The CT Evaluation of Neoarytenoid Soft Tissue after an Arytenoidectomy during a Supracricoid Partial Laryngectomy

OBJECTIVE: To evaluate the postoperative laryngeal CT findings of neoarytenoid soft tissue at an arytenoidectomy site during a supracricoid partial laryngectomy, and to compare its thickness to the mucosa over the spared arytenoid cartilage. MATERIALS AND METHODS: Thirty-one patients underwent a supracricoid partial laryngectomy with (n = 14) or without (n = 17) an arytenoidectomy. A postoperative laryngeal CT examination was performed to statistically compare the thickness of the neoarytenoid soft tissue to the mucosa over the spared arytenoids. RESULTS: The neoarytenoid soft tissue revealed an eccentric prominence in all 14 arytenoidectomy sites. Further, the neoarytenoid soft tissue was consistently thicker than the mucosa over spared arytenoids cartilage (p < 0.01), however did not exceed 11 mm. CONCLUSION: The eccentric prominence of neoarytenoid soft tissue at the arytenoidectomy site during a supracricoid partial laryngectomy should be identified and distinguished from a recurrent mass when compared to spared arytenoid cartilage on a postoperative laryngeal CT.

Three-Dimensional CT Laryngography: Clinical Application

PURPOSE: To evaluate the clinical usefulness of 3D volume-rendering (VR) CT laryngography during quiet breathing, Valsalva, and modified Valsalva maneuvers, in those with laryngeal and pyriform sinus lesions. MATERIALS AND METHODS: Twenty-seven patients with various laryngeal and hypopharyngeal lesions were examined by means of four-channel multidetector-row helical CT (LightSpeed QX/i; GE Medical Systems, Milwaukee, Wis., U.S.A.) during quiet breathing, Valsalva, and modified Valsalva maneuvers. The protocol included 1.25-mm slice thickness, 3.75-mm rotation, 1.25 mm interval, and a pitch ratio of 3:1. Using an Advantage Windows 3.1 workstation (GE Medical Systems), 3D VR was generated in regions of interest, including all structures with a CT attenuation of between -1022 and -125 HU. Visual assessment of the findings of 3D CT laryngography, including the images obtained during the three different breathing maneuvers, were analyzed by three radiologists, who reached a consensus. These results were then compared with the findings of axial CT. The lesions discovered, in descending order of frequency, included laryngeal cancer (n=12), pyriform sinus cancer with an intact apex (n=6), pyriform sinus cancer with apex involvement (n=6), laryngeal papilloma (n=2), and hypopharyngeal obstruction with (n=1) and without (n=2) associated vocal cord palsy. In each case, the findings were confirmed by surgical biopsy, direct laryngoscopy, or CT. RESULTS: 3D CT laryngography using the VR technique can supplement the information provided by axial images, and in the assessment of subglottic invasion and pyriform sinus apical invasion, its findings are consistent. In many of our cases, its use during quiet breathing was able to determine whether or not glottic cancer involved subglottic invasion. In laryngeal cancer cases, furthormore, modified Valasalva can be used to clarify the condition of the pyriform sinus apex. Dynamic-phase 3D CT laryngography can be used to elucidate the condition of a patient with vocal cord palsy. CONCLUSION: 3D CT laryngography is a new method for the visual diagnosis of vocal cord and laryngeal cancer. When employed after dynamic diagnosis, it is useful for the evaluation of subglottic extension, pyriform sinus apical invasion and vocal cord palsy, important indicators in the staging of cancer.

CT Findings of Supraglottitis in Adults

PURPOSE: To determine the CT findings and to evaluate the role of CT scanning in adult supraglottitis. MATERIALS AND METHODS: The CT findings of five male patients aged between 29 and 69 (mean, 53) years with adult supraglottitis were reviewed and evaluated. Particular attention was focussed on swelling of epiglottis and laryngeal structures, abscess formation and extension of the inflammatory process to adjacent neck spaces. In addition, the findings of CT were compared with those of plain radiography. RESULTS: In all patients, CT revealed swelling of the epiglottis and aryepiglottic folds, while in four, swelling of the paralaryngeal space was noted. Abscesses in the epiglottis were seen in four patients, and in three of these, small abscesses in the preepiglottic, parapharyngeal, or peritonsillar space or palatine tonsil, were also noted. One patient had an emphysematous epiglottitis, and in three, inflammation extended to adjacent regions of the neck, namely the parapharyngeal, retropharyngeal, submandibular, or peritonsillar space. Plain radiographs gave only restricted information regarding abscess formation and the extension of inflammation to adjacent neck space. CONCLUSION: CT is useful for assessing the extent of adult supraglottitis and for evaluating ensuing complications. It may also be useful for differentiating this condition from other supraglottic diseases, for the planning of treatment, and for evaluating the results of therapy.

Laryngeal Schwannoma: A Case Report

Laryngeal schwannoma is extremely rare. We report the CT and MRI findings of a case occurring in a 65-year-oldwoman, and describe the pathologic correlation. Pre-contrast CT scanning revealed a right supraglot-tic mass witha slightly hyperdense central part and a hypodense peripheral part. Post-contrast CT scanning re-vealed anenhanced hyperdense central part and a rim-like hypodense peripheral part. The density of the pe-ripheral part waslower than that of muscle. The mass showed homogeneous low signal intensity on T1-weighted MR images, homogeneoushigh signal intensity on T2-weighted MR images, and an enhanced high signal intensity central part and a lowsignal intensity peripheral part on gadolinium enhanced T1-weighted images. The enhanced central part correlatedwith Antoni A areas and the peripheral part, showing low attenuation, correlated with Antoni B areas.

Dynamic Study of the Larynx with Spiral CT in the Tumors of the Pyriform Sinus and Supraglottis

PURPOSE: To evaluate the CT findings of tumor in the pyriform sinus, and to assess by functional study of thelarynx the extent the extent to which its characteristic findings differ from those of supraglottic tumor. MATERIALS AND METHODS: CT scans of 14 patients with tumor in the pyriform sinus were reviewed and compared withthose of 17 patients with supraglottic tumor. In all cases, spiral CT scanning linvolved both quiet breathing andmodified breath holding; we evaluated the images and analysed the primary site of tumors and the displacement ofair in the pyriform sinus. Extra and intralaryngeal extension of the tumors was also assessed. RESULTS: In tumorsin the pyriform sinus, CT findings were thickening of more than two walls in 14, the displacement of air in 9,extralaryngeal extension in 13, extension to the post-cricoid space in 11, invasion of the pre-epiglottic space in13, and widening of the cricothyroid space in 8 patients. In supraglottic tumors, CT findings were thickening ofthe medial wall in 17, extralaryngeal extension in 1, extension to the post-cricoid space in 1, invasion of theipsilateral paralaryngeal space in 17, and of the contralateral paralaryngeal space in 6, invasion of thepre-epiglottic space in 11, and widening of the cricothyroid space in 9 patienhts. In this type of tumor thedisplacement of air was not seen. CONCLUSION: The characteristic CT findings of tumor in the pyriform sinus werethickening of more than two walls of the pyriform sinus and the anterior or medial displacement of air. To assessthe site at which a tumor originates, spiral CT scanning is needed, together with functional study.

The Normal Width of the Anterior Commissure of the True Vocal Cord in Korean Adults Measured by Helical CT

PURPOSE: To evaluate the mean width of anterior commissure of true vocal cord in Korean adults by measuringits dimension on spiral CT scans. MATERIALS AND METHODS: We reviewed the CT scans of 53 Korean adults(age range,23-73years; mean age 39.2years; M:F=41:12) without laryngeal disorders. Spiral CT scanning was performed aroundthe anterior commissure with 1mm slice thickness and table incrementation for 15 seconds. The anteroposteriorwidth of the anterior commissure was measured on CT scan where the true vocal cord and arytenoid, cricoid andthyroid cartilages were all present. We determined the mean width of the anterior commissure and whether there wasa relationship between age and the width of the anterior commissure. RESULTS: The width of the anteriorcommissure was between 0.9mm and 2.3mm ; mean width was 1.60+/-0.38mm(mean+/-SD). Using two SDs above the mean wouldhave defined 2.36mm as the upper limit of normal width. Statistically, no significant correlation existed betweenthe age and the width of the anterior commissure(p>0.05). CONCLUSION: An awareuess of the normal width range ofthe anterior commissure in Korean adults evaluated by spiral CT enhances the possibility of early detection ofinvasion of the anterior commissure by glottic cancer.

Primary Malignant Lymphoma of Larynx: A Case Report

Primary malignant laryngeal lymphoma is rare. In this case, diffuse wall thickening of the vocal cord and infraglottic larynx was seen on initial CT scan. After chemotherapy, follow-up CT neck scans showed a marked decrease of diffuse wall thickening of the vocal cord and infraglottic larynx ; diffuse laryngeal wall thickening is, however, a nonspecific finding which can be seen in other disease processes. If clinical evidence of infection and inflammation or remarkable change after antibiotics treatment is not definite, biopsy should be performed to rule out laryngeal lymphoma.

CT Grading of Laryngeal Cancer According to the Degree of its Extension: Emphasis on T2 and T3 Tumors

PURPOSE: To analyze the degree of tumor extension in T2 and T3 laryngeal cancer, independently of vocal cord fixation, and to introduce a new CT grading system for use in preoperative T-stage assessment. MATERIALS AND METHODS: Retrospective analysis of degree of tumor extension was performed in 36 patients with laryngeal cancer (T2 glottic, 4 ; T2 supraglottic, 12 ; T3 glottic, 12 ; and T3 supraglottic, 8). T-stage was determined according to clinical and pathologic findings, and based on the TNM classification of AJCC (1992). The degree of tumor extension seen on CT was determined by the number of involved anatomic subsites and compared with T-stage and lymph node metastasis. On the basis of statistical analysis(Fisher's exact test) of those results, we suggest new CT grading system for laryngeal cancer. RESULTS: Fifteen of 20 supraglottic cancer patients showed six or less involved anatomic subsites ; twelve of these 15 (80%) were at stage T2 and three (20%) were T3. Four of the 15 showed lymph node metastasis. The five patients whose number of involved anatomic subsites was seven or more were all T3 ; four (80%) of these showed lymph node metastasis. The difference in the number of involved anatomic subsites in T2 and T3 tumor was statistically significantly different (p<0.05) ; the incidence of LN metastasis was more prevalent in the group with seven or more involved subsites. In glottic cancer, however, no statistically significant difference was observed between T2 and T3 tumors in the number of involved subsites. CONCLUSION: In supraglottic cancer, T1 and T4 stages are determined by degree of tumor extension, irrespective of vocal cord mobility ; T2 and T3 stages are suggested by the number of involved anatomic subsites, without reference to vocal cord mobility. A new CT grading system may thus be made, based on degree of tumor extension. In glottic cancer, however, laryngoscopy or dynamic study with spiral CT are needed for T-stage assessment.

CT Evaluation of the Neck after Total Laryngectomy

PURPOSE: The purpose of this study was to determine normal CT appearance of the neck after total laryngectomy and to evaluate the role of CT in accessing recurrent neoplasm. MATERIALS AND METHODS: In 65 patients who had undergone total laryngectomy, CT findings relating to shape of the neopharynx and alterations of normal anatomic structures were retrospectively reviewed. Fifty-five patients had also undergone neck dissection, and 47 patients had had adjuvant radiation therapy. RESULTS: In 27 patients, a normal neopharynx with a round or ovoid structure connecting the base of the tongue with the cervical esophagus had even wall thickness and iso- or slight hyperdensity to muscle. Fourteen of 32 patients with recurrent neoplasm showed an ill-defined, peripherally enhancing hypodense mass. Twenty-three patients developed metastatic lymphadenopathy and five patients developed coincidental local recurrent mass and lymphadenopathy. Hypodense masses mimicking recurrence were found in six patients and two cases revealed granulation tissues in the oropharynx(n = 2) and abscesses(n = 2). Another four patients were considered to be cases of immediate postoperative fluid collection or lymphocele. CONCLUSION: Aknowledge of normal CT findings of the neck after total laryngectomy is useful in the evaluation of recurrent laryngeal carcinoma.

Fixed Vocal Cord in Laryngeal Cancers: Mechanisms and Spiral CT Findings

PURPOSE: To analyze the causes of vocal cord fixation in laryngeal cancer and to demonstrate its spiral CT findings. MATERIALS AND METHODS: We retrospectively applied the five pathologic mechanisms of vocal cord fixationto spiral CT findings and evaluated mechanisms of fixed vocal cord in 16 patients with laryngeal cancer of T3 or more on staging. CT findings of another six patients (T2) showing one or more suspicious mechanisms of vocal cord fixation in conventional CT were compared with those of the 16 patients (T3 or more). RESULTS: In 16 patients with laryngeal cancer of T3 or more, the most common finding of vocal cord fixation was the complete replacement of the true vocal cord (including the thyroarytenoid and vocalis muscle) by the tumor and tumor invasion of the paralaryngeal space (n = 16). Other findings were tumor invasion and fixation of the cricoarytenoid joint (n = 9), interference with cord mobility by the bulky mass (n = 6), tumor invasion of the thyroid cartilage, with vocalcord fixation (n = 4) and subglottic tumor spread (n = 3). In another six patients (T2) with suspicious vocal cordfixation, conventional CT showed partial vocal cord invasion and intact or minimal invasion of the paralaryngeal space (n = 3), a bulky mass without vocal cord invasion (n = 1) and subglottic extension but movable vocal cord (n= 2). CONCLUSION: Although the cause of vocal cord fixation from laryngeal cancer may be due to one of five patterns of cancer spread, or to a combination of these, the most common spiral CT finding is complete replacement of true vocal cord by the cancer and tumor invasion of the paralaryngeal space. Accurate evaluation of vocal cord fixation and the extent of the tumor could be evaluated with spiral CT using the breathing technique.

CT Findings of Laryngeal Tuberculosis: Comparison with Laryngeal Carcinoma

PURPOSE: To determine the value of CT(Computerized Tomography) in the diagnosis of laryngeal tuberculosis and to assess to what extent its characteristic findings different from those of aryngeal carcinoma. Materials and Methods : CT scans of twelve patients with laryngeal tuberculosis were reviewed and compared with those of fifteen patients with laryngeal cancer, retrospectively. Clinical symptoms, laryngoscopic examinations and the presence of pulmonary tuberculosis on chest radiographs were also reviewed. RESULTS: In laryngeal tuberculosis, bilater alsymmetric or asymmetric involvement was noted in nine(75%) patients, while unilateral involvement was seen in three(25%). This was significantly different from laryngeal cancer in which unilateral involvement was noted in twelve patients(80%). Diffuse thickening of the free margin of the epiglottis was a characteristic and frquent finding in tuberculosis(n=6, 50%). No deep submucosal infiltration of preepiglottic and paralaryngeal fat spacesis seen in tuberculosis in spite of large areas of involvement of laryngeal mucosa, while twelve patients(80%) with laryngeal cancer showed thickened deep infiltration which resulted in a submucosal mass. CONCLUSION: CT was useful in the diagnosis of laryngeal tuberculosis and its CT findings wee characterized by bilateral involvement, thickening of the free margin of the epiglottis and good preservation of preepiglottic and paralaryngeal fatspaces in spite of large areas of involvement.