Diagnostic Imaging of Paranasal Sinuses PDF

DIAGNOSTIC IMAGING OF PARANASAL SINUSES Presentor: Dr. Sonali Vedraj Sharma Contents  Introduction  Functions of the sinuses  Diseases associated with the paranasal sinuses Introduction  Paranasal sinuses are air-filled cavities of the craniofacial complex - maxillary, frontal, sphenoid sin...

DIAGNOSTIC IMAGING OF PARANASAL SINUSES Presentor: Dr. Sonali Vedraj Sharma Contents  Introduction  Functions of the sinuses  Diseases associated with the paranasal sinuses Introduction  Paranasal sinuses are air-filled cavities of the craniofacial complex - maxillary, frontal, sphenoid sinuses, and the ethmoid air cells.  The maxillary sinuses are of particular importance to the dentist proximity to the dental structures  diseases of the sinuses may mimic odontogenic disease  Odontogenic disease may spread to the sinuses or mimic sinus disease.  Intrinsic: Diseases originating primarily from tissues within the sinus.  Extrinsic : Those that originate outside the sinus (most commonly diseases arising from odontogenic tissues) that either impinge on or infiltrate the sinus. These types of diseases include infl ammatory odontogenic disease, odontogenic cysts, benign and malignant odontogenic neoplasms, bone dysplasias, and trauma. NORMAL VARIATIONS OF Mx Sinus A 00 0 second B The range of normal of the position of the maxillary sinus relative to the premolar and molar teeth are shown in periapical images A to D. There is no apparent floor in A, with progressively more pneumatization of the alveolar process in B and C; draping of the maxillary sinus border over the apices of the teeth is particularly evident in D. C D wary Septation accord 800 4 Panoramic image of a loculus (arrows) of the left maxillary sinus draping mimicking a benign space-occupying lesion. close Diseases Associated with the Paranasal Sinuses MDCR       Sinus pathology checklist Haziness in sinus: If yes, which sinus Boundaries- Visualized or not- Tumors obliterate sinus boundaries Mucosal thickening: Nonspecific radiopacity attached to sinus walls- Chronic sinusiits Dome shaped radiopacity attached to sinus floor: MRC Continuity of sinus walls: Breach in continuity of sinus walls Radiopacity in the sinus space not attached to walls: Antrolith/ displaced root Intrinsic Diseases of the Paranasal Sinuses INFLAMMATORY DISEASE  MUCOSITIS  Normal sinus mucosa is not visualized on a radiograph;  The image of thickened mucosa is readily detectable in the radiograph as a non-corticated band noticeably more radiopaque than the air-filled sinus, paralleling the bony wall of the sinus SINUSITIS Need clinical features to diagnose  Acute maxillary sinusitis is often a complication of the common cold, which is accompanied by a clear nasal discharge or pharyngeal drainage.  After a few days, the stuffiness and nasal discharge increase, and the patient may complain of pain and tenderness to pressure or swelling over the involved sinus.  The pain may also be referred to the premolar and molar teeth on the affected side, and these teeth may also be sensitive to percussion, although this is more commonly seen in bacterial sinusitis. ACUTE SINUSITIS Our rule that there are not pain in teeth, so ?  Under these conditions, a green or greenish yellow nasal discharge may also be appreciated. This finding requires that the teeth be ruled out as a possible source of the pain or infection.  However, the key signs and symptoms are those of sepsis: fever, chills, malaise, and an elevated leukocyte count. Acute sinusitis is the most common of the sinus conditions that cause pain. CHRONIC SINUSITIS  Chronic maxillary sinusitis is typically a sequela of an acute infection that fails to resolve by 3 months. In general, no external signs occur, except during periods of acute exacerbations when increased pain and discomfort are apparent. Dental cause associated with it  Chronic sinusitis is often associated with anatomic derangements including deviation of the nasal septum and the presence of concha bullosa (pneumatization of the middle concha) that inhibit the outflow of mucus. Chronic sinusitis is also often associated with allergic rhinitis, asthma, cystic fibrosis, and dental infections. Q: what is DNS? A: Deviatied nasal symptom Radiographic features We didn’t take OPJ tue to tenderness to frontal sisnus and need to capture it  Thickening of sinus mucosa and the accumulation of secretions that accompany sinusitis reduce the air content of the sinus and cause it to become increasingly radiopaque.  Waters view demonstrating complete radiopacification of the left maxillary and frontal sinuses, and ethmoid air cells. An air-fluid level is visible in the right maxillary sinus (arrows). Compare the normal to abnormal CHRONIC MAXILLARY SINUSITIS 10sec Acute: Haziness Chronic: mucosal thickness Sagittal conebeam CT images show peripheral bony thickening of the left maxillary sinus from chronic sinusitis. RETENTION PSEUDOCYSTS  Etiology – Most common condition here in clinics, incididental ndings  Pathologic submucosal accumulation of secretions, resulting in swelling of the tissue or serous non secretory retention cyst arises as a result of cystic degeneration within an inflamed, thickened sinus lining. Both types of lesions are called pseudocysts because they are not lined with epithelium.  Radiographically: Usually project from the floor of the maxillary sinus; appear as non-corticated, smooth, domeshaped radiopaque masses; internal aspect is homogeneous and more radiopaque The non-corticated, dome-shaped retention pseudocyst imaged on periapical and panoramic projection. Retention pseudocysts have non-corticated borders, indicating that they arise from within the sinus. 00 Exclusive attached to oor Reconstructed panoramic (C), and coronal (D) cone-beam CT images. Retention pseudocysts have non-corticated borders, indicating that they arise from within the sinus. O SINUS POLYPS If it grows bigger, it can destroy the nasal parts, No mucosal thickness on walls, only in oor  The thickened mucous membrane of a chronically inflamed sinus frequently forms into irregular folds called polyps. Polyposis of the sinus mucosa may develop in an isolated area or in a number of areas throughout the sinus. Polyps may cause displacement or destruction of bone  A polyp may be differentiated from a retention pseudocyst on a radiograph by noting that a polyp usually occurs with a thickened mucous membrane lining because the polypoid mass is no more than an accentuation of the mucosal thickening. In the case of a retention pseudocyst the adjacent mucous membrane lining is not usually apparent. Destroy the sinus walls, we take MRI imaging A T2-weighted, axial MR image shows multiple areas of high signal intensity (white), consistent with sinus polyps (arrows). ANTROLITHS Complete radio plaque, not attached f any of bones, deposition of calcium salts,  Antroliths occur within the maxillary sinuses and are the result of deposition of mineral salts such as calcium phosphate, calcium carbonate, and magnesium around a nidus, which may be introduced into the sinus (extrinsic) or could be intrinsic, such as masses of stagnant mucous in sites of previous inflammation.  Asymptomatic and are usually discovered as incidental findings on radiographic examination. Radiographic features of Antrolith  Location. Antroliths occur within the maxillary sinus and thus are positioned above the floor of the maxillary antrum in either periapical or panoramic radiographs.  Periphery and Shape. Antroliths have a well-defined periphery and may have a smooth or irregular shape.  Internal Structure. The internal aspect may vary in density from a barely perceptible radiopacity to an extremely radiopaque structure. The internal density may be homogenous or heterogeneous, and in some instances alternating layers of radiolucency and radiopacity in the form of laminations may be seen. B A The alternating circular radiopaque and radiolucent pattern of an antrolith is seen on a panoramic image (A) superimposed over the posterior wall of the right maxillary sinus. The coronal multidirectional tomographic image (B) confirms the location of the antrolith within the sinus and, furthermore, shows the antrolith not to be attached to the adjacent sinus wall. MUCOCELE Q: A:1? Mucus 2 Mucocele extravasation cysts  An expanding, destructive lesion that results from a blocked sinus ostium.Blockage may result from intraantral or intranasal inflammation, polyp, or neoplasm.  The entire sinus thus becomes the pathologic cavity or cyst-like lesion.  As mucus is accumulated and the sinus cavity has filled, the increase in intraantral pressure results in a thinning, displacement and, in some cases, destruction of the sinus walls. Radiographic Features  90% of mucoceles occur in the ethmoidal and frontal sinuses  The normal shape of the sinus is changed into a more circular shape as the mucocele enlarges; uniformly radiopaque  Effects on surrounding structures The shape of the sinus changes with the bony expansion.  Septa and the bony walls may be thinned or destroyed  When the mucocele is associated with the maxillary antrum, teeth may be displaced or roots resorbed.  In the frontal sinus the usually scalloped border is-smoothed by expansion, and the inter-sinus septum may be displaced Cause teeth displacements and root resorption are There are symptoms due to blockage No y sinus floor MUCOCELE A mucocele has caused the radiopacification of the right maxillary sinus. Note the lack of a distinct border to the sinus on the panoramic image BENIGN NEOPLASMS OF THE PARANASAL SINUSES     PAPILLOMA The epithelial papilloma is a rare neoplasm of respiratory epithelium that occurs in the nasal cavity and paranasal sinuses. It occurs predominantly in men. Radiographic Features Location. The epithelial papilloma is usually in the ethmoidal or maxillary sinus. It may also appear as an isolated polyp in the nose or sinus. Internal Structure. This neoplasm appears as a homogeneous radiopaque mass of soft tissue density. Effects on Surrounding Structures. If bone destruction is apparent, it is the result of pressure erosion. OSTEOMA MA  The osteoma is the most common of the mesenchymal neoplasms in the paranasal sinuses.      Radiographic Features Location. Although osteomas occasionally develop in the maxillary sinus, they more often occur in the frontal and ethmoidal sinuses. The incidence in the maxillary antrum varies between 3.9% and 28.5% of the incidence in all paranasal sinuses. Periphery and Shape. The osteoma is usually lobulated or rounded and has a sharply defined margin. Internal Structure. The internal aspect is homogeneous and erential diagnosis , KNOW extremely radiopaque. Di THEM DOCTOR ASK Differential Diagnosis The differential diagnosis includes antrolith, mycolith, teeth, odontomas, or odontogenic neoplasms, although these are all usually not as homogeneous in appearance as the osteoma. A Ethmoid sinuses Frontal sinus B Coronal cone-beam CT images show an osteoma attached to the lateral wall of an anterior ethmoid air cell (A) and axial CT images of an osteoma in the frontal sinus (B) . its usually Unilateral not Bilateral Symptoms similar to common cold MALIGNANT NEOPLASMS OF SINUSES if  Malignant neoplasms of the paranasal sinuses are rare, accounting for less than 1% of all malignancies in the body.  Squamous cell carcinoma, comprising 80% to 90% of the cancers in this site, is by far the most common primary malignant neoplasm of the paranasal sinuses. Other primary neoplasms include adenocarcinoma, carcinomas of salivary gland origin, soft and hard tissue sarcomas, melanoma, and malignant lymphoma.  Factors that contribute to a poor prognosis for cancer of the paranasal sinuses include the advanced stage of the disease when it is finally diagnosed and the close proximity of vital anatomic structures. MALIGNANT NEOPLASMS OF SINUSES .  The clinical signs and symptoms may masquerade as an inflammatory sinusitis. The early primary lesions may only appear as a soft tissue mass in the sinus before they cause bone destruction. Symptoms are preceding the signs  The lesion may become extensive, involving the entire sinus, with radiographic evidence of bone destruction before symptoms become apparent. Therefore any unexplained radiopacity in the maxillary sinus of an individual older than 40 years should be investigated thoroughly. RA SQUAMOUS CELL CARCINOMA OF THE SINUS  Facial pain or swelling, nasal obstruction, and a lesion in the oral cavity. The mean age of the patient is 60 years; M:F= 2:1, lymphadenopathy in 10% cases  The symptoms produced by malignant neoplasms in the maxillary sinus depend on which wall(s) of the sinus is/are involved.  The medial wall is usually the first to become eroded, leading to such nasal signs and symptoms as obstruction, discharge, bleeding, and pain.  Lesions that arise on the floor of the sinus may first produce dental signs and symptoms, including expansion of the alveolar process, unexplained pain and altered sensation of the teeth, loose teeth, swelling of the palate or alveolar ridge, and ill-fitting dentures. SCC OF THE SINUS The symptoms DEPEND ON WHCIH WALL IS DESTROYED to see  The neoplasm may erode the sinus floor and penetrate into the oral cavity.  When the lesion penetrates the lateral wall, facial and vestibular swelling becomes apparent and the patient may complain of pain and hyperesthesia of the maxillary teeth.  Involvement of the sinus roof and the floor of the orbit cause signs and symptoms related to the eye: diplopia, proptosis, pain, and hyperesthesia or anesthesia and pain over the cheek and upper teeth.  Invasion and penetration of the posterior wall lead to invasion of the muscles of mastication, causing painful trismus.  Obstruction of the eustachian tube causing a stuffy ear, and referred pain and hyperesthesia over the distribution of the second and third divisions of the fifth nerve. RADIOGRAPHIC FEATURES OF SCC  Location. Most carcinomas occur in the maxillary sinuses, but      involvement of the frontal and sphenoid sinuses is also comparatively common. Internal Structure. The internal aspect of the maxillary sinus has a soft tissue radiopaque appearance. Effects on Surrounding Structures. As the lesion enlarges, it may destroy sinus walls and in general, cause irregular radiolucent areas in the surrounding bone. bone destruction around the teeth or irregular widening of the periodontal ligament space. medial wall of the maxillary sinus is thinned or destroyed, although there may also be destruction of the floor and anterior or posterior walls that may be detected in the panoramic film. In addition to loss of the medial wall, it may extend into the nasal cavity. A floor vKEY B A, This panoramic image of a SCC shows a loss of definition of the cortex of the left maxillary sinus, nasal floor, and alveolar crest. B, The Waters view of the same patient shows a similar loss of cortical integrity to the lateral wall of the left maxilla and radiopacification of the left maxillary sinus. EXTRINSIC DISEASES  Localized dental inflammatory diseases: The involved mucosa presents as a homogeneous radiopaque, ribbon shaped shadow that follows the contour of the floor of the maxillary sinus. The thickened mucosa is usually centered directly above the inflammatory lesion The halo-like appearance of bone surrounding the roots of a maxillary second molar is the result of periosteal new bone formation and displacement of the adjacent maxillary sinus floor BENIGN ODONTOGENIC CYSTS AND TUMORS ODONTOGENIC CYSTS  The most common group of extrinsic lesions that encroach on the maxillary sinuses –( radicular cysts, followed by dentigerous cysts and odontogenic keratocysts)  Radiographic Features  The invaginating cyst has a curved or oval shape defined by a corticated border.  internal structure of the cyst is homogeneous and radiopaque relative to the sinus cavity  The cyst may displace the floor of the maxillary antrum. In some cases the cyst may enlarge to the point that it has encroached on almost the entire sinus A , An odontogenic cyst or tumor develops adjacent to the floor of a sinus ( I ). As the lesion enlarges, it abuts the maxillary sinus fl oor (II) and ultimately displaces the floor superiorly as it enlarges (III). The border of the cyst and the border of the sinus are now the same line of bone. B, The lesion, as it continues to enlarge, may encroach on almost all the space of the sinus, leaving a small saddle-like sinus over it (arrow). The appearance may mimic sinusitis. B listen A At emanation domeshare cyik.in inns saddle shape Sinus become one with cyst C, Axial CT-image of a large radicular cyst; note the peripheral cortex (arrow) inside the outer cortex of the sinus. They invade the sinus RADIOGRAPHIC FEATURES OF BENIGN ODONTOGENIC TUMORS  Periphery and Shape. The enlarging tumor may have a curved, oval, or multilocular shape that may be defined by a thin cortical border as it encroaches on the sinus.  Internal Structure. The internal structure of the tumor may have coarse or fine septae or regions of dystrophic calcification, depending on the histopathologic nature of the tumor.  Effects on Surrounding Structures. The tumor may displace the floor of the maxillary antrum and cause thinning of the peripheral cortex. As with odontogenic cysts, in some cases the tumor may enlarge to the point where it has almost completely encroached on the sinus air space, and this residual space may appear as a thin saddle over the tumor.  The bony walls of the sinus may be thinned or eroded, and adjacent structures may be displaced. A tooth or part of a tooth may be embedded in the neoplasm. disease B, Axial CT image of the same case revealing almost complete filling of the sinus; a small medial segment remains (arrows). Note the very fine homogeneous bone pattern of the fibrous dysplasia. A, Panoramic image of involvement of the left maxillary sinus with fibrous dysplasia; note the radiopacification of the left maxillary sinus compared with the right sinus. again ROOT IN ANTRUM  Location. Premolar or molar teeth or root fragments may be displaced into the sinus because of their proximity. These may be found anywhere within the sinus, but more often they are located near the floor of the sinus because of gravity.  The dental fragment may appear as a radiopaque mass of a size corresponding to the missing tooth or tooth root fragment.  Effects on Surrounding Structures. a sinusitis may result. A break in the floor of the maxillary sinus caused by the displacement of the tooth or fragment into the sinus may be present but difficult to appreciate. Not attached to the walls THANK YOU THANK YOU