The use of magnetic resonance imaging in the diagnosis and followup of pediatric pelvic rhabdomyosarcoma.
OBJECTIVE
Previous radiological descriptions of pelvic rhabdomyosarcoma emphasized ultrasonography and computerized tomography (CT). Few reports are available on the use of magnetic resonance imaging (MRI) for diagnosing and following pelvic rhabdomyosarcoma. We retrospectively compared MRI to CT for diagnosing and following children with pelvic rhabdomyosarcoma.


METHODS
We treated 4 boys and 3 girls for pelvic rhabdomyosarcoma. Initial and followup evaluations included pelvic CT and MRI at intervals determined by treatment and disease status. We retrospectively reviewed the clinical charts and imaging studies of these patients. The initial radiological report was evaluated and then 1 radiologist reviewed all studies. Attention was directed toward identifying lesions revealed by CT or MRI but not by the other modality.


RESULTS
MRI detected all lesions shown by CT. On the other hand, MRI detected residual disease in 1 case that was not demonstrated by CT. In 2 other patients MRI was superior to CT for delineating the local extent of disease, especially urethral involvement.


CONCLUSIONS
Compared with CT, MRI improves the detection of residual pelvic rhabdomyosarcoma. Tissue planes are well delineated, allowing more accurate assessment of tumor invasion into adjacent structures. MRI is the imaging modality of choice for following pediatric patients with pelvic rhabdomyosarcoma.
Finelli
A
A
Division of Urology and Department of Radiology, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
Babyn
P
P
Lorie
G A
GA
Bägli
D
D
Khoury
A E
AE
Merguerian
P A
PA
D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D008297:Male; D010386:Pelvic Neoplasms / Q000175:diagnosis*; D012208:Rhabdomyosarcoma / Q000175:diagnosis*; D014057:Tomography, X-Ray Computed; D014565:Urogenital Neoplasms / Q000175:diagnosis*