Laryngeal CT Research Articles

Clinical features and management analysis of 11 cases of laryngocele

Objective: To summarize clinical features and our experience of the diagnosis and treatment of laryngocele. Methods: Clinical data of 11 laryngocele patients in department of Otorhinolaryngology Head and Neck Surgery of the Second Affiliated Hospital of Shanxi Medical University from January 2012 to December 2021 were retrospectively reviewed, including 9 men and 2 women, aged from 12 to 75 years, with median age of 56 years. Electronic laryngoscope was performed in 10 of all patients, laryngeal CT in 10 and cervical color ultrasound in 5 before operation.All the operations were performed under general anesthesia, and the external cervical approach was used for external and combined laryngocele. The internal laryngocele was resected by low temperature plasma through transoral endoscopy. Patients were followed up regularly after operation to evaluate the effect. Clinical feature, types of lesions, imaging findings, surgical approaches and follow-up results were analyzed through descriptive statistical method. Results: Eleven laryngocele patients were divided into mixed type (n=6), internal type (n=4) and external type (n=1).Nine patients presented with hoarseness or dysphonia, 7 with cervical mass and 1 with airway obstruction. Surgical resections were done through external cervical approach (n=7)or transoral endoscopic approach (n=4). All the operations were successful and no complication occurred. All cases were followed up from 17 to 110 months. No recurrence was encountered. Conclusions: Laryngocele is a rare lesion with atypical clinical presentation. Preoperative imaging including CT scan and electronic laryngoscope is essential to evaluate the location, and extent of the lesion, and to make the surgical plan.Complete surgical excision is required. Surgical resection is the only effective method for the treatment of laryngocele.

Mobility of the arytenoid cartilage in glottic carcinoma: a CT image study

Background Laryngeal carcinomas cause vocal cord (VC) mobility problems. Other than evaluation through flexible laryngoscopy, rare reports concerning CT findings for the motion of the VC or arytenoid cartilage (AC) are found. Aims/objectives To explore a novel evaluation of the mobility of the AC in glottic carcinoma. Material and Methods In 39 patients with glottic carcinoma grouped upon lesion locations and AC mobilities, laryngeal CT scans were collected during inspiration and phonation. AC static position and motion data were compared between paired lesion and control sides. Results No significant difference showed in the group with glottic carcinoma invading the anterior 2/3 of VC. In the abnormal mobility group, significant AC position changes and weaker motion of most measurements were proved on the lesion side. Lesion invading the posterior 1/3 of VC also resulted in an adducted, medially rotated and forward-tilted AC, rotation of axial angle (RAA) was the only motion item that decreased significantly. Conclusions and Significance In most glottic cancer cases, CT and laryngoscope had similar judgments for AC mobility. For lesions extending to the cartilaginous VC with laryngoscopically confirmed normal mobility, CT measurement of RAA showed the feasibility of being an indicator for the earliest motion problem.

Automated measurement of inter-arytenoid distance on 4D laryngeal CT: A validation study.

Changes to the voice are prevalent and occur early in Parkinson's disease. Correlates of these voice changes on four-dimensional laryngeal computed-tomography imaging, such as the inter-arytenoid distance, are promising biomarkers of the disease's presence and severity. However, manual measurement of the inter-arytenoid distance is a laborious process, limiting its feasibility in large-scale research and clinical settings. Automated methods of measurement provide a solution. Here, we present a machine-learning module which determines the inter-arytenoid distance in an automated manner. We obtained automated inter-arytenoid distance readings on imaging from participants with Parkinson's disease as well as healthy controls, and then validated these against manually derived estimates. On a modified Bland-Altman analysis, we found a mean bias of 1.52 mm (95% limits of agreement -1.7 to 4.7 mm) between the automated and manual techniques, which improves to a mean bias of 0.52 mm (95% limits of agreement -1.9 to 2.9 mm) when variability due to differences in slice selection between the automated and manual methods are removed. Our results demonstrate that estimates of the inter-arytenoid distance with our automated machine-learning module are accurate, and represents a promising tool to be utilized in future work studying the laryngeal changes in Parkinson's disease.

Glottic Insufficiency in the Vertical Plane in Patients With Unknown-Source Unilateral Vocal Fold Hypomobility

To observe the laryngeal CT and strobe laryngoscopy signs of unilateral vocal fold hypomobility (UVFHM) in patients with well-closed glottises in the horizontal plane. A retrospective analysis was performed on 18 subjects with well-closed glottises in the horizontal plane using strobe laryngoscopy, 9 patients diagnosed with unilateral vocal fold hypomobility with an unknown etiology were enrolled in the UVFHM group, and 9 healthy matched subjects with symmetrical bilateral vocal fold movement were enrolled in the control group. Vertical plane distances of bilateral vocal folds and three-dimensional structural parameters of vocal folds were measured through laryngeal CT. Glottic insufficiency in the vertical plane and reflux findings scores (RFS) were assessed under laryngeal CT and strobe laryngoscopy. Reflux symptom index (RSI) were collected. SPSS25.0 software was used for statistical analysis. The height differences in vertical plane and thicknesses of bilateral vocal folds in the UVFHM group were larger than those in the control (P < 0.05), while the length, width and subglottic convergence angle of the vocal folds were not statistically significant between the two groups (P > 0.05). In the UVFHM group, laryngeal CT showed that 77.78% of patients (7/9) had glottic insufficiency in the vertical plane, with height differences ranging from 0.3 to 1.9 mm and a mean of 0.76mm. However, strobe laryngoscopy showed that 33.33% (3/9) had glottic insufficiency in the vertical plane. The proportion of patients with glottic insufficiency in vertical plane in the UVFHM group was significantly higher than that in the control group (P < 0.05). RSI and RFS scores of the UVFHM group were higher than those of the control group (P < 0.05). Glottic insufficiency in the vertical plane often occurred in patients with UVFHM with an unknown cause of hoarseness, so the presence of glottic insufficiency in the vertical plane should be considered when hoarseness is detected by clinicians. Laryngeal dynamic CT can enhance the diagnostic rate compared to strobe laryngoscopy. Unexplained UVFHM patients have higher RSI and RFS compared to control subjects, warranting further research about the relationship between UVFHM and laryngopharyngeal reflux.

Radiological correlates of vocal fold bowing as markers of Parkinson's disease progression: A cross-sectional study utilizing dynamic laryngeal CT.

To determine whether arytenoid cartilage position and dynamics change with advancing duration and severity (as graded by MDS-UPDRS part III scores) in Parkinson's disease, in a cross-sectional study design, we performed laryngeal four-dimensional computed tomography (4D-CT) in people with Parkinson's disease and controls. 31 people with Parkinson's disease covering a range of disease duration and severity and 19 controls underwent laryngeal 4D-CT whilst repeatedly vocalizing. We measured on each CT volume the glottic area (GA), inter-arytenoid distance (IAD), IAD-Area index (IAI) and arytenoid cartilage velocity ([Formula: see text]). People with Parkinson's disease had reductions in the mean/effective minimum IAD when compared to controls, while mean/effective minimum GA and mean/effective maximum IAI were increased. Arytenoid cartilage velocities showed no difference. On Spearman correlation analyses, advancing disease duration and severity of PD showed moderately strong and significant correlations with increasing mean/effective minimum GA, increasing mean/effective maximum IAI and decreasing effective minimum IAD. Linear mixed models which considered the effects of intra and inter-individual variation showed that both disease duration (b = -0.011, SEb = 0.053, 95% CI [-0.022, 0], t(27) = -2.10, p = 0.045) and severity (b = -0.069, SEb = 0.032, 95% CI [-0.14,-0.0039], t(27) = -2.17, p = 0.039) were significant predictors for IAD, and also for transformed values of the GA and IAI. There are progressive alterations in phonatory posturing as Parkinson's disease advances. The increases in GA despite reductions in IAD are concordant with prior observations of vocal fold bowing. Our study provides a basis for using laryngeal 4D-CT to assess disease progression in Parkinson's disease.

Diagnosis and endoscopic treatment of blunt laryngeal trauma with arytenoid injury

Objective: To investigate the clinical characteristics, diagnosis, endoscopic surgical procedures, and therapeutic effect of blunt laryngeal trauma with arytenoid injury. Methods: We retrospectively reviewed 12 patients who suffered blunt laryngeal trauma with laryngeal mucosa avulsion and arytenoid region injury at the Department of Otorhinolaryngology Head and Neck Surgery, Beijing Tongren Hospital from April 2007 to December 2018. Among the 12 patients, 10 were males, 2 were females, aged from 7 to 48 years old, with a median age of 21 years old. All patients were performed with transoral endoscopic laryngeal microsurgery under general anesthesia. Clinical characteristics, laryngoscopic signs, laryngeal CT, endoscopic surgical findings and procedures, and therapeutic effect were analyzed. The subjective and objective parameters of the voice quality of patients before and after surgery were compared using SPSS 22.0 statistical software by paired T test. Results: All patients had a history of obvious dysphonia immediately after trauma, accompanied by throat pain and hemoptysis without obvious dyspnea and dysphagia. Slight subcutaneous emphysema was found in 3 patients by physical examination. Laryngoscope revealed that 14 sides of vocal folds immobilized, arytenoid and/or ventricular region and posterior glottis mucosa were avulsed in 4 patients within 48 h of injury, and arytenoid cartilage was exposed in 4 sides. The arytenoid and ventricular regions were covered with thick pseudo-membrane or granulation, with abnormal structure in 8 patients with damage of more than 48 h. Intraoperative exploration revealed that there were 17 sides of arytenoid region (bilateral 5 cases, unilateral 7 cases) with varying degrees of injury. There was only limited laceration on three sides of the vocal folds. The lateral ventricular and vocal fold mucosae were avulsed vertically from the arytenoid region and arytenoid cartilage was exposed in 14 sides, among which 6 sides had abnormal arytenoid cartilage morphology and 8 sides had fracture displacement. Laryngeal CT showed irregular thickening of lateral glottis and/or supratroglottic structures in patients with vocal folds immobility, among which asymmetry of arytenoid cartilage structure on both sides in 3 cases and displacement in 2 cases were found. Restoration and microsuture of the fractured arytenoid, perichondrium and avulsion laryngeal mucosa under the direct laryngoscope were performed. The degree of dysphonia was significantly improved immediately after laryngeal microsurgery, the voice significantly improved in G, R, B, A, jitter, shimmer, NHR, and MPT three months after surgery(t=12.792, 12.792, 10.340, 3.276, 2.865, 3.781, 3.173, 3.090, respectively, P<0.05). Except for 1 patient with scar on vocal fold, all the other patients had normal laryngeal morphology and normal vocal fold movement. No laryngeal stenosis was found during the follow-up period. Conclusions: For patients with blunt laryngeal trauma, the injury of arytenoid region and arytenoid cartilage should be evaluated if there is obvious hoarseness, vocal fold immobility, avulsion of ventricular/vocal folds mucosa, or structural abnormality of arytenoid region under laryngoscopic examination. For highly suspected cases, microrphonosurgery under the direct laryngoscope should be performed as soon as possible, which can effectively reduce the occurrence of vocal fold movement disorders and laryngeal scar/stenosis, reconstruct the normal laryngeal structure, and restore the vocal function.

Prognostic indicators of short-term outcome in dogs undergoing surgery for brachycephalic obstructive airway syndrome

BackgroundThe aims of this study were to assess the impact of epidemiological variables, severity of presurgical respiratory signs, diagnostic findings from pharyngeal and laryngeal examination using a new grading scheme...

CT-Scan vs MRI in Diagnosing Laryngeal Carcinoma

Background: MRI imaging offers more sensitivity than CT to cartilage invasion but results in a high rate of false-positive studies which decreases their overall accuracy. The objective is to compare accuracy of CT scan vs MRI in the laryngeal carcinoma. Subjects and Methods: All patients have been diagnosed, with and without contrast, including neck MRI and CT. In order to prevent invalidation, before laryngeal biopsy, MRI and CT scanning have been done such that the images are not altered by peri tumorous inflammation. Results: The MRI classification was right for 20 out of 25 patients (80 percent) and 5 outsized cases: three cT1b lesions were pT1a and two cT1a lesions were squamous cell papilloma’s during pathological examination. CT was accurately identified in 17 out of 25 patients (68%), with 8 understated cases: 3 cT1a lesions by CT were pT1b, 3 cT1a lesions were pT3, and 2 tumours had not been found in the CT scan. Conclusion: Our research showed that MRI in preoperative stage early glottic cancer is more sensitive than CT to accurately select eligible patients for conservatory larynx surgery like super cricoid laryngectomy and cordectomy.

Relationship between laryngopharyngeal reflux and calcification of arytenoid cartilage in male patients with idiopathic laryngeal contact granuloma

Objective:To investigate the relationship between laryngopharyngeal reflux and arytenoid cartilage calcification in male idiopathic laryngeal contact granuloma. Method:The clinical data of 92 male patients with idiopathic laryngeal contact granuloma who had the thin laryngeal CT scan images and laryngeal reflux symptom index（RSI） scale data before treatment were analyzed retrospectively. The effect of laryngopharyngeal reflux on the calcification of arytenoid cartilage in laryngeal contact granuloma patients was analyzed by Chi-square statistics with SPSS 16.0 software. Result:Among the 92 patients, 44 patients with RSI>13（47.83%） and 48 patients with RSI≤13（52.17%）. Unilateral granuloma was found in 87 cases（94.57%） and bilateral granuloma in 5 cases（5.43%）. A total of 97 sides of the diseased side, there were 87 sides of arytenoid cartilage with calcification（89.69%） and 10 sides without calcification（10.31%）. Among the patients with RSI>13, there were 45 sides of arytenoid cartilage with calcification（45/46, 97.83%） and one side without calcification（1/46, 2.17%）, and in the patients with RSI≤13, there were 42 sides of arytenoid cartilage with calcification（42/51, 82.35%） and 9 sides without calcification（9/51, 17.65%）. The calcification rate of arytenoid cartilage in patients with RSI>13 group was significantly higher than that in RSI≤13 group（χ²=4.701, P=0.030）. Conclusion:The calcification rate of arytenoid cartilage in male idiopathic laryngeal contact granuloma patients with laryngopharyngeal reflux is higher than that in patients without laryngopharyngeal reflux. Laryngopharyngeal reflux may aggravate or promote the inflammatory reaction of granuloma and accelerate the calcification of arytenoid cartilage.

Preliminary study of medialization thyroplasty for unilateral vocal fold immobility

Objective:To explore the feasibility and effectiveness of medialization thyroplasty for the treatment of unilateral vocal fold immobility （UVFI）. Method:Eight UVFI patients were performed medialization thyroplasty under local anesthesia. We made a window in the thyroid cartilage under local anesthesia, then insert the preformed silicone implant. The paralyzed vocal fold was medialized to make the glottis closed. Fibrolaryngoscope video recording, subjective voice analysis and CT thin slice scan of larynx were done before and after surgery to evaluate closure of vocal cords, improvement of voice and position of implantation. Result:The preoperative and postoperative voice handicap index 30（VHI-30） of the 8 patients were 91.5（64.5, 97.5） and 22.5（5.0, 47.5） respectively, which showed statistical difference（P<0.05）. GRBAS results: The postoperative G, R, B, A were all smaller than preoperative ones, which showed statistical difference（P<0.05）; the pre and postoperative S was both 0. The fibrolaryhgoscope recording showed the preoperative and postoperative score of incomplete glottis closure was 1.0（1.0, 1.0） and 4.0（2.5, 5.0） respectively, which showed statistical difference（P<0.05）. Postoperative laryngeal CT showed significant vocal cord medialization on the affected side. Aspiration was significantly improved in 4 patients who were suffered from this symptom before the surgery. No complication occurred with the 8 patients during 5 to 48 months follow up. Conclusion:Medialization thyroplasty can effectively improve vocalization and quality of life in patients with UVFI.

Clinical analysis of arytenoid cartilage reposition with snake mouth forceps for the arytenoid cartilage dislocation

To investigate the clinical effect of the arytenoid cartilage reposition using snake mouth reduction forceps under general anesthesia. Data of twenty-six cases accepted arytenoid cartilage reposition under intravenous general anesthesia were analyzed, nineteen cases accepted laryngeal CT scan and cricoarytenoid joint reconstruction, all patients underwent endolaryngeal muscle electromyography examination. According to the position of cartilage dislocation prompted by laryngoscope and CT, the arytenoid cartilage was repositoned under the visual laryngoscope using special snake mouth reduction forceps. If bilateral arytenoid cartilage were still asymmetrically at the end of the surgery, patients needed repeated reposition 1 to 2 times 1 week after operation. The efficacy was evaluated 4 weeks later. All patients had a hoarse and breathing voice preoperative. Under laryngoscope, there were different degrees of vocal cord movement disorders accompanied by incomplete glottis closure, 22 cases happened in left side and 4 in right side. The arytenoid cartilage was dislocated anteromedially in 25 cases and posterolaterally in 1 case. CT showed that 15 cases of arytenoid cartilage were tilted anteromedially; the interval of the cricoarytenoid joint was widened. In axial CT images, there were no direct signs of the arytenoid cartilage dislocation in the 4 cases, but the abnormal position was seen in the reconstruction images. The laryngeal electromyography indicated that 7 cases were abnormal, duration of motor unit potential were visible and the raising potential were mixed. There were 4 patients with normal voice in the first day after surgery, and 19 cases underwent twice and 3 cases underwent three times surgery. Vioce became normal in 4 weeks. Swallowing pain and bucking were all disappeared. Vocal cords movement were recovered to normal level in 25 cases. In 1 case with neck strangulation, the vocal cord movement was slightly worse than health side, but significantly better than that before operation. The arytenoid cartilage reposition using snake mouth reduction forceps under general anesthesia was an effective method for the treatment of the cricoary-tenoid joint dislocation.

Arytenoid cartilage feature point detection using laryngeal 3D CT images in Parkinson's disease.

Parkinson's disease is a neurodegenerative disorder that results in progressive degeneration of nerve cells. It is generally associated with the deficiency of dopamine, a neurotransmitter involved in motor control of humans and thus affects the motor system. This results in abnormal vocal fold movements in majority of the Parkinson's patients. Analysis of vocal fold abnormalities may provide useful information to assess the progress of Parkinson's disease. This is accomplished by measuring the distance between the arytenoid cartilages during phonation. In order to automate this process of identifying arytenoid cartilages from CT images, in this work, a rule-based approach is proposed to detect the arytenoid cartilage feature points on either side of the airway. The proposed technique detects feature points by localizing the anterior commissure and analyzing airway boundary pixels to select the optimal feature point based on detected pixels. The proposed approach achieved 83.33% accuracy in estimating clinically-relevant feature points, making the approach suitable for automated feature point detection. To the best of our knowledge, this is the first such approach to detect arytenoid cartilage feature points using laryngeal 3D CT images.

Automatic segmentation of the rima glottidis in 4D laryngeal CT scans in Parkinson's disease.

Parkinson's disease (PD) is a progressive, incurable neuro-degenerative disease. Symptoms appear when approximately 70% of mid-brain dopaminergic neurons have died. Temporal analysis of the calculated area of the rima glottidis may give an indication of vocal impairment. In this paper, we present an automatic segmentation algorithm to segment the rima glottidis from 4D CT images using texture features and support vector machines (SVM). Automatic two dimensional region growing is then applied as a post processing step to segment the area accurately. The proposed segmentation algorithm resulted in accurate segmentation and we demonstrate a high correlation between the manually segmented area and automatic segmentation.

Clinical characteristics of 23 cases in two months old of neonatal lingual thyroglossal duct cysts

Objective To analyse the clinical characteristics of infants in two months old of lingual thyroglossal duct cysts (LTGDC) and raise the levels of diagnosis and treatment. Methods A comparative analysis was made between the clinical data of 23 cases in two months old of LTGDC and those of 20 cases in one to seven years old of cervical thyroglossal duct cysts (TGDC) (control group). Results The clinical manifestation appeared obviously differences between LTGDC and TGDC. The main performance of LTGDC was laryngeal stridor, and 74% of them went to emergency department because of dyspnea. They would be misdiagnosed as congenital laryngomalacia or laryngomalacia with pneumonia. The lesion located in the posterosuperior of lingual bone and behind the root of tongue, which was easy to lead to throat obstruction because it extruded laryngeal cavity. Electronic laryngoscopy was the first choice, it helped to identify laryngomalacia, epiglottis cyst and hemangioma. Laryngeal CT or MRI was very important to diagnose LTGDC which was quasi-circular low density shadow with clear boundary, or not extruded to laryngeal cavity, or show lesion range and surrounding structures avoiding misdiagnosis. As treatment depended surgery which was self-retaining laryngoscope, it was minimally invasive and without scar. Cervical anterior mass in the midline was the first symptoms in all 20 cases of TGDC. The neck ultrasound examination was the first selection, and the lesion showed fluid dark space with clear boundary, it should take the neck percutaneous surgical operation. Conclusion The clinical manifestation of infants in two months old of LTGDC appears obviously different from TGDC. LTGDC is a common cause of laryngeal stridor with breathing difficulties. It will be misdiagnosed as congenital laryngomalacia and lead to asphyxia or death easily. Key words: Lingual thyroglossal duct cyst; Dyspnea; Infants

Functional imaging of larynx via 256-Slice Multi-Detector Computed Tomography in patients with laryngeal tumors: A faster, better and more reliable pre-therapeutic evaluation

To determine the clinical utility of using dynamic maneuvers during imaging of larynx via 256-Slice Multi-Detector Computed Tomography in the pre-therapeutic evaluation of laryngeal tumors. A total of 27 patients (7 women, 20 men; aged 53-76 years) diagnosed with laryngeal squamous cell carcinoma were evaluated pre-therapeutically via contrast enhanced axial CT scans during consecutive phases of phonation (PP), inspiration (IP) and Valsalva maneuver (VP). In 2 of 5 patients diagnosed with T1a glottic tumor, scans obtained during VP and PP were normal while the CT scans obtained during IP clearly showed a mass. In all patients (27/27) PP provided visualization of the ventricle, on coronal plane images and the pyriform sinus apices, on axial plane images. Involvement of the anterior commissure was best assessable on axial plane IP images (sensitivity 93%, specificity 92%). In cases of stage T1-T3 tumors use of dynamic maneuvers during laryngeal CT imaging showed the location and extension of the tumor better than the single phase CT scans did. We did not find a significant improvement in the pre-therapeutic evaluation in stage T4 tumors. Providing markedly clearer and more detailed evaluation of mucosal surfaces and deep structures of the larynx and mobility of the cords than do conventional scans, use of dynamic laryngeal maneuvers during laryngeal CT imaging seems to be an useful alternative in the pre-therapeutic assessment of laryngeal tumors.

Staging of Laryngeal Cancer Using 64-Channel Multidetector Row CT: Comparison of Standard Neck CT with Dedicated Breath-Maneuver Laryngeal CT

With a 64-channel multidetector row CT, imaging acquisition during speech, swallowing, or phonation has become feasible. However, the actual benefit of these additional focused images should be critically evaluated with respect to radiation dose. The purpose of this study was to determine if dedicated laryngeal CT using breath-holding and straw-blowing improved the accuracy of TNM-staging for patients with biopsy-proved laryngeal carcinomas in comparison with a standard neck CT. A total of 27 patients underwent a standard neck CT and a laryngeal CT with additional images acquired while patients held their breath or blew through a straw. Two radiologists interpreted the neck CT and later the laryngeal CT and assigned a TNM-stage for each case. These interpretations were compared with a TNM-stage determined by surgery and/or clinical examination for the individual patients. The accuracy of standard neck CT was compared with the accuracy of laryngeal CT. The overall accuracy was not significantly different between standard neck CT and the additional laryngeal CT and was, in fact, lower in cases with additional larynx images. The accuracy of staging was slightly improved with the additional laryngeal CT for glottic cancers; however, it was decreased for supraglottic cancers. The accuracy of a dichotomous diagnosis of early-versus-advanced-stage cancer was 0.86 for the standard neck CT and 0.80 for the laryngeal CT. The readers' confidence levels did not improve with the use of the additional images. In the era of isovoxel multidetector CT technology and judicious monitoring of radiation dose, a standard neck CT with coronal and sagittal reformats should suffice for the staging of laryngeal cancer.

A Computational Study of the Effect of False Vocal Folds on Glottal Flow and Vocal Fold Vibration During Phonation

The false vocal folds are believed to be components of the acoustic filter that is responsible for shaping the voice. However, the effects of false vocal folds on the vocal fold vibration and the glottal aerodynamic during phonation remain unclear. This effect has implications for computational modeling of phonation as well as for understanding laryngeal pathologies such as glottal incompetence resulting from unilateral vocal fold paralysis. In this study, a high fidelity, two-dimensional computational model, which combines an immersed boundary method for the airflow and a continuum, finite-element method for the vocal folds, is used to examine the effect of the false vocal folds on flow-induced vibration (FIV) of the true vocal folds and the dynamics of the glottal jet. The model is notionally based on a laryngeal CT scan and employs realistic flow conditions and tissue properties. Results show that the false vocal folds potentially have a significant impact on phonation. The false vocal folds reduce the glottal flow impedance and increase the amplitude as well as the mean glottal jet velocity. The false vocal folds also enhance the intensity of the monopole acoustic sources in the glottis. A mechanism for reduction in flow impedance due to the false vocal folds is proposed.

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

ObjectiveTo 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 MethodsThirty-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.ResultsThe 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.ConclusionThe 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.

Usefulness of Laryngeal Phonation CT in the Diagnosis of Vocal Cord Paralysis

The purpose of this study was to determine the effectiveness of laryngeal phonation CT for the diagnosis of vocal cord paralysis by examining the physiologic and functional changes in the larynx during vowel phonation in patients with vocal cord paralysis. For the control study, three healthy volunteers underwent laryngeal phonation CT while vocalizing the vowels /hee/, /ih/, and /ah/, and reconstructed coronal images of the larynx were obtained. After the control study, 28 patients with unilateral vocal cord paralysis underwent laryngeal phonation CT during /hee/ phonation, which was chosen as a most appropriate vowel for this purpose. Changes in the paralyzed and normal vocal cords were evaluated quantitatively and qualitatively on coronal reconstruction images. On the coronal reconstructed images from the healthy volunteers, the normal cords had a shoulder formation appearance, and the cords lay within 1 mm lateral to the midline during phonation. For patients with vocal cord paralysis during /hee/ phonation, the average angle formed by the long axis of the vocal cord and the midline was 71.67 degrees on the affected side and 92.21 degrees on the normal side (p = 0.001). The vocal cord edges lay 1.5 mm lateral to the midline on the affected side and 0.44 mm lateral to the midline on the normal side (p = 0.003). In the qualitative study, the two observers found the coronal reconstructions of the laryngeal phonation CT scans yielded a higher detection rate than did conventional axial CT. Laryngeal phonation CT proved more useful for evaluating vocal cord paralysis than did conventional CT and can be used as a primary diagnostic tool when vocal cord paralysis is suspected.

Lingual thyroglossal duct cyst in newborns: Previously misdiagnosed as laryngomalacia

To distinguish lingual thyroglossal duct cyst (LTDC) from laryngomalacia in newborn. The clinical data of five newborns who were diagnosed as LTDC were retrospectively analyzed. Inspiratory stridor with chest wall retraction was cardinal symptom of newborn with LTDC. A slightly gray and round cyst with smooth surface at the base of the tongue was found with laryngoscopy. In computed tomography examination of larynx, a well-circumscribed lesion with low intensity was detected at the base of the tongue protruding into the air passage. Pathological examination demonstrated the cyst wall was composed of tabular and columnar epithelium. LTDC is a common disease in newborns, which is similar with laryngomalacia. For neonate suspected of LTDC, laryngoscopy examination should be taken first, while laryngeal CT scan is an important diagnosis basis to be reg. Cyst puncture can ameliorate the symptoms of LTDC, while surgical removal serves as a radical cure for LTDC.