الفهرس | Only 14 pages are availabe for public view |
Abstract This work enrolled 35 patients, presented to the department of radiology at the faculty of medicine, Alexandria University. The patients had clinically approved CSF rhinorrhea, and imaging was requested for the aim of localizing the site of the defects and pre-surgical road mapping for the repair of the defects as well as discovering associated abnormalities. This referral followed an initial assessment by Otorhinolaryngologists including thorough clinical examination and history taking, followed by B-2 transferrin test of the collected fluids in all our included cases. They were eight males and 27 females. Their ages ranged between six and 64 years with a median age of 46 years. Mean age 42.34 years. Majority of cases were ≥50 years old group This work aimed to study the role of combined non-contrast high resolution computed tomography (HRCT) with bone algorithm and non-contrast magnetic resonance cisternography (MRC) in accurate localization of the CSF fistulas whether they were actively leaking or not. These patients underwent multi-detector high-resolution CT and MRI examinations in a closed 1.5-tesla Magnet with adherence to adequate technical parameters that ensure good image quality; this aimed at high spatial and contrast resolution by using standardized parameters. Usage of intravenous GAD was needed only in four patients with tumoral and infectious etiologies. 3D heavily T2-weighted sequence is 3D MRI sequence using a high spatial resolution, to depict small structures surrounded by cerebrospinal fluid (CSF) with both high contrast and spatial resolution and therefore in our study, 3D heavily T2-weighted sequence (3D SPACE) provided us with excellent and supreme details for the accurate identification of the leaking CSF column. The study included 27 cases with single skull base defects (77.1%) and eight cases with multiple defects (22.9%) Regarding the size of the defect: we measured the skull base bony defect in two different planes (coronal and sagittal planes) and we found that the minimum defect sizes ranged between 1mm and 13mm. While the maximum defect sizes ranging between 1mm and 33mm. The most common cause of CSF leakage in our study was the spontaneous type 17 cases account for 48.6%, followed by traumatic causes whether accidental (nine cases, 25.7%) or iatrogenic (four cases, 11.4%) and the non-traumatic causes were reported as causes, whether infectious (two cases, 5.7%) or tumoral (three cases, 8.6%). All spontaneous leaks in our study presented in female patients. This is an important statistically significant observation, where males are more commonly involved in road traffic accidents and other causes of accidental injury and related trauma. Summary 121 The most common site of the skull base defects was the cribriform plates of ethmoid bone and ethmoid roof (12 cases for each 34.3%) followed by sphenoid sinus walls (eight cases, 22.9%), then the frontal sinus walls (four cases, 11.4%), followed by the petrous apex and the clivus (three cases for each, 8.6%). Out of 35 cases; 24 cases presented with active CSF leakage while the remaining 11 cases complained of intermittent leakage described to have inactive CSF fistula. Seventeen cases had meningoencephalocele associated with the skull base defects. Meningoencephalocele is seen mainly among ≥50 years age group followed by 30-40 years age group and the majority of them were female patients 12 cases out of 17 Our study included 19 cases presented by idiopathic intracranial hypertension with multiple signs confirming the diagnosis including empty sella, bilateral optic hydrops with papilledema, enlarged arachnoid granulations. Out of 35 patients, only five cases had recurrent CSF leakage after surgery, they were four females and one male patient. The most common cause of CSF leakage between them was iatrogenic etiology in three cases followed by traumatic accidental etiology in two cases. A combination of both non-contrast high-resolution CT and MR Cisternography provided complementary information, with CT demonstrating the bone defect and MR depicting the leaking CSF column. As a result, the combined sensitivity and specificity improved to 95% and 100% respectively. Another important finding was that the accuracy of non-contrast CT was equally good in active and inactive CSF leaks. Finally, it is to be concluded that, imaging has an indispensable role in accurate localization of the skull base osteo-dural defects and pre-operative planning for repair. |