Funding source: None.
CLINICAL AND LOW-FIELD MRI CHARACTERISTICS OF INJECTION SITE SARCOMA IN 19 CATS
Article first published online: 13 JUN 2013
© 2013 Veterinary Radiology & Ultrasound
Veterinary Radiology & Ultrasound
Volume 54, Issue 6, pages 623–629, November/December 2013
How to Cite
Rousset, N., Holmes, M. A., Caine, A., Dobson, J. and Herrtage, M. E. (2013), CLINICAL AND LOW-FIELD MRI CHARACTERISTICS OF INJECTION SITE SARCOMA IN 19 CATS. Veterinary Radiology & Ultrasound, 54: 623–629. doi: 10.1111/vru.12067
- Issue published online: 8 NOV 2013
- Article first published online: 13 JUN 2013
- Manuscript Accepted: 2 MAY 2013
- Manuscript Received: 14 NOV 2012
- injection site sarcoma;
- low-field MRI
Magnetic resonance imaging (MRI) has been recommended for staging and surgical planning in cats with injection site sarcomas (ISS). The purpose of this retrospective study was to describe low-field MRI characteristics of confirmed injection site sarcomas in a group of cats. Low-field MR images, thoracic radiographs, histopathology findings, and medical records of cats that fulfilled histological criteria of injection site sarcoma were retrieved and reviewed retrospectively. Presence or absence of tumor mineralization and pulmonary metastases were recorded from thoracic radiographs. Characteristics recorded from low-field MRI studies included tumor number, volume (ellipsoid method), intensity relative to surrounding musculature, homogeneity, regions of signal void (mineralization) or cavitation, degree and pattern of contrast enhancement, tumor margination, presence of a peripheral T2W hyperintense zone, and bone contact. A total of 19 cats met inclusion criteria. Cats with multiple tumors were more likely to have had previous excisional biopsy, and were less likely to undergo definitive surgery. All tumors were hyperintense relative to surrounding musculature on T1W and T2W images. Larger tumors were more likely to exhibit mineralization (P < 0.05). Tumor volume could not predict tumor-free margins at definitive surgery. The majority of tumors showed moderate to marked heterogeneous contrast enhancement. Infiltrative margins and the presence of a peripheral T2W hyperintense zone were more prevalent following excisional biopsy, while cavitation was more prevalent following incisional biopsy. Findings indicated that low-field MRI characteristics of injection site sarcoma may vary widely and may be affected by prior incisional or excisional biopsy.