Article Figures & Data
Figures
- FIG 1.
CT findings of UVFP images from 2 patients with proven left UVFP. A, Coronal CT image demonstrates dilation of the left laryngeal ventricle (star) and loss of the subglottic arch (arrow). B, Axial CT image demonstrates medial positioning of the left posterior vocal fold margin (arrow). C, Axial CT image demonstrates anterior positioning of the left arytenoid cartilage (arrow). D, Axial CT image demonstrates rotation and thickening of the left aryepiglottic fold and enlargement of the left pyriform sinus (star). E, Axial CT image demonstrates the mushroom sign, tilting toward the left (star).
- FIG 2.
Radiologists’ subjectivity on a single axial postcontrast CT scan demonstrates questionable findings of the mushroom sign. This was read by 2 radiologists as negative for this sign and by 1 radiologist as positive for the sign with the left side as the affected side. By laryngoscopic examination, this patient did indeed have left-sided vocal fold paralysis.
Tables
Indirect CT Signs of UVFP 1 Dilation of the ipsilateral pyriform sinus 2 Medial rotation of the ipsilateral aryepiglottic fold 3 Thickening of the ipsilateral aryepiglottic fold 4 Dilation of the ipsilateral laryngeal ventricle 5 Medial displacement of the posterior aspect of the ipsilateral true vocal fold 6 Mushroom sign,4 ipsilateral laryngeal ventricle dilation with medialization of the posterior cord margin combined with contralateral anterior subglottic air to generate a mushroom appearance on axial imaging 7 Anteromedial displacement of the ipsilateral arytenoid cartilage 8 Loss of the ipsilateral subglottic arch Overall (n = 143) UVFP (n = 104) No UVFP (n = 39) P Value Age (mean) (SD) (yr) 62.9 (14.5) 65.5 (13.5) 56.0 (15.0) <.001 Sex (No.) (%) Male 71 (49.7) 48 (46.2) 23 (59.0) .1 Female 72 (50.3) 56 (53.8) 16 (41.0) Laterality (No.) (%) Left 76 (53.1) 76 (73.1) – – Right 28 (19.6) 28 (26.9) – – No paralysis 39 (27.3) – 39 (100.0) – Note:— indicates not applicable.
Diagnosis κ (95% CI) Dilation of ipsilateral pyriform sinus 0.77 (0.68–0.86) Medial rotation of ipsilateral aryepiglottic fold 0.66 (0.56–0.75) Thickening of ipsilateral aryepiglottic fold 0.32 (0.17–0.47) Anteromedial displacement of ipsilateral arytenoid cartilage 0.46 (0.34–0.57) Medial displacement of posterior aspect of ipsilateral vocal fold 0.54 (0.42–0.65) Mushroom sign 0.19 (0.09–0.29) Dilation of ipsilateral laryngeal ventricle 0.50 (0.39–0.61) Loss of subglottic arch 0.15 (0.00–0.30) Final diagnosis of paralysis 0.58 (0.48–0.69) Majority Positive (No.) (%) Sensitivity Specificity Positive Predictive Value Negative Predictive Value Dilation of ipsilateral pyriform sinus 91 (63.6%) 68.3% 48.7% 78.0% 36.5% Medial rotation of ipsilateral aryepiglottic fold 76 (53.1%) 60.6% 66.7% 82.9% 38.8% Thickening of ipsilateral aryepiglottic fold 19 (13.3%) 16.3% 94.9% 89.5% 29.8% Anteromedial displacement of ipsilateral arytenoid cartilage 42 (29.4%) 36.5% 89.7% 90.5% 34.7% Medial displacement of posterior aspect of ipsilateral vocal fold 100 (69.9%) 78.8% 53.8% 82.0% 48.8% Mushroom sign 9 (6.3%) 7.7% 97.4% 89.9% 28.4% Dilation of ipsilateral laryngeal ventricle 87 (60.8%) 69.2% 61.5% 82.8% 42.9% Loss of subglottic arch 7 (4.9%) 5.8% 97.4% 85.7% 27.9% Final diagnosis of paralysisa 84 (59.2%) 68.0% 64.1% 83.3% 43.0% ↵a n = 142: omitted 1 tie (1 positive, 1 negative, 1 missing value).
Radiologist, Majority Otolaryngologist Vocal Cord Paralysis No Vocal Cord Paralysis Vocal cord paralysis 70 (49.3) 14 (9.9) No vocal cord paralysis 33 (23.2) 25 (17.6) Odds Ratio (95% CI) P Value Medial displacement of posterior aspect of ipsilateral vocal fold 3.09 (1.32–7.24) .009 Dilation of ipsilateral laryngeal ventricle 2.40 (1.03–5.5) .04 No. Sensitivity Specificity PPV NPV CT finding Either finding 113 86.5% 41.0% 79.6% 53.3% Both findings 74 61.5% 74.4% 86.5% 42.0% Note:—PPV indicates positive predictive value; NPV, negative predictive value.
