OsteoEd

Practice Cases

Bone Density Measurement Basics

Mary B. Laya, MD, MPH Literature reviewed July 30, 2006. Updated March 30, 2009

A 66-year-old woman presents to you for an annual examination after newly moving to the area. She brings a copy of a forearm bone density report she obtained at a local drug store (see image below). The report states she has osteopenia; she is concerned but also wonders about the accuracy of the test.

She is a postmenopausal woman taking estrogen replacement therapy and atenolol for hypertension. She has no personal or family history of fracture and is a non-smoker. She weighs 158 pounds.


Click to see a larger image.

Click an answer under each question.

  1. What kind of peripheral bone density testing does her report represent?

    • Option A Single X-ray absorptiometry (SXA)
    • Option B Peripheral dual X-ray absorptiometry (pDXA)
    • Option C Ultrasound densitometry
    • Option D X-ray absorptiometry
  2. Which of the following statements about this type of peripheral bone density measurement is true?

    • Option A Peripheral bone density readings are inaccurate in women without risk factors and should be disregarded
    • Option B Peripheral bone density testing strongly predicts fracture risk at the hip and spine, and she should start on treatment based on the result.
    • Option C Peripheral bone density testing results should be confirmed by another testing modality at more central sites
  3. What is the best technique for measuring her bone density at this time?

    • Option A Quantitative computed tomography (QCT)
    • Option B Dual photon absorptiometry (DPA)
    • Option C Dual X-ray absorptiometry (DXA)
  4. Which of the following statements about Medicare reimbursement for bone density testing is true?

    • Option A Medicare will reimburse only for bone density testing every year for women at risk for osteoporosis
    • Option B Medicare will not reimburse for a confirmatory test since the patient has had one this year
    • Option C Medicare will reimburse for a confirmatory test and repeat testing to monitor therapy every 2 years
  5. Her confirmatory DXA shows total hip bone mineral density 0.93 SD above the 66-year-old mean and 0.36 SD below the 25-year-old mean. Which of the statements concerning her report is correct?

    • Option A Her average/total hip T-score is +0.93
    • Option B Her average/total hip T-score is -0.36
    • Option C Her average/total hip Z-score is -0.36
    • Option D She has osteoporosis
Last edited July 03, 2009