ABSTRACT
I. Introduction 242
II. Plain Radiographs 243
III. Computed Tomography 244
IV. Magnetic Resonance Imaging 244
V. Normal Anatomy 244
VI. The Frontal Sinus 244
A. Normal Frontal Recess 245
B. Maxillary Sinus 246
C. Maxillary Sinus Ostium 246
D. Ethmoid Sinuses 247
E. The Anterior Ethmoid Sinuses 247
F. The Cribriform Plate and Fovea Ethmoidalis 247
G. Ethmoid Infundibulum 249
H. Hiatus Semilunaris 249
I. The Middle Meatus 249
VII. The Ethmoidal Bulla 250
VIII. The Posterior Ethmoid Sinuses 250
IX. The Sphenoid Sinus 250
A. Sphenoid Sinus Ostium 253
X. The Important Anatomical Structures of the Ostiomeatal
Complex and Their Variations 254
XI. Maxillary Sinus Hypoplasia 258
XII. Sinusitis 261
A. Radiographic Features of Sinusitis 261
B. Chronic Sinusitis 264
C. Fungal Sinusitis 268
Plain Radiographs and CT Scan Findings 270
MR Findings of Fungal Sinusitis 271
Mucormycosis 271
D. Polyps 272
Nasal Polyposis 272
Antrochoanal Polyp 274
The CT Scan Appearance of Polyps 274
E. Retention Cysts 275
CT and MR Features of Retention Cysts 276
XIII. Complications of Sinusitis 276
XIV. Mucoceles of the Paranasal Sinuses 277
A. Radiological Features of a Mucocele 277
B. MR Features of Mucoceles 278
XV. Osteomyelitis 279
A. Radiographic Appearance of Osteomyelitis 279
XVI. Intraorbital Complications 279
A. Preseptal Orbital Cellulitis 281
B. Postseptal Orbital Cellulitis 281
C. Features of Extraconal Orbital Cellulitis 281
D. Features of Intraconal Orbital Cellulitis 282
E. Features of Diffuse Intraconal and Extraconal
Orbital Cellulitis 282
XVII. Intracranial Complications 282
A. CT Appearance of Intracranial Infection 282
References 283
I. Introduction
Messerklinger has demonstrated that ventilation and drainage of the anterior
ethmoidal sinus, the maxillary sinus, and the frontal sinus are dependent on the
patent “ostiomeatal complex”.
