artery-to-aorta ratio greater than 3.5. Patients were included who had an elevated PSV in the mid-main renal artery and had a confirmatory imaging study (angiography, magnetic resonance angiography, or computed tomography angiography). RESULTS: Of the 16 arteries demonstrating a PSV in the mid-renal artery, 15 did not have significant stenosis on the subsequent study. The 1 true positive was a patient with fibromuscular dysplasia. DISCUSSION: This study demonstrates a high false-positive rate (94%) when the PSV is in the mid-main renal artery. We suspect this pattern is due to the tortuous mid-main renal artery causing falsely elevated velocities that meet criteria for RAS. Fibromuscular dysplasia may also produce the same pattern and should be distinguished from vessel tortuosity. If the false-positive rate of Doppler ultrasound can be decreased, fewer patients will be subjected to an unnecessary follow-up study and possibly invasive procedures. Copyright © 2013 by Lippincott Williams & Wilkins. Source


Radosevich A.J.,Northwestern University | Rogers J.D.,Northwestern University | Turzhitsky V.,Northwestern University | Mutyal N.N.,Northwestern University | And 6 more authors.
IEEE Journal on Selected Topics in Quantum Electronics | Year: 2012

Since the early 1980s, the enhanced backscattering (EBS) phenomenon has been well-studied in a large variety of nonbiological materials. Yet, until recently, the use of conventional EBS for the characterization of biological tissue has been fairly limited. In this study, we detail the unique ability of EBS to provide spectroscopic, polarimetric, and depth-resolved characterization of biological tissue using a simple backscattering instrument. We first explain the experimental and numerical procedures used to accurately measure and model the full azimuthal EBS peak shape in biological tissue. Next, we explore the peak shape and height dependencies for different polarization channels and spatial coherence of illumination. We then illustrate the extraordinary sensitivity of EBS to the shape of the scattering phase function using suspensions of latex microspheres. Finally, we apply EBS to biological tissue samples in order to measure optical properties and observe the spatial length scales at which backscattering is altered in early colon carcinogenesis. © 1995-2012 IEEE. Source

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