Learning objectives
· To know the radiological anatomy of lymph nods and the corresponding territories of lymphatic drainage areas in the abdominopelvic cavity.
· To know the pathways of lymphatic dissemination of abdomino-pelvic tumors.
· To evaluate the lymphatic extension of an abdominal tumor according to the TNM classification.
Background
CT investigation of lymphatic nods,
particularly in tumoral pathologies requires to know the radiological anatomy of abdominal and pelvic lymphatic territories and the normal and pathological aspect of these lymphatic nods.
In fact,
the lymphatic extension of abdominal and pelvic cancers is important for the treatment and the prognosis.
The diagnosis is facilitated by optimal imaging techniques and a knowledge of the various nodal chains,
their complex interconnections and preferential pathways of spread.
Findings and procedure details
We realize a CT scan without and with contrast at arterial (25 à 35 s) and venous (70 à 90 s) times to identify vascular axes and to study contrast enhancement of lymph node.
We should inject from 1 to 2cc / Kg of body weight with iode concentration of 300 to 370 mg / ml
Suspected lymph node criteria:
· The size: minor axis of the lymph node superior to:
6 mm in retro-crural and porta hepatis nodes
8 mm for gastrohepatic ligament
10...
Conclusion
Many malignant processes cause abdominal lymphadenopathy and CT scan has become the primary modality for its detection.
The knowledge of the diagnostic criteria of size and morphology of adenomegaly as well as the spread of each abdominopelvic tumors is essential for the radiologist.
The detailed description of the lymph node involvement allows the reproducibility of the interpretation for a comparative study after treatment.
References
1- Einstein DM.,
Singer AA.,
Chilcote WA.,
Desai RK.
Abdominal Lymph
adenopathy: spectrum of CT Findings,
Radiographics 1991; 11:457-472.
2- Korobkin M.
Computed tomography of the retroperitoneal vasculature and
lymph nodes.
Semin Roentgenol.1981;16:251-267.
3- Des jardins AU.
Retroperitoneal lymph nodes their importance in casesof malignant tumors.
Arch Surg.1939;38(4):714-754.
4- Lee JKT.,
Stanley RJ.,
Sagel SS.,
Levitt RG.,
Accuracy of computed tomography in detecting intra-abdminal and pelvic adenopathy in lymphoma.
AJR 1978; 131:311-315.