 So, my topic on paper is a megal sinus at true imaging L.M. of this study have various pathology of megal sinus on plane and quanta city. Megal sinus is a most common perinus sinus affected by various diseases, pathology involving other infectious that include sinusitis could be bacteria, fungal and allergic retentions cyst, cyanonezol polyp, osteomyelitis, neoplastic include inverted papilloma and tralcasinoma other are pibrous dysplasia, silent sinus syndrome, extra-medical hematopoiesis, the gross anatomy of the megal sinus, this is a paired pyramid separenus sinus in the megal bone, the drain via megal ostium into infallible lung, then through the height of separenus into the middle this is the large parenidzol sinus. The pyramid of the megal sinus have a base on the lateral border of the nose with apex pointing toward the diagrammatic process of the maxilla, the floor is found by the elbow process of the maxilla, a roof is the orbital floor, the posterior wall from the anterior border of the terioploid posa, here this is the maxilla sinus unsinnet process and the pelletine bone, this is the coronal plane CT showing the drainage of the maxilla sinus, this is the unsinnet process, middle terminate, bulla etymodelis and this is the infarndibulum, height assembleris and drain in the middle miatus. Method plane and contrast CT of the parenis sinus on the 16th slice GCT machine, first case effiprin air mail, complaint slowly, progressive pain less swelling on the left cheek 4 to 5 year not associated with fever and blood reports are normal, here this is the bone window axial CT showing ground glass bone matrix with bony expansion involving the left megal sinus with significant narrowing of the left megal sinus case 2, 8 year mail and one case of the thalassemia recurrent blood transfusion and frontal bossing, depressed nasal bridge and protruding maxilla, here the axial bone window CT showing hyponematization of the bilateral megal sinus and the megal sinus filled with marrow containing bone, next case is a 15 year mail, complaint of the north breather since one year of the multiple upset of the recurrent sinusitis from the infancy on the history taking to give the history of dextrocardia, then we go for HR CT showing the bilateral lower lobe showing bronchoctasis then final diagnosis with cartagena syndrome, here the axial non-contrast CT showing soft tissue density thickening with air fluid level in the bilateral megal sinus, rarefication of the medial wall of the megal sinus and the contrast axial and coronal CT showing multiple well-defined hyperdense polyploidal lesion involving the both megal sinus and the fourth case is a third year mail, non-case of the B cell ALL on chemotherapy present with swelling on right cheek with pain and redness, here the bone window of the axial CT showing soft tissue mu-posal thickening and opacification and air fluid level in the right megal sinus and the soft tissue window showing preceptile and premaxillary edema in the right side. Discussion in the fibrous dysphagia of the mexilla, it is a radio lucent to radio opec pattern is a result from the lesion transforming from ground glass appearance to a mixed appearance as a adulthood approaches, the mixed appearance of the lesion result in a blending due to the absence of the distinct edge, the appearance of a homogenous pattern can be attributed to the loss of the lamina dura, the obliteration of the megal sinus is thereby due to presence of this lesion which is blend with its boundary. Thalassemia is the most common known single gene disorder in the wide world which have a variety of types hyperplasia and the mexilofacial expansion developed that can lead to mexilofacial deformities, the impact of the thalassemia on the jaw and the skull include decrease of the general bone density due to bone marrow or growth, thin cortical bone and absence of inferior aloe canal and small mexil sinus. The characteristic finding of the sinusoidal include air fluid level, mucosal thickening and opacification of the normal irritated sinus lumen. The single distinguishing feature of the acute sinusoidal is the air fluid level as an isolated finding where the only characteristic finding in the chronic sinusitis is the sclerotic, thickened bone of the sinus fold. Mucosal thickening is common in both acute and chronic sinusitis. Hyperdense, intracinus secretion or bony erosion on CTs suggestive fungal sinusitis. CT skin is a good investigation tool for identifying anatomy, pathology and extent of the disease in pathology of the mexil sinus with reasonable good sensitivity and specificity for the diagnosis. It also depicts the anatomical variation in the mexil sinus, alerting surgeon about the possible complication and also add in preoperative planning. Now, the CT scan should be performed preoperatively in order to guide the surgeon for phase. Osteo-meatal complex pathologies is a frequent indication for phase. The most common condition that determines the blockage of the OMC and need for surgical treatment is concavulosa. These are the reference. Thank you.