Percutaneous computed tomography lymphography in the rabbit by subcutaneously injected nanoparticulates.
OBJECTIVE
Surgical lymphangiography is infrequently used in staging cancer because of its inherent limitations. Radiopaque nanoparticulates target lymph nodes draining interstitial tissues and could make percutaneous lymphography feasible.


METHODS
Experimental nanoparticulate contrast agent formulations were injected subcutaneously in the forepaw or hindpaw of normal rabbits or rabbits with induced reactive nodal hyperplasia. Axillary and popliteal nodes were imaged with thin-section computed tomography (CT) using quantitative methods to measure node enhancement. Dose-response (0.1-2.0 ml) and time course (4 hr to 10 weeks) of enhancement were assessed.


RESULTS
Nodal enhancement above 100 Hounsfield units was consistently obtained. Enhancement was significantly related to dose and peaked at 10 hr with slow washout over the observation period. Nodes with reactive hyperplasia were larger and had heterogeneous enhancement patterns distinctly different from normal nodes.


CONCLUSIONS
Percutaneous CT lymphography effectively depicts the macroscopic intranodal architecture in rabbits.
Wolf
G L
GL
Center for Imaging and Pharmaceutical Research, Massachusetts General Hospital, Charlestown 02129-2060, USA.
Gazelle
G S
GS
McIntire
G L
GL
Bacon
E R
ER
Toner
J L
JL
Cooper
E R
ER
Haley
P J
PJ
D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage*; D003973:Diatrizoate / Q000008:administration & dosage / Q000031:analogs & derivatives*; D004305:Dose-Response Relationship, Drug; D006965:Hyperplasia / Q000000981:diagnostic imaging / Q000209:etiology; D007279:Injections, Subcutaneous; D007472:Iohexol; D008198:Lymph Nodes / Q000000981:diagnostic imaging; D008220:Lymphography / Q000295:instrumentation / Q000379:methods*; D010316:Particle Size; D011817:Rabbits; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*
D003287:Contrast Media; D003973:Diatrizoate; C089670:ethyl diatrizoate; D007472:Iohexol