Authors: (including presenting author): :
Drs Ngai KS (1), Luk WH (1), Pan NY (1)
Affiliation: :
(1) Department of Diagnostic and Interventional Radiology, Princess Margaret Hospital
Keyword 1: :
Osteoporosis
Keyword 2: :
Dual-energy X-ray absorptiometry (DXA)
Keyword 3: :
Bone mineral density (BMD)
Keyword 4: :
Clinical audit
Introduction: :
According to the 2024 OSHK Guideline for Clinical Management of Postmenopausal Osteoporosis in Hong Kong, osteoporosis is a major public health concern that carries significant implications for morbidity, mortality and health care systems. One in three women and one in five men over the age of 50 will suffer from an osteoporotic fracture in their lifetime. Hip fractures are the most serious complication of osteoporosis, carrying 20–24% one-year mortality, with 40% of patients losing independent mobility and 33% requiring long-term care. In Hong Kong, the age-standardised incidence was 190.4 per 100,000 from 2005–2018, projected to double by 2050 with population ageing. Vertebral fractures are also common but often underdiagnosed, affecting 12–22% of older women. Early and accurate diagnosis with DXA and clinical risk assessment is vital to prevent fractures and improve outcomes in the aging population. With reference to the World Health Organization (WHO) criteria, for postmenopausal women and men older than 50 years, a T-score of ≤ -2.5 at the lumbar spine, one-third (33%) radius, femoral neck, or total hip is indicative of osteoporosis; T-score between -2.5 and -1.0 is classified as “osteopenia,” “low bone mass,” or “low bone density”; and T-score of ≥ -1.0 normal bone mineral density (BMD). Diagnostic classification is based on the lowest T-score at any of the recommended DXA regions. In a recent endorsed publication from European Association of Nuclear Medicine (EANM) - Updated practice guideline for dual energy X ray absorptiometry (DXA), it states that a known diagnosis of osteoporosis is durable and should remain unchanged, even if follow-up scans show improved BMD with T-scores > -2.5. Repeat imaging aims to monitor BMD changes over time but does not alter the original diagnosis of osteoporosis. The principle is also consistent with recommendations outlined in other clinical guidelines, such as American Association of Clinical Endocrinologists/American College of Endocrinology (AACE/ACE) Clinical Practice Guidelines for the Diagnosis and Treatment of Postmenopausal Osteoporosis—2020 Update, and National Osteoporosis Foundation (NOF) The clinician’s guide to prevention and treatment of osteoporosis. Serial DXA scans are routinely performed in our unit; however, patients with a prior diagnosis of osteoporosis are sometimes re-labelled as osteopenia based on subsequent improvements in BMD. This audit aims to highlight this potential inconsistency and promote greater awareness to ensure the use of accurate and consistent medical terminology.
Objectives: :
To ensure the use of accurate and consistent medical terminology in DXA report interpretation for patients who were previously diagnosed with osteoporosis with imaging, and subsequently reclassified as osteopenia.
Methodology: :
We have reviewed the EANM endorsed imaging guideline - Updated practice guideline for DXA – published in September 2024, and two respective clinical guidelines - AACE/ACE Clinical Practice Guidelines for the Diagnosis and Treatment of Postmenopausal Osteoporosis—2020 Update, and NOF The clinician’s guide to prevention and treatment of osteoporosis in 2022. They recommended when the initial diagnosis of osteoporosis is made according to a T-score of −2.5 or below, the diagnosis should remain even when a subsequent DXA measurement shows a T-score better than −2.5. The rationale is that the diagnosis reflects the patient’s lifetime increased risk of fracture and not just BMD at a single point in time. Data were collected retrospectively over a 6-month period from 1 June to 31 December 2024 through the Radiology information System (RIS) PMH. The search criteria were ‘age 0-99’, ‘exam code 9981 Bone Den Spine OR 9980 Bone Den Hip’, ‘reported by all radiologists’, Keywords ‘Consistent with the diagnosis of osteopenia’ AND ‘interval’. Interval follow-up DXA reports with interpretation of “Consistent with the diagnosis of osteopenia” issued from 1 June to 31 December 2024 were reviewed on RIS system (Total 236 cases). Each of their previous DXA reports done in PMH were also reviewed and analysed. Of those, only reports with previous imaging diagnosis of osteoporosis by DXA done in PMH (Total 46 cases) were further analysed and included in this audit.
Result & Outcome: :
Total of 46 cases were included in phase I during the period from 1 June to 31 December 2024. All of these 46 cases, on retrospective review, had prior imaging diagnosis of osteoporosis by DXA done earlier in PMH. However, the DXA report conclusions issued from June to Dec 2024 did not address the established diagnosis of osteoporosis based on prior imaging (0%). Instead, DXA report conclusions (100%) commented “Consistent with diagnosis of osteopenia”. According to the EANM guideline and several other clinical guidelines, a known diagnosis of osteoporosis based on prior imaging remains unchanged with subsequent follow-up scans. Instead, repeated imaging is primarily utilized to monitor changes in bone mineral density (BMD) over time. The current practice, as demonstrated in this audit, raises a potential concern: the phrase "consistent with a diagnosis of osteopenia" may inadvertently give the false impression that the prior diagnosis of osteoporosis has been superseded by osteopenia. This is especially relevant when patients undergo serial DXA scans. In some instances, with favourable treatment response, the originally established diagnosis of osteoporosis may be overshadowed by subsequent studies where the bone mineral density (BMD) falls into the osteopenia category (T-scores improve to > -2.5), as defined by the WHO criteria. However, it is crucial to emphasize that the initial diagnosis of osteoporosis remains valid, even if subsequent BMD measurements improve. Otherwise, with the implementation of the electronic health record sharing system (eHealth) in Hong Kong, patients without prior medical training who access their radiology reports may be falsely led to believe that their condition has reverted from osteoporosis to osteopenia, leading to potential confusion and misunderstanding about their medical condition. Finally, it is considered good practice for radiologists to explicitly denote the established diagnosis of osteoporosis in their reports. This serves as a clear medical record, ensuring that both clinicians and radiologists do not overlook the patient’s prior diagnosis and that it remains appropriately acknowledged in ongoing care. Proposed Sample Radiology Report Template: Interpretation: 1. Known diagnosis of osteoporosis based on previous DXA dated . 2. There has been no significant interval change/ significant increase/ significant decrease in lumbar spine, and no significant interval change/ significant increase/ significant decrease total hip BMD since previous study dated .
