Automatic opportunistic osteoporosis screening in routine CT: improved prediction of patients with prevalent vertebral fractures compared to DXA

In the paper

“Previously published HU-to-BMD conversion equations were used for all CT scanners in this study [22].”

What the sources say

• Disputed

  The Methods (Opportunistic QCT) state that HU-to-BMD conversion equations were calculated by linear regression using phantom measurements for the scanners in this study. Table 4 (Results) lists the resulting scanner-specific equations. The paper does not describe using previously published conversion equations for all scanners; the previously investigated values mentioned in Methods are contrast-enhancement correction offsets. (LLM, conf=0.92)

  Checked by a reasoning model — may be wrong.

  cites [22] Löffler MT, Jacob A, Valentinitsch A et al (2019) Improved prediction of incident vertebral fractures using opportunistic QCT compared to DXA. Eur Radiol. https://doi.org/10.1007/s00330-019-06018-w sourceExperimental — accuracy not yet measured

In the paper

“First, vertebrae were automatically segmented in CT scans using a framework of CNNs that identifies the spine, labels each vertebral body, and creates segmentation masks [16].”

What the sources say

• Supported

  The Materials and Methods section (Vertebral Segmentation) describes a CNN framework that detects the spine, labels vertebrae, and segments vertebral patches that are fused into a labeled mask. The resulting masks were subsequently refined manually; this does not negate the described automatic segmentation step. (LLM, conf=0.92)

  cites [16] Löffler MT, Sekuboyina A, Jacob A et al (2020) A vertebral segmentation dataset with fracture grading. Radiol Artif Intell 2:e190138. https://doi.org/10.1148/ryai.2020190138 source

In the paper

“Besides hip fractures, vertebral fractures are the most common and most consequential osteoporotic fractures [4].”

What the sources say

• Partly supported

  The Vertebral Fractures section calls vertebral fractures the most common manifestation of osteoporosis and describes associations with pain, disability, mortality, and subsequent fractures. It does not establish that they are the most consequential after hip fractures; it reports that clinical vertebral fractures accounted for only 6% of fracture-related costs in the United States in 2005. (LLM, conf=0.84)

  cites [4] Ensrud KE (2013) Epidemiology of fracture risk with advancing age. J Gerontol A Biol Sci Med Sci 68:1236–1242. https://doi.org/10.1093/gerona/glt092 sourceExperimental — accuracy not yet measured

In the paper

“These differences in the study population—paired with the focus on prevalent instead of incident fractures and better sensitivity to detect fractures by using ≤ 1-mm instead of 2.5-mm axial slices [26]—could lead to the relatively higher ORs compared to Allaire et al (OR = 2.7 vs. 1.6 for CT-based aBMD, OR = 4.8 vs. 2.8 for integral vBMD, and OR = 6.8 vs. 2.1 for trabecular vBMD) [27]; though, CT–”

What the sources say

• ?Not checked — no full text of the sourcecites [26] Bauer JS, Müller D, Ambekar A et al (2006) Detection of osteoporotic vertebral fractures using multidetector CT. Osteoporos Int 17:608–615. https://doi.org/10.1007/s00198-005-0023-8 source
• Partly supported

  The Methods and Results identify Allaire et al.’s study as examining incident vertebral fractures, and the Results report an OR of 1.6 for CT-based aBMD. Our copy says integral and trabecular vBMD were associated with incident fracture, but the passages do not give the specific ORs of 2.8 and 2.1 attributed to Allaire et al. The proposed reasons for the higher ORs are the citing authors’ interpretation; the slice-thickness comparison is attached to a different citation. (LLM, conf=0.82)

  cites [27] Allaire BT, Lu D, Johannesdottir F et al (2019) Prediction of incident vertebral fracture using CT-based finite element analysis. Osteoporos Int 30:323–331. https://doi.org/10.1007/s00198-018-4716-1 sourceExperimental — accuracy not yet measured

In the paper

“Second, there is significant variability in the access to DXA services and many fall short of international quality standards [14].”

What the sources say

• Supported

  The Abstract conclusion says access to DXA services varies significantly and many centres fall short of IOF-ISCD Osteoporosis Essentials standards. The survey concerns established Fracture Liaison Services worldwide. (LLM, conf=0.94)

  cites [14] Clynes MA, Westbury LD, Dennison EM et al (2020) Bone densitometry worldwide: a global survey by the ISCD and IOF. Osteoporos Int 31:1779–1786. https://doi.org/10.1007/s00198-020-05435-8 source

In the paper

“Bias of BMD values due to intravenous injection of contrast medium was corrected for using linear correction equations for arterial and portal/venous contrast phases [23].”

What the sources say

• Supported

  The Methods describe BMD measurements in arterial and portal-venous contrast phases and linear fitting for each phase. The Discussion refers to additional correction equations defined in the study, and the Conclusions state that adjustment with simple linear regression can even out contrast-related BMD bias. Page numbers are not available in our copy. (LLM, conf=0.91)

  cites [23] Kaesmacher J, Liebl H, Baum T, Kirschke JS (2017) Bone mineral density estimations from routine multidetector computed tomography: a comparative study of contrast and calibration effects. J Comput Assist Tomogr 41:217–223. https://doi.org/10.1097/RCT.0000000000000518 source

In the paper

“Compared to a study of incident vertebral fractures in the Osteoporotic Fractures in Men (MrOS) Study cohort of elderly men, the AUCs we report seem considerably higher for trabecular vBMD (AUC = 0.885 vs. 0.79), but lower for DXA-based aBMD (AUC = 0.668 vs. 0.72) [28].”

What the sources say

• Partly supported

  The Discussion (page unavailable) identifies this as a MrOS study and reports that trabecular spine vBMD predicted spine fractures better than DXA-based spine aBMD. The cited paper passages do not give the specific AUCs of 0.79 and 0.72, so those numerical comparisons are not verified by our copy. (LLM, conf=0.78)

  cites [28] Chalhoub D, Orwoll ES, Cawthon PM et al (2016) Areal and volumetric bone mineral density and risk of multiple types of fracture in older men. Bone 92:100–106. https://doi.org/10.1016/j.bone.2016.08.014 sourceExperimental — accuracy not yet measured

In the paper

“Age- and sex-adjusted associations with fracture status were strongest for manual vBMD (OR = 7.3, [95%] CI 3.8–14.3) followed by automatically assessed trabecular vBMD (OR = 6.9, CI 3.5–13.4) and integral vBMD (OR = 4.3, CI 2.5–7.6).”

In the paper

“All automatically assessed CT-based bone measures had a highly significant association with the prevalence of osteoporotic vertebral fractures with no significant differences between automatic and manual measurements.”

In the paper

“and showed significantly lower values in all bone measures (DXA-based aBMD, CT-based aBMD, manual vBMD, trabecular vBMD, integral vBMD, and BMC, p < 0.001 each; DXA-based T-score, p = 0.001) compared to patients without fractures”

In the paper

“We included 192 patients (141 women, 51 men; age 70.2 ± 9.7 years) who had lumbar DXA and CT available (within 1 year).”

• Also stated in: § Results · plain

  “Overall, 192 patients (141 women, 51 men) with a mean age of 70.2 ± 9.7 years were included in this study.”

In the paper

“However, most CT-based measures performed significantly better than DXA, e.g., when comparing DXA-based aBMD with intergral, trabecual, or manual vBMD (AUC = 0.668 vs. 0.735, 0.860, or 0.885, respectively, p < 0.001 each; Table 3).”

In the paper

“We reported on elderly patients that all received DXA scans, thereby implicating that osteoporosis was already suspected; thus, the high prevalence of at least mild (Genant grade 1) osteoporotic vertebral fractures (77%) is not surprising.”

In the paper

“Opportunistic quantitative evaluation of preexisting clinical routing CT entails neither additional costs nor radiation exposure [15].”

What the sources say

• ?Not checked — no full text of the sourcecites [15] Löffler MT, Sollmann N, Mei K et al (2020) X-Ray-based quantitative osteoporosis imaging at the spine. Osteoporos Int 31:233–250. https://doi.org/10.1007/s00198-019-05212-2 source

In the paper

“CT scans of the remaining 258 patients were screened for prevalent osteoporotic vertebral fractures using the semi-quantitative technique by Genant [18].”

What the sources say

• ?Not checked — no full text of the sourcecites [18] Genant HK, Wu CY, van Kuijk C, Nevitt MC (1993) Vertebral fracture assessment using a semiquantitative technique. J Bone Miner Res 8:1137–1148. https://doi.org/10.1002/jbmr.5650080915 source

In the paper

“The local institutional review board approved this monocentric retrospective study (ethics committee’s reference number 27/19S/SR) and waived written informed consent.”

In the paper

“To date, the standard screening method includes assessing clinical risk factors and measuring areal bone mineral density (aBMD) using dual-energy X-ray absorptiometry (DXA) [1].”

What the sources say

• ?Not checked — no full text of the sourcecites [1] NIH Consensus Development Panel on Osteoporosis Prevention, Diagnosis, and Therapy (2001) Osteoporosis prevention, diagnosis, and therapy. JAMA 285:785–795 source

In the paper

“For trabecular vBMD, we used the diagnostic thresholds for osteoporosis (BMD < 80 mg/cm3) and for low bone mass (80 ≤ BMD ≤ 120 mg/cm3) proposed by the American College of Radiology (ACR) [24].”

What the sources say

• Not checked yetcites [24] American College of Radiology (2018) ACR–SPR–SSR practice parameter for the performance of musculoskeletal quantitative computed tomography (QCT). American College of Radiology, Reston. Available via https://www.acr.org/-/media/ACR/Files/Practice-Parameters/QCT.pdf?la=en. Accessed 7 Nov 2018

In the paper

“First, less than half of women (44%) and even fewer men (21%) with osteoporotic fractures exhibited low aBMD in a large observational study [12]”

What the sources say

• ?Not checked — no full text of the sourcecites [12] Schuit SCE, van der Klift M, Weel AEAM et al (2004) Fracture incidence and association with bone mineral density in elderly men and women: the Rotterdam Study. Bone 34:195–202 source

In the paper

“Scans were performed by trained technologists and quality was assured through evaluation by experienced physicians following current recommendations [19].”

What the sources say

• ?Not checked — no full text of the sourcecites [19] Shepherd JA, Schousboe JT, Broy SB, Engelke K, Leslie WD (2015) Executive summary of the 2015 ISCD Position Development Conference on Advanced Measures From DXA and QCT: fracture prediction beyond BMD. J Clin Densitom 18:274–286. https://doi.org/10.1016/j.jocd.2015.06.013 source

In the paper

“Yet, other methods of bone densitometry exhibit even more disadvantages: quantitative computed tomography (QCT) has limited availability, is more expensive, and is associated with a substantially higher radiation dose (> 100-fold) [15].”

What the sources say

• ?Not checked — no full text of the sourcecites [15] Löffler MT, Sollmann N, Mei K et al (2020) X-Ray-based quantitative osteoporosis imaging at the spine. Osteoporos Int 31:233–250. https://doi.org/10.1007/s00198-019-05212-2 source