Differentiation of periapical granulomas and cysts by using dental MRI: a pilot study

• Published in: International journal of oral science 2018-05, Vol.10 (2), p.17-8, Article 17
• Main Authors: Juerchott, Alexander, Pfefferle, Thorsten, Flechtenmacher, Christa, Mente, Johannes, Bendszus, Martin, Heiland, Sabine, Hilgenfeld, Tim
• Format: Article
• Language: English
• Subjects: Contrast Media; Cysts; Dentistry; Diagnosis, Differential; Granulomas; Humans; Image processing; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Medicine; NMR; Nuclear magnetic resonance; Oral and Maxillofacial Surgery; Orthopedics; Periapical Granuloma - diagnostic imaging; Periodontitis; Pilot Projects; Radicular Cyst - diagnostic imaging; Reproducibility of Results; Sensitivity and Specificity; Statistical analysis; Surgery; Surgical Orthopedics
• ISSN: 2049-3169; 1674-2818; 2049-3169
• DOI: 10.1038/s41368-018-0017-y

The purpose of this pilot study was to evaluate whether periapical granulomas can be differentiated from periapical cysts in vivo by using dental magnetic resonance imaging (MRI). Prior to apicoectomy, 11 patients with radiographically confirmed periapical lesions underwent dental MRI, including fat-saturated T2-weighted (T2wFS) images, non-contrast-enhanced T1-weighted images with and without fat saturation (T1w/T1wFS), and contrast-enhanced fat-saturated T1-weighted (T1wFS+C) images. Two independent observers performed structured image analysis of MRI datasets twice. A total of 15 diagnostic MRI criteria were evaluated, and histopathological results (6 granulomas and 5 cysts) were compared with MRI characteristics. Statistical analysis was performed using intraclass correlation coefficient (ICC), Cohen’s kappa (κ), Mann–Whitney U -test and Fisher’s exact test. Lesion identification and consecutive structured image analysis was possible on T2wFS and T1wFS+C MRI images. A high reproducibility was shown for MRI measurements of the maximum lesion diameter (intraobserver ICC = 0.996/0.998; interobserver ICC = 0.997), for the “peripheral rim” thickness (intraobserver ICC = 0.988/0.984; interobserver ICC = 0.970), and for all non-quantitative MRI criteria (intraobserver-κ = 0.990/0.995; interobserver-κ = 0.988). In accordance with histopathological results, six MRI criteria allowed for a clear differentiation between cysts and granulomas: (1) outer margin of lesion, (2) texture of “peripheral rim” in T1wFS+C, (3) texture of “lesion center” in T2wFS, (4) surrounding tissue involvement in T2wFS, (5) surrounding tissue involvement in T1wFS+C and (6) maximum “peripheral rim” thickness (all: P