امراض نظري 4.docx

The nasal and paranasal sinuses imaging   The sinonasal cavity serves a number of functions: 1. Smell. 2. respiration. 3. air conditioning (heat exchange, humidification and cleaning). 4) immune response to antigen (antibodies in nasal mucosa fi...

The nasal and paranasal sinuses imaging   The sinonasal cavity serves a number of functions: 1. Smell. 2. respiration. 3. air conditioning (heat exchange, humidification and cleaning). 4) immune response to antigen (antibodies in nasal mucosa first line 5. of defence). 6. sound quality (listen to anyone with a cold, the sinonasal cavity acts as a resonant chamber). Radiology and Pathology - The patient has failed medical treatment. - FESS(functional endoscopic sinus surgery) is being considered. - There is an acute presentation such as orbital cellulitis or mucocoele. - differentiate tumour from inflammation. -.assess tumour extent and exclude non-sinonasal causes of anosmia~.~  Rhinosinusitis ==================================== - Allergic: very common and may develop into polyposis. - Vasomotor: a disorder of autonomic regulation of mucus production. - Infective: as in the common cold. - Ciliary disorders: Kartagener syndrome(primary ciliary dyskinesia).  Iatrogenic: overuse of nasal decongestants. Radiological assessment should include the following: 1. Identification of relevant anatomical variants. 2. Identification of the extent of disease in relation to the mucociliary pathways. 3. Identification of bony thickening suggesting [chronicity], or bony erosion/destruction suggesting a [more aggressive process]. 4. Identification of dental disease that may cause a reactive inflammatory change in the overlying antra and be the underlying cause of the patient's symptoms. 5. Identification of orbital or, rarely, intracranial extension. 6. Assessment of the postnasal space. 7. Identification of previous surgery including extent. 8. Review of soft-tissue reconstructed images in order to identify fungal disease ,particular importance in immunocompromised patients who are at risk of invasive fungal sinusitis. Nasal Polyposis ===============  Antrochoanal Polyp ======================================== Mucocoeles ========== a. frontal swelling or more rarely headache. b. Frontal and anterior ethmoidal mucocoeles may extend into the orbit, giving rise to proptosis. c. Mucocoeles are usually sterile but can occasionally become infected and result in osteomyelitis and subperiosteal abscess leading to a dramatic fluctuant swelling in the glabella, which also can be  Epistaxis =============================== - the bleeding is profuse - recurrent then a source for the bleeding may require investigation usually with CT post intravenous contrast medium performed in the (arterial phase). Nasal and Paranasal Sinus Tumours ================================= - The early symptoms are similar to chronic sinusitis. - Because tumours enlarge within hollow cavities, thus not exerting pressure effects until relatively late. Early diagnosis requires a [high index of suspicion] in patients who have unilateral or recurrent symptoms and do not respond to medical treatment. Early symptoms of malignancy include : - Unilateral facial pain. - Nasal obstruction. - unilateral nasal discharge and epistaxis. Late symptoms include: - epiphora (excess tears due to disruption of nasolacrimal drainage). - trismus ( muscle spasm in the temporomandibular joint due to infiltration of the lateral pterygoid muscle). There are two main prognostic factors in sinonasal malignancy: - Tumour type. - intracranial and orbital involvement.  Osteoma ============================= [They are slow growing and often not requiring treatment although surgery] [is considered if the osteoma is compromising the drainage pathway or] [\>50% of the sinus volume.] Inverted Papilloma ================== - They frequently present as a middle meatal mass causing unilateral nasal obstruction. - The sex ratio is M:F 4 : 1. - 10% demonstrate calcification at the site of tumoral attachment. - They have a characteristic lobulated outline on CT and a cerebriform pattern on MRI. - Surgery must include subperiosteal resection at the site of attachment to avoid recurrence. - Assessment with CT is usually satisfactory, with MRI used mainly to assess recurrence.  Juvenile Angiofibroma =========================================== [Adolescent boys with heavy epistaxis characterise this lesion]. - This benign, locally invasive mass originates at the sphenopalatine foramen(The sphenopalatine foramen is a fissure of the skull that connects the nasal cavity and the pterygopalatine fossa). - widens the PPF, extends into the nasal cavity and erodes the adjacent medial pterygoid plate and skull base in the region of the vidian canal aperture (contain vidian artery and nerve).  [The presence of a nasal mass and a widened PPF in an adolescent male is] [pathognomonic.]  Sinonasal Malignancy ========================================== - approximately 65--70% are SCCs. - Adenocarcinoma. - adenoid cystic carcinoma. - lymphoma comprising most of the remainder. - Rarer sinonasal malignancies include olfactory neuroblastoma melanoma and sarcomas. 1. To define the tumour extent to form the basis of any treatment planning. 2. Careful assessment of any intracranial, orbital, PPF, palatal or nodal involvement. [Multiplanar MR is the technique of choice with fat-saturated sequences for] [assessing any orbital,dural involvement or perineural extension.] - skull base erosion, - dural involvement - extension through the dura. - whether there is erosion of the lamina papyracea. - involvement of the orbital periosteum, - extension through the periosteum or if the disease has directly extended from the PPF via the inferior orbital fissure. THANKS ======