Browsing by Subject "computed tomography"
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Item Bisphosphonate-Functionalized Gold Nanoparticles for Contrast-Enhanced X-Ray Detection of Breast Microcalcifications(Elsevier B.V., 2014-02) Cole, Lisa E.; Vargo-Gogola, Tracy; Roeder, Ryan K.; Department of Biochemistry & Molecular Biology, IU School of MedicineMicrocalcifications are one of the most common abnormalities detected by mammography for the diagnosis of breast cancer. However, the detection of microcalcifications and correct diagnosis of breast cancer are limited by the sensitivity and specificity of mammography. Therefore, the objective of this study was to investigate the potential of bisphosphonate-functionalized gold nanoparticles (BP-Au NPs) for contrast-enhanced radiographic detection of breast microcalcifications using two models of breast microcalcifications which allowed for precise control over levels of hydroxyapatite (HA) mineral within a low attenuating matrix. First, an in vitro imaging phantom was prepared with varying concentrations of HA uniformly dispersed in an agarose hydrogel. The X-ray attenuation of HA-agarose compositions labeled by BP-Au NPs was increased by up to 26 HU compared to unlabeled compositions for HA concentrations ranging from 1–10 mg/mL. Second, an ex vivo tissue model was developed to more closely mimic the heterogeneity of breast tissue by injecting varying concentrations of HA in a Matrigel carrier into murine mammary glands. The X-ray attenuation of HA-Matrigel compositions labeled by BP-Au NPs was increased by up to 289 HU compared to unlabeled compositions for HA concentrations ranging from 0.5–25 mg/mL, which included an HA concentration (0.5 mg/mL) that was otherwise undetectable by micro-computed tomography. Cumulatively, both models demonstrated the ability of BP-Au NPs to enhance contrast for radiographic detection of microcalcifications, including at a clinically-relevant imaging resolution. Therefore, BP-Au NPs may have potential to improve clinical detection of breast microcalcifications by mammography.Item Breast calcifications following electrical defibrillation: An unusual mammographic appearance(Radiology Case Reports U of Washington, 2010) Westphal, Steven M.; Jani, Manish; Badve, Sunil; Department of Radiology and Imaging Sciences, IU School of MedicineWe present a case of a 57-year-old woman with a past medical history of end-stage renal disease and a recent history of electrical defibrillation who arrived for her annual mammogram with no breast-related complaints. The mammogram showed interval development of unusual clusters of heterogeneous calcifications. The patient underwent stereotactic core-needle biopsy for definitive diagnosis. The pathologic evaluation revealed fibrosis, abnormal adipocytes, and calcifications with no evidence of malignancy. The constellation of findings was consistent with fat necrosis and fibrosis related to tissue damage sustained during the recent defibrillation.Item Calvarium Thinning in Patients with Spontaneous Cerebrospinal Fluid Leaks of the Anterior Skull Base(Wiley, 2021-06) Sharma, Dhruv; Tucker, Brady J.; Millay, David S.; Rubel, Kolin E.; Saltagi, Mohamad; Nelson, Rick F.; Illing, Elisa A.; Ting, Jonathan Y.; Otolaryngology -- Head and Neck Surgery, School of MedicineObjectives/Hypothesis Patients with spontaneous cerebrospinal fluid leaks (sCSF-L) of the temporal bone have isolated calvarial and skull base thinning that is independent of obesity. This study determines if anterior skull base (ASB) sCSF-L patients also have calvarial thinning. Study Design Retrospective Cohort Study. Methods This was a retrospective cohort study of ASB sCSF-L patients compared to nonobese (body mass index [BMI] < 30 kg/m2) and obese (BMI ≥ 30) control groups. Twenty-one patients in the ASB sCSF-L group and 25 patients in each control group were included. Calvarium and extracranial zygoma thicknesses were measured bilaterally with blinded, standardized, volumetric analysis. Results ASB sCSF-L patients had a mean (SD) age of 50.43 (10.19) years, an average (SD) BMI of 38.81 (8.92) kg/m2, and most were female (85.71%). The calvarium in patients with ASB sCSF-L was significantly thinner than the nonobese (2.55 mm [0.77] vs. 2.97 [0.67] mm; P = .006; 95% confidence intervals [CI], 0.12–0.30; Cohen d, 0.58) and obese control groups (2.55 [0.77] vs. 2.92 [0.76] mm; P = .02; 95% CI, 0.05–0.34; Cohen d, 0.66). The calvarium thickness of the nonobese patients was not significantly different from the obese patient controls (2.97 [0.67] vs. 2.92 [0.76] mm, P = .9). The extracranial zygoma was not significantly different among the groups (analysis of variance, P = .33). Conclusions ASB sCSF-L patients have isolated calvarial thinning that is independent of obesity. Like lateral skull base sCSF-L patients, these data suggest that the additional obesity-associated intracranial process contributes to skull thinning.Item Computed Tomography and Magnetic Resonance Imaging of Bone Tumors(Elsevier, 2017) Ladd, Lauren M.; Roth, Trenton D.; Department of Radiology and Imaging Sciences, IU School of MedicineImaging is the key to diagnosing and guiding management of bone tumors. Although radiographs are the gold standard for initial imaging evaluation and may make the diagnosis, computed tomography (CT) and magnetic resonance (MR) imaging are important adjunct tools for further characterization as a benign or aggressive lesion, accurately determining matrix composition, assessing lesion extent as well as secondary involvement of nearby structures if malignant, and staging tumors when applicable. In this article, we will highlight important features of CT and MR imaging for bone tumor evaluation and review the cross-sectional imaging features of a broad spectrum of benign and malignant bone tumors.Item Computed Tomography Characterization and Comparison With Polysomnography for Obstructive Sleep Apnea Evaluation(Elsevier, 2017) Chousangsuntorn, Khaisang; Bhongmakapat, Thongchai; Apirakkittikul, Navarat; Sungkarat, Witaya; Supakul, Nucharin; Laothamatas, Jiraporn; Radiology and Imaging Sciences, School of MedicinePurpose We hypothesized that computed tomography (CT) combined with portable polysomnography (PSG) might better visualize anatomic data related to obstructive sleep apnea (OSA). The present study evaluated the CT findings during OSA and assessed their associations with the PSG data and patient characteristics. Patients and Methods We designed a prospective cross-sectional study of patients with OSA. The patients underwent scanning during the awake state and apneic episodes. Associations of the predictor variables (ie, PSG data, respiratory disturbance index [RDI]), patient characteristics (body mass index [BMI], neck circumference [NC], and waist circumference [WC]), and outcome variables (ie, CT findings during apneic episodes) were assessed using logistic regression analysis. The CT findings during apneic episodes were categorized regarding the level of obstruction, single level (retropalatal [RP] or retroglossal [RG]) or multilevel (mixed RP and RG), degree of obstruction (partial or complete), and pattern of collapse (complete concentric collapse [CCC] or other patterns). Results A total of 58 adult patients with OSA were scanned. The mean ± standard deviation for the RDI, BMI, NC, and WC were 41.6 ± 28.55, 27.80 ± 5.43 kg/m2, 38.3 ± 4.3 cm, and 93.8 ± 13.6 cm, respectively. No variables distinguished between the presence of single- and multilevel airway obstruction in the present study. A high RDI (≥30) was associated with the presence of complete obstruction and CCC (odds ratio 6.33, 95% confidence interval 1.55 to 25.90; and odds ratio 3.77, 95% confidence interval 1.02 to 13.91, respectively) compared with those with a lesser RDI. Conclusions An increased RDI appears to be an important variable for predicting the presence of complete obstruction and CCC during OSA. Scanning during apneic episodes, using low-dose volumetric CT combined with portable PSG provided better anatomic and pathologic findings of OSA than did scans performed during the awake state.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 Diagnostic Yield and Clinical Utility of Abdominopelvic CT Following Emergent Laparotomy for Trauma(RSNA, 2016-09) Haste, Adam K.; Brewer, Brian L.; Steenburg, Scott D.; Department of Surgery, IU School of MedicinePurpose To determine the incidence of unexpected injuries that are diagnosed with computed tomography (CT) after emergent exploratory laparotomy for trauma and whether identification of such injuries results in additional surgery or angiography. Materials and Methods This HIPAA-compliant retrospective study was approved by the institutional review board, and the requirement for informed consent was waived. The trauma databases of two urban level 1 trauma centers were queried over a period of more than 5 years for patients who underwent abdominopelvic CT within 48 hours of emergent exploratory laparotomy for trauma. Comparisons were made between CT findings and those described in the surgical notes. Descriptive statistics were generated, and 95% confidence intervals (CIs) were determined by using an exact method based on a binomial distribution. Results The study cohort consisted of 90 patients, including both blunt and penetrating trauma victims with a median injury severity score of 17.5 (interquartile range, 9.25–34). Seventy-three percent (66 of 90) of patients sustained penetrating trauma, 82% (74 of 90) of whom were male. A total of 19 patients (21.1%; 95% CI: 13.2, 31.0) had additional injuries within the surgical field that were not identified during laparotomy. There were 17 unidentified solid organ injuries, and eight patients had active bleeding within the surgical field. Eight patients (8.9%; 95% CI: 3.9, 16.8) had unexpected injuries at CT that were substantial enough to warrant additional surgery or angiography. In addition, previously undiagnosed fractures were found in 45 patients (50%; 95% CI: 39.3, 60.7). Conclusion Performing CT after emergent exploratory laparotomy for trauma is useful in identifying unexpected injuries and confirming suspected injuries that were not fully explored at initial surgery.Item Effects of bisphosphonate ligands and PEGylation on targeted delivery of gold nanoparticles for contrast-enhanced radiographic detection of breast microcalcifications(Elsevier, 2018) Cole, Lisa E.; McGinnity, Tracie L.; Irimata, Lisa E.; Vargo-Gogola, Tracy; Roeder, Ryan K.; Biochemistry and Molecular Biology, School of MedicineA preclinical murine model of hydroxyapatite (HA) breast microcalcifications (µcals), which are an important clinical biomarker for breast cancer detection, was used to investigate the independent effects of high affinity bisphosphonate (BP) ligands and a polyethylene glycol (PEG) spacer on targeted delivery of gold nanoparticles (Au NPs) for contrast-enhanced radiographic detection. The addition of BP ligands to PEGylated Au NPs (BP-PEG-Au NPs) resulted in five-fold greater binding affinity for targeting HA µcals, as expected, due to the strong binding affinity of BP ligands for calcium. Therefore, BP-PEG-Au NPs were able to target HA µcals in vivo after intramammary delivery, which enabled contrast-enhanced radiographic detection of µcals in both normal and radiographically dense mammary tissues similar to previous results for BP-Au NPs, while PEG-Au NPs did not. The addition of a PEG spacer between the BP targeting ligand and Au NP surface enabled improved in vivo clearance. PEG-Au NPs and BP-PEG-Au NPs were cleared from all mammary glands (MGs) and control MGs, respectively, within 24–48 h after intramammary delivery, while BP-Au NPs were not. PEGylated Au NPs were slowly cleared from MGs by lymphatic drainage and accumulated in the spleen. Histopathology revealed uptake of PEG-Au NPs and BP-PEG-Au NPs by macrophages in the spleen, liver, and MGs; there was no evidence of toxicity due to the accumulation of NPs in organs and tissues compared with untreated controls for up to 28 days after delivery.Item Geometric characteristics of 3D reconstructed anode electrodes of lithium ion batteries(Office of the Vice Chancellor for Research, 2014-04-11) Lim, Cheolwoong; Yan, Bo; Yin, Leilei; Zhu, LikunThe realistic 3D microstructure of lithium ion battery electrodes plays a key role in studying the effects of inhomogeneous microstructures on the performance of LIBs. However, the complexity of realistic microstructures implements significant computational cost on numerical simulation of large size samples. In this work, we used tomographic data obtained for a commercial lithium ion battery graphite electrode to evaluate the geometric characteristics of the reconstructed electrode microstructure. Based on the analysis of geometric properties, such as porosity, specific surface area, tortuosity, and pore size distribution, a representative volume element that retains the geometric characteristics of the electrode material was obtained for further numerical studies. In this work, X-ray micro-CT with 0.56 μm resolution was employed to capture the inhomogeneous porous microstructures of lithium ion battery anode electrodes. The Sigmoid transform function was employed to convert the initial raw tomographic images to binary images. Moreover, geometric characteristics of an anode electrode after 2400 1 C charge/discharge cycles were compared with those of a new anode electrode to investigate morphological change of the electrode. In general, the cycled electrode shows larger porosity, smaller tortuosity, and similar specific surface area compared to the new electrode.Item Mapping of HIE CT terms to LOINC®: analysis of content-dependent coverage and coverage improvement through new term creation(Oxford Academic, 2019-01) Peng, Paul; Beitia, Anton Oscar; Vreeman, Daniel J..; Loo, George T.; Delman, Bradley N.; Thum, Frederick; Lowry, Tina; Shapiro, Jason S.; Medicine, School of MedicineObjective: We describe and evaluate the mapping of computerized tomography (CT) terms from 40 hospitals participating in a health information exchange (HIE) to a standard terminology. Methods: Proprietary CT exam terms and corresponding exam frequency data were obtained from 40 participant HIE sites that transmitted radiology data to the HIE from January 2013 through October 2015. These terms were mapped to the Logical Observations Identifiers Names and Codes (LOINC®) terminology using the Regenstrief LOINC mapping assistant (RELMA) beginning in January 2016. Terms without initial LOINC match were submitted to LOINC as new term requests on an ongoing basis. After new LOINC terms were created, proprietary terms without an initial match were reviewed and mapped to these new LOINC terms where appropriate. Content type and token coverage were calculated for the LOINC version at the time of initial mapping (v2.54) and for the most recently released version at the time of our analysis (v2.63). Descriptive analysis was performed to assess for significant differences in content-dependent coverage between the 2 versions. Results: LOINC's content type and token coverages of HIE CT exam terms for version 2.54 were 83% and 95%, respectively. Two-hundred-fifteen new LOINC CT terms were created in the interval between the releases of version 2.54 and 2.63, and content type and token coverages, respectively, increased to 93% and 99% (P < .001). Conclusion: LOINC's content type coverage of proprietary CT terms across 40 HIE sites was 83% but improved significantly to 93% following new term creation.