Rajesh Vanagundi1, Jyoti Kumar2, Alpana Manchanda1, Sujata Mohanty3, Ravi Meher4. 1. Department of Radiodiagnosis, Maulana Azad Medical College, New Delhi, India. 2. Department of Radiodiagnosis, Maulana Azad Medical College, New Delhi, India. Electronic address: Drjyotikumar@gmail.com. 3. Department of Oromaxillofacial Surgery, Maulana Azad Institute of Dental Sciences, New Delhi, India. 4. Department of Otorhinolaryngology, Maulana Azad Medical College, New Delhi, India.
Abstract
OBJECTIVES: The aim of this study was to evaluate diffusion-weighted imaging (DWI) in comparison with morphologic magnetic resonance imaging (MRI) in differentiating among odontogenic keratocyst (OKC), unicystic ameloblastoma (UAB), and dentigerous cyst (DC). STUDY DESIGN: Contrast-enhanced MRI, including DWI, was performed on 27 patients with the 3 lesions. Signal intensity characteristics were evaluated on T1- and T2-weighted MRI. The apparent diffusion coefficient (ADC) cutoff value to most effectively differentiate among the 3 lesions was calculated with receiver operating characteristic analysis. RESULTS: In total, 17 OKCs, 5 UABs, and 5 DCs were diagnosed histologically. There were no significant differences among them in signal intensity on T1- or T2-weighted images (P ≥ .13). On DWI, 14 of 17 OKCs showed restricted diffusion with a mean ADC value of 0.954 × 10-3 mm2/s. All 5 UABs and all 5 DCs exhibited facilitated diffusion with ADC values ≥ 2.150 × 10-3 mm2/s. The ADC cutoff to differentiate OKCs from UABs was 2.137 × 10-3 mm2/s (P = .01); UABs from DCs was 2.422 × 10-3 mm2/s (P = .03); and OKCs from DCs was 2.347 × 10-3 mm2/s (P = .01). CONCLUSIONS: Addition of diffusion-weighted sequences to MRI jaw protocols can assist in the characterization of OKCs, UABs, and DCs.
OBJECTIVES: The aim of this study was to evaluate diffusion-weighted imaging (DWI) in comparison with morphologic magnetic resonance imaging (MRI) in differentiating among odontogenic keratocyst (OKC), unicystic ameloblastoma (UAB), and dentigerous cyst (DC). STUDY DESIGN: Contrast-enhanced MRI, including DWI, was performed on 27 patients with the 3 lesions. Signal intensity characteristics were evaluated on T1- and T2-weighted MRI. The apparent diffusion coefficient (ADC) cutoff value to most effectively differentiate among the 3 lesions was calculated with receiver operating characteristic analysis. RESULTS: In total, 17 OKCs, 5 UABs, and 5 DCs were diagnosed histologically. There were no significant differences among them in signal intensity on T1- or T2-weighted images (P ≥ .13). On DWI, 14 of 17 OKCs showed restricted diffusion with a mean ADC value of 0.954 × 10-3 mm2/s. All 5 UABs and all 5 DCs exhibited facilitated diffusion with ADC values ≥ 2.150 × 10-3 mm2/s. The ADC cutoff to differentiate OKCs from UABs was 2.137 × 10-3 mm2/s (P = .01); UABs from DCs was 2.422 × 10-3 mm2/s (P = .03); and OKCs from DCs was 2.347 × 10-3 mm2/s (P = .01). CONCLUSIONS: Addition of diffusion-weighted sequences to MRI jaw protocols can assist in the characterization of OKCs, UABs, and DCs.