Giải phẩu xoang trên CT

Giải phẩu xoang CT BS Nguyễn Đình Hồ Lớp CK1-CĐHA Năm 2010-2012 • • • • • • • • • Fig 2.1 The ethmoid plates and fovea ethmoidalis A midline (perpendicular plate, PP) and two lateral vertical laminae: the medial one made by the vertical lamella of the middle turbinate (vlMT) on the top of which is the vertical lamella of the cribriform plate (vlCP), the lateral one is the lamina papyracea (LP) Horizontal lamella of the cribriform plate (hlCP), horizontal (hGL) and vertical (vGL) – ascending part – of ground lamella of the middle turbinate, crista galli (CG), fovea ethmadalis (FE) Fig 2.2a–c CT coronal reconstructions through the ethmoid labyrinth a Anterior nasal fossa, level of the uppermost insertion of both uncinate processes on the vertical lamellae of the middle turbinates – type according to Landsberg and Friedman (2001) (white arrows on left side) b Bilateral pneumatization of the horizontal (non-attached) free portion of the uncinate processes (white arrows on left side) c The horizontal portion of the uncinate process (white arrows on left side) and the inferior surface of the ethmoid bulla (B) limit the oblique and narrow ethmoid infundibulum The maxillary sinus ostium is detectable at the bottom of the infundibulum (white ellipse) Curved white arrows show the path along the ostium and the infundibulum Fig 2.3a–c CT coronal reconstructions through the ethmoid labyrinth a Middle nasal fossa at the level of the short horizontal portion of the uncinate process posterior to the ethmoid infundibulum (white arrowheads on left side) A large ethmoid bulla (B) impinges the left middle turbinate on left side b The CT section cuts the posterior part of the bulla (B) The horizontal portion of the cribriform plates (arrowheads) appears thinner than the bone of the fovea ethmoidalis (FE) Bilateral pneumatization of the superior turbinate (ST) is present c Lateral attachment of the middle turbinate – the ground lamella (opposite arrows) – onto the lateral nasal wall Posterior ethmoid cells (PEC) extend between the lamina papyracea and the supreme turbinate (SuT) Fig 2.4a–c CT coronal reconstructions through the posterior ethmoid labyrinth and the sphenoid sinus a Level of the sphenoethmoid recess (asterisks) Lateral attachment of all four turbinates (IT, MT, ST, and SuT) is shown Anterior aspect of the sphenoid sinus (SS) and posterior ethmoid cells (PEC) are demonstrated on the same level A posterior ethmoid cell extends over the right sphenoid sinus – Onodi cell (onC) on (b) and (c) Inferior orbital fi ssure (IOF), superior orbital fi ssure (SOF), sphenopalatine foramen (SPF), greater palatine canal (GPC a Level of the alveolar process, teeth roots are seen The inferior portion of medial pterygoid plates – hamulus – is detected (h) Alveolar recess of maxillary sinus (arMS) b Hard palate level Greater (GPC) and lesser (LPC) palatine canals result from the articulation of the vertical portion of the perpendicular plate of the palatine bone with the maxillary bone Opening of the canal – the greater palatine foramen (GPF) – appears as an ovoid groove on the right side c The inferior concha and the surrounding inferior turbinate (IT) are demonstrated An accessory ostium is located within the posterior third of the medial maxillary sinus wall (ao) d Level of the inferior aspect of the nasolacrimal ducts (NLD) The postero-superior limit of the middle turbinates reaches the choanae (MT) e Level of the middle meatus The uncinate processes (UP) attach onto the medial aspect of the NLD The narrow space between the UP and the medial maxillary sinus wall belongs to the ethmoid infundibulum (EI) Arrowheads indicate the ground lamella of the MT, signing the border between anterior and posterior ethmoid labyrinth (see also f), into which the inferior tip of the superior turbinates (ST) projects f The ethmoid bullae (B) border the posterior limit of the EI Rostrum of the sphenoid bone (rs) g The vertical portion of the UP (vUP) attaches onto the vertical lamellae of the MT on both sides A clear separation between anterior and posterior ethmoid cells (PEC) cannot be identified on axial planes The narrow channel-like olfactory fi ssure (asterisks) reach the sphenoethmoidal recess where the ostium of the right sphenoid sinus appears as a small opening close to the midline (oSS) Common lamina onto which the middle, superior (and supreme) turbinates attach (L) Arrowheads indicate the thin lamina papyracea h Olfactory groove (OG) level Because the groove extends down into the labyrinth, it results bordered by ethmoid cells The thin vertical lamella of the cribriform plate (vlCP) separates the groove from the ethmoid cells i At the level of the mid crista galli (CG) the olfactory groove is bordered laterally by the thicker frontal bone – fovea ethmoidalis (FE) suOC, supraorbital ethmoid cell • • • • • • • • • • • • • • • • • • • • • • • • • Fig 2.6a–d Same patient as in Fig 2.5 a,b Right side c,d Left side a Sagittal plane closer to midline From the hourglass ostium of the frontal sinus (oFS) the mucus follows a curved path (broken curved arrow) into the frontal recess between the agger nasi cell (A) and the anterior surface of the bulla (B) Asterisks on (a) and (b) indicate the course of the hiatus semilunaris bordered by the uncinate process – horizontal (hUP) and part of the vertical portion – and the bulla suR, suprabullar recess c Sagittal plane closer to midline The left frontal sinus ostium is wider than on the opposite side Because the agger nasi cell (A) is smaller, the frontal recess is more vertically oriented (broken curved arrow) d On a more lateral plane the horizontal portion of the uncinate process is demonstrated (hUP) Asterisks indicate the hiatus semilunaris Small arrows on (a)/(b) and (d) point to the opening of small anterior ethmoid cells into the bulla ethmoidalis Fig 2.7a–f The left vertical portion of the uncinate process inserts on both the lateral surface of a large agger nasi cell (A) and the lamina papyracea As a result, the frontal recess runs medial to the uncinate process (broken curved white arrows) Moreover, a terminal recess (TR) is created between the superior surface of the bulla and the insertion of the UP onto the lamina papyracea On coronal scans the agger nasi cell may be differentiated from the bulla ethmoidalis because it is located anterior to the infundibulum ethmoidalis On the right side, a large bulla is associated with a paradoxically curved middle turbinate (opposite arrows) Pneumatization of the vertical lamella of left middle turbinate (lamellar concha, LC) • • • • • Fig 11.15a,b, Follow up of juvenile angiofi broma one year after microendoscopic surgery Resection of left middle turbinate, sphenoid sinus fl oor is noted a On pre-contrast T1 image, thickening of the mucosa along the lateral wall of the sphenoid sinus and the choana (arrowheads) is seen The resected left pterygoid process has been replaced by hypointense signal (white arrows), which on post-contrast T1 image (b) does not show any signifi cant enhancement (black arrows), appearing clearly hypointense when compared with the adjacent enhancing mucosa (arrowheads) • • • • • • • Fig 11.16a,b Follow up of ethmoid adenocarcinoma after anterior craniofacial resection a On coronal TSE T2, bilateral medialization of medial orbital wall is seen Dehiscence of left medial orbital wall with fat content (arrowheads) is present A quite thick duraplasty has a linear hypointense inner signal in its lower aspect (possible autologous bone, short arrows) The duraplasty is invested on nasal surface by a thickened mucosa (long arrows) Post-surgical focal encephalomalacia is seen on right side (asterisk) b On axial TSE T2, the medial prolapse of left medial orbital wall results more evident (arrowheads) A small fl uid collection faceting the anterior portion of left lamina papyracea is also present The lesion has the potential to mucocele development (arrows) • • • • • • • Fig 11.17 Follow up of anterior craniofacial resection nine years after removal of an ethmoid recurrent inverted papilloma with foci of squamous cell carcinoma The coronal Fat sat T2 image show two large cavities within the frontal lobes with fl uid content (black arrows) Both reach the anterior cranial fossa fl oor Quite regular lining of the nasal surface of the meningo-galeal complex is seen (white arrows) • • • • • • • • • • • • • • Fig 11.18a-d Follow up of anterior craniofacial resection one year after removal of a left ethmoid olfactory neuroblastoma On coronal TSE T2 (a-c), the meningo-galeal complex is not cut perpendicularly on all images, therefore appearing with apparent different thickness and a more hypointense signal in the most anterior plane (a), because of the oblique course of the complex at this level (asterisk) For the same reason the superior limit of the complex has an unsharp appearance (arrows) Removal of the ethmoid associates with mild medial prolapse of the orbits (double arrowheads arrow) b-c The meningo-galeal complex has an asymmetric mild thickness, three main layers, which are all demonstrated only on the most perpendicular plane (b, c) The nasal mucosal lining (thin arrows) is quite hypointense and borders an intermediate layer with heterogeneous hyperintense signal (asterisk), which is limited superiorly by the inner layer (thick arrows), which faces the CSF d On the contrast sagittal T1 plane, the meningo-galeal complex separable in its different components: nasal mucosa (a); intermediate layers (b and c), dura (d) At the integration with the posterior wall of the marsupialized frontal sinus (asterisk) the dura is thicker (arrowheads) Sphenoid sinus (SS), Onodi cell (OnC) • • • • • • • • • Fig 11.19 a Follow up of anterior craniofacial resection and left rhinotomy nine months after removal of an ethmoid adenocarcinoma invading the skull base, olfactory fi la, and nasal septum The sagittal post-contrast T1 image permits to separate the thicker than usual meningo-galeal complex into separate layers: nasal mucosa (a); more (b) and less mature (c) fi brotic scar; residual bone ad the periphery of the resection (d); restored dura mater (e) The thickened dura lines the restored anterior cranial fossa and the posterior aspect of frontal bone (arrowheads) Clear cur resection of the frontal bone cortical rim is seen (1) Small fl uid collection between dura and facial bone (double asterisks) Mucus retention within the blocked sphenoid sinus has high signal intensity (asterisk) b Follow up of anterior craniofacial resection and total rhinectomy for squamous cell carcinoma 10 years before, sagittal post-contrast T1 image The thickness of the meningo-galeal complex is mild; the dural lining (arrows) is similar for enhancement and thickness to non-involved areas • • • • • Fig 11.20a,b Follow up CT after radical maxillectomy for adenoid cystic carcinoma of right hard palate three years before In the absence of the prosthetic obturator, a large defect results in a single oro-nasal cavity Smooth surface is seen (white arrows on a) Resection of the right maxillary and vidian nerve with exploration of the respective canals was performed at surgery Dense sclerosis of right pterygoid process is demonstrated by CT around the foramen rotundum (black arrows on b) Soft tissue fi lls the area previously occupied by the vidian canal (white arrow) • • • • Fig 11.21 a Squamous cell carcinoma of left maxillary sinus Remodeling of posterolateral wall is clearly shown on fat saturated T2 axial image (arrows) b Three years after treatment with radical maxillectomy, the TSE T2 axial image shows a regular double layer lining of the cavity: the internal one corresponding to the mucosa (arrows); the external one to the mature scar (arrowheads) Hypointensity is shown at the level of pterygoid process (PP) possibly consistent with sclerotic changes • • • • • • • Fig 11.22 Temporalis muscle fl ap The patient had been treated with right radical maxillectomy and left subtotal maxillectomy for an adenoid cystic carcinoma of right hard palate two years before Adjuvant radiation therapy was delivered (56Gy) A free fl ap had to be removed for necrosis after irradiation On TSE T2 coronal image the muscle is partially replaced by fat (white arrows) • • • • • • • • • • • • • • • • • • • • Fig 11.23a,b Temporalis muscle fl ap a The patient had been treated with left radical maxillectomy extended to infratemporal fossa for an adenoid cystic carcinoma of the hard palate Three years after surgery, on the plain T1 axial image the muscle is clearly detected, its architecture well preserved (black arrows) Sclerotic changes of left pterygoid process are present (white arrows) b The patient was operated on with left radical maxillectomy, ethmoidectomy, orbital exenteration, the defect reconstructed with temporalis muscle, for a squamous cell carcinoma arising from maxillary sinus Adjuvant radiation therapy was given (60Gy) Trismus developed about one month after irradiation Follow up MR one year after surgery On the post-contrast T1 axial image, the enhancing fatty muscle enters the cavity left by orbital exenteration running behind the sclerotic frontal orbital process of frontal bone The hypointense aponeurosis is well appreciated (black arrows) Asymmetric enlargement of cavernous sinus is seen after orbital exenteration (white arrows) The straight external outline does not suggest perineural spread (confi rmed on subsequent MR studies) Blockage of left sphenoid sinus is present (asterisk) • Fig 11.24a,b Follow of a patient treated for ethmoid inverted • papilloma with foci of squamous cell carcinoma nine years • after surgery (same patient of fi gure 11.7) Post-contrast T1 • in the axial plane a Marked thickening of the mucosa lining • the sinonasal cavities (arrows) b Incidental detection of a T1 • undifferentiated carcinoma within left Rosenmüller fossa (arrows) • • • • • • • • • Fig 11.25 Follow up after exclusive radiation therapy for a sphenoid sinus adenoid cystic carcinoma The axial postcontrast T1 image is obtained four months after adjuvant of therapy Subcutaneous and deep fat tissue (buccal fat pad, black asterisk) show a diffuse increase of reticulations indicating thickening Reactive mucosal changes are seen in the maxillary sinuses (white asterisk in the left), asymmetric enhancement is observed in the right medial pterygoid muscle (arrows) • Fig 11.26 Postradiation changes in both lateral pterygoid • muscles (arrows) are characterized by non homogeneous enhancement; • the typical muscular striation is preserved ... sinus ostium is detectable at the bottom of the infundibulum (white ellipse) Curved white arrows show the path along the ostium and the infundibulum Fig 2.3a–c CT coronal reconstructions through the... mucous fi lling the frontal sinus contact the bone from below Fig 4.5a–d Recurrent myxosarcoma TSE T2 (a), plain CT (b), enhanced T1 (c), and enhanced CT (d) Intraspongiotic spread within the... on left side) A large ethmoid bulla (B) impinges the left middle turbinate on left side b The CT section cuts the posterior part of the bulla (B) The horizontal portion of the cribriform plates