Assessment of vascular invasion by musculoskeletal tumors of the limbs: use of contrast-enhanced MR angiography.
OBJECTIVE
To prospectively evaluate the accuracy of contrast material-enhanced magnetic resonance (MR) angiography in the evaluation of vascular invasion by bone and soft-tissue tumors, with surgery serving as the reference standard.


METHODS
This study was approved by the regional ethics committee, and all patients gave informed consent. Preoperative MR angiograms and MR images of 31 sites in 30 patients with bone or soft-tissue sarcomas (n = 21) or other tumors (n = 9) were assessed for features of vascular invasion. All images were prospectively evaluated by two musculoskeletal radiologists working in consensus. MR images were evaluated for the presence of a fat plane between the vessels and the tumor and partial or total encasement of vessels. MR angiograms were evaluated for the presence of vascular displacement, stenosis, or occlusion. MR imaging and MR angiographic features of vascular invasion were graded. Imaging findings were correlated with surgical findings and classified as negative if there was no vascular invasion and as positive if there was vascular invasion.


RESULTS
Among the 31 cases, 20 were classified as negative and 11 were classified as positive at surgery. All but three cases with a gap between the tumor and the vessels on MR images were classified as free and without adhesions at surgery. All cases with arterial stenoses at MR angiography had tumoral adhesion or tumoral encasement at surgery. MR imaging had a sensitivity of 64%, a specificity of 95%, a positive predictive value of 88% a negative predictive value of 83%, and an accuracy of 84% in the detection of vascular invasion on the basis of findings of partial or total encasement. MR angiography had a sensitivity of 82%, a specificity of 85%, a positive predictive value of 75%, a negative predictive value of 90%, and an accuracy of 84% in the detection of vascular invasion on the basis of the findings of a stenosis.


CONCLUSIONS
On contrast-enhanced MR angiograms, findings of stenosis were sensitive and specific in the detection of arterial invasion. MR imaging evidence of partial or total encasement is highly specific in the detection of vascular invasion, while MR imaging evidence of a gap between the tumor and the vessels excludes an arterial invasion.
Feydy
Antoine
A
Service de Radiologie B, Service de Chirurgie Orthopédique, Hôpital Cochin, 27 rue du Faubourg Saint Jacques, 75679 Paris Cedex 14, France. antoine.fyde@cch.aphp.fr
Anract
Philippe
P
Tomeno
Bernard
B
Chevrot
Alain
A
Drapé
Jean-Luc
JL
D000293:Adolescent; D000328:Adult; D000368:Aged; D001859:Bone Neoplasms / Q000473:pathology*; D003287:Contrast Media; D005260:Female; D006801:Humans; D007867:Leg Bones; D018810:Magnetic Resonance Angiography / Q000379:methods; D008297:Male; D008875:Middle Aged; D019042:Muscle Neoplasms / Q000473:pathology*; D009361:Neoplasm Invasiveness; D011446:Prospective Studies; D019043:Vascular Neoplasms / Q000175:diagnosis*
D003287:Contrast Media