Martins Victor Guerra, Torres Cecilia Vidal S, Mermejo Livia Mara, Tucci Silvio, Molina Carlos Augusto Fernandes, Elias Jorge, Muglia Valdair Francisco
Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Ribeirão Preto, SP, Brazil.
Radiol Bras. 2022 May-Jun;55(3):145-150. doi: 10.1590/0100-3984.2021.0083.
To estimate the frequency of lipid-poor adenomas (LPAs) in magnetic resonance imaging (MRI) examinations.
We retrospectively investigated adrenal lesions on MRI examinations performed in a total of 2,014 patients between January 2016 and December 2017. After exclusions, the sample comprised 69 patients with 74 proven adenomas. Two readers (reader 1 and reader 2) evaluated lesion size, laterality, homogeneity, signal drop on out-of-phase (OP) images, and the signal intensity index (SII). An LPA was defined as a lesion with no signal drop on OP images and an SII < 16.5%. For 68 lesions, computed tomography (CT) scans (obtained within one year of the MRI) were also reviewed.
Of the 69 patients evaluated, 42 (60.8%) were women and 27 (39.2%) were men. The mean age was 59.2 ± 14.1 years. Among the 74 confirmed adrenal adenomas evaluated, the mean lesion size was 18.5 ± 7.7 mm (range, 7.0-56.0 mm) for reader 1 and 21.0 ± 8.3 mm (range, 7.0-55.0 mm) for reader 2 ( = 0.055). On the basis of the signal drop in OP MRI sequences, both readers identified five (6.8%) of the 74 lesions as being LPAs. When determined on the basis of the SII, that frequency was three (4.0%) for reader 1 and four (5.4%) for reader 2. On CT, 21 (30.8%) of the 68 lesions evaluated were classified as LPAs.
The prevalence of LPA was significantly lower on MRI than on CT. That prevalence tends to be even lower when the definition of LPA relies on a quantitative analysis rather than on a qualitative (visual) analysis.
评估磁共振成像（MRI）检查中乏脂性腺瘤（LPA）的发生率。
我们回顾性研究了2016年1月至2017年12月期间共2014例患者的MRI肾上腺病变情况。排除相关病例后，样本包括69例患者的74个经证实的腺瘤。两名阅片者（阅片者1和阅片者2）评估病变大小、位置、均匀性、同相位（OP）图像上的信号下降情况以及信号强度指数（SII）。LPA定义为OP图像上无信号下降且SII < 16.5%的病变。对于68个病变，还回顾了计算机断层扫描（CT）扫描图像（在MRI检查后一年内获得）。
在评估的69例患者中，42例（60.8%）为女性，27例（39.2%）为男性。平均年龄为59.2±14.1岁。在评估的74个确诊肾上腺腺瘤中，阅片者1测得的平均病变大小为18.5±7.7mm（范围7.0 - 56.0mm），阅片者2测得的平均病变大小为21.0±8.3mm（范围7.0 - 55.0mm）（P = 0.055）。根据OP MRI序列中的信号下降情况，两名阅片者均将74个病变中的5个（6.8%）判定为LPA。基于SII进行判定时，阅片者1判定的发生率为3个（4.0%），阅片者2判定的发生率为4个（5.4%）。在CT上，68个评估病变中的21个（30.8%）被分类为LPA。
MRI上LPA的患病率显著低于CT。当LPA的定义依赖于定量分析而非定性（视觉）分析时，其患病率往往更低。
