Jun Nakayama MD, Presenter: Nothing to Disclose

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

Tokuhiko Omatsu, Abstract Co-Author: Nothing to Disclose

Yuya Onodera MD, Abstract Co-Author: Nothing to Disclose

Satoshi Terae MD, Abstract Co-Author: Research grant, J-MAC SYSTEM, Inc Research grant, Medical Image Lab Research grant, FUJIFILM Holdings Corporation

Hiroki Shirato MD, PhD, Abstract Co-Author: Nothing to Disclose

To evaluate diffusion-weighted (DW) magnetic resonance (MR) imaging for detection of metastases in lymph nodes by using apparent diffusion coefficients (ADCs).

This study was approved by the institutional review board, and informed consent was waived. Seventy patients(38 men and 32 women) with non-small cell lung cancer who ranged in age from 48 to 82 years (mean age,68.7 years) were examined with DW and STIR TSE MR imaging.ADC of each detected lung cancer and lymph node was calculated from DW MR imeges obtained with low and high b values.Difference of the ADC in a lung cancer and a lymph node was calculated(Lymph mpde-lung cancer difference[D1]).And Ratios of ADC in a lymph node and a lung cancer to that in a 0.9% saline phantom(Lymph node-saline ratios[LSRs1])(lung cancer-saline ratios[LSRs2]) was calculated.And difference of LSRs1 and LSRs2 was calculated(|LSRs1-LSRs2|:LSRs1-2).From STIR TSE MR imaging,Ratios of signal intensity in a lymph node and a lung cancer to that in a 0.9% saline phantom(Lymph node-saline ratios[LSRs3])(lang cancer-saline ratios[LSRs4] was calculated.And And difference of LSRs3 and LSRs4 was calculated(|LSRs3-LSRs4|:LSRs3-4).Each LSRs were compared by using pathologic diagnosis as the standard of reference.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 of DW MR images and STIR MR images were compared on a per-patient basis with McNemar testing.

In 70 patients,36 of 433 lmph nodes were pathologically diagnosed as containing metastases,while 397 lymph nodes did not contain metastases.Mean D1 in the lymph node group with metastases was higher than that in the group without metastases(P＜0.001).When an D1 of 0.24×10-3mm2/sec. was used as the positive-test threshold at Quantitative analysis,sensitivity was 90.0%、and specificity was 90.1% on a per-patient basis.There was no significant difference(P＜0.05) between resuts of quantitative analyses of DW MR images and STIR MR images.  

Quantitative analysis of DW MR images enables differentiation of lymph nodes with metastasis from lymph nodes without metastasis.

Quantitative analysis of DW MR images enables differentiation of lymph nodes with metastasis from lymph nodes without metastasis.

Nakayama, J, Miyasaka, K, Omatsu, T, Onodera, Y, Terae, S, Shirato, H, Metastases in Mediastinal and Hilar Lymph Nodes in Patients with Non-Small Cell Lung Cancer: Diffusion-weighted MR Imaging Evaluation with Apparent Diffusion Coefficient.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6014109.html