Does the Type of MRI Sequence Influence Perceived Quality and Measurement Consistency in Investigations of the Anatomy of the Velopharynx?

PURPOSE: The purpose of this study was to evaluate perceived image quality, confidence in identifying key velopharyngeal landmarks, and reliability of making velopharyngeal measures between 3-dimensional (3-D) and 2-D magnetic resonance imaging (MRI) methods and between T1-, T2-, and proton density (PD)-weighted sequences. METHODS: Twelve healthy participants completed an MRI study. Three raters assessed overall image quality and their ability to identify key anatomic features within the images. A single rater evaluated the reliability of making measures between imaging methods and sequence types to determine if image type (2-D and 3-D) or image sequence (T1, T2, PD weighted) resulted in different values for key velopharyngeal landmarks. RESULTS: An analysis of variance test revealed image quality was rated significantly different based on the scan type (P < .001) and the sequence used (P = .015). Image quality was rated higher among 2-D MR images compared to 3-D, and higher among T2 sequences compared to T1- and PD-weighted imaging methods. In contrast, raters favored 3-D sequences over 2-D sequences for identifying velopharyngeal landmarks. Measures of reliability revealed scan type significantly impacted 2 of the 6 variables but to a minimal degree; however, sequence type had no impact on measures of reliability across all variables. CONCLUSION: Results of the study suggest the scan type and sequence used are factors that likely do not impact the reliability of measures. Based on image quality, the recommended technique for velopharyngeal imaging would be using a 2-D T2-weighted technique. However, based on the ability to identify key landmarks, a 3-D T1- or PD-weighted technique was favored.

Observational management of penetrating occult pneumothoraces: Outcomes and risk factors for interval tube thoracostomy placement.

BACKGROUND: Guidelines for penetrating occult pneumothoraces (OPTXs) are based on blunt injury. Further understanding of penetrating OPTX pathophysiology is needed. In observational management of penetrating OPTX, we hypothesized that specific clinical and radiographic features may be associated with interval tube thoracostomy (TT) placement. Our aims were to (1) describe OPTX occurrence in penetrating chest injury, (2) determine the rate of interval TT placement in observational management and clinical outcomes compared with immediate TT placement, and (3) describe risk factors associated with failure of observational management. METHODS: Penetrating OPTX patients presenting to our level 1 trauma center from 2004 to 2019 were reviewed. Occult pneumothorax was defined as a pneumothorax on chest computed tomography but not on chest radiograph. Patient groups included immediate TT placement versus observation. Clinical outcomes compared were TT duration and complications, need for additional thoracic procedures, length of stay (LOS), and disposition. Clinical and radiographic factors associated with interval TT placement were determined by multivariable regression. RESULTS: Of 629 penetrating pneumothorax patients, 103 (16%) presented with OPTX. Thirty-eight patients underwent immediate TT placement, and 65 were observed. Twelve observed patients (18%) needed interval TT placement. Regardless of initial management strategy, TT placement was associated with longer LOS and more chest radiographs. Chest injury complications and outcomes were similar. Factors associated with increased odds of interval TT placement included Chest Abbreviated Injury Scale score of ≥4 (adjusted odds ratio [aOR], 7.38 [95% confidence interval, 1.43-37.95), positive pressure ventilation (aOR, 7.74 [1.07-56.06]), concurrent hemothorax (aOR, 6.17 [1.08-35.24]), and retained bullet fragment (aOR, 11.62 [1.40-96.62]) (all p < 0.05). CONCLUSION: The majority of patients with penetrating OPTX can be successfully observed with improved clinical outcomes (LOS, avoidance of TT complications, reduced radiation). Interval TT intervention was not associated with risk for adverse outcomes. In patients undergoing observation, specific clinical factors (chest injury severity, ventilation) and imaging features (hemothorax, retained bullet) are associated with increased odds for interval TT placement, suggesting need for heightened awareness in these patients. LEVEL OF EVIDENCE: Prognostic, level IV.

Morphology of the Musculus Uvulae In Vivo Using MRI and 3D Modeling Among Adults With Normal Anatomy and Preliminary Comparisons to Cleft Palate Anatomy.

PURPOSE: To investigate the musculus uvulae morphology in vivo in adults with normal velopharyngeal anatomy and to examine sex and race effects on the muscle morphology. We also sought to provide a preliminary comparison of musculus uvulae morphology in adults with normal velopharyngeal anatomy to adults with repaired cleft palate. METHODS: Three-dimensional magnetic resonance imaging data and Amira 5.5 Visualization Modeling software were used to evaluate the musculus uvulae in 70 participants without cleft palate and 6 participants with cleft palate. Muscle length, thickness, width, and volume were compared among participant groups. RESULTS: Analysis of covariance analysis did not yield statistically significant differences in musculus uvulae length, thickness, width, or volume by race or sex among participants without cleft palate when the effect of body size was accounted for. Two-sample t test revealed that the musculus uvulae in participants with repaired cleft palate is significantly shorter (P = .008, 13.65 mm vs 16.07 mm) and has less volume (P = .002, 51.08 mm3 vs 97.62 mm3) than participants without cleft palate. CONCLUSION: In adults with normal velopharyngeal anatomy, the musculus uvulae is a cylindrical oblong-shaped muscle lying on the nasal surface of the soft palate, with its greatest bulk located just nasal to the levator veli palatini muscle sling. In participants with repaired cleft palate, the musculus uvulae is substantially reduced in volume. This diminished muscle bulk located just at the point where the palate contacts the posterior pharyngeal wall may contribute to velopharyngeal insufficiency in children with repaired cleft palate.