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.

Long-Term Polysomnographic Findings and Subjective Results in Sleep Apnea Patients Treated with Laser Assisted Uvulopalatoplasty / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Laser-assisted uvulopalatoplasty (LAUP) is well established in the treatment of snoring and obstructive sleep apnea syndrome (OSAS), although most reports are based on short-term follow-up results. This study was performed to determine the long-term effects on symptoms and polysomnographic measures in patients with OSAS after 5yrs of LAUP. MATERIALS AND METHOD: Fifty patients with OSAS underwent LAUP, and of these patients, 20 have completed postoperative polysomnographic studies. Questionnaires ranking snoring and apneic symptoms were completed by the patient and bed partner before LAUP. The parameters of measurement were apnea index (AI), respiratory disturbance index (RDI), SaO2, and sleep stages. The statistical analysis was performed using Wilcoxon signed rank test. RESULTS: Subjective questionnaires showed statistically significant improvements in snoring, falling asleep while day work, headache upon wakening. The symptomatic improvement persisted long time. The AI decreased from 15.9 to 10.5, RDI decreased from 23.2 to 14.9, and the mean, lowest O2 saturation increased from 85, 93 to 92, 97 (p<0.05). The RDI was reduced to 10 or less in 40% of patients. CONCLUSION: LAUP is an effective method for the management of mild OSAS. Authors have demonstrated long-term improvement in subjective and polysomnographic measures.

An Acoustic and Radiologic Study on Voice Change after Tonsillectomy and Adenotonsillectomy / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Some patients who have undergone tonsillectomy complain of voice change, but few studies for the mechanism of voice change were found. To solve this problem, study of voice change after tonsillectomy and adenotonsillectomy was done. MATERIALS AND METHODS: We analyzed voice change of 22 patients who underwent tonsillectomy and 15 patients who underwent adenotonsillectomy at CSL (computerized speech laboratory), St. Benedict Hospital. With the measured cross sectional area of vocal tract and its length from the glottis on MR images, we presented the change of cross sectional area schematically after tonsillectomy. RESULTS: Acoustically, the frequencies of the second formant of /e/ and /i/ increased and that of the first formant of /u/ decreased significantly after tonsillectomy and the frequency of the second formant of /o/ and those of the second and third formants of /i/ and /u/ increased significantly after adenotonsillectomy. It was also showed acoustically that the formant bandwidths of /a/ and /hana/ after tonsillectomy and those of /e/ and /hana/ after adenotonsillectomy increased due to nasalization. Anatomically, it was showed that the cross sectional area of oropharyngeal cavity increased and coupling effect of vocal tract happened after tonsillectomy. CONCLUSION: This study showed that acoustic characteristics and vocal tract shapes of the patients did change following tonsillectomy and adenotonsillectomy. It is imperative that we explain to patients about the postoperative voice change. Research should also be done to find ways to induce better voice changes following the operations.

Mechanism of Vocal Phonation in T-E Shunt Patients after Total Laryngectomy / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Total laryngectomy has become a usual treatment for any advanced carcinoma of the larynx, but most patients who have undergone total laryngectomy have shown permanent disability in voice production. To solve this problem, studies of voice rehabilitation after total laryngectomy have been done. MATERIALS AND METHODS: We have developed an accurate method to measure the vocal tract shape along its length from magnetic resonance images acquired during the sustained phonation of Korean vowels by T-E shunt patients and normal subject. We estimated the accuracy of MRI and also compared the vocal tract spape of the normal and T-E shunt patients by comparing the first three formant frequencies estimated from MRI to those measured directly from speech data of the T-E patients and the normal subject. RESULTS: The length of T-E shunt patient's vocal tract is 17-18.5 cm. T-E shunt patients phonated strained voice. The length of resonant chamber of T-E shunt patients are shorter than that of the normal subject. The vocal tract is shortened during the phonation by T-E shunt patients. In cases of /e/ and /i/, front cavities are constricted while back cavities are shortened. The pseudoglottis of the T-E shunt patients is located at the region 14-15 cm from lip. CONCLUSION: Acoustic characteristics and vocal tract shapes of the T-E shunt patients are relatively similar to those of the normal subject. To achieve normal voice, reconstruction of pharyngeal and superior glottal resonant chamber will be desirable.

The Characteristics of Nasal Cycle and Nasal Cavity Volume inLaryngectomees Using Acoustic Rhinometry / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The nasal cycle of laryngectomized patients has been thought to be far different from the normal subjects. This study was performed to evaluate the difference in the patterns and activities of nasal cycles, the total nasal cavity volume, and the degree of change in the nasal cavity volume between laryngectomees (LG) and normal controls. MATERIALS AND METHODS: Twentythree laryngectomized patients and twenty-three normal controls were studied. Acoustic rhinometry measurements were taken 3 times from each nostril at intervals of 30 minutes during 8 hrs. The total nasal cavity volume was measured from the first 7 cm of nostril. RESULTS: There were four types of nasal cycle patterns in both laryngectomees and controls: classical pattern in 6 (26.1%) LG and 5 (21.7%) controls, in concert pattern in 3 (13.1%) LG an 8 (34.8%) controls, mixed pattern in 4 (17.4%) LG and 3 (13.0%) controls, irregular pattern in 11 (47.8%) LG and 6 (26.1%) controls. In laryngectomees, the total nasal cavity volume was increased (p0.05). CONCLUSION: Although the afferent input from the airflow receptor in the nasal cavity may play a role in modulating the pattern of nasal cycle, we suggest that the central nervous system is more important than the feedback mechanism for regulation and control of nasal cycle.

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.

Role of 3-D CT Reconstruction of Laryngeal IVlucosal Surface in Preoperative Staging of Laryngeal Cancer

PURPOSE: CT or MRT is performed in preoperative staging of laryngeal cancer. These methods are used in assessment of the deep tissues and cartilage of the larynx, but cannot compete with laryngoscopy in the evaluation of the laryngeal surface. The purpose of this study is to evaluate feasibilty and clinical value of the 3-D reconstruction of the mucosal surface in laryngeal cancer. METHODS AND MATERIALS: Twenty two patients with laryngeal cancer proved by means of surgical.exploration (pathologic) or clinical examinations including laryngoscope, imaging studies and biopsy underwent preoperative staging with computed tomography(G-P);and three dimensional(3D) CT reconstruction. The TNM classification of the American Joint Committee on Cancer was used to compare the imaging findings with pathologic or clinical staging. RESULTS: When the extension of primary tumor(T staging) was evaluated, the findings at only transaxial CT and those at pathologic or clinical examination were concordant in 8 of 14 cases(57.1%) of supraglottic tumor, and 3 of 6 cases(50%) of glottic tumor. The overall accuracy of CT with additional 3D-reconstruction was 85.7% for assessment of supraglottic tumor, and 66.6% for glottic tumor. CONCLUSION: 3D CT reconstruction after transaxial CT may improve outcome in preoperative staging of laryngeal cancer and has a potential value in guiding management decisions.

Dynamic Study of the Larynx with Spiral CT

PURPOSE: It is essential to know the functional and morphologic changes of the larynx in the evaluation of laryngeal lesions. Conventional CT which has relatively long examination time is not suitable for this aim. The purposes of this study are to evaluate the capability of spiral CT in the dynamic study of the larynx and to know whether this new technique can replace conventional laryngography or not. MATERIALS AND METHODS: Five healthy volunteers and 20 patients with laryngeal lesions underwent spiral dynamic CT scans with 3-dimensional reconstruction of the mucosal surface. A series of spiral CT scans were done while the volunteers performed various laryngeal positions to obtain the functional and morphologic information. The maneuvers used were:quite breathing, "E" phonation, Valsalva maneuver, modified Valsalva maneuver, and a new method of our own, "modified breath holding" technique. The patients were scanned when in quite breathing. Additioal scans were obtained by using the "modified breath holding" technique. RESULTS: The dynamic study with spiral CT could provide high resolutional images which nicely depicted the mobility of vocal cords and the mucosal changes of the laryngeal cavity in both healthy volunteer and patient groups. In patient group, the new "modified breath holding" technique was easier and more reproducible than other maneuvers. CONCLUSION: Spiral CT allows a dynamic study of the larynx and can be a new alternative of laryngography.

Three-dimensional CT reconstruction of the surface of the sinonasal cavities, pharynx and larynx: Normal anatomy

Simulated three-dimensional (3D) imaging represents reformation of conventional sectional imaging data into a series of images that closely resemble the original studied structure. We tried to make 3D mucosal surface images of the sinonasal cavities, pharynx and larynx, and evaluated the feature of normal anatomy in 28 subjects. In the sinonasal cavities, 3D imaging was capable of demonstrating the inner wall of paranasal sinuses and its openings, and general status status of the nasal cavity. In the nasal cavity. In the nasopharynx, 3D imaging provided an easy concept of sectional images as 3D picture and displayed anatomic subsites and lesions comparable to that in fiberscope. In addition, 3D imaging had advantages in overcoming the technical limitations in fiberscope. In the larynx and hypopharynx, 3D imaging gave a 3D concept of the laryngeal structures and presented additive information not seen in axial iamges thus enabling access to regions beyond the scope of fiberscope. In conclusion, 3D imaging allows an easy conceptualization of transaxial CT images in complex anatomic areas and provides additional in formations undetectable in transaxial CT. We believe that the spaces of the sinonasal cavities, pharynx and larynx would be a new field of application of 3D image.

Three-dimensional CT reconstruction of the surface of the sinonasal cavities, pharynx and larynx: Normal anatomy

Simulated three-dimensional (3D) imaging represents reformation of conventional sectional imaging data into a series of images that closely resemble the original studied structure. We tried to make 3D mucosal surface images of the sinonasal cavities, pharynx and larynx, and evaluated the feature of normal anatomy in 28 subjects. In the sinonasal cavities, 3D imaging was capable of demonstrating the inner wall of paranasal sinuses and its openings, and general status status of the nasal cavity. In the nasal cavity. In the nasopharynx, 3D imaging provided an easy concept of sectional images as 3D picture and displayed anatomic subsites and lesions comparable to that in fiberscope. In addition, 3D imaging had advantages in overcoming the technical limitations in fiberscope. In the larynx and hypopharynx, 3D imaging gave a 3D concept of the laryngeal structures and presented additive information not seen in axial iamges thus enabling access to regions beyond the scope of fiberscope. In conclusion, 3D imaging allows an easy conceptualization of transaxial CT images in complex anatomic areas and provides additional in formations undetectable in transaxial CT. We believe that the spaces of the sinonasal cavities, pharynx and larynx would be a new field of application of 3D image.

Effect of scopolamine and glycopyrrolate on the secretory function of salivary glands / 대한이비인후과학회지

No abstract available.