C F Hildebolt

Washington University in St. Louis, San Luis, Missouri, United States

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Publications (168)470.81 Total impact

  • [show abstract] [hide abstract]
    ABSTRACT: The aim of this study was to compare diffusion-weighted MRI (DW-MRI) with positron emission tomography/computed tomography (PET/CT) for the staging and evaluation of the treatment response in patients with diffuse large B-cell lymphoma (DLBCL). Institutional review board approval was obtained for this study; all subjects gave informed consent. Twelve patients were imaged before treatment and eight of these were also imaged after two cycles of chemotherapy using both DW-MRI and PET/CT. Up to six target lesions were selected at baseline for response assessment based on International Working Group criteria (nodes > 1.5 cm in diameter; extranodal lesions > 1 cm in diameter). For pretreatment staging, visual analysis of the numbers of nodal and extranodal lesions based on PET/CT was performed. For interim response assessment after cycle 2 of chemotherapy, residual tumor sites were assessed visually and the percentage changes in target lesion size, maximum standardized uptake value (SUVmax) and apparent diffusion coefficient (ADC) from pretreatment values were calculated. In 12 patients studied pretreatment, there were 46 nodal and 16 extranodal sites of lymphomatous involvement. Agreement between DW-MRI and PET/CT for overall lesion detection was 97% (60/62 tumor sites; 44/46 nodal and 16/16 extranodal lesions) and, for Ann Arbor stage, it was 100%. In the eight patients who had interim assessment, five of their 49 tumor sites remained abnormal on visual analysis of both DW-MRI and PET/CT, and there was one false positive on DW-MRI. Of their 24 target lesions, the mean pretreatment ADC value, tumor size and SUVmax were 772 µm2/s, 21.3 cm2 and 16.9 g/mL, respectively. At interim assessment of the same 24 target lesions, ADC values increased by 85%, tumor size decreased by 74% and SUVmax decreased by 83% (all p < 0.01 versus baseline). DW-MRI provides results comparable with those of PET/CT for staging and early response assessment in patients with DLBCL. Copyright © 2014 John Wiley & Sons, Ltd.
    NMR in Biomedicine 04/2014; · 3.45 Impact Factor
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    ABSTRACT: The Doppler Tei index is an independent predictor of outcomes in adult heart failure. Tissue Doppler imaging (TDI) may be a superior method to measure the Tei index in children because it is less affected by heart rate variability. We hypothesized that the TDI Tei index reflects severity of illness in pediatric heart failure. Twenty-five pediatric heart failure patients were prospectively enrolled. Listing for heart transplantation or death were the outcomes used to define severity of illness. Baseline demographics, brain natriuretic peptide (BNP), and standard echocardiographic and TDI-derived parameters were analyzed to determine outcome indicators. Ten of the 25 patients (40 %) were listed for transplantation. There were no deaths. Multivariate analysis combining age, heart rate, standard echocardiographic parameters, and BNP resulted in shortening fraction (p = 0.002) as the best indicator of listing for transplantation (R (2) = 0.32). A second multivariate analysis combining age, heart rate, TDI parameters, and BNP resulted in age (p = 0.03) and septal Tei index (p = 0.03) as the best predictive model (R (2) = 0.36). The area under the receiver operating characteristic (ROC) curve for septal Tei index was 0.84 (95 % confidence interval = 0.64-0.96,), and it was comparable with the ROC curve for shortening fraction, p = 0.76. Optimal values of sensitivity (100 %) and specificity (60 %) were obtained with septal Tei index values >0.51. The TDI septal Tei index is an indicator of disease severity in pediatric heart failure patients and offers potential advantages compared with standard echocardiographic measures of left-ventricular ejection.
    Pediatric Cardiology 09/2013; · 1.20 Impact Factor
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    ABSTRACT: Conventional magnetic resonance imaging (MRI) methods do not quantify the severity of multiple sclerosis (MS) white matter lesions or measure pathology within normal-appearing white matter (NAWM). Gradient Echo Plural Contrast Imaging (GEPCI), a fast MRI technique producing inherently co-registered images for qualitative and quantitative assessment of MS, was used to 1) correlate with disability; 2) distinguish clinical MS subtypes; 3) determine prevalence of veins co-localized within lesions in WM. Thirty subjects representing relapsing-remitting MS (RRMS), secondary progressive MS (SPMS) and primary progressive MS (PPMS) subtypes were scanned with clinical and GEPCI protocols. Standard measures of physical disability and cognition were correlated with magnetic resonance metrics. Lesions with central veins were counted for RRMS subjects. Tissue damage load (TDL-GEPCI) and lesion load (LL-GEPCI) derived with GEPCI correlated better with MS functional composite (MSFC) measures and most other neurologic measures than lesion load derived with FLAIR (LL-FLAIR). GEPCI correctly classified clinical subtypes in 70% subjects. A central vein could be identified in 76% of WM lesions in RRMS subjects on GEPCI T2*-SWI images. GEPCI lesion metrics correlated better with neurologic disability than lesion load derived using FLAIR imaging, and showed promise in classifying clinical subtypes of MS. These improvements are likely attributable to the ability of GEPCI to quantify tissue damage.
    Multiple Sclerosis 07/2013; · 4.47 Impact Factor
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    ABSTRACT: Charcot neuropathic osteoarthropathy associated foot deformity can result in joint instability, ulceration, and even amputation. The purpose of the present study was to follow patients with and without active Charcot osteoarthropathy for as long as two years to examine the magnitude and timing of foot alignment changes. We studied fifteen subjects with Charcot osteoarthropathy and nineteen subjects with diabetes mellitus and peripheral neuropathy without Charcot osteoarthropathy for one year; eight of the subjects with osteoarthropathy and five of the subjects with diabetes and peripheral neuropathy were followed for two years. Bilateral weight-bearing radiographs of the foot were made at baseline for all subjects, with repeat radiographs being made at six months for the osteoarthropathy group and at one and two years for both groups. Radiographic measurements included the Meary angle, cuboid height, calcaneal pitch, and hindfoot-forefoot angle. The Meary angle, cuboid height, and calcaneal pitch worsened in feet with Charcot osteoarthropathy over one year as compared with the contralateral, uninvolved feet and feet in patients with diabetes and peripheral neuropathy. Cuboid height continued to worsen over the two-year follow-up in the feet with Charcot osteoarthropathy. These feet also had a greater change in the hindfoot-forefoot angle at one year as compared with the feet in patients with diabetes and peripheral neuropathy and at two years as compared with the contralateral, uninvolved feet. In patients with Charcot neuropathic osteoarthropathy, radiographic alignment measurements demonstrate the presence of foot deformity at the time of the initial clinical presentation and evidence of progressive changes over the first and second years. The six-month data suggest worsening of medial column alignment prior to lateral column worsening. This radiographic evidence of worsening foot alignment over time supports the need for aggressive intervention (conservative bracing or surgical fixation) to attempt to prevent limb-threatening complications. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.
    The Journal of Bone and Joint Surgery 07/2013; 95(13):1206-13. · 3.23 Impact Factor
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    ABSTRACT: Normative values of pediatric skull circumference, cranial index, and braincase volume would inform multiple disciplines including neurosurgery, plastic surgery and anthropology. Semi-automated methods exist for obtaining these data but are time consuming and require expertise. We report on a new method for automated extraction of in vivo measures of pediatric crania based on x-ray computed tomography scans (CT). Data were obtained from a clinical image repository for pediatric populations in whom no pathology was noted. The automated process showed good agreement with semi-automated measures, although there was a small bias for both braincase volume and circumference. We developed an open source program to automatically extract measures of skull circumference, cranial index, and braincase volume that are likely to prove useful in multiple disciplines.
    Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 07/2013; 2013:3977-3980.
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    ABSTRACT: The purpose of this study was to compare digital periapical and cone-beam computed tomography (CBCT) images to determine the number of canals in the mesiobuccal root of maxillary molars and to compare these counts with micro computed tomography (μCT), which was also used to determine canal configuration. Digital periapical (RVG 6100), CBCT (9000 3D), and μCT images (the reference standard) were obtained of 18 hemi-maxillas. With periapical and CBCT images, 2 endodontists independently counted the number of canals in each molar and repeated the counts 2 weeks later. Teeth were extracted and scanned with μCT, and 2 additional endodontists, by consensus, determined the number and configuration of canals. The Friedman test was used to test for differences. In mesiobuccal roots, 2 canals were present in 100% of maxillary first molars (13 of 13) and 57% of second molars (8 of 14), and 69% (9 of 13) and 100% (8 of 8) of these exited as 2 or more foramina. There was no difference in canal counts for original and repeat reads by the 2 observers with periapical (P = .06) and with CBCT (P = .88) and no difference when CBCT counts were compared with μCT counts (P = .52); however, when periapical counts were compared with μCT counts, there was a significant difference (P = .04). For cadaver maxillary molars, μCT canal counts were significantly different from digital periapical radiograph counts but not different from Carestream9000 3D CBCT counts.
    Journal of endodontics 07/2013; 39(7):901-5. · 2.95 Impact Factor
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    ABSTRACT: A proximal humeral articular surface from an ancient domestic dog deliberate burial was examined during survey of small mammal bones from a prehistoric early Late Woodland archaeological site.An unusual lesion on the caudolateral articular surface prompted micro-computed tomography todefine detailed structure. Results indicate cortical or immature woven bone arising subchondrally, replac-ing normal trabeculae, extending through a breach in the cortical surface, and having sharp transitionwith surrounding normal bone. Organized bone within the lesion indicates that the dog lived for months-to-years following insult.Differential diagnoses initially included: sharp penetrating trauma; intrinsic or extrinsic blunt fracturing force; osteochondrosis or complication of an osteochondral lesion; unusual osteoarthritis; andneoplasia. Computed tomography ruled out normal or unusual osteoarthritis, and neoplasia. The natureand small size of the lesion, relatively small size of the dog, and lack of evidence for complicating infection,suggest against sharp penetrating trauma as a sole cause.The most plausible differential diagnoses include: uncommon fracture-producing force in a companion animal, and blunt intrinsic or extrinsic force causing fracture at a weak point, such as an early osteochondral lesion, that was obliterated by healing.Combined gross examination, micro-computed tomography, and archaeological-anthropological influences facilitated refinement of differential diagnosis.
    International Journal of Paleopathology. 07/2013;
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    ABSTRACT: BACKGROUND: Fractures are common in foot bones, but clinicians lack adequate indices of bone strength. OBJECTIVES: We used dual-energy X-ray absorptiometry (DXA) to measure bone mineral density (BMD) and content (BMC) of excised human metatarsals, determined intra- and inter-rater measurement precision, and assessed associations between BMD/BMC and ex vivo bone fracture strength. METHODS: Two raters each made two measurements of whole-bone and sub-regional BMD and BMC in both second and third metatarsals from 10 cadavers. Variance components analysis was used to assess variability attributable to repeat measurements, raters, sub-regions, bones, sides, and cadavers. Root-mean-square standard deviation (RMS-SD) and least-significant change (LSC) were used to assess rater precision and ultimate forces during 3-point bending were tested for correlations with BMD and BMC. RESULTS: Variation due to repeat measurements and rater was low (<1% combined) for BMD and BMC. RMS-SD for whole metatarsal BMD of both metatarsals ranged from 0.004 to 0.010g/cm(2) and 0.062 to 0.086g for BMC. Whole metatarsal and sub-region BMD and BMC were strongly correlated to ex vivo fracture force (r(2)=0.67-0.93). CONCLUSIONS: DXA measurements of BMD and BMC have high intra- and inter-rater precision and are strongly correlated to ex vivo bone strength.
    The Foot 05/2013;
  • Marilyn J Siegel, Charles Hildebolt, David Bradley
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    ABSTRACT: Purpose:To assess effects of an automated kilovoltage selection tool on radiation dose, tube current, and image quality in pediatric contrast material-enhanced thoracoabdominal computed tomography (CT) and CT angiography.Materials and Methods:The institutional review board approved this retrospective study of 87 children (median age, 10.5 years; age range, 1 day to 19 years) who underwent thoracic CT, abdominal CT, or CT angiography with an automated kilovoltage protocol between November 2010 and July 2011. Volumetric CT dose index (CTDIvol) and milliamperage were compared with estimated prescanning calculations from a standard 120-kVp protocol. Image quality was subjectively scored on a scale of 1 to 5. In 15 patients who underwent scanning with both automated kilovoltage and standard 120-kVp protocols, image contrast and noise were quantitatively measured and the contrast-to-noise ratio (CNR) was calculated. Parametric and/or nonparametric testing of independent and/or paired samples was performed.Results:Estimated median CTDIvol for all 87 studies was 4.8 mGy for the automated kilovoltage protocol versus 7.1 mGy for the 120-kVp protocol, yielding a 27% dose reduction (25% and 75% percentiles: 23% and 37%, respectively; P < .001). The median milliamperage was 125.0 with the automated protocol and 87 with the 120-kVp protocol (P < .001). Use of automated kilovoltage selection resulted in kilovoltage reduction from 120 kVp in 82 of the 87 patients (94%), with the percentage dose reduction greater for CT angiography than for chest CT (P < .001). Reduction in kilovoltage showed a significant correlation with patient size (P < .01). Diagnostic image quality was achieved in all patients. Mean contrast and noise were higher with the automated kilovoltage protocol than with the 120-kVp protocol (P ≤ .04), but CNRs for liver and portal vein were similar (P = .54 and .73, respectively).Conclusion:In pediatric CT and CT angiography, the use of automated kilovoltage selection technology significantly reduces radiation dose while maintaining image quality and CNR.© RSNA, 2013Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13122438/-/DC1.
    Radiology 04/2013; · 6.34 Impact Factor
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    ABSTRACT: PURPOSE: The purpose of this study was to compare the effects of combined automated tube voltage selection and automated tube current modulation on radiation dose and image quality in small-sized phantoms undergoing computed tomography angiography (CTA) with the use of automated current modulation alone. MATERIALS AND METHODS: Three semianthropomorphic phantoms, corresponding to a neonate, a small child, and a small adult, underwent simulated abdominal CTA using an automated tube voltage selection technology, which simultaneously optimizes kilovoltage (in kilovolt [peak]) and tube-current/milliamperage (in milliampere-second) on the basis of the patient topogram and clinical task. The phantoms were scanned with 2 protocols: protocol A, using the combination of automated kilovoltage and milliamperage, and protocol B, using only automated milliamperage with the standard 120 kV(p). Radiation doses were measured for each phantom, and the measurements were then used to estimate volume computed tomography dose index. Image noise and iodine contrast, contrast-to-noise ratio, and the relative dose factor were assessed. Differences were tested using paired t tests, and percentage differences for various technical factors and the phantom sizes were calculated. RESULTS: The computed tomography dose index was significantly lower in protocol A (mean, 3.3 mGy) compared with that in protocol B (mean, 7.7 mGy), representing a 56.0% dose reduction (P = 0.01). In protocol A, tube potential dropped from 120 to 70 kV(p) in the small and medium phantoms and to 80 kV(p) in the large phantom. For each phantom size, image noise and iodine contrast increased significantly in protocol A relative to those in protocol B (P = 0.03 and P < 0.01, respectively). Corresponding contrast-to-noise ratio values increased by 9.1% in protocol A relative to those in protocol B (P = 0.04). The relative dose factor values for protocol A relative to those for protocol B were 31%, 36%, and 44% for the small, medium, and large phantoms, respectively. CONCLUSIONS: Combined use of automated kilovoltage selection and automated tube current modulation is more effective for reducing radiation dose and maintaining image quality during simulated pediatric CTA than is automated tube current modulation in isolation.
    Investigative radiology 04/2013; · 4.85 Impact Factor
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    ABSTRACT: The purpose of our study was to determine, first, if gallbladder wall striations in patients with sonographic findings suspicious for acute cholecystitis are associated with gangrenous changes and certain histologic features; and, second, if WBC count or other sonographic findings are associated with gangrenous cholecystitis. Sixty-eight patients who underwent cholecystectomies within 48 hours of sonography comprised the study group. Sonograms and reports were reviewed for wall thickness, striations, Murphy sign, pericholecystic fluid, wall irregularity, intraluminal membranes, and luminal short-axis diameter. Medical records were reviewed for WBC count and pathology reports for the diagnosis. Histologic specimens were reviewed for pathologic changes. Statistical analyses tested for associations between nongangrenous and gangrenous cholecystitis and sonographic findings and for associations between wall striations and histologic features. Ten patients had gangrenous cholecystitis and 57, nongangrenous cholecystitis. One had cholesterolosis. Thirty patients had wall striations: 60% had gangrenous and 42% nongangrenous cholecystitis. There was no association with the pathology diagnosis (p = 0.32). There was no association between any histologic feature and wall striations (p ≥ 0.19). A Murphy sign was reported in 70% of patients with gangrenous cholecystitis and in 82% with nongangrenous cholecystitis; there was no association with the pathology diagnosis (p = 0.39). Wall thickness and WBC count were greater in patients with gangrenous cholecystitis than in those with nongangrenous cholecystitis (p ≤ 0.04). Gallbladder wall thickening and increased WBC counts were associated with gangrenous cholecystitis; however, there was considerable overlap between the two groups. Wall striations and a negative Murphy sign were not associated with gangrenous cholecystitis.
    American Journal of Roentgenology 02/2013; 200(2):363-9. · 2.90 Impact Factor
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    ABSTRACT: The aim of this study is to evaluate the effectiveness over application time of different formulations of a novel endodontic irrigant (QMix™ 2in1) composed of a polyaminocarboxylic acid chelating agent, a bisbiguanide antimicrobial agent, a surfactant and deionized water to remove the root canal smear layer and expose patent dentinal tubules compared to a standard solution of 17 % EDTA. Eighty human tooth roots from extracted, single-rooted teeth were instrumented (size 40.06) using 0.2 mL of sodium hypochlorite (6.15 %) between each file size with a 3 mL water rinse after final instrumentation. Eight groups of 10 roots were irrigated with 3 mL of different formulations of QMix: QMix A, QMix B, and QMix C, or 17 % EDTA for 60 and 90 s, respectively, then rinsed with 5 mL of sterile water. The roots were irrigated using a standard irrigation syringe and a 30 ga side-vent needle with an apical-coronal motion to within 1 mm of the working length. The coronal, middle and apical thirds of one canal surface of each root was evaluated at 1000× using scanning electron microscopy. The presence of smear layer was scored using a 5-point scale. Data were analyzed with the Kruskal-Wallis rank sums test, the Steel-Dwass, all-pairs comparison test, and the Steel method (with control) test. Irrigant type was highly significant (p < 0.007). Combined 60 and 90 s exposure data indicated QMix A (p = 0.014) and QMix C (p = 0.028) were superior to EDTA. While at the 90 s exposure time, smear layer removal by solutions QMix A (p = 0.043), QMix B (p = 0.018), and QMix C (p = 0.011) was superior to EDTA. All irrigants removed smear layer more effectively at the coronal and middle levels compared to the apical level (p < 0.001). Analysis showed all three QMix formulations were superior to EDTA in smear layer removal and exposure of dentinal tubules in the root canal system in single-rooted teeth.
    Odontology 01/2013; · 1.58 Impact Factor
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    ABSTRACT: We present an atlas-based registration method for bones segmented from quantitative computed tomography (QCT) scans, with the goal of mapping their interior bone mineral densities (BMDs) volumetrically. We introduce a new type of deformable atlas, called subdivision-embedded atlas, which consists of a control grid represented as a tetrahedral subdivision mesh and a template bone surface embedded within the grid. Compared to a typical lattice-based deformation grid, the subdivision control grid possesses a relatively small degree of freedom tailored to the shape of the bone, which allows efficient fitting onto subjects. Compared with previous subdivision atlases, the novelty of our atlas lies in the addition of the embedded template surface, which further increases the accuracy of the fitting. Using this new atlas representation, we developed an efficient and fully automated pipeline for registering atlases of 12 tarsal and metatarsal bones to a segmented QCT scan of a human foot. Our evaluation shows that the mapping of BMD enabled by the registration is consistent for bones in repeated scans, and the regional BMD automatically computed from the mapping is not significantly different from expert annotations. The results suggest that our improved subdivision-based registration method is a reliable, efficient way to replace manual labor for measuring regional BMD in foot bones in QCT scans.
    Journal of Digital Imaging 10/2012; · 1.10 Impact Factor
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    ABSTRACT: Skull thickness and density measures of normal pediatric crania would inform multiple disciplines including neurosurgery, optical and magnetoelectrophysiological imaging, and biomechanical modeling of head trauma. We report on a new method for automated extraction of in vivo skull thickness and density measures of pediatric crania based on x-ray computed tomography scans (CT). Data were obtained from a clinical image repository for pediatric populations in whom no pathology was noted. Skull thickness and density measures were systematically obtained across the calvarium. We find a set of measures that correlated with physiological age that are likely to prove useful in multiple disciplines.
    Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 08/2012; 2012:4462-5.
  • Lina Nayak, Charles F Hildebolt, Suresh Vedantham
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    ABSTRACT: To describe the short-term efficacy of a strategy of imaging-guided endovascular intervention for the treatment of patients with established postthrombotic syndrome (PTS). The medical records of 183 patients with venous disease who were seen in a single interventional radiology clinic were retrospectively reviewed. Study inclusion criteria were (i) endovascular intervention performed to treat established PTS from January 1, 2000, to March 10, 2009; (ii) patient age greater than 18 years; and (iii) availability of follow-up records. A total of 44 patients (20 men, 24 women; mean age, 42.2 y ± 14.1) with PTS who had received 72 interventions (iliac vein stent placement [n = 52] and endovenous laser ablation [EVLA; n = 20]) were identified. A reviewer who did not participate in their care evaluated the follow-up records; recorded the presence or absence of pain, swelling, and active ulceration; and categorized the degree of symptom improvement. Of 45 treated limbs in 40 patients with available follow-up, complete, partial, or no improvement of overall symptoms was observed in 46.7%, 33.3%, and 20.0%, respectively. The proportions of limbs with pain (35.0% after treatment vs 82.5% before; McNemar test, P < .01) and swelling (50.0% after treatment vs 90.0% before; P < .01) were significantly reduced after treatment with iliac vein stent placement and/or EVLA. Six of seven ulcerated limbs showed significant healing. The use of an endovascular strategy to treat patients with established PTS was associated with complete or partial symptom relief in 80% of patients at short-term follow-up.
    Journal of vascular and interventional radiology: JVIR 07/2012; 23(9):1165-73. · 1.81 Impact Factor
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    ABSTRACT: A Position Paper Subcommittee of the American Academy of Oral and Maxillofacial Radiology (AAOMR) reviewed the literature since the original position statement on selection criteria for radiology in dental implantology, published in 2000. All current planar modalities, including intraoral, panoramic, and cephalometric, as well as cone beam computed tomography (CBCT) are discussed, along with radiation dosimetry and anatomy considerations. We provide research-based, consensus-derived clinical guidance for practitioners on the appropriate use of specific imaging modalities in dental implant treatment planning. Specifically, the AAOMR recommends that cross-sectional imaging be used for the assessment of all dental implant sites and that CBCT is the imaging method of choice for gaining this information. This document will be periodically revised to reflect new evidence.
    Oral surgery, oral medicine, oral pathology and oral radiology. 06/2012; 113(6):817-26.
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    ABSTRACT: Foot deformity associated with diabetes mellitus (DM) and peripheral neuropathy (PN) contributes to joint instability, ulceration and amputation. This study reports the intrarater and inter-rater measurement precision and least significant change (LSC) of radiological measures of foot deformity in subjects with DM, PN, and foot related complications. Cuboid height, Meary's angle, calcaneal pitch and hindfoot-forefoot angle were measured from plain-film radiographs on 15 subjects with DM, PN, and foot-related complications. A foot and ankle fellowship-trained orthopedic surgeon with 23 years of experience (Rater 1) measured radiographs twice. A foot and ankle fellowship-trained orthopedic surgeon with 2 years of experience (Rater 2) and a radiologist in residency training (Rater 3) measured radiographs once. Root mean square standard deviation and LSC were calculated to determine measurement precision and the smallest change considered biologically real, not the result of chance. Intrarater measurement precision was: 0.9 mm for cuboid height, 3 degrees for Meary's angle, and 2 degrees for calcaneal pitch and hindfoot-forefoot angle. Inter-rater measurement precision for rater 1 versus 2 and 1 versus 3 were: 1.7 and 1.6 mm for cuboid height, 4 degrees for Meary's angle, 2 degrees for calcaneal pitch, and 3 degrees for the hindfoot-forefoot angle. The LSC was less than or equal to: 4.7 mm for cuboid, 12 degrees for Meary's angle, 6 degrees for calcaneal pitch, and 8 degrees for hindfoot-forefoot angle. Cuboid height, calcaneal pitch, and hindfoot-forefoot angle measures can be completed with relatively good measurement precision.
    Foot & Ankle International 09/2011; 32(9):867-72. · 1.47 Impact Factor
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    ABSTRACT: Diabetic foot diseases, such as ulcerations, infections, and neuropathic (Charcot's) arthropathy, are major complications of diabetes mellitus (DM) and peripheral neuropathy (PN) and may cause osteolysis (bone loss) in foot bones. The purposes of our study were to make computed tomography (CT) measurements of foot-bone volumes and densities and to determine measurement precision (percent coefficients of variation for root-mean-square standard deviations) and least significant changes (LSCs) in these percentages that could be considered biologically real with 95% confidence. Volumetric quantitative CT scans were performed and repeated on 10 young healthy subjects and 13 subjects with DM and PN. Two raters used the original- and repeat-scan data sets to make measurements of volumes and bone mineral densities (BMDs) of the tarsal and metatarsal bones of the 2 feet (24 bones). Precisions for the bones ranged from 0.1% to 0.9% for volume measurements and from 0.6% to 1.9% for BMD measurements. The LSCs ranged from 0.4% to 2.5% for volume measurements and from 1.5% to 5.4% for BMD measurements. Volumetric quantitative CT provides precise measurements of volume and BMD for metatarsal and tarsal bones, where diabetic foot diseases commonly occur.
    Journal of Clinical Densitometry 06/2011; 14(3):313-20. · 1.71 Impact Factor
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    ABSTRACT: A previous study reported by this group found that patients in periodontal maintenance programs taking vitamin D and calcium supplementation had a trend for better periodontal health compared to patients not taking supplementation. The objective of the present study is to determine, for the same cohort of subjects, whether such differences persist over a 1-year period. Fifty-one patients enrolled in maintenance programs from two dental clinics were recruited. Of these, 23 were taking vitamin D (≥400 IU/day) and calcium (≥1,000 mg/day) supplementation, and 28 were not. All subjects had at least two interproximal sites with ≥3 mm clinical attachment loss. For mandibular-posterior teeth, gingival index, plaque index, probing depth, attachment loss, bleeding on probing, calculus index, and furcation involvement were evaluated. Photostimulable-phosphor, posterior bitewing radiographs were taken to assess alveolar bone. Daily vitamin D and calcium intakes were estimated by nutritional analysis. Data were collected at baseline, 6 months, and 12 months. Total daily calcium and vitamin D intakes were 1,769 mg (95% confidence interval, 1,606 to 1,933) and 1,049 IU (781 to 1,317) in the taker group, and 642 mg (505 to 779) and 156 IU (117 to 195) in the non-taker group, respectively (P <0.001 for both). Clinical parameters of periodontal health improved with time in both groups (P <0.001). When clinical measures were considered collectively, the differences between supplement takers and non-takers had the following P values: baseline (P = 0.061); 6 months (P = 0.049); and 12 months (P = 0.114). After adjusting for covariates, the P values for the effect of supplementation were as follows: baseline (P = 0.028); 6 months (P = 0.034); and 12 months (P = 0.058). Calcium and vitamin D supplementation (≤1,000 IU/day) had a modest positive effect on periodontal health, and consistent dental care improved clinical parameters of periodontal disease regardless of such supplements. Our findings support the possibility that vitamin D may positively impact periodontal health and confirm the need for randomized clinical trials on the effects of vitamin D on periodontitis.
    Journal of Periodontology 01/2011; 82(1):25-32. · 2.40 Impact Factor
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    ABSTRACT: Reports from studies of twins, disease aggregation in families, animal models for periodontal disease, and various genetic-analysis studies have determined that genetics plays a role in the susceptibility to periodontal disease. The purpose of this pilot study is to evaluate the effect of genetics on periodontal disease by evaluating the heritability of alveolar bone loss in a captive baboon population. A collection of baboon skulls from a pedigreed colony (for which scientists and veterinarians maintain complete genealogic and veterinary records) was obtained from the Southwest National Primate Research Center, San Antonio, Texas and used in this pilot study. Measurements of alveolar bone loss were performed on 390 dry baboon skulls. A periodontal probe was used to measure alveolar bone loss. Maximum likelihood methods (designed to handle complex genealogies) were used to determine the heritability of alveolar bone loss. This software used known pedigrees in the captive baboon sample and tested the relationship between pairwise kinship and alveolar bone loss data to determine the heritability of alveolar bone loss from periodontal disease. Genetic data were available for 347 of the 390 specimens. Using age and sex as covariates, genetic analysis indicated a heritability of 35% (standard error = 20%; P = 0.01). Although gender was not a significant factor in periodontal disease (P = 0.96), age was highly significantly associated with periodontal disease (P <0.0001). In this pilot study, analysis of alveolar bone loss measurements from captive baboons indicates that bone loss increases with age and that a portion of periodontal disease risk may be caused by genetic variance. These findings provide evidence that periodontal disease is heritable in captive baboons and indicate that a larger, more-detailed study is warranted.
    Journal of Periodontology 11/2010; 82(4):575-80. · 2.40 Impact Factor

Publication Stats

2k Citations
470.81 Total Impact Points


  • 1989–2014
    • Washington University in St. Louis
      • • Department of Orthopaedic Surgery
      • • Department of Radiology
      San Luis, Missouri, United States
  • 2009–2013
    • Saint Louis University
      • Center for Advanced Dental Education "CADE"
      Saint Louis, MI, United States
  • 1990–2011
    • University of Washington Seattle
      • Department of Radiology
      Seattle, WA, United States
  • 2005–2009
    • Southern Illinois University School of Medicine
      Springfield, Illinois, United States
    • Florida State University
      • Department of Anthropology
      Tallahassee, FL, United States
  • 2007
    • University of Pittsburgh
      • School of Medicine
      Pittsburgh, PA, United States
  • 2005–2007
    • University of California, San Francisco
      San Francisco, California, United States
  • 1990–2003
    • Georgia Health Sciences University
      • College of Dental Medicine
      Augusta, GA, United States
  • 1991–1994
    • Washington & Lee University
      Lexington, Virginia, United States
    • University at Albany, The State University of New York
      • Department of Anthropology
      New York City, NY, United States
  • 1989–1990
    • Northwestern University
      • Department of Anthropology
      Evanston, IL, United States