Abstract：
OBJECTIVE: To determine if macroscopic intralesional fat detected in bone lesions on CT by Hounsfield unit (HU) measurement and on MRI by macroscopic assessment excludes malignancy.
METHODS: All consecutive CT-guided core needle biopsies (CNB) of non-spinal bone lesions performed at a tertiary center between December 2005 and September 2021 were reviewed. Demographic and histopathology data were recorded. All cases with malignant histopathology were selected, and imaging studies were reviewed. Two independent readers performed CT HU measurements on all bone lesions using a circular region of interest (ROI) to quantitate intralesional fat density (mean HU < -30). MRI images were reviewed to qualitatively assess for macroscopic intralesional fat signal in a subset of patients. Inter-reader agreement was assessed with Cronbach\'s alpha and intraclass correlation coefficient.
RESULTS: In 613 patients (mean age 62.9 years (range 19-95 years), 47.6% female), CT scans from the CNB of 613 malignant bone lesions were reviewed, and 212 cases had additional MRI images. Only 3 cases (0.5%) demonstrated macroscopic intralesional fat on either CT or MRI. One case demonstrated macroscopic intralesional fat density on CT in a case of metastatic prostate cancer. Two cases demonstrated macroscopic intralesional fat signal on MRI in cases of chondrosarcoma and osteosarcoma. Inter-reader agreement was excellent (Cronbach\'s alpha, 0.95-0.98; intraclass correlation coefficient, 0.90-0.97).
CONCLUSIONS: Malignant lesions rarely contain macroscopic intralesional fat on CT or MRI. While CT is effective in detecting macroscopic intralesional fat in primarily lytic lesions, MRI may be better for the assessment of heterogenous and infiltrative lesions with mixed lytic and sclerotic components.
CONCLUSIONS: Macroscopic intralesional fat is rarely seen in malignant bone tumors and its presence can help to guide the diagnostic workup of bone lesions.
CONCLUSIONS: • Presence of macroscopic intralesional fat in bone lesions has been widely theorized as a sign of benignity, but there is limited supporting evidence in the literature. • CT and MRI are effective in evaluating for macroscopic intralesional fat in malignant bone lesions with excellent inter-reader agreement. • Macroscopic intralesional fat is rarely seen in malignant bone lesions.
METHODS: All consecutive CT-guided core needle biopsies (CNB) of non-spinal bone lesions performed at a tertiary center between December 2005 and September 2021 were reviewed. Demographic and histopathology data were recorded. All cases with malignant histopathology were selected, and imaging studies were reviewed. Two independent readers performed CT HU measurements on all bone lesions using a circular region of interest (ROI) to quantitate intralesional fat density (mean HU < -30). MRI images were reviewed to qualitatively assess for macroscopic intralesional fat signal in a subset of patients. Inter-reader agreement was assessed with Cronbach\'s alpha and intraclass correlation coefficient.
RESULTS: In 613 patients (mean age 62.9 years (range 19-95 years), 47.6% female), CT scans from the CNB of 613 malignant bone lesions were reviewed, and 212 cases had additional MRI images. Only 3 cases (0.5%) demonstrated macroscopic intralesional fat on either CT or MRI. One case demonstrated macroscopic intralesional fat density on CT in a case of metastatic prostate cancer. Two cases demonstrated macroscopic intralesional fat signal on MRI in cases of chondrosarcoma and osteosarcoma. Inter-reader agreement was excellent (Cronbach\'s alpha, 0.95-0.98; intraclass correlation coefficient, 0.90-0.97).
CONCLUSIONS: Malignant lesions rarely contain macroscopic intralesional fat on CT or MRI. While CT is effective in detecting macroscopic intralesional fat in primarily lytic lesions, MRI may be better for the assessment of heterogenous and infiltrative lesions with mixed lytic and sclerotic components.
CONCLUSIONS: Macroscopic intralesional fat is rarely seen in malignant bone tumors and its presence can help to guide the diagnostic workup of bone lesions.
CONCLUSIONS: • Presence of macroscopic intralesional fat in bone lesions has been widely theorized as a sign of benignity, but there is limited supporting evidence in the literature. • CT and MRI are effective in evaluating for macroscopic intralesional fat in malignant bone lesions with excellent inter-reader agreement. • Macroscopic intralesional fat is rarely seen in malignant bone lesions.
摘要：
目的：确定通过Hounsfield单位（HU）测量CT和通过宏观评估MRI在骨病变中检测到的宏观病灶内脂肪是否排除恶性肿瘤。
方法：回顾了2005年12月至2021年9月在三级中心进行的所有连续CT引导的非脊柱骨病变的核心针活检（CNB）。记录人口统计学和组织病理学数据。选择所有恶性组织病理学的病例，和影像学研究进行了回顾。两个独立的阅读器使用圆形感兴趣区域（ROI）对所有骨病变进行CTHU测量，以定量病灶内脂肪密度（平均HU<-30）。对MRI图像进行了检查，以定性评估部分患者的宏观病灶内脂肪信号。用Cronbach的α和组内相关系数评估读者间的一致性。
结果：在613名患者中（平均年龄62.9岁（范围19-95岁），47.6％女性），对613个恶性骨病变的CNB的CT扫描进行了回顾，212例有额外的MRI图像。只有3例（0.5％）在CT或MRI上显示出肉眼可见的病灶内脂肪。在转移性前列腺癌的情况下，一例在CT上显示肉眼可见的病灶内脂肪密度。2例软骨肉瘤和骨肉瘤在MRI上显示宏观病灶内脂肪信号。读者间的协议非常好(克朗巴赫的阿尔法，0.95-0.98；组内相关系数，0.90-0.97）。
结论：恶性病变在CT或MRI上很少包含肉眼可见的病灶内脂肪。虽然CT可有效检测主要是溶解性病变的宏观病灶内脂肪，MRI可能更好地评估具有混合溶解和硬化成分的异质性和浸润性病变。
结论：宏观病灶内脂肪在恶性骨肿瘤中很少见，其存在有助于指导骨病变的诊断工作。
结论：•骨病变中存在宏观病灶内脂肪已被广泛认为是良性的标志，但文献中的支持证据有限。•CT和MRI可有效评估恶性骨病变中的宏观病灶内脂肪，并具有出色的读者共识。•在恶性骨病变中很少见到宏观病灶内脂肪。
方法：回顾了2005年12月至2021年9月在三级中心进行的所有连续CT引导的非脊柱骨病变的核心针活检（CNB）。记录人口统计学和组织病理学数据。选择所有恶性组织病理学的病例，和影像学研究进行了回顾。两个独立的阅读器使用圆形感兴趣区域（ROI）对所有骨病变进行CTHU测量，以定量病灶内脂肪密度（平均HU<-30）。对MRI图像进行了检查，以定性评估部分患者的宏观病灶内脂肪信号。用Cronbach的α和组内相关系数评估读者间的一致性。
结果：在613名患者中（平均年龄62.9岁（范围19-95岁），47.6％女性），对613个恶性骨病变的CNB的CT扫描进行了回顾，212例有额外的MRI图像。只有3例（0.5％）在CT或MRI上显示出肉眼可见的病灶内脂肪。在转移性前列腺癌的情况下，一例在CT上显示肉眼可见的病灶内脂肪密度。2例软骨肉瘤和骨肉瘤在MRI上显示宏观病灶内脂肪信号。读者间的协议非常好(克朗巴赫的阿尔法，0.95-0.98；组内相关系数，0.90-0.97）。
结论：恶性病变在CT或MRI上很少包含肉眼可见的病灶内脂肪。虽然CT可有效检测主要是溶解性病变的宏观病灶内脂肪，MRI可能更好地评估具有混合溶解和硬化成分的异质性和浸润性病变。
结论：宏观病灶内脂肪在恶性骨肿瘤中很少见，其存在有助于指导骨病变的诊断工作。
结论：•骨病变中存在宏观病灶内脂肪已被广泛认为是良性的标志，但文献中的支持证据有限。•CT和MRI可有效评估恶性骨病变中的宏观病灶内脂肪，并具有出色的读者共识。•在恶性骨病变中很少见到宏观病灶内脂肪。
