应用双能 CT 检测腰椎骨转移：体模结果及初步临床验证。

Detection of Lumbar Spine Osseous Metastases Using Dual-Energy CT: Phantom Results and Preliminary Clinical Validation.

机构信息

1 Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628.

2 Department of Medical Imaging, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.

出版信息

AJR Am J Roentgenol. 2019 Feb;212(2):402-410. doi: 10.2214/AJR.18.19933. Epub 2018 Dec 12.

DOI:10.2214/AJR.18.19933

PMID:30667316

Abstract

OBJECTIVE

The purpose of this study was to evaluate the sensitivity, tumor conspicuity, and image quality of different material decomposition images of phantoms and patients with nearly isodense bone metastases using rapid-kilovoltage-switching dual-energy CT (DECT).

MATERIALS AND METHODS

Fifty-one semianthropomorphic lumbar spine phantoms embedded with 75 simulated tumors were scanned without and with outer torso-attenuating encasement under the same scan settings. Two radiologists independently reviewed the 70-keV virtual monochromatic and material decomposition images (hydroxyapatite-water, water-hydroxyapatite, cortical bone-water, water-cortical bone). The sensitivity of tumor detection, tumor conspicuity (on a 3-point scale), and image quality (on a 3-point scale) were recorded by two independent readers. McNemar and Wilcoxon signed rank tests were used to compare results between the image reconstructions. Six clinical abdominopelvic DECT scans (three men, three women; mean age, 52 years) with nine nearly isodense lumbar spine tumors missed in the clinical report but confirmed on other scans were also evaluated.

RESULTS

The hydroxyapatite-water material decomposition algorithm showed improved sensitivity for isodense lesion detection (without torso phantom encasement, 94% vs 82%, p = 0.031; with torso phantom encasement, 38% vs 18%, p = 0.013), and higher tumor conspicuity scores (p < 0.0001) compared with 70-keV virtual monoenergetic images. Artifacts were more prevalent with all material decomposition images than with 70-keV virtual monoenergetic images. Similar results were seen in the patient study.

CONCLUSION

Dual-energy CT with hydroxyapatite-water material decomposition may improve the detection of bone marrow metastases, especially for subtle isodense tumors. Further study in prospective clinical scans is warranted.

摘要

目的

本研究旨在评估快速千伏切换双能 CT（DECT）不同物质分解图像对模拟几乎等密度骨转移瘤的 phantom 和患者的灵敏度、肿瘤显著性和图像质量。

材料和方法

在相同的扫描设置下，扫描了 51 个半人体腰椎 phantom，其中嵌入了 75 个模拟肿瘤，同时扫描了没有和有外部躯干衰减外壳的 phantom。两名放射科医生独立对 70keV 虚拟单能量和物质分解图像（羟磷灰石水、水羟磷灰石、皮质骨水、水皮质骨）进行了回顾。两位独立读者记录了肿瘤检测的灵敏度、肿瘤显著性（3 分制）和图像质量（3 分制）。采用 McNemar 和 Wilcoxon 符号秩检验比较不同图像重建结果。还评估了 6 例临床腹部盆腔 DECT 扫描（3 名男性，3 名女性；平均年龄 52 岁），其中 9 例临床报告中漏诊但在其他扫描中确认的几乎等密度腰椎脊柱肿瘤。

结果

羟磷灰石水物质分解算法对等密度病变检测的灵敏度更高（无躯干 phantom 外壳时，94%比 82%，p=0.031；有躯干 phantom 外壳时，38%比 18%，p=0.013），肿瘤显著性评分也更高（p<0.0001），与 70keV 虚拟单能量图像相比。与 70keV 虚拟单能量图像相比，所有物质分解图像的伪影更为常见。在患者研究中也观察到了类似的结果。