[High-resolution T1-weighted MR-lymphography of inguinal lymph nodes after interstitial application of Gadomer-17 in animal experiments].
OBJECTIVE
To evaluate the microstructural anatomy of inguinal lymph nodes in pigs after interstitial MR-lymphography with the dendritic contrast agent Gadomer-17.


METHODS
High-resolution T1-weighted MR-lymphography was performed in inguinal lymph nodes of 10 domestic pigs (39 - 46 kg) after subcutaneous injection of 10 mumol/kg body weight Gadomer-17 in the hind legs of the animals. A 1.5T MR scanner and a ring-shaped surface coil were used. Two different high-resolution gradient-echo sequences with additionally reconstructed maximum-intensity projections were evaluated in a total of 20 lymph nodes. The high-resolution MR-findings were correlated with the histologic sections of the excised inguinal lymph nodes.


RESULTS
Coronal T1-weighted 3D gradient-echo images (TR = 20 msec, TE = 6.1 - 8.3 msec, FA = 20 degrees ) with a slice thickness of 1 mm, a field-of-view of 120 mm and a matrix size of 256 x 256 (reconstructed to 1024 x 1024 voxels) yielding a reconstructed in-plane resolution of 117 x 117 microm (2) were best suited for the high-resolution MR lymphography of inguinal lymph nodes and enabled the differentiation of the hyperintense lymph node sinuses and hypointense lymphoid parenchyma of each lymph node (100 %). Even dilated lymphatic vessels evident in the histologic specimen were best demonstrated on the MIP images.


CONCLUSIONS
High-resolution interstitial MR lymphography with Gadomer-17 allows the visualization of different tissue compartments of inguinal lymph nodes. This new technique is feasible on a routine 1.5T scanner and may offer potential for the detection of micrometastases in lymph nodes of cancer patients.
Klinik für Radiologische Diagnostik, Universitätsklinikum der RWTH Aachen. staatz@rad.rwth-aachen.de
G
G
Staatz
E
E
Spüntrup
B
B
Klosterhalfen
B
B
Misselwitz
D
D
Pflüger
R W
RW
Günther
A
A
Bücker
D000818:Animals; D003287:Contrast Media; D005682:Gadolinium / Q000008:administration & dosage; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007264:Inguinal Canal; D007279:Injections, Subcutaneous; D008198:Lymph Nodes / Q000166:cytology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013552:Swine
D003287:Contrast Media; C402765:gadomer 17; D005682:Gadolinium