Retrospective Review of Midpoint Vestibular Aqueduct Size in the 45° Oblique (Pöschl) Plane and Correlation with Hearing Loss in Patients with Enlarged Vestibular Aqueduct.

BACKGROUND AND PURPOSE: Vestibular aqueduct measurements in the 45° oblique (Pöschl) plane provide a reliable depiction of the vestibular aqueduct; however, adoption among clinicians attempting to counsel patients has been limited due to the lack of correlation with audiologic measures. This study aimed to determine the correlation between midpoint vestibular aqueduct measurements in the Pöschl plane in patients with an enlarged vestibular aqueduct with repeat audiologic measures. MATERIALS AND METHODS: Two radiologists independently measured the midpoint vestibular aqueduct diameter in the Pöschl plane reformatted from CT images in 54 pediatric patients (77 ears; mean age at first audiogram, 5 years) with an enlarged vestibular aqueduct. Four hundred nineteen audiograms were reviewed, with a median of 6 audiograms per patient (range, 3-17; mean time between first and last audiograms, 97.4 months). The correlation between midpoint vestibular aqueduct size and repeat audiologic measures (pure tone average, speech-reception threshold, and word recognition score) using a linear mixed-effects model was determined. RESULTS: The mean midpoint vestibular aqueduct size was 1.78 mm (range, 0.81-3.46 mm). There was excellent interobserver reliability with intraclass correlation coefficients for the 2 readers measuring 0.92 (P < .001). Each millimeter increase in vestibular aqueduct size was associated with an increase of 10.5 dB (P = .006) in the pure tone average, an increase of 14.0 dB (P = .002) in the speech-reception threshold, and a decrease in the word recognition score by 10.5% (P = .05). CONCLUSIONS: Midpoint vestibular aqueduct measurements in the Pöschl plane are highly reproducible and demonstrate a significant correlation with audiologic data in this longitudinal study with repeat measures. These data may be helpful for clinicians who are counseling patients with an enlarged vestibular aqueduct using measurements obtained in the Pöschl plane.

Imaging appearance of the lateral rectus-superior rectus band in 100 consecutive patients without strabismus.

BACKGROUND AND PURPOSE: The lateral rectus-superior rectus band is an orbital connective tissue structure that has been implicated in a form of strabismus termed sagging eye syndrome. Our purpose was to define the normal MR imaging and CT appearance of this band in patients without strabismus. MATERIALS AND METHODS: Orbital MR imaging and CT examinations in 100 consecutive patients without strabismus were evaluated. Readers graded the visibility of the lateral rectus-superior rectus band on coronal T1WI, coronal STIR, and coronal CT images. Readers determined whether the band demonstrated superotemporal bowing or any discontinuities and whether a distinct lateral levator aponeurosis was seen. Reader agreement was assessed by κ coefficients. Association between imaging metrics and patient age/sex was calculated by using the Fisher exact test. RESULTS: The lateral rectus-superior rectus band was visible in 95% of coronal T1WI, 68% of coronal STIR sequences, and 70% of coronal CT scans. Ninety-five percent of these bands were seen as a continuous, arc-like structure extending from the superior rectus/levator palpebrae muscle complex to the lateral rectus muscle; 24% demonstrated superotemporal bowing; and in 82% of orbits, a distinct lateral levator aponeurosis was visible. Increasing patient age was negatively associated with lateral rectus-superior rectus band visibility (P=.03), positively associated with lateral rectus-superior rectus band superotemporal bowing (P=.03), and positively associated with lateral levator aponeurosis visibility (P=.01). CONCLUSIONS: The lateral rectus-superior rectus band is visible in most patients without strabismus on coronal T1WI. The age effect with respect to its visibility and superotemporal bowing could represent age-related connective tissue degeneration.

Facial reanimation procedures depicted on radiologic imaging.

Various facial reanimation procedures can be performed for treating patients with chronic facial nerve paralysis. The radiologic imaging features of static and dynamic techniques are reviewed in this article with clinical correlation, including brow lift, eyelid weights and springs, gracilis free flaps, fascia lata grafts, temporalis flaps, and Gore-Tex suspension slings. Although the anatomic alterations resulting from facial reanimation surgery may not necessarily be the focus of the imaging examination, it is important to recognize such changes and be familiar with MR imaging compatibility of the associated implanted materials. Furthermore, imaging is sometimes used to specifically evaluate the postoperative results, such as vessel patency following free gracilis transfer.

Imaging findings in auto-atticotomy.

BACKGROUND AND PURPOSE: An acquired attic cholesteatoma may spontaneously drain externally into the external auditory canal, leaving a cavity in the attic with the shape of the original cholesteatoma but now filled with air, a phenomenon referred to as "nature's atticotomy" or auto-atticotomy. We describe and quantify the CT appearance of the auto-atticotomy cavity as it pertains to the appearance of the scutum and the lateral attic wall. MATERIALS AND METHODS: Twenty-one patients with erosion of the scutum and loss of the lower attic wall on MDCT were identified during a 5-year span. Images were assessed for measureable widening of the space between the ossicles and the lower lateral attic wall in the axial and coronal planes. Three measurements of the lateral attic were made on the axial images. Findings were compared with the same measurements in 20 control subjects. RESULTS: The 21 patients had a characteristic blunting of the scutum with loss of the lower lateral attic wall and widening of the lateral attic, consistent with an auto-atticotomy. There was a statistically significant (P < .001) widening of the lateral attic dimensions in the axial plane in the patients with auto-atticotomy. CONCLUSIONS: Spontaneously evacuated cholesteatoma may mimic a surgical atticotomy on MDCT. Scutal erosion and attic enlargement with a smoothly contoured bony remodeling of the lower lateral attic wall in a patient with no history of surgery suggest that a cholesteatoma was previously present and spontaneously drained.

Comparison of 45 degrees oblique reformats with axial reformats in CT evaluation of the vestibular aqueduct.

BACKGROUND AND PURPOSE: Measurement of the vestibular aqueduct on CT scans of the temporal bone is important for the detection of large vestibular aqueduct syndrome; typically this is done in the axial plane. We sought to determine the usefulness of reformats performed in the 45 degrees oblique plane for evaluating the vestibular aqueduct. In addition, we provide reference measurements for the vestibular aqueduct in the 45 degrees oblique plane. MATERIALS AD METHODS: We selected 15 subjects referred for reasons other than sensorineural hearing loss, and without radiographic evidence of abnormality of the inner ear. Two neuroradiologists independently evaluated both axial and 45 degrees oblique images for ease in visualizing the vestibular aqueduct. Then, one of the readers (B.O.) performed reference measurements of the diameter at the mouth and midpoint of the aqueduct. RESULTS: Combining the results of both observers, we judged 82% of vestibular aqueducts as well-defined or easily traced on 45 degrees oblique views, whereas we judged only 55% as well-defined or easily traced on axial views. The difference in the degrees of visualization between the 45 degrees oblique and axial reformats was significant for observer 1 (P =.022) and observer 2 (P =.001). Intraobserver agreement about the visibility of the aqueduct was higher on the 45 degrees oblique than the axial views: (kappa = 0.682, SE = 0.171) for 45 degrees oblique reformats; (kappa = 0.480, SE = 0.145) for axial reformats. On the 45 degrees oblique reformats, the mean external aperture dimension of the vestibular aqueduct was measured as 0.616 +/- 0.133 mm, and the postisthmic segment had a mean width of 0.482 +/- 0.099 mm. CONCLUSIONS: The 45 degrees oblique plane gives a more reliable depiction of the vestibular aqueduct than the axial plane in CT evaluation of the temporal bone. This technique can be useful in cases of borderline enlargement of the vestibular aqueduct.

Small flat umbilicated tumors of the colon: radiographic and pathologic findings.

OBJECTIVE: We describe the radiographic and pathologic findings of small flat umbilicated tumors of the colon detected on double-contrast barium enema examinations performed in a Western population. CONCLUSION: Unlike those reported by Japanese authors, the small flat umbilicated tumors of the colon in our patients were usually hyperplastic polyps, previously called "inverted hyperplastic polyps." Nevertheless, colonoscopy with excisional biopsy is warranted for such tumors detected on double-contrast barium enema examinations because of the small possibility that these tumors represent adenoma or even early adenocarcinoma.