Research Topics
| John A ShepherdSummaryAffiliation: University of California Country: USA Publications
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Detail Information
Publications
Do fatty breasts increase or decrease breast cancer risk?John A Shepherd
Departments of Medicine and Epidemiology and Biostatistics, University of California, 4150 Clement Street VAMC 111A1, San Francisco, CA 94121, USA
Breast Cancer Res 14:102. 2012..Understanding the interplay of body mass index, menopause status, and measurement of non-dense breast area would help to clarify the contribution of non-dense breast area to breast cancer risk...
A multinational study to develop universal standardization of whole-body bone density and composition using GE Healthcare Lunar and Hologic DXA systemsJohn A Shepherd
Department of Radiology and Bioimaging, University of California San Francisco, San Francisco, CA 94143, USA
J Bone Miner Res 27:2208-16. 2012..The equations we derived reduce differences between BMD and body composition as determined by GE Healthcare Lunar and Hologic systems and will facilitate combining study results in clinical or epidemiological studies...- A comparison of breast density measures between mothers and adolescent daughtersGertraud Maskarinec
Epidemiology Program, University of Hawaii Cancer Center, Honolulu, USA
BMC Cancer 11:330. 2011..Based on the importance of breast density as a predictor of breast cancer risk, we examined the heritable component of breast measures in mothers and daughters using Dual Energy X-ray Absorptiometry (DXA)... - Volume of mammographic density and risk of breast cancerJohn A Shepherd
Department of Radiology, University of California, San Francisco, CA 94143, USA
Cancer Epidemiol Biomarkers Prev 20:1473-82. 2011.... 
Clinical comparison of a novel breast DXA technique to mammographic densityJohn A Shepherd
Musculoskeletal and Quantitative Imaging Research Group, Department of Radiology, University of California, San Francisco, California 94143, USA
Med Phys 33:1490-8. 2006..We conclude that breast composition can be precisely evaluated and assessed with clinical DXA densitometers at a lower dose than with mammographic breast density methods...- Single x-ray absorptiometry method for the quantitative mammographic measure of fibroglandular tissue volumeSerghei Malkov
Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California 94143, USA
Med Phys 36:5525-36. 2009.... - Novel use of single X-ray absorptiometry for measuring breast densityJohn A Shepherd
Musuloskeletal and Quantitative Imaging Research Group, Department of Radiology, University of California, San Francisco, CA 94143, USA
Technol Cancer Res Treat 4:173-82. 2005..Using phantoms, BD(SXA) has been shown to have a long-term repeatability of better than 2% for a breast composition range of 0 to 100% fibroglandular density... - Compositional breast imaging using a dual-energy mammography protocolAurelie D Laidevant
Department of Radiology and Biomedical Imaging, University of California, San Francisco, California 94143, USA
Med Phys 37:164-74. 2010..This article describes a novel approach to dual-energy mammography, full-field digital compositional mammography (FFDCM), which can independently image the three compositional components of breast tissue: water, lipid, and protein... - Accuracy of mammographic breast density analysis: results of formal operator trainingSven Prevrhal
Department of Radiology, University of California, San Francisco, California 94143-1250, USA
Cancer Epidemiol Biomarkers Prev 11:1389-93. 2002.... - Breast density assessment in adolescent girls using dual-energy X-ray absorptiometry: a feasibility studyJohn A Shepherd
Musuloskeletal and Quantitative Imaging Research Group, Department of Radiology, University of California at San Francisco, San Francisco, CA 94143 0946, USA
Cancer Epidemiol Biomarkers Prev 17:1709-13. 2008..4% and 16.6 cm(3)). These pilot data indicate that dedicated DXA breast scans may be useful in studies exploring breast density in girls... - Cross-calibration and minimum precision standards for dual-energy X-ray absorptiometry: the 2005 ISCD Official PositionsJohn A Shepherd
Department of Radiology, University of California, San Francisco, CA 94143 0946, USA
J Clin Densitom 9:31-6. 2006..We present here the ISCD Official Positions on these topics that were established as a result of the 2005 PDC, together with the associated rationales and supportive evidence... - Comparing BMD results between two similar DXA systems using the generalized least significant changeJohn A Shepherd
Department of Radiology, University of California at San Francisco, San Francisco, CA 94143 0946, USA
J Clin Densitom 11:237-42. 2008..A revision of the International Society for Clinical Densitometry's policies for comparing scans from systems of the same technology may be appropriate... - A generalized least significant change for individuals measured on different DXA systemsJohn A Shepherd
Department of Radiology, University of California, San Francisco, CA 94143 0946, USA
J Clin Densitom 10:249-58. 2007..We conclude that the GLSC, defined using commonly used clinical cross-calibration and precision assessments, is the most accurate method to compare scans between dual-energy X-ray absorptiometry systems... - Dual-energy X-ray absorptiometry-based body volume measurement for 4-compartment body compositionJoseph P Wilson
University of California, Berkeley University of California, San Francisco Graduate Program in Bioengineering, USA
Am J Clin Nutr 95:25-31. 2012..Total body volume (TBV), with the exclusion of internal air voids, is necessary to quantify body composition in Lohman's 4-compartment (4C) model... - T-scores and Z-scoresJohn A Shepherd
Department of Radiology, University of California, San Francisco, CA, USA
J Clin Densitom 10:349-50. 2007 - Optimal monitoring time interval between DXA measures in childrenJohn A Shepherd
Department of Radiology, Bone and Breast Density Research Group, University of California, San Francisco, San Francisco, CA, USA
J Bone Miner Res 26:2745-52. 2011..MTI was neither useful nor stable in late adolescence and young adulthood. Alternative criteria to determine scan intervals must be used in this age range... - Computer-assisted technique to delineate osteolytic lesions around the femoral component in total hip arthroplastySven Prevrhal
Department of Radiology, University of California, San Francisco, California 94107, USA
J Arthroplasty 23:833-8. 2008..2% to 4.8%. The new technique compares favorably to precision of qualitative visual assessment and permits more accurate detection and quantitation of osteolytic lesions... - Comparison of DXA hip structural analysis with volumetric QCTSven Prevrhal
Department of Radiology, UCSF, San Francisco, CA 94107, USA
J Clin Densitom 11:232-6. 2008..5 for CSMI) and standard DXA at the neck (r2=0.82 for BMD). HSA and volumetric QCT compared favorably, which supports the validity of a projective technique such as DXA to derive geometrical properties of the proximal hip... - Measurement of breast density with dual X-ray absorptiometry: feasibilityJohn A Shepherd
Department of Radiology, Osteoporosis and Arthritis Research Group, University of California at San Francisco, 94143, USA
Radiology 223:554-7. 2002..998) and with density at mammography (r(adjusted) = 0.83). DXA precision (SD) was 0.5% without and 1.1% with breast repositioning. DXA devices can be used to accurately and precisely estimate breast tissue density... - Accuracy of CT-based thickness measurement of thin structures: modeling of limited spatial resolution in all three dimensionsSven Prevrhal
Osteoporosis and Arthritis Research Group, Department of Radiology, University of California-San Francisco, San Francisco, California 94117, USA
Med Phys 30:1-8. 2003.... - Dual-energy and low-kVp CT in the abdomenBenjamin M Yeh
Department of Radiology and Biomedical Imaging, University of California, San Francisco, Box 0628, M 372, 505 Parnassus Ave, San Francisco, CA 94143 0628, USA
AJR Am J Roentgenol 193:47-54. 2009..Further clinical research and technique refinement will be needed as the usage of these exciting technologies spreads... - Improved 4-compartment body-composition model for a clinically accessible measure of total body proteinJoseph P Wilson
University of California, San Francisco, CA, USA
Am J Clin Nutr 97:497-504. 2013..Unfortunately, there is not a clinically accessible method to measure total body protein, which is the functional mass of muscle... - Dual-energy X-ray absorptiometry with serum ferritin predicts liver iron concentration and changes in concentration better than ferritin aloneJohn A Shepherd
Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, CA 94115, USA
J Clin Densitom 13:399-406. 2010.... - Growth and metabolic consequences of bladder augmentation in children with myelomeningocele and bladder exstrophyGerald C Mingin
Department of Urology, University of California, San Francisco, Children's Hospital, San Francisco, California 94143-0738, USA
Pediatrics 110:1193-8. 2002..CONCLUSION: Bladder augmentation is safe and does not impact negatively on the linear growth or bone densities of patients with myelomeningocele or bladder exstrophy... - Universal standardization of forearm bone densitometryJohn A Shepherd
Department of Radiology, University of California San Francisco, 94143-1349, USA
J Bone Miner Res 17:734-45. 2002.... - Effect of 1 year of an intentional weight loss intervention on bone mineral density in type 2 diabetes: results from the Look AHEAD randomized trialAnn V Schwartz
Department of Biostatistics and Epidemiology, University of California San Francisco, San Francisco, CA 94107, USA
J Bone Miner Res 27:619-27. 2012..One year of an intensive lifestyle intervention in adults with type 2 diabetes, resulting in weight loss, was associated with a modest increase in hip bone loss despite improved fitness and glycemic control...