title: Magnetic resonance imaging: a useful tool to distinguish between keratocystic odontogenic tumours and odontogenic cysts.
abstract: In contrast to odontogenic cysts, keratocystic odontogenic tumours often recur and require more aggressive surgical treatment, so we tried to find features that distinguished between them on magnetic resonance imaging (MRI). Without knowing the diagnosis, two radiologists reviewed intensity (low, intermediate, or high) and homogeneity (homogeneous or heterogeneous) of signals in short-tau-inversion-recovery (STIR), T1- and T2-weighted, and fat-suppressed, contrast-enhanced MRI in 20 consecutive patients with oval, radiolucent lesions of the mandible on panoramic radiography, and who were subsequently confirmed histopathologically to have either an odontogenic cyst or a keratocystic odontogenic tumour (n=10 in each group). Fisher's exact test was statistically significant at p<0.05. Delineation of a contrast-enhanced wall of a cyst with high signal intensity distinguished odontogenic cysts (9/10 and 8/10, respectively) from keratocystic odontogenic tumours (3/10, p=0.02, and 1/10, p=0.01, respectively). One radiologist found odontogenic cysts were more likely to be homogeneous on unenhanced T1-weighted images (odontogenic cysts 9/10, keratocystic odontogenic tumours 3/10, p=0.02) and one on contrast-enhanced MRI, when the cyst wall was enhanced (odontogenic cysts 7/9, keratocystic odontogenic tumours 0/3, p=0.01). There were no other significant distinguishing features on MRI. In conclusion, the signal intensity of the enhanced wall seems to be a feature on contrast-enhanced MRI that differentiates odontogenic cysts from keratocystic odontogenic tumours.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Ludwig-Maximilians-Universität München, Munich, Germany. Electronic address: flo.probst@web.de.
authors.forename: F A
authors.initials: FA
authors.lastname: Probst
authors.affiliation: Department of Neuroradiology, Technische Universität München, Munich, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Probst
authors.affiliation: Clinic for Oral and Maxillofacial and Plastic Surgery, Lenbachplatz 2a, 80333 Munich, Germany.
authors.forename: Ch
authors.initials: Ch
authors.lastname: Pautke
authors.affiliation: Department of Oral and Maxillofacial Surgery, Ludwig-Maximilians-Universität München, Munich, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Kaltsi
authors.affiliation: Department of Oral and Maxillofacial Surgery, Ludwig-Maximilians-Universität München, Munich, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Otto
authors.affiliation: Department of Oral and Maxillofacial Surgery, Ludwig-Maximilians-Universität München, Munich, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Schiel
authors.affiliation: Department of Oral and Maxillofacial Surgery, Ludwig-Maximilians-Universität München, Munich, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Troeltzsch
authors.affiliation: Department of Oral and Maxillofacial Surgery, Ludwig-Maximilians-Universität München, Munich, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Ehrenfeld
authors.affiliation: Department of Oral and Maxillofacial Surgery, Ludwig-Maximilians-Universität München, Munich, Germany.
authors.forename: C P
authors.initials: CP
authors.lastname: Cornelius
authors.affiliation: Institute of Clinical Radiology, Ludwig-Maximilians-Universität München, Munich, Germany.
authors.forename: U G
authors.initials: UG
authors.lastname: Müller-Lisse
mesh_terms: D001706:Biopsy; D003287:Contrast Media; D003937:Diagnosis, Differential; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008336:Mandibular Diseases / Q000175:diagnosis; D008339:Mandibular Neoplasms / Q000175:diagnosis; D009807:Odontogenic Cysts / Q000175:diagnosis*; D009808:Odontogenic Tumors / Q000175:diagnosis*; D011862:Radiography, Panoramic; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: Contrast-enhanced MRI; Cystic lesions of the jaw; Keratocystic odontogenic tumour; Maxillofacial Surgery; Odontogenic cyst