Kang Bo-Kyeong, Kim Jin Hee, Byun Jae Ho, Lee Seung Soo, Kim Hyoung Jung, Kim So Yeon, Lee Moon-Gyu
Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea
Acta Radiol. 2014 Dec;55(10):1157-65. doi: 10.1177/0284185113513760. Epub 2013 Nov 20.
Image findings of intrapancreatic accessory spleen (IPAS) can closely resemble those of neuroendocrine tumor (NET) of the pancreas.
To investigate the usefulness of diffusion-weighted imaging (DWI) for differentiating IPAS from small (≤3 cm) hypervascular NET of the pancreas.
The visually assessed signal intensity of pancreatic lesions compared with the spleen on DWI (b value of 1000 s/mm(2)) and the apparent diffusion coefficient (ADC) values were compared in 25 patients with IPAS and 31 patients with small hypervascular NET. Two blinded radiologists independently rated their confidence in differentiating the two conditions and compared the diagnostic performance of contrast-enhanced magnetic resonance imaging (CE-MRI) alone with that of combined CE-MRI and DWI.
The isointensity of the pancreatic lesions compared with the spleen on DWI was more frequently observed in IPAS than in NET (92% vs. 12.9%, P < 0.001). The mean ADC value was significantly lower in IPAS than in NET (0.90 × 10(-3) mm(2)/s vs. 1.44 × 10(-3) mm(2)/s, P < 0.001). The sensitivity and specificity of ADC quantification for differentiating the two conditions when using 1.07 × 10(-3) mm(2)/s as the cut-off value were 96% and 93.5%, respectively. For both readers, the area under the receiver operating characteristic curve and accuracy in differentiating the two conditions of combined CE-MRI and DWI were significantly greater than those of CE-MRI alone (P ≤ 0.039).
Visual assessment of DWI and ADC quantification were useful in differentiating IPAS from small hypervascular NET of the pancreas.
胰腺内副脾（IPAS）的影像表现可能与胰腺神经内分泌肿瘤（NET）极为相似。
探讨扩散加权成像（DWI）在鉴别IPAS与胰腺小（≤3 cm）高血供NET中的应用价值。
比较25例IPAS患者和31例胰腺小高血供NET患者胰腺病变在DWI（b值为1000 s/mm²）上与脾脏相比的视觉评估信号强度及表观扩散系数（ADC）值。两位放射科医生在不知情的情况下独立评估区分这两种情况的信心，并比较单纯对比增强磁共振成像（CE-MRI）与CE-MRI联合DWI的诊断性能。
DWI上胰腺病变与脾脏等信号在IPAS中比在NET中更常见（92%对12.9%，P<0.001）。IPAS的平均ADC值显著低于NET（0.90×10⁻³ mm²/s对1.44×10⁻³ mm²/s，P<0.001）。以1.07×10⁻³ mm²/s为临界值时，ADC定量鉴别这两种情况的敏感性和特异性分别为96%和93.5%。对于两位阅片者，联合CE-MRI和DWI在区分这两种情况时的受试者操作特征曲线下面积和准确性均显著高于单纯CE-MRI（P≤0.039）。
DWI的视觉评估和ADC定量有助于鉴别IPAS与胰腺小高血供NET。
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