skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Normal mediastinal lymph node size and number: CT and anatomic study

Abstract

Normal lymph nodes were studied retrospectively by computed tomography (CT) in 39 patients and by dissection at autopsy in 12 cadavers. The mediastinum was divided arbitrarily into four zones relating to the left innominate vein (zone 1), pretracheal space (zone 2), precarinal/subcarinal compartment (zone 3), and aorticopulmonary window (zone 4). Of 225 lymph nodes from all zones in the CT study, 99% measured less than 16 mm in largest diameter. Using contiguous 10-mm CT scans, lymph nodes were detected in 65%-95% of patients, depending on the zone studies. The mean number of lymph nodes on a representative section was 1.1. There was a significant size difference between lymph nodes residing in the superior mediastinum compared with those in the middle mediastinum contiguous to the carina. Thus, only 7% of lymph nodes in zone 1 were larger than 5 mm, whereas 90% and 67% of lymph nodes in zones 3 and 4, respectively, were larger, in the 6-10 mm range.

Authors:
;
Publication Date:
Research Org.:
Univ. of Saskatchewan Hospital, Saskatoon
OSTI Identifier:
7015063
Resource Type:
Journal Article
Resource Relation:
Journal Name: AJR, Am. J. Roentgenol.; (United States); Journal Volume: 142:6
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; 59 BASIC BIOLOGICAL SCIENCES; LYMPH NODES; ANATOMY; COMPUTERIZED TOMOGRAPHY; AUTOPSY; MEDIASTINUM; PATIENTS; BODY; BODY AREAS; CHEST; DIAGNOSTIC TECHNIQUES; LYMPHATIC SYSTEM; TOMOGRAPHY; 550602* - Medicine- External Radiation in Diagnostics- (1980-); 550800 - Morphology

Citation Formats

Genereux, G.P., and Howie, J.L. Normal mediastinal lymph node size and number: CT and anatomic study. United States: N. p., 1984. Web. doi:10.2214/ajr.142.6.1095.
Genereux, G.P., & Howie, J.L. Normal mediastinal lymph node size and number: CT and anatomic study. United States. doi:10.2214/ajr.142.6.1095.
Genereux, G.P., and Howie, J.L. 1984. "Normal mediastinal lymph node size and number: CT and anatomic study". United States. doi:10.2214/ajr.142.6.1095.
@article{osti_7015063,
title = {Normal mediastinal lymph node size and number: CT and anatomic study},
author = {Genereux, G.P. and Howie, J.L.},
abstractNote = {Normal lymph nodes were studied retrospectively by computed tomography (CT) in 39 patients and by dissection at autopsy in 12 cadavers. The mediastinum was divided arbitrarily into four zones relating to the left innominate vein (zone 1), pretracheal space (zone 2), precarinal/subcarinal compartment (zone 3), and aorticopulmonary window (zone 4). Of 225 lymph nodes from all zones in the CT study, 99% measured less than 16 mm in largest diameter. Using contiguous 10-mm CT scans, lymph nodes were detected in 65%-95% of patients, depending on the zone studies. The mean number of lymph nodes on a representative section was 1.1. There was a significant size difference between lymph nodes residing in the superior mediastinum compared with those in the middle mediastinum contiguous to the carina. Thus, only 7% of lymph nodes in zone 1 were larger than 5 mm, whereas 90% and 67% of lymph nodes in zones 3 and 4, respectively, were larger, in the 6-10 mm range.},
doi = {10.2214/ajr.142.6.1095},
journal = {AJR, Am. J. Roentgenol.; (United States)},
number = ,
volume = 142:6,
place = {United States},
year = 1984,
month = 6
}
  • Purpose: Primary lung tumors can be visualized mostly with cone beam computed tomography (CT), whereas visualization is much more difficult for mediastinal lymph nodes (LN). If the volumetric and positional changes of the primary tumor could be used as a surrogate for the LN, this would facilitate image-guided radiotherapy. The purpose of this study was to investigate the relationship between the positional and volumetric changes in primary tumors and the involved LN during (chemo)radiotherapy treatment of non-small-cell lung cancer patients. Methods and Materials: [{sup 18}F]fluorodeoxyglucose positron emission tomography/computed tomography imaging was performed before radiotherapy and in the second week ofmore » treatment in 35 patients. Gross tumor volumes (GTV) of the primary tumor (GTVprim) and of the involved LN (GTVlymph) were delineated. Changes in position and volume of GTVprim with respect to GTVlymph and the bony anatomy were compared. Results: In individual cases, large displacements up to 1.6 cm and volume changes of 50% of the primary tumor may occur that are not correlated to the changes in involved LN. The volume of GTVprim reduced, on average, by 5.7% {+-} 19.0% and was not correlated with the small increase of 1.4% {+-} 18.2% in involved LN volume. Compared to bony anatomy, displacement of the primary tumor was statistically correlated to the involved LN displacement. Conclusions: Volume and position changes of the primary tumor are not always predictive for LN changes. This suggests that for characterization of involved LN, repeated state-of-the-art mediastinal imaging during radiotherapy may be necessary.« less
  • Using a size criterion of 1 cm or greater as evidence for abnormality, the size of mediastinal lymph nodes identified by computed tomography (CT) was a poor predictor of mediastinal lymph node metastases in a series of 86 patients who had surgery for bronchogenic carcinoma. The surgery included full nodal sampling in all patients. Of the 86 patients, 36 had nodes greater than or equal to 1 cm identified by CT. Of the 21 patients with mediastinal metastases proven at surgery, 14 had nodes greater than or equal to 1 cm (sensitivity = 67%). Of the 65 patients without mediastinalmore » metastases, 22 had nodes greater than or equal to 1 cm. Obstructive pneumonia and/or pulmonary collapse distal to the cancer was present in 39 patients (45%). Obstructive pneumonia and/or pulmonary collapse is a common occurrence in bronchogenic carcinoma, but mediastinal nodes greater than or equal to 1 cm in this circumstance cannot be presumed to represent metastatic disease. Metastatic mediastinal lymph node involvement was related to nodal size also in patients with evidence of prior granulomatous disease and in patients with no putative benign cause for nodes greater than or equal to 1 cm.« less
  • CT was used to investigate the number and size of normal mediastinal lymph nodes at 11 intrathoracic nodal stations defined by the American Thoracic Society lymph-node mapping scheme. Nodal size was measured both as short- and long-axis diameters in the transverse plane. Findings for 56 patients show the largest normal mediastinal nodes to be in the subcarinal and right tracheobronchial regions. Upper paratracheal nodes were smaller than lower paratracheal or tracheobronchial nodes, and right-sided tracheobronchial nodes were larger than left-sided ones. From the distributions of node sizes, thresholds were set above which nodes in any region might be considered enlarged.more » These thresholds, in agreement with a prior investigation of patients with lung cancer, suggest 1.0 cm as the upper limit of normal for the short axis of a mediastinal node in the transverse plane.« less