Differential Diagnosis between Chronic Otitis Media with and Mass Effect

PURPOSE: In order to determine specific differences, we compared the temporal bone CT findings of chronic otitis media(COM) with and without cholesteatoma, focusing on bone change. MATERIALS AND METHODS: Between 1997 and 1998, 82 patients(84 cases) underwent temporal bone CT and were shown to have COM, with or without cholesteatoma after mastoidectomy and tympanoplasty. There were 36cases of COM with cholesteatoma(26 patients, M:F=11:15; age range, 16 -61 [mean, 36.2] years), and 58 cases without cholesteatoma(56 patients, M:F=25:31, age range, 15 -61 [mean, 36.2]years). The findings of temporal bone CT were analyzed at the point of bony changes including erosion and medial displacement of ossicles(malleus, incus, and stapes), erosion or destruction of the scutum, tegmen, facial canal, and lateral semicircular canal, and ballooning of the tympanic cavity and mastoid antrum. In addition, the soft tissue changes seen on temporal bone CT were analyzed at the site of lateral bulging of soft tissue in Prussak's space, perforation of the pars flaccida, tympanic membrane retraction, and tympanosclerosis. We retrospectively compared the findings of temporal bone CT with the surgical findings, and to assess statistical significance, the Chi-square test was used. RESULTS: Bone erosion or destruction was seen in 36.2 % of COM cases without cholesteatoma, and in 96.2% of cases with cholesteatoma. Comparing COM with and without cholesteatoma, the erosion of ossicles includ-ing the malleus(81%, 24%), incus(88%, 14%), stapes(58%, 10%), scutum(88%, 10%), facial canal(8%, 0%), and lateral semicircular canal(8%, 0%), was more common in COM with cholesteatoma(p-value0.05). CONCLUSION: Bone erosion or destruction was seen in COM without cholesteatoma, but expansile bone erosion or destruction with mass effect suggested COM with cholesteatoma. These findings of temporal bone CT in COM demonstrate the existence and extent of combined cholesteatoma, and are therefore valuable.

Differential Diagnosis between Chronic Otitis Media with and Mass Effect

PURPOSE: In order to determine specific differences, we compared the temporal bone CT findings of chronic otitis media(COM) with and without cholesteatoma, focusing on bone change. MATERIALS AND METHODS: Between 1997 and 1998, 82 patients(84 cases) underwent temporal bone CT and were shown to have COM, with or without cholesteatoma after mastoidectomy and tympanoplasty. There were 36cases of COM with cholesteatoma(26 patients, M:F=11:15; age range, 16 -61 [mean, 36.2] years), and 58 cases without cholesteatoma(56 patients, M:F=25:31, age range, 15 -61 [mean, 36.2]years). The findings of temporal bone CT were analyzed at the point of bony changes including erosion and medial displacement of ossicles(malleus, incus, and stapes), erosion or destruction of the scutum, tegmen, facial canal, and lateral semicircular canal, and ballooning of the tympanic cavity and mastoid antrum. In addition, the soft tissue changes seen on temporal bone CT were analyzed at the site of lateral bulging of soft tissue in Prussak's space, perforation of the pars flaccida, tympanic membrane retraction, and tympanosclerosis. We retrospectively compared the findings of temporal bone CT with the surgical findings, and to assess statistical significance, the Chi-square test was used. RESULTS: Bone erosion or destruction was seen in 36.2 % of COM cases without cholesteatoma, and in 96.2% of cases with cholesteatoma. Comparing COM with and without cholesteatoma, the erosion of ossicles includ-ing the malleus(81%, 24%), incus(88%, 14%), stapes(58%, 10%), scutum(88%, 10%), facial canal(8%, 0%), and lateral semicircular canal(8%, 0%), was more common in COM with cholesteatoma(p-value0.05). CONCLUSION: Bone erosion or destruction was seen in COM without cholesteatoma, but expansile bone erosion or destruction with mass effect suggested COM with cholesteatoma. These findings of temporal bone CT in COM demonstrate the existence and extent of combined cholesteatoma, and are therefore valuable.

Tympanosclerosis of the Middle Ear: Radiologic-Surgical Correlation

PURPOSE: Tympanosclerosis is a common problem causing conductive hearing loss accompanied by chronic otitismedia. The purpose of this study was to evaluate the CT findings of tympanosclerosis, and correlate them with thesurgical findings. MATERIALS AND METHODS: The CT scans of 17 patients with surgically-proven tympanosclerosis andthose of a control group of 34 patients with nontympanosclerotic chronic otitis media were reviewed. According totheir location, they were assigned to one of three groups; tympanic membrane, epitympanum, or ossicles. RESULTS: Tympanosclerosis was found during surgery to be located in the tympanic membrane (n=11), the epitympanum (n=6), oraround the ossicles(n=8). Calcification of the tympanic membrane, ossicular thickening, narrowing of theepitympanum and calcification of the tympanic cavity occurred to a significant extent, and were more often afeature of tympanosclerosis than of nontympanosclerotic chronic otitis media (p <0.05). As an indicater of tympanicmembrane involvement, sensitivity and specificity of calcification of the tympanic membrane were 73% and 83%,respectively. As an indicator of ossicular involvement, the corresponding figures for ossicular thickening were50% and 93% ; as an indicator of involvement of the tympanic cavity (especially the epitympanum) the figures fornarrowing of the epitympanum and calcification of the tympanic cavity were 50% and 50% (respective sensitivities),and 89% and 93%(respective specificities). CONCLUSION: Tympanosclerosis usually appears on CT as ossicularthickening, narrowing of the epitympanum, calcification of the tympanic membrane and/or tympanic cavity. CT isvery helpful in evaluating ossicular involvement and determining the appropriate surgical treatment oftympanosclerosis.

CT Angiography in the Diagnosis of Cerebral Aneurysm: Comparison of MIP and SSD Techniques

PURPOSE: To evaluate the usefulness of CT angiography and to compare SSD(Shaded Surface Display) andMIP(Maximum Intensity Projection) in the diagnosis and preoperative evaluation of the cerebral aneurysms. MATERIALS AND METHODS: Twenty-six aneurysms in 20 patients were diagnosed on conventional angiography and surgerywas performed. For preoperative evaluation, all patients underwent CT angiography, with spiral CT for preoperativeevaluation. Using SSD and MIP techniques, the results were proccessed and compared; three radiologistsretrospectively analysed detectability, size, neck visualization, delineation of shape, direction, therelationship with surrounding vessels-including the feeding artery of the aneurysm-and intraluminal thrombicontaining calcification. RESULTS: Twenty five of 26 aneurysms (96.2%) were detected by CT angiography, while MIPand SSD depicted 25 (96.2%) and 24 (92.3%), respectively. The largest diameter of the aneurysms was 11-15mm infour cases, 6-10mm in ten, and 3-5mm in 12 (mean 7.38mm, SD=3.34). With regard to detectability, MIP led to onefalse negative result, and SSD to two false negative and one false-positive results. Aneurysm neck assessment byMIP was clear in 96.0% of cases (24/25), and by SSD in 83.3% (20/24). For the depiction of directions and feedingvessels of the aneurysms, and intraluminal thrombi containing calcification, MIP was superior to SSD, while fordepicting shape and the relationship with surrounding structures, SSD was superior to MIP. CONCLUSION: For theassessment of cerebral aneurysms, MIP is somewhat superior to SSD. The characteristics of aneurysms and theirrelationship with surrounding structures can, however, be better evaluated by combining the two techniques.

MR Imaging of Herniated Lumbar Disc: Morphologic Change between Supine and Flexed-Prone Position

PURPOSE: To determine morphologic change in a herniated lumbar disc, as seen on MR imaging, according to position change (supine and flexed-prone positions). MATERIALS AND METHODS: A hundred and twenty-two patients with herniated lumbar discs , as seen on supine MR imaging, underwent repeat MR imaging in the flexed-prone position; 100 patients, who showed more than 2 degrees of flexion angle difference, were included in this study. Sixty-two were men and thirty-eight were women, and their ages ranged from 13 to 59 (mean, 30) years. Disc degeneration was graded as 1, 2, or 3, depending on the area of decreased signal intensity seen on a T2-weighted MR image. Difference in the angle of flexion is defined as the angle difference of lumbar curvature, calculated by the Begg-Falconer method in supine and flexed-prone positions. Morphologic changes in herniated discs in different positions were analysed on the basis of shape change of anterior epidural spaces, thecal sacs and posterior margins of herniated discs, and classified as either A (not changed) or B (changed). Group B was subtyped as type I (decreased herniation without change of shape), type II (decreased herniation with change of shape) or type III(increased disc herniation). We statistically analysed correlation between a patient's age, morphologic change in a herniated disc in different positions, and degree of degeneration in such a disc, as well as the correlation between morphologic change in a herniated disc in different positions and the degree of the flexion angle. RESULTS: Disc degeneration was apparent in 99 of 100 patients. Grades 1, 2, and 3 were seen in 32 (32.3%), 49 (49.5%), and 18 (18.2%) patients, respectively; the difference in the angle of flexion ranged from 2 to 24 degrees (mean 7.97; SD=6.20). Group A consisted of 37 (37.4%) patients, and group B of 62 (62.6%) (type I in 29 (29.3%), type II in 27 (27.3%), and type III in 6 (6.0%)). There was no significant statistical correlation between a patient's age and morphologic change in a herniated disc in different positions (correlation coefficient=0.0183; p=0.086), and between the degree of degeneration of a herniated disc and morphologic change in such a disc in different positions (correlation coefficient=0.1736; p=0.249). The mean angle of flexion was 5.15 degrees (SD=4.94) in group A and 10.06 degrees (SD=6.28) in group B; there was significant statistical correlation between this and morphologic change in a herniated disc (p=0.0017). CONCLUSION: In the flexion-prone position, which is similar to that used during surgery, MRI can reveal various morphologic changes in a herniated lumbar disc, mainly decreased herniation, and is helpful in making decisions related to surgery.

Multiple Metastases of Paraganglioma: A case report

Paragangliomas of the carotid body are rare tumors, usually regarded as benign. We report a case of multiple metastases from a paraganglioma which occurred in a 34-year-old man. Paraganglioma, which has originated two years previously in the right carotid body, was diagnosed. We performed neck and thoracic spine MRI, whole body bone scan, and neck and thoracic spinal angiography revealed multiple metastatic lesions in cervical lymph nodes, spines, ribs, and ilia. Metastatic lesions showed hypervascularity similar to that of a primary tumor.