The accuracy of limited CT in the evaluation of chronic rhinosinusitis and for endoscopic sinus surgery: a multicenter study.

Objective: To compare the accuracy of Limited CT with the Full CT as the standard evaluation for inflammatory disease of PNS and the identification of anatomical variations. Methods: From Full CT of PNS, Limited CT were retrieved. Computerized tomographic scans were performed for the preoperative planning of endoscopic sinus surgery (ESS) in 3 tertiary care university hospitals in Thailand. The two types of examinations were reviewed independently and in random order by two experienced radiologists. Using Full CT as the standard, the accuracy of Limited CT were evaluated for 1) the radiologic staging of rhinosinusitis (Lund-Mckay scoring system) and 2) the anatomic variations which are an important landmark for surgical operations in rhinosinusitis. Results: Totally 132 patients were included. Two hundred and sixty four half-faces were reviewed. Lund-McKay radiographic sinus staging system showed 97-99% specificity except for the ostiomeatal complex region. Regarding anatomic variation, Limited CT was able to yield accurate results for the frontal cell type II-IV, Haller cell, Agger nasi cell, paradoxical middle turbinate, concha bullosa and the protrusion of the optic nerve. Conclusion: Limited CT can be used as a surgical roadmap for the cases with the anterior group of sinus involvement. It may be utilized for surgical planning of chronic CRS involving the anterior group of sinuses. For the posterior group of sinuses, it may not yield enough accuracy and the standard Full CT should be requested to prevent erroneous estimation.

Normal measurements of extraocular muscle using computed tomography.

OBJECTIVE: Establish criteria for the diameters of normal extraocular muscles using computerized tomography in a Thai population. MATERIAL AND METHOD: Diameters of extraocular muscles (medial, lateral, superior complex, and inferior rectus) were calculated for 200 patients on coronal direction of screening paranasal sinuses. The effects of age and sex were also analyzed. RESULT: Normal ranges for the diameters (mean +/- 2 SDs) of extraocular muscles were 3.7 +/- 0.9 mm for medial rectus, 3.6 +/- 1.2 mm for lateral rectus, 4.0 +/- 1.4 mm for inferior rectus and 3.8 +/- 1.4 mm for the superior group. The mean diameter of the extraocular muscles in male patients was not significantly larger than in female patients (p > 0.05). There was also no statistically significant correlation between age, diameter of each extramuscular muscle and the sum of all four muscles. CONCLUSION: The present result may help radiologists and ophthalmologists to accurately assess enlargement of the extraocular muscles, particularly in Oriental populations.

Successful resection of Hypothalamic Hamartoma with intractable gelastic seizures--by transcallosal subchoroidal approach.

A 19-year old female with intractable gelastic seizures was found to have 0.7 x 1.8 x 1.8 cm elliptical mass on the floor of the third ventricle. The signal intensity on the Magnetic Resonance Imaging (MRI) was consistent with the Hypothalamic Hamartoma (HH). Ictal EEG demonstrated rhythmic 7 Hz waves over Fp2, F4, and C4 with spreading to the right temporal region and then bilaterally. Ictal Single Photon Emission Computerized Tomography (SPECT) showed hyperperfusion at hypothalamic and medial frontopolar regions. The patient underwent surgical resection using Trans Callosal Subchoroidal Approach (TCSA) to the third ventricle. Pathological finding confirmed the diagnosis of hypothalamic hamartoma. Following the operation, she has been seizure free up to 12 months. Thereafter, provoked seizures seldom occurred and there has been improvement in her memory, emotional control and independence. This appears to be the first report of this surgical approach for HH, which is less likely to disturb memory function compared to previously described interfoniceal approach.

Prevalence of anatomic variation demonstrated on screening sinus computed tomography and clinical correlation.

Screening sinus computed tomography (SCCT) of 133 patients performed from March 2003 to February 2004, were retrospectively reviewed, concerning anatomic variation at ostiomeatal unit (OMU) and nasal septal deviation. Six patterns of inflammatory sinus disease were designated: maxillary infundibulum, nasofrontal duct, OMU, sphenoethmoidal recess, polyposis and sporadic. The most common anatomic variation was concha bullosa (14.3%), followed by Haller cell (9.4%), large Agger nasi cell (7.9%) and paradoxical middle turbinate (5.3%). Nasal septal deviation was presented in 75 patients (56.4%). Inflammatory sinus disease was presented in 181 lateral nasal walls (68%) and maxillary infundibular pattern was the most common (33.1%). There was significant correlation between large Agger nasi cell and nasofrontal duct pattern (p < 0.05). The remaining anatomic variations and nasal septal deviation had no significant correlation to the inflammatory sinus disease. Overall, the anatomic variation which can compromise the mucociliary drainage was frequently observed, however, only the large Agger nasi cell had significant correlation to the inflammatory sinus disease.

MR imaging of CNS leiomyosarcoma in AIDS patients.

Leiomyosarcomas of the central nervous system are extremely rare; however they are becoming more prevalent in immunocompromised patients. The authors present MRI (Magnetic Resonance Imaging) of six cases of pathological proved leiomyosarcomas of the central nervous system in patients infected with human immunodeficiency virus. MR images of 4 cases of intraspinal leiomyosarcoma showed lobulated masses expanding multilevel of neural foramina with extradural and intradural extension, giving dumbbell appearance which mimic neurofibroma. Two cases of intracranial leiomyosarcoma revealed a mass at the left cavernous sinus involving prepontine cistern in one case and two lesions in the other case showing masses with dural based appearance at the region of the planum sphenoidale and the posterior aspect of the falx cerebri which mimiced a meningioma. The leiomyosarcoma should be included in the differential diagnosis of extra-axial CNS lesions in HIV-infected patients.

Idiopathic superficial siderosis: a case report.

Superficial siderosis of the central nervous system (SSCN) is a very rare disorder. The clinical syndrome of SSNC consists of sensorineural hearing loss, cerebellar ataxia and myelopathy. The clinical syndrome together with the typical appearance on magnetic resonance imaging (MRI) of hyposignal intensity along the leptomeninges in T2 sequence permit the diagnosis of SSCN. A 58 year-old man who has a history of chronic progressive hearing loss and gait instability for 5 years is presented. The neurological examination revealed bilateral sensorineural hearing loss, cerebellar ataxia and mild spasticity of the lower extremities. MRI showed classical superficial siderosis in the form of hyposignal intensity along the leptomeninges in T2 sequence. The prominent sites of hemosiderin deposition in this case were cerebellar vermis, trigeminal nerves, vestibulocochlear nerves, around the brain stem and spinal cord surface. Cerebrospinal fluid findings confirmed chronic subarachnoid hemorrhage but bleeding site could not be demonstrated. There is no specific treatment available for idiopathic SSCN.