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A retrospective study was carried out to determine the prevalence of abnormality in the paranasal sinuses in a British population having magnetic resonance imaging (MRI) scans for neurological signs and symptoms. The T2-weighted scans of 130 patients were studied. Abnormalities in the paranasal sinuses show as high signal on the T2-weighted scans and thus are clearly seen. Abnormalities included mucosal thickening, fluid levels, sinus opacification and retention cysts/polyps. Of the patients studied, 49.2 per cent showed one or more abnormality. Mucosal thickening was the most common abnormality noted and the ethmoid sinuses the most commonly affected.

Sinus-induced intracranial sepsis can represent a genuine medical and surgical emergency. We review 12 cases presenting to our hospitals over a five-year period. Nine were male and three were female with an age range of 16 to 74 years (mean 35.5 years). Four patients had their sinusitis diagnosed prior to admission and eight did not. Nine patients had bilateral sinus disease, the most common sinus involved was the frontal followed by the ethmoid, maxillary and sphenoid. Neurosurgical drainage was via a craniotomy in seven cases and burr hole in three. Nine patients underwent sinus surgery and three did not. Of the nine who had sinus surgery three had frontal drainage, four fronto-ethmoidal and two transsphenoidal drainage. The most common organism was Streptococcus milleri. Our series confirms that sinus-induced intracranial sepsis is a serious problem needing early diagnosis and aggressive treatment. We would recommend a high index of suspicion of sinusitis in patients with intracranial infection.

Maxillary sinusitis due to dental causes is usually secondary to periodontal disease or periapical infection and is commonly associated with mucosal thickening of the floor of the maxillary antrum. Computed tomography (CT) is currently the modality of choice for evaluating the extent of disease and any predisposing factors in patients with symptoms of chronic maxillary sinusitis, but it is unable to diagnose dental disease reliably. The presence of restorative dentistry is, however, easily seen at CT and is associated with both periapical and periodontal disease. We aimed to determine whether its presence at CT may predispose to maxillary sinusitis, and in particular to focal mucosal thickening of the sinus floor characteristic of dental origin. Three hundred and thirty maxillary sinus CT images in 165 patients were reviewed for the presence of restorative dentistry in the adjacent teeth, focal maxillary sinus floor mucosal thickening, any maxillary sinus disease (including complete opacification, air fluid levels, diffuse mucosal thickening, focal mucosal thickening) and evidence of a rhinogenic aetiology (osteomeatal complex pathology, mucosal thickening in other sinuses). One hundred and ninety two sinuses adjacent to restorative dentistry and 178 sinuses not adjacent to restorative dentistry were analysed. Focal floor thickening both with, and without, evidence of a rhinogenic aetiology, was significantly more common adjacent to restorative dentistry. Maxillary sinus disease overall was no more common adjacent to restorative dentistry. This work demonstrated that the presence of restorative dentistry predisposes to focal mucosal thickening in the floor of the maxillary sinus and its presence should prompt clinical and radiographical assessment to exclude dental disease as a source of chronic maxillary sinusitis.

SUMMARY:Conventional imaging protocols are unable to visualize the intraforaminal/canalicular segments of the lower cranial nerves (IX-XII). On the basis of previous successful demonstration of individual cranial nerves within the cavernous sinus by constructive interference in steady-state MR imaging, we describe the use of contrast-enhanced 3D fast imaging employing steady-state acquisition MR imaging to demonstrate normal in vivo intraforaminal and canalicular segments of cranial nerves IX-XII in 10 patients by using a standardized imaging protocol.T he detection of individual cranial nerves in the intraforaminal portion of the jugular foramen and hypoglossal canal is useful in diagnostic imaging 1 ; however, visualization by using conventional MR imaging protocols does not provide adequate detail of individual nerves.2,3 Recently, contrastenhanced 3D constructive interference in steady state (CISS) MR imaging has successfully demonstrated the trigeminal ganglion and its divisions and individual cranial nerves within the cavernous sinus.4,5 3D fast imaging employing steady-state acquisition (FIESTA) is a similar form of steady-state sequence MR imaging. Evidence has shown a proportional increase in contrast between the background structures and the cranial nerves within the cisterns as the concentration of gadolinium-based contrast agent increases with 3D steady-state imaging sequences. 4,6 This Technical Note describes the use of 3D-FIESTA imaging after intravenous administration of gadodiamide hydrate contrast to demonstrate the normal anatomy of the intraforaminal and canalicular portions of cranial nerves IX-XII. Description of the TechniqueDetectability of the intraforaminal/canalicular segments of cranial nerves IX-XII was evaluated in 10 consecutive patients undergoing routine follow-up imaging for vestibular schwannomas. Patients included 6 men and 4 women (mean age, 56.8; range, 36 -68 years). MR ImagingThe examinations were performed on a 1.5T unit (Signa Excite HD; GE Healthcare, Bucks, UK) with a standard head coil and pre-and postcontrast enhancement with a standardized FIESTA MR imaging protocol. Gadodiamide hydrate (Omniscan; GE Healthcare) was administered at 0.1-mmol/kg body weight as an intravenous contrast agent. The pulse sequence used was the following: 3D FIESTA-C (TR/ TE/NEX, 5.5/1.7/3.00; 180 ϫ 180 mm [read x phase encode] FOV; 0.4-mm effective section thickness; 448 ϫ 448 matrix; and imaging time of 8 minutes 21 seconds). Image AnalysisThe datasets obtained were reconstructed in the 3 orthogonal/oblique planes in relation to the cisternal course of the cranial nerves. Images were viewed on high-resolution monitors with a multiplanar reconstruction program (Advantage Workstations; GE Healthcare).The initial evaluation involved an assessment of the division of the jugular foramen into the pars nervosa and pars vascularis, separated by the fibrous or bony septum (jugular ligament) represented by a dark line (Fig 1). A further attempt was then made to identify cranial nerves IX-XII within...