Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany.
Invest Radiol. 2012 Jan;47(1):65-70. doi: 10.1097/RLI.0b013e31823003d2.
To assess the correlation of true nonenhanced (TNE) and virtually nonenhanced (VNE) images of abdominal dual-energy computed tomography (DECT) in patients with metastatic gastrointestinal stromal tumors (GIST), and further to investigate the correlation of iodine-related attenuation (IRA) of DECT with the Choi criteria.
Twenty-four consecutive patients (5 women aged 61 ± 10 years) with metastatic GIST underwent DECT of the abdomen (80 kV, 140 kV) using first-generation dual-source computed tomography (CT). All patients had at least one or more liver lesions (median, 4; maximum, 9). Image data were processed with a dedicated DECT software algorithm designed for evaluation of iodine distribution in soft tissue lesions, and VNE CT images were generated. The tumor density (according to Choi criteria) and the maximum transverse diameter of the lesions (according to Response Evaluation Criteria in Solid Tumors [RECIST]) were determined. TNE and VNE lesion attenuation and Choi criteria and IRA were correlated with each other.
A total of 291 liver lesions were evaluated, of which 220 were cystic and 71 were solid. The mean lesion size was 4.5 ± 3.2 cm (1.1-18.7 cm). The mean attenuation of all lesions was significantly higher in the TNE images than in the VNE images (P=0.0001). Pearson statistics revealed an excellent correlation of r=0.843 (P=0.0001) between IRA and Choi criteria for all lesions. DECT showed significantly higher IRA in progressive (23.3 ± 9.5 HU) lesions compared with stable or regressive (17.8 ± 9.1 HU) lesions (P=0.0185). Similarly, the Choi criteria differed significantly between progressive (39.9 ± 12.8 HU) and stable/regressive (31.1 ± 10.3 HU) lesions (P=0.0003).
DECT is a promising imaging method for the assessment of treatment response in GIST, as IRA might be a more robust response parameter than the Choi criteria. VNE CT data calculated from DECT may eliminate the need for acquisition of a separate unenhanced data set.
评估腹部双能 CT（DECT）实性非增强（TNE）和虚拟非增强（VNE）图像在转移性胃肠道间质瘤（GIST）患者中的相关性，并进一步探讨 DECT 的碘相关衰减（IRA）与 Choi 标准的相关性。
24 例连续的转移性 GIST 患者（5 例女性，年龄 61 ± 10 岁）接受了腹部第一代双源 CT（DECT）检查（80 kV，140 kV）。所有患者均有 1 个或多个肝脏病变（中位数 4 个，最大 9 个）。使用专为评估软组织病变碘分布而设计的专用 DECT 软件算法处理图像数据，并生成 VNE CT 图像。根据 Choi 标准确定肿瘤密度（根据实体瘤反应评估标准[RECIST]）和病变的最大横径。比较 TNE 和 VNE 病变衰减以及 Choi 标准和 IRA 之间的相关性。
共评估了 291 个肝脏病变，其中 220 个为囊性，71 个为实性。病变平均大小为 4.5 ± 3.2 cm（1.1-18.7 cm）。所有病变的 TNE 图像平均衰减明显高于 VNE 图像（P=0.0001）。Pearson 统计分析显示，IRA 与所有病变的 Choi 标准之间的相关性非常好（r=0.843，P=0.0001）。DECT 显示进展性病变的 IRA 显著高于稳定或退行性病变（23.3 ± 9.5 HU 比 17.8 ± 9.1 HU，P=0.0185）。同样，进展性病变的 Choi 标准也明显高于稳定/退行性病变（39.9 ± 12.8 HU 比 31.1 ± 10.3 HU，P=0.0003）。
DECT 是评估 GIST 治疗反应的一种很有前途的成像方法，因为 IRA 可能比 Choi 标准更能作为一个可靠的反应参数。从 DECT 计算得出的 VNE CT 数据可能无需采集单独的未增强数据集。
