Comparison of Radiographic and Computed Tomography Lymphangiography for Identification of the Canine Thoracic Duct

Abstract

Standard radiographic lymphangiograms and computed tomography (CT) lymphangiograms were performed on 10 female dogs without intrathoracic disease. Positive contrast lymphagiography was performed by injection into a catheterized mesenteric lymphatic vessel, and lateral thoracic radiographs, ventrodorsal thoracic radiographs, and thoracic CTs were obtained. The number of visible ducts was recorded for each image at the midbody of the ninth thoracic vertebra (T9) through the first lumbar vertebra (L1). Data were combined for all dogs at each data acquisition point. Data were analyzed by comparing data from all three images independently, and then by combining data for the radiographs and comparing the study with the highest number of visible duct branches to the CT. Significant differences in numbers of branches were found at T11 and L1. This study suggests that CT may be able to quantify branches of the thoracic duct more accurately than standard radiographic lymphangiography.

Determination of Optimal Dosage and Delay Time for Computed Tomographic Lymphography after Percutaneous Injection of Iohexol into Popliteal Lymph Nodes in Dogs

“…When performing computed tomography at the established time, we could identify thoracic ducts in all 5 subject dogs. In a previous study, Esteline concluded that computed tomography allows users to identify more thoracic duct branches than is possible with radiographic lymphangiography [4]. Unlike previous studies, our study revealed that there was no significant difference between CT and radiographic image in terms of the number of thoracic ducts in any region.…”

“…However, patients do not need to be repositioned, images can be manipulated to better observe the target tissue, image contrast is vastly enhanced and small differences in contrast can be detected during computed tomographic scanning [3]. Lymphography using computed tomography for identification of the thoracic duct would be useful for ligation of the thoracic duct [4,12]. Therefore, although the number of thoracic ducts detected by computed tomography and conventional radiography did not significantly differ, it is assumed that computed tomography is the superior modality for delineation of the thoracic duct after popliteal lymphography.…”

“…Esterline et al suggested that CT may be cable of quantifying the branches of the thoracic duct more accurately than standard radiographic lymphangiography; however, they injected the contrast media by laparotomy, and their method could not overcome the disadvantages of the long anaesthesia time and laparotomy [4].…”

Comparison of Single‐slice Computed Tomography Protocols for Detection of Pulmonary Nodules in Dogs

“…R adiography is the most widely used imaging modality for detection of pulmonary nodules in animals. However, computed tomography (CT) has many advantages over radiography for evaluating thoracic disease, 1–4 namely superior contrast resolution and lack of superimposition. CT is more accurate than radiography for detection of lung metastases in dogs and humans 4,5 …”

Comparison of Computed Tomographic and Radiographic Popliteal Lymphangiography in Normal Dogs

“…Open mesenteric lymphadenography with slow injection of contrast medium directly in a mesenteric lymph node has been described 9 . After mesenteric lymphangiography, a greater number of TD branches were identified by computed tomography (CT) compared with radiography in normal dogs 10 . Regardless of technique used for TD imaging, additional morbidity is associated with the surgical procedure (celiotomy) and with the longer anesthetic time required for the imaging studies 10 …”