Staging of carcinoma of the palatine tonsils by computed tomography

A Proposal to Perform High Contrast Imaging of Human Palatine Tonsil with Cross Polarized Optical Coherence Tomography

The palatine tonsils provide the first line of immune defense against foreign pathogens inhaled or ingested. However, a disruption in the epithelial layer within the tonsil crypts can lead to recurrent acute tonsillitis (RAT). Current imaging techniques suffer from poor resolution and contrast and do not allow a classification of the severity of RAT. We have developed a cross-polarized optical coherence tomography system. The system can detect a change in the polarization of the light after the light-tissue interaction. We demonstrate improved resolution and contrast in tonsil imaging with the developed method. Intensity, as well as retardance images of the excised tonsil tissue, were acquired. Features such as crypt epithelium, lymphoid follicles, and dense connective tissue were observed with improved contrast. Cross polarized optical coherence tomography can be a valuable tool in the clinic to evaluate palatine tonsils as it would allow visualizing common tonsil features without the need for any external contrast agent.

Prognostic Significance of Contrast Enhancement and Tumor Demarcation at CT of Squamous Cell Carcinomas of the Oral Cavity and Oropharynx

A retrospective analysis of the CT examinations of 45 patients with squamous cell carcinomas of the tongue, floor of the mouth and tongue base with long-term follow-up is presented. The aim of the study was to determine whether differences in tumor contrast enhancement and tumor demarcation at contrast-enhanced CT were correlated to prognosis in terms of posttreatment residual tumor or local recurrence. Ill-defined tumor margins were by means of multiple regression analysis significantly correlated to local failures (p = 0.043). This feature was, however, not associated with a significant decreased survival. The degree of tumor contrast enhancement did not parallel variations in the histopathologic composition of the tumors.

Optical coherence tomography and autofluorescence imaging of human tonsil

For the first time, we present co-registered autofluorescence imaging and optical coherence tomography (AF/OCT) of excised human palatine tonsils to evaluate the capabilities of OCT to visualize tonsil tissue components. Despite limited penetration depth, OCT can provide detailed structural information about tonsil tissue with much higher resolution than that of computed tomography, magnetic resonance imaging, and Ultrasound. Different tonsil tissue components such as epithelium, dense connective tissue, lymphoid nodules, and crypts can be visualized by OCT. The co-registered AF imaging can provide matching biochemical information. AF/OCT scans may provide a non-invasive tool for detecting tonsillar cancers and for studying the natural history of their development.

Diagnóstico por imagem da cavidade oral

A ressonância magnética e a tomografia computadorizada são importantes métodos de exames complementares para o diagnóstico das doenças da cavidade oral. Aspectos técnicos de cada método são discutidos, assim como suas vantagens e limitações. A anatomia da cavidade oral é revista, assim como alguns aspectos do carcinoma de células escamosas, que é a neoplasia maligna mais freqüente dessa região.

Staging of squamous cell carcinoma of the oral cavity and oropharynx: a comparison of MRI and CT in T- and N-staging

PURPOSE

Our purpose was to assess the accuracy of CT and MRI in staging of squamous cell carcinoma (SCC) of the oral cavity and oropharynx.

METHOD

Fifty-one episodes of primary and recurrent SCC were assessed with CT and MRI. The results were compared with pathological staging.

RESULTS

For staging primary tumours, the accuracy of MR was 77% and that of CT was 67%. For detecting recurrent tumour, the accuracy of MR was 89% and that of CT was 100%. For N-staging, nodal sites were divided, according to the site of the primary tumour, into high and low risk. Sensitivity for high risk sites was 60% for clinical assessment, 35% for CT, and 75% for MR. Negative predictive value (NPV) was < or = 50% for all methods. For low risk sites, the NPV was > or = 95% for all methods.

CONCLUSION

For T-staging, MR scanning is overall more accurate than CT. If degraded images and T1 tumours are excluded, the techniques are comparable. MR scanning is oversensitive for recurrent disease. For N-staging, all methods failed to detect small metastatic deposits.

Head and neck carcinoma: detection of extraorgan spread with MR imaging and CT

A retrospective analysis of the Magnetic resonance (MR) and CT findings in 18 untreated carcinomas of the oral cavity (7), oropharynx (2), hypopharynx (7), and larynx (2) was performed to assess the accuracy in evaluating extraorgan tumor spread and nodal involvement. Surgical and pathologic correlation was available for 13 primary tumors and nodal status was analyzed in 18. Nine primary tumors had extraorgan extension. MR had a tendency to be superior to CT in predicting tumor invasion of the cartilage and muscle. Sensitivity, specificity and accuracy for extraorgan spread of primary tumors were 89%, 100% and 92%, respectively, for MR and 78%, 75% and 77% for CT. Accuracy for nodal classification (83%) and carotid invasion (94%) of MR was equal to that of CT. CT was more sensitive than MR for demonstrating necrosis within the nodes and vice versa for detecting retropharyngeal nodes. MR imaging is a useful radiologic modality in evaluating extraorgan tumor spread and nodal levels of the head and neck carcinomas.