Jun Nakayama MD, Presenter: Nothing to Disclose

Kazuo Miyasaka MD, PhD, Abstract Co-Author: Nothing to Disclose

To evaluate DW- and STIR- MR imaging for detection of metastases in lymph nodes by using quantitative analyses.

78 patients with lung cancer who ranged in age from 46 to 84 were examined with DW- and STIR- MR imaging. Ratios of signal intensity in lung cancer and lymph node to that in spinal cord(LcScR1s and LnScR1s) and to that in 0.9% saline phantom (LcSR1s and LnSR1s) were calculated from DW MR images with high b values. ADCs in each lung cancer and lymph node were calculated from DW MR images obtained with low and high b values. The difference of LcScR1s and LnScR1s(D1), that of LcSR1s and LnSR1s(D2), and that of the ADC in lung cancer and lymph node(D3) were calculated. Ratios of signal intensity in lung cancer and lymph node to that in spinal cord(LcScR2s and LnScR2s) and to that in 0.9% saline phantom (LcSR2s and LnSR2s) were calculated from STIR MR images. The difference of LcScR2s and LnSc2Rs(D4), that of LcSR2s and LnSR2s(D5) were calculated. For quantitative analysis, the threshold value for positive test was determined on a per-node basis and tested for ability to enable a correct diagnosis on a per-patient basis. Results of quantitative analyses were compared on a per-patient basis with McNemar testing.

Mean LnScR1, LnSR1, LnSR2, ADC in lymph node, D1, D2, D3, and D5 in the lymph node group with metastasis was significantly different from those in the lymph node group without metastasis(P<.05). When LnScR1 of 0.629, LnSR1 of 0.774, LnSR2 of 0.320, ADC of 1.681×10-3mm2/sec., D1 of 0.598, D2 of 0.761, D3 of 0.296×10-3mm2/sec.. and D5 of 0.104 were used as the positive-test threshold, sensitivities were 87.5%, 87.5%, 93.8%, 81.3%, 68.8%, 87.5%, 93.8%, and 87.5%, respectively. Specificities were 83.9%, 87.1%, 87.1%, 80.6%, 68.7%, 87.5%, 96.8%, and 84.4%, respectively. In terms of the results of quantitative analyses of DW- and STIR- MR images on a per patient basis, the sensitivity, specificity of D3 were greater than or equal to those of LnScR1, LnSR1, LnSR2, ADC, D1, D2, and D5.

Quantitative analyses by using LnScR1s, LnSR1s, LnSR2s, ADC, D1s, D2s, D3s, and D5s enable characterization of lymph nodes. D3s measurement may be especially useful.

The difference of the ADC value in a lung cancer and a lymph node measurement may be especially useful for differenting between lymph nodes with metastasis and those without metastasis.

Nakayama, J, Miyasaka, K, Metastases in Mediastinal and Hilar Lymph Nodes in Patients with Lung Carcinoma : Quantitative Assessments with DW- and STIR- MR Imaging—What is the Appropriate Method for Detection of Metastases in Lymph Nodes on the DW- and STIR- MR Images?.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14006360.html