J A Shepherd

Summary

Affiliation: University of California
Country: USA

Publications

  1. ncbi request reprint Cross-calibration and minimum precision standards for dual-energy X-ray absorptiometry: the 2005 ISCD Official Positions
    John A Shepherd
    Department of Radiology, University of California, San Francisco, CA 94143 0946, USA
    J Clin Densitom 9:31-6. 2006
  2. pmc Does standardized BMD still remove differences between Hologic and GE-Lunar state-of-the-art DXA systems?
    B Fan
    Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA
    Osteoporos Int 21:1227-36. 2010
  3. pmc Optimal monitoring time interval between DXA measures in children
    John 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
  4. pmc Breast density assessment in adolescent girls using dual-energy X-ray absorptiometry: a feasibility study
    John 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
  5. ncbi request reprint Comparison of BMD precision for Prodigy and Delphi spine and femur scans
    J A Shepherd
    Department of Radiology, University of California, 185 Berry Street, STE 350, San Francisco, CA 94143 0946, USA
    Osteoporos Int 17:1303-8. 2006
  6. ncbi request reprint Metacarpal index and bone mineral density in healthy African-American women
    J A Shepherd
    Department of Radiology, University of California, San Francisco, 185 Berry Street, Suite 350, San Francisco, CA 94107 0946, USA
    Osteoporos Int 16:1621-6. 2005
  7. ncbi request reprint Novel use of single X-ray absorptiometry for measuring breast density
    John 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
  8. doi request reprint Improved precision with Hologic Apex software
    B Fan
    Department of Radiology, University of California, 185 Berry Street, Suite 350, San Francisco, CA 94107, USA
    Osteoporos Int 19:1597-602. 2008
  9. ncbi request reprint Evaluation of a gel-coupled quantitative ultrasound device for bone status assessment
    C F Njeh
    Osteoporosis and Arthritis Research Group, Department of Radiology, University of California San Francisco, 94143-1349, USA
    J Ultrasound Med 20:1219-28. 2001
  10. ncbi request reprint Towards standardization of dual X-ray absorptiometry (DXA) at the forearm: a common region of interest (ROI) improves the comparability among DXA devices
    S Prevrhal
    Department of Radiology, University of California, San Francisco, California, USA
    Calcif Tissue Int 76:348-54. 2005

Detail Information

Publications33

  1. ncbi request reprint Cross-calibration and minimum precision standards for dual-energy X-ray absorptiometry: the 2005 ISCD Official Positions
    John 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...
  2. pmc Does standardized BMD still remove differences between Hologic and GE-Lunar state-of-the-art DXA systems?
    B Fan
    Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA
    Osteoporos Int 21:1227-36. 2010
    ..Spine L1-L4 and L2-L4 sBMD mean differences between the two systems were 0.042 g/cm(2) (4.1%) and 0.035 g/cm(2) (3.2%), respectively...
  3. pmc Optimal monitoring time interval between DXA measures in children
    John 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...
  4. pmc Breast density assessment in adolescent girls using dual-energy X-ray absorptiometry: a feasibility study
    John 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...
  5. ncbi request reprint Comparison of BMD precision for Prodigy and Delphi spine and femur scans
    J A Shepherd
    Department of Radiology, University of California, 185 Berry Street, STE 350, San Francisco, CA 94143 0946, USA
    Osteoporos Int 17:1303-8. 2006
    ..Minimization and characterization of these errors is essential for reliable assessment of BMD change over time...
  6. ncbi request reprint Metacarpal index and bone mineral density in healthy African-American women
    J A Shepherd
    Department of Radiology, University of California, San Francisco, 185 Berry Street, Suite 350, San Francisco, CA 94107 0946, USA
    Osteoporos Int 16:1621-6. 2005
    ..The differences were found to be entirely due to larger bone size, cortical diameter and bone width in the African-American women...
  7. ncbi request reprint Novel use of single X-ray absorptiometry for measuring breast density
    John 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...
  8. doi request reprint Improved precision with Hologic Apex software
    B Fan
    Department of Radiology, University of California, 185 Berry Street, Suite 350, San Francisco, CA 94107, USA
    Osteoporos Int 19:1597-602. 2008
    ..2 software and is comparable to GE Lunar Prodigy v7.5 software. Apex and Delphi precisions were, respectively, 1.0% vs. 1.2% (L1-L4 spine), 1.l % vs. 1.3% (total femur), 1.6% vs. 1.9% (femoral neck), and 0.7% vs. 0.9% (dual total femur)...
  9. ncbi request reprint Evaluation of a gel-coupled quantitative ultrasound device for bone status assessment
    C F Njeh
    Osteoporosis and Arthritis Research Group, Department of Radiology, University of California San Francisco, 94143-1349, USA
    J Ultrasound Med 20:1219-28. 2001
    ....
  10. ncbi request reprint Towards standardization of dual X-ray absorptiometry (DXA) at the forearm: a common region of interest (ROI) improves the comparability among DXA devices
    S Prevrhal
    Department of Radiology, University of California, San Francisco, California, USA
    Calcif Tissue Int 76:348-54. 2005
    ..ROI standardization dramatically improves interdevice comparability...
  11. ncbi request reprint Clinical comparison of a novel breast DXA technique to mammographic density
    John 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...
  12. pmc Compositional breast imaging using a dual-energy mammography protocol
    Aurelie 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...
  13. ncbi request reprint Vertebral fractures in osteoporosis: a new method for clinical assessment
    H K Genant
    Osteoporosis and Arthritis Research Group, Department of Radiology, University of California, San Francisco, CA 94143 0628, USA
    J Clin Densitom 3:281-90. 2000
    ..We also review clinical data supporting the feasibility of visual evaluation of lateral spine images obtained using a fan-beam DXA system, and discuss the potential positive impact of this new methodology on clinical patient evaluation...
  14. ncbi request reprint Does osteoporosis classification using heel BMD agree across manufacturers?
    M Grigorian
    Osteoporosis and Arthritis Research Group, Department of Radiology, University of California at San Francisco, San Francisco, CA, USA
    Osteoporos Int 13:613-7. 2002
    ..We found that PIXI and Apollo are highly correlated. Differences in BMD values are mainly due to different region of interest (ROI) definitions and additional T-score disagreement reflects the difference in normative databases...
  15. pmc Dual-energy and low-kVp CT in the abdomen
    Benjamin 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
    ..The purpose of this article is to discuss the influence of tube potential on CT images and explore the potential impact of dual-energy CT on imaging of the abdomen and pelvis...
  16. pmc Single x-ray absorptiometry method for the quantitative mammographic measure of fibroglandular tissue volume
    Serghei Malkov
    Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California 94143, USA
    Med Phys 36:5525-36. 2009
    ....
  17. ncbi request reprint Measurement of breast density with dual X-ray absorptiometry: feasibility
    John 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...
  18. ncbi request reprint A generalized least significant change for individuals measured on different DXA systems
    John 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...
  19. doi request reprint Comparing BMD results between two similar DXA systems using the generalized least significant change
    John 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...
  20. doi request reprint Dual-energy X-ray absorptiometry with serum ferritin predicts liver iron concentration and changes in concentration better than ferritin alone
    John 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
    ....
  21. doi request reprint Comparison of DXA hip structural analysis with volumetric QCT
    Sven 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...
  22. ncbi request reprint Universal standardization of forearm bone densitometry
    John A Shepherd
    Department of Radiology, University of California San Francisco, 94143 1349, USA
    J Bone Miner Res 17:734-45. 2002
    ....
  23. ncbi request reprint Accuracy of CT-based thickness measurement of thin structures: modeling of limited spatial resolution in all three dimensions
    Sven 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
    ....
  24. ncbi request reprint Accuracy of mammographic breast density analysis: results of formal operator training
    Sven Prevrhal
    Department of Radiology, University of California, San Francisco, California 94143 1250, USA
    Cancer Epidemiol Biomarkers Prev 11:1389-93. 2002
    ....
  25. ncbi request reprint T-scores and Z-scores
    John A Shepherd
    Department of Radiology, University of California, San Francisco, CA, USA
    J Clin Densitom 10:349-50. 2007
  26. doi request reprint Computer-assisted technique to delineate osteolytic lesions around the femoral component in total hip arthroplasty
    Sven 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...
  27. ncbi request reprint Growth and metabolic consequences of bladder augmentation in children with myelomeningocele and bladder exstrophy
    Gerald C Mingin
    Department of Urology, University of California, San Francisco, Children s Hospital, San Francisco, California 94143 0738, USA
    Pediatrics 110:1193-8. 2002
    ..We studied changes in calcium metabolism, height, bone chemistry, and bone density in exstrophy and myelomeningocele patients after bladder augmentation...
  28. ncbi request reprint The bone mineral density in childhood study: bone mineral content and density according to age, sex, and race
    Heidi J Kalkwarf
    Division of General and Community Pediatrics, Cincinnati Children s Hospital Medical Center, Cincinnati, OH 45229, USA
    J Clin Endocrinol Metab 92:2087-99. 2007
    ..Low bone mass may increase risk of fracture. Several chronic medical conditions, medications, and lifestyle factors affect bone mineral accrual. Appropriate reference values are essential for identification of children with bone deficits...
  29. doi request reprint Peripheral dual-energy X-ray absorptiometry in the management of osteoporosis: the 2007 ISCD Official Positions
    Didier B Hans
    Geneva University Hospital, Geneva, Switzerland
    J Clin Densitom 11:188-206. 2008
    ....
  30. ncbi request reprint Osteoporosis assessment by whole body region vs. site-specific DXA
    L Joseph Melton
    Division of Epidemiology, Department of Health Sciences Research, Mayo Clinic College of Medicine, 200 First Street S W, Rochester, MN 55905, USA
    Osteoporos Int 16:1558-64. 2005
    ....
  31. ncbi request reprint Recalculation of the NHANES database SD improves T-score agreement and reduces osteoporosis prevalence
    Neil Binkley
    University of Wisconsin Osteoporosis Clinical Center and Research Program, Madison, Wisconsin, USA
    J Bone Miner Res 20:195-201. 2005
    ..Use of a recalculated young-normal SD for the GE Lunar-adjusted NHANES III database improved diagnostic agreement and is recommended...
  32. ncbi request reprint Effect of random BMD measurement errors on diagnostic classification using T-scores
    Glen M Blake
    J Clin Densitom 10:415-7; author reply 417-8. 2007
  33. ncbi request reprint Official positions of the international society for clinical densitometry
    E Michael Lewiecki
    New Mexico Clinical Research and Osteoporosis Center, Albuquerque, New Mexico 87106, USA
    J Clin Endocrinol Metab 89:3651-5. 2004
    ..Recommendations that are accepted become the Official Positions of the ISCD. This Special Report summarizes the methodology of the ISCD Position Development Conferences and presents selected Official Positions of general interest...