Indirect computed tomography lymphography of subdiaphragmatic lymph nodes using iodinated nanoparticles in normal dogs.
OBJECTIVE
We evaluated the imaging characteristics of an iodinated particulate contrast agent for indirect computed tomography (CT) lymphography of normal subdiaphragmatic lymph nodes in dogs.


METHODS
Four milliliters of a 15% (wt/vol) iodinated nanoparticle suspension was injected into the gastric, colonic, rectal, or cervical submucosa, loose paraprostatic fascia, or metatarsal subcutaneous tissues in 10 healthy beagles. Endoscopic, CT, or ultrasound guidance was used when necessary to facilitate contrast agent delivery. CT and radiographic images were obtained prior to contrast administration and at 4 hr, 24 hr, and 7 days postcontrast injection. Postmortem examinations were then conducted.


RESULTS
CT images showed enhancement of regional lymph nodes draining the various injection sites. The mean attenuation of opacified nodes was 678 +/- 463 Hounsfield units 24 hr after injection and remained elevated 7 days later. Lymph node opacification on CT images correlated well with the node location observed on postmortem examinations.


CONCLUSIONS
Subdiaphragmatic lymph nodes can be effectively opacified using an iodinated nanoparticle contrast agent for indirect CT lymphography.
Wisner
E R
ER
Department of Radiology, University of California Davis Medical Center, Sacramento 95817, USA.
Katzberg
R W
RW
Koblik
P D
PD
McGahan
J P
JP
Griffey
S M
SM
Drake
C M
CM
Harnish
P P
PP
Vessey
A R
AR
Haley
P J
PJ
D000005:Abdomen; D000818:Animals; D003287:Contrast Media; D003973:Diatrizoate / Q000008:administration & dosage / Q000031:analogs & derivatives*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004333:Drug Administration Routes; D005260:Female; D005500:Follow-Up Studies; D008198:Lymph Nodes / Q000166:cytology / Q000000981:diagnostic imaging*; D008220:Lymphography / Q000379:methods*; D008297:Male; D011856:Radiographic Image Enhancement; D014057:Tomography, X-Ray Computed / Q000379:methods*
D003287:Contrast Media; D003973:Diatrizoate; C089670:ethyl diatrizoate