Yoshiaki Morita MD, Presenter: Nothing to Disclose

Kei Takase MD, Abstract Co-Author: Nothing to Disclose

Takayuki Yamada MD, PhD, Abstract Co-Author: Nothing to Disclose

Akihiro Sato MD, Abstract Co-Author: Nothing to Disclose

Shuichi Higano MD, PhD, Abstract Co-Author: Nothing to Disclose

Shoki Takahashi MD, Abstract Co-Author: Nothing to Disclose

To assess the ability of MDCT in diagnosis of lymph node metastasis in patients with esophageal cancer.

We evaluated consecutive 30 patients with esophageal cancer who underwent dynamic study by 16-detector row CT before esophagectomy. Among a total of 837 lymph nodes excised at surgery, 71 nodes were positive while 766 nodes negative for metastasis at pathology. Regional lymph nodes were retrospectively reviewed on 0.5mm-thick images by paging method. The review identified 274 nodes including 61 positive and 213 negative groups. The short- and long-axis distances of lymph nodes and increase in CT attenuation value in arterial and delayed phases were measured in both groups, and were analyzed separately for four locations (paratracheal, subcarinal, paraesophageal and paragastric). The presence of central necrosis was also recorded.

The mean short- and long-axis distances of positive nodes were significantly larger than those of negative ones (short axis: 8.3mm vs. 5.8mm, p0.05). In paratracheal, paraesophageal and paragastric regions, cut-off value of 7mm in short axis gave the highest accuracy (89%, 80% and 76%). Whereas, in subcarinal region, cut-off value of 9mm in short axis provided the highest accuracy (93%). In paraesophageal, paragastric and subcarinal regions, combination of 50HU increase in arterial phase and cut-off value in size shown above improved accuracy (85 %, 80% and 95%). All six lymph nodes with central necrosis were histologically positive.

Measurement of short-axis distance combined with CT attenuation increase in arterial phase can provide high diagnostic accuracy in predicting lymph node metastasis in esophageal cancer. Although central necrosis was less frequent, it was characteristic of positive nodes.

Measurement of CT attenuation increase in arterial phase on dynamic CT in addition to size could improve diagnosis of lymph node metastasis in esophageal cancer.

Morita, Y, Takase, K, Yamada, T, Sato, A, Higano, S, Takahashi, S, Detecting Lymph Node Metastasis of Esophageal Cancer with 16-detector-row Dynamic MDCT: Which Parameter Improves Diagnostic Accuracy?.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4439503.html