四维[18F]FDG PET/CT中葡萄糖代谢率用于区分肉芽肿病变与恶性病变

在18F-氟脱氧葡萄糖（FDG）PET/CT中，活跃的肉芽肿病变常难以与恶性病变区分开来。我们研究了来自线性Patlak分析的直接重建方法的葡萄糖代谢动力学新定量指标——MRglc（毫克/分钟/100毫升），以区分结节病与恶性病变的潜力。共纳入100例心脏结节病（CS）患者和67例癌症患者，均接受了四维FDG PET/CT扫描。标准扫描中SUV ≥ 2.7的病变被作为活动病变纳入分析。SUV和MRglc均由在四维FDG PET/CT扫描的30至50分钟之间获得的数据计算得出，测量体积（大小1.5cm^3）中的平均值。利用受试者工作特征（ROC）分析评估了MRglc和SUV在结节病诊断中的表现。分析共涉及44例CS患者的90个肉芽肿病变（18男性，平均63.4±12.2岁）及57名癌症患者的87个恶性病变（32男性，平均65±14岁）。结果显示，肉芽肿病变的SUV和MRglc显著低于恶性病变（SUV：4.98±2.00 vs 6.21±2.14；MRglc：2.52±1.39 vs 3.68±1.61；p < 0.01）。ROC分析表明，利用MRglc和SUV区分肉芽肿患者与恶性患者的曲线下面积（AUC）分别为0.703和0.754，敏感性为64%和77%，特异性为75%和72%，对应的阈值分别为5.025和2.855。MRglc在肉芽肿病变中的值明显低于恶性病变，并优于单纯使用SUV，有助于更准确识别肉芽肿淋巴结，减少延迟扫描时间。活跃的肉芽肿病变有时伴随FDG积聚，应与恶性病变区分。SUV和葡萄糖代谢率（MRglc）呈强正相关，MRglc能有效区分肉芽肿与恶性病变，支持其在恶性病变的评估和分期中的应用。

On 18F-Fludeoxyglucose (FDG) PET/CT, active sarcoid lesions are often difficult to differentiate from malignant lesions. We investigated the potential of the glucose metabolic rate (MRglc, mg/min/100 mL), a new quantification of glucose metabolic kinetics derived from direct reconstruction based on linear Patlak analysis, to distinguish between sarcoidosis and malignant lesions.A total of 100 patients with cardiac sarcoidosis (CS) and 67 patients with cancer who underwent four-dimensional FDG PET/CT were enrolled. The lesions with a standardized uptake value (SUV) ≥ 2.7 on the standard scan were included as active lesions in the analysis. SUV and MRglc were derived using data acquired between 30 min and 50 min on four-dimensional FDG PET/CT. The mean value in the volume of interest (size 1.5 cm3) was measured. The diagnostic performance of sarcoidosis using MRglc and SUV was evaluated using receiver-operating-characteristic (ROC) analysis.A total of 90 sarcoidosis lesions from 44 CS patients (18 males, 63.4 ± 12.2 years) and 87 malignant lesions from 57 cancer-bearing patients (32 males, 65 ± 14 years) were analyzed. SUV and MRglc for sarcoid lesions were significantly lower than those for malignant lesions (SUV, 4.98 ± 2.00 vs 6.21 ± 2.14; MRglc, 2.52 ± 1.39 vs 3.68 ± 1.61; p < 0.01). ROC analysis indicated that the ability to discriminate sarcoid patients from those with malignancy yielded areas under the curves of 0.703 and 0.754, with sensitivities of 64% and 77% and specificities of 75% and 72% for SUV 5.025 and MRglc 2.855, respectively.MRglc was significantly lower in sarcoid lesions than malignant lesions, and improved sarcoid lesions identification over SUV alone.MRglc improves sarcoid lymph node identification over SUV alone and is expected to shorten the examination time by eliminating delayed scans.Active sarcoid lesions are sometimes associated with FDG accumulation and should be differentiated from malignant lesions. SUV and metabolic rate of glucose (MRglc) strongly positively correlated, and MRglc could differentiate sarcoid and malignant lesions. MRglc allows for accurate evaluation and staging of malignant lesions.