Can Velopharyngeal MRI be Used in Individuals with Orthodontic Devices?

OBJECTIVE

To evaluate the influence of common pediatric orthodontic appliances on velopharyngeal (VP) MRI and to compare MR image sequences to determine if sequence parameters impact the visibility of key VP structures commonly assessed in clinical VP MRI.

DESIGN

Participants undergoing orthodontic treatment completed a VP MRI study. Level of distortion caused by orthodontic devices on 8 anatomical sites of interest and using variable MRI sequences was evaluated.

SETTING

Single institution.

PARTICIPANTS

Nineteen participants undergoing orthodontic treatment.

MAIN OUTCOME

Level of distortion caused by metal artifacts and MR sequence used.

RESULTS

The results of this study demonstrate that appliances such as hyrax palatal expanders and braces with stainless steel brackets are acceptable for a VP MRI, while class II corrector springs are not recommended. The HASTE MRI sequence with 2D imaging techniques should be utilized if the child has orthodontic devices, while FSE and 3D imaging techniques are not recommended. The presence of wire spring coils and molar bands are likely to not to interfere with the MRI evaluation.

CONCLUSIONS

Findings from this study suggest that the presence of orthodontic appliances does not hinder visualization of all velopharyngeal structures during an MRI. Therefore, careful consideration must be made prior to disqualifying or recommending patients for VP MRI.

Assessment of pharyngeal airway space with MRI In oral submucous fibrosis: A cross-sectional observational study

Introduction

Oral submucous fibrosis (OSMF) alters the pharynx, which may affect airway size. MRI will be useful for diagnosing pharyngeal abnormalities. MRI is used to evaluate pharyngeal airway and soft palate changes in OSMF patients.

Materials and methods

This study is a cross-sectional observational study that included a sample size of 42 patients. Group A consisted of 21 patients with OSMF, while Group B consisted of 21 volunteers without OSMF, who served as the control group. The patients with OSMF were classified into Stages I, II, and III according to the categorization established by Pindborg JJ in 1989, Stop-Bang questionnaire was employed to assess obstructive sleep apnoea. Magnetic Resonance Imaging (MRI) was utilized to acquire evaluations of the pharyngeal airway, encompassing measurements in the midsagittal, cross-sectional width, length planes, and cross-sectional area with volume, for all participants. The Shapiro-Wilk test determines distribution normality. We utilized one-way ANOVA to compare the means between groups.

Results

The average age of OSMF patients was 45.9 ± 8.16, while the control group was 39.19 ± 4.21. Stage I of OSMF had the highest mean Stop Bang questionnaire score (2.75), followed by stage III (2.22), and stage II (1.75). Statistically significant differences (p < 0.001) were seen in volume, linear midsagittal planes, cross-sectional width and length planes, cross-sectional area, and soft palate breadth and length between OSMF and control groups.

Conclusion

MRI can effectively examine early changes in the pharyngeal airway of patients with OSMF thereby serving as a constructive diagnostic and motivational tool.

Real-Time Magnetic Resonance Imaging

Real-time magnetic resonance imaging (RT-MRI) allows for imaging dynamic processes as they occur, without relying on any repetition or synchronization. This is made possible by modern MRI technology such as fast-switching gradients and parallel imaging. It is compatible with many (but not all) MRI sequences, including spoiled gradient echo, balanced steady-state free precession, and single-shot rapid acquisition with relaxation enhancement. RT-MRI has earned an important role in both diagnostic imaging and image guidance of invasive procedures. Its unique diagnostic value is prominent in areas of the body that undergo substantial and often irregular motion, such as the heart, gastrointestinal system, upper airway vocal tract, and joints. Its value in interventional procedure guidance is prominent for procedures that require multiple forms of soft-tissue contrast, as well as flow information. In this review, we discuss the history of RT-MRI, fundamental tradeoffs, enabling technology, established applications, and current trends. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY STAGE: 1.