Of these, ADC value of immature ovarian cancer can be lowest although ADC values clear cell carcinoma and highly differentiated carcinoma are relatively high.
Case 266
【Discussion】
Apparent diffusion coefficient (ADC mm2/s) indicates the degree of the diffusion of water molecules. ADC of each tumor equals to the slope of the curve using the acquired signal intensity values of b0 and b1000 or b2000 (ADC = Loge Sb/Sb0) (1, 2). An ADC map is drawn using the slope data of each pixel (2).
Diffusion b0 means the image before motion probing diffusion (MPD) and Diffusion b1000 means the image after MPD with b1000. In short, Diffusion b1000 and diffusion b2000 indicates the image created by the acquisition data at MPD with 1000 and MPD with 2000, respectively (1, 2). The difference between diffusion b1000 and diffusion b2000 implies the higher b value brings about the prominent contrast, compared to the surroundings : the tumor with the diffusion repression more markedly stands out in diffusion b2000 than b1000 since the surrounding with the diffusion low-repression drops the signal intensity more significantly in b2000 than in b1000 (2).
ADC value indicates the slope: numerical signal intensity between b0 and b1000 or between b0 and b2000 / b1000 - b0 or b0 - b2000. ADC value is calculated using the formula: b = γ² G² δ² (Δ−δ/3) that means the amplitude (G), time of applied gradients (δ) and duration between the paired gradients (Δ), implies the strength of MPG. ADC values depend on diffusion of water molecule. Namely, free wider spaces for water molecules induces higher ADC values. Meanwhile, fresh infarction, dense abscess and fresh hematoma induces repression of water molecule, inducing lower value of ADC. In general, ADC values of malignant tumor are lower than those of benign tumor because more dense tumor cell accumulation induces less free space for water molecules. However, malignant tumor is probably hard to survive of least diffusion of water molecules simply because of necessity of water diffusion for their survives. It is possible that there are differences of ADC values among malignant tumors. In fact, it is reported that Malignant lymphoma (ADC 0.5 10-3mm2/s), Adenocarcinoma (ADC 0.9 10-3mm2/s), Squamous cell carcinoma (ADC 0.7 10-3mm2/s) (3-7). On liver, cholangiocarcinoma ADC 1.1 10-3mm2/s, hepatocellular carcinoma ADC 1.0 10-3mm2/s, metastatic liver carcinoma from colon ADC 0.9 10-3mm2/s (5, 6). On ovary, ADC values of ovary carcinoma vary because it produces assorted carcinoma: clear cell carcinoma (ADC 1.2 10-3mm2/s), serous carcinoma (ADC 0.8 10-3mm2/s), endometrioid carcinoma (ADC 0.8 10-3mm2/s) whose differences are dependent on tumor cellularity (8). Furthermore, ADC values of infarction, abscess and hematoma vary from 0.2 to 1.4 whose differences are dependent on stages from fresh to absorbing process (1, 2). In our case, ADC values of metastatic liver tumor from sigmoid colon cancer 0.7-0.9 10-3mm2/s, metastatic ovary carcinoma from gastric cancer 0.8-0.9 10-3mm2/s, uterine cervical cancer 0.65-0.69 10-3mm2/s and ovarian carcinoma 0.53-0.65 10-3mm2/s.
【Summary】
We present four cases of metastatic tumor from sigmoid colon cancer, uterine cervical cancer, ovary cancer, metastatic ovary cancer. MRI with diffusion weighted image can be useful for their differentiation by comparing their ADC values: metastatic liver tumor from sigmoid colon cancer 0.7-0.9 10-3mm2/s, metastatic ovary carcinoma from gastric cancer 0.8-0.9 10-3mm2/s, uterine cervical cancer 0.65-0.69 10-3mm2/s and ovarian carcinoma 0.53-0.65 10-3mm2/s. It is borne in mind that although tumor dense cellularity with less interstitial space induces lowering ADC values, tumor needs some diffusion of water molecule for their surviving. It leads the delicate difference of ADC values among tumors; Malignant lymphoma (ADC 0.5 10-3mm2/s), Adenocarcinoma (ADC 0.9 10-3mm2/s), Squamous cell carcinoma (ADC 0.7 10-3mm2/s) ; On liver, cholangiocarcinoma ADC 1.1 10-3mm2/s, hepatocellular carcinoma ADC 1.0 10-3mm2/s, metastatic liver carcinoma from colon ADC 0.9 10-3mm2/s:On ovary, clear cell carcinoma (ADC 1.2 10-3mm2/s), serous carcinoma (ADC 0.8 10-3mm2/s), endometrioid carcinoma (ADC 0.8 10-3mm2/s).
【References】
1.Aoki S et al. Diffusion MRI 3rd edition. Syujunnsha 2013 (Japanese)
2.Kita M. Personal communication in Fuchu Hospital
3.Shim WH et al. Comparison of Apparent Diffusion Coefficient and Intravoxel Incoherent Motion for Differentiating among Glioblastoma, Metastasis, and Lymphoma Focusing on Diffusion-Related Parameter. PLoS One. 2015 30;10:e0134761. doi: 10.1371/journal.pone.0134761. eCollection 2015.
4.Doskaliyev A et al. Lymphomas and glioblastomas: differences in the apparent diffusion coefficient evaluated with high b-value diffusion-weighted magnetic resonance imaging at 3T. Eur J Radiol. 2012;81:339-344. doi: 10.1016/j.ejrad.2010.11.005. Epub 2010 Dec 3.
5.Kong E, et al. Quantitative assessment of simultaneous F-18 FDG PET/MRI in patients with various types of hepatic tumors: Correlation between glucose metabolism and apparent diffusion coefficient. PLoS One. 2017; 12(7): e0180-184
6.Lee J, et al. Mass-forming Intrahepatic Cholangiocarcinoma: Diffusion-weighted Imaging as a Preoperative Prognostic Marker. Radiology 2016; 281: 119-128
7.Liu Y, et al. Clinical Application of Diffusion-Weighted Magnetic Resonance Imaging in Uterine Cervical Cancer. Int J Gynecol Cancer 2015 Jul;25(6):1073-8.
8.Ono T, et al. Apparent diffusion coefficient (ADC) values of serous, endometrioid, and clear cell carcinoma of the ovary: pathological correlation. Acta Radiol. 2020 Jul;61(7):992-1000.
2022.5.20