Accuracy of Phantomless Calibration of Routine Computed Tomography Scans for Opportunistic Osteoporosis Screening in the Spine Clinic.

IF 2.6 2区医学 Q2 CLINICAL NEUROLOGY

Spine Pub Date : 2025-04-15 Epub Date: 2024-06-26 DOI:10.1097/BRS.0000000000005080

Riza M Cetik, Charles H Crawford, Steven D Glassman, John R Dimar, Jeffrey L Gum, Mladen Djurasovic, Leah Y Carreon

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Abstract

Study design: Diagnostic accuracy study.

Objective: To establish a simple method of phantomless bone mineral density (BMD) measurement by using preoperative lumbar computed tomography (CT) scans, and compare the accuracy of reference tissue combinations to diagnose low BMD against uncalibrated Hounsfield units (HUs).

Summary of background data: HUs are used as a measure of BMD; however, associations between HU and T-scores vary widely. Quantitative CT (qCT) scans are more accurate, but they require density calibration with an object of known density (phantom), which limits feasibility. As an emerging technique, phantomless (internal) calibration of routine CT scans may provide a good opportunity for screening.

Materials and methods: Patients who were scheduled to undergo lumbar surgery, with a preoperative CT scan, and a dual-energy x-ray absorptiometry (DXA) scan within six months were included. Four tissues were selected for calibration: subcutaneous adipose (A), erector spinae (ES), psoas (P), and aortic blood (AB). The HUs of these tissues were used in linear regression against ground-truth values. Calibrations were performed by using two different internal tissues at a time to maintain simplicity and in-office applicability.Volumetric bone mineral densities (vBMD) derived from internally calibrated CT scans were analyzed for new threshold values for low bone density. Areas under the curve (AUC) were calculated with 95% CI.

Results: Forty-five patients were included (M/F=10/35, mean age: 63.3). Calibrated vBMDs had stronger correlations with DXA T -scores when compared with HUs, with L2 exhibiting the highest coefficients. Calibration by using A and ES with the threshold of 162 mg/cm 3 had a sensitivity of 90% in detecting low BMD (AUC=0.671).

Conclusions: This novel method allows simple, in-office calibration of routine preoperative CT scans without the use of a phantom. Calibration using adipose and erector spinae with a threshold of 162 mg/cm 3 is proposed for low bone density screening with high sensitivity (90%).

Level of evidence: Level III.

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用于脊柱门诊骨质疏松症机会性筛查的常规计算机断层扫描无幻影校准的准确性。

研究设计诊断准确性研究：利用术前腰椎计算机断层扫描（CT）建立一种测量无模型骨密度（BMD）的简单方法，并比较参考组织组合与未校准的霍恩斯费尔德单位（HUs）诊断低BMD的准确性：背景数据摘要：HUs 被用作衡量 BMD 的标准；然而，HU 与 T 值之间的关联却存在很大差异。定量 CT（qCT）扫描更为精确，但需要用已知密度的物体（模型）进行密度校准，这限制了其可行性。作为一项新兴技术，常规 CT 扫描的无模型（内部）校准可能会为筛查提供一个良好的机会：方法：将计划接受腰椎手术、术前接受 CT 扫描并在 6 个月内接受双能 X 射线吸收测定（DXA）扫描的患者包括在内。选取了四个组织进行校准：皮下脂肪（A）、竖脊肌（ES）、腰肌（P）和主动脉血液（AB）。这些组织的 HU 与地面真实值进行线性回归。校准一次使用两个不同的内部组织，以保持简便性和诊室适用性。对内部校准 CT 扫描得出的体积骨矿密度（vBMD）进行分析，以确定新的低骨密度阈值。对内部校准 CT 扫描得出的骨矿物质密度（vBMD）进行分析，以确定低骨密度的新阈值，并计算出曲线下面积（AUC）和 95% 的置信区间（CI）：共纳入 45 名患者（男/女=10/35，平均年龄：63.3 岁）。与 HU 值相比，校准后的 vBMD 值与 DXA T 值的相关性更强，其中 L2 值的相关系数最高。使用阈值为 162 mg/cm3 的 A 和 ES 进行校准，检测低 BMD 的灵敏度为 90%（AUC=0.671）：这种新方法可在诊室内对常规术前 CT 扫描进行简单校准，无需使用模型。建议使用脂肪和竖脊骨进行校准，阈值为 162 mg/cm3，用于低骨密度筛查，灵敏度高（90%）：证据等级：三级。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Spine 医学-临床神经学

CiteScore

5.90

自引率

6.70%

发文量

361

审稿时长

6.0 months

期刊介绍： Lippincott Williams & Wilkins is a leading international publisher of professional health information for physicians, nurses, specialized clinicians and students. For a complete listing of titles currently published by Lippincott Williams & Wilkins and detailed information about print, online, and other offerings, please visit the LWW Online Store. Recognized internationally as the leading journal in its field, Spine is an international, peer-reviewed, bi-weekly periodical that considers for publication original articles in the field of Spine. It is the leading subspecialty journal for the treatment of spinal disorders. Only original papers are considered for publication with the understanding that they are contributed solely to Spine. The Journal does not publish articles reporting material that has been reported at length elsewhere.