Normal Development of Sutures and Synchondroses in the Central Skull Base: CT Study

PURPOSE: To evaluate the developmental patterns of the sutures and synchondroses in the central skull base. MATERIALS AND METHODS: We evaluated the CT scans of 109 children(age range, 29 days to 15 years) with no skull base abnormality who had undergone axial CT of the skull base with 1-mm collimation. Using a five-tier scheme, we analyzed the developmental patterns of the 18 sutures and synchondroses related to the sphenoid and occipital bones. RESULTS: Fusion of the sutures and synchondroses related to the sphenoid bone progressed rapidly during the first two years. Thereafter, changes in the sphenoid bone were dominated by pneumatization of the sphenoid sinus. Fusion of the synchondroses within the sphenoid body, including intersphenoidal, intrapresphenoidal, and intrapostsphenoidal synchondrosis occurred early and in most cases was graded <=4. Fusion of the sphenosquamosal, sphenoethmoidal, and frontosphenoidal sutures was delayed, and residual sclerosis was a common finding. Except for Kerckring-supraoccipital synchondrosis, fusion of the six sutures and synchon-droses related to the occipital bone occurred more gradually than that of those related to the sphenoid bone. Among these, fusion of the occipitomastoidal suture and petro-occipital synchondrosis was the last to occur. CONCLUSION: A knowledge of the developmental patterns of sutures and synchondroses can help differentiate normal conditions from those such as fracture, osseous dysplasia, or congenital malformation, which are abnormal. Our results provide certain basic informations about skull base maturity in children.

CT of Normal Variations of the Minute Central Skull Base Foramina

PURPOSE: To evaluate the CT appearance of normal variations in the minute central skull base foramina in infants and children. MATERIALS AND METHODS: One hundred and fourteen children under the age of 17 years without skull base abnormality underwent CT scanning. A high spatial frequency algorithm was used, and contiguous axial scanning parallel to the orbitomeatal line was performed from the foramen magnum to the orbital roof, with a 1-mm slice thickness. The presence or absence of eight foramina, pseudoforamina, or ossification centers including anterior presphenoidal foramen, posterior presphenoidal foramen, rostro-orbital pseudoforamen, intralateromedial postsphenoidal pseudoforamen, intrapostsphenoidal pseudoforamen, spheno-occipital pseudo-foramen, canalis basilaris medianus and intrasynchondral ossified bodies was analysed according to age. The presence of foramina or pseudoforamina was indicated if a ring-shaped structure was seen on two or more CT scans at the location anatomically predicted, and intrasynchondral ossified bodies were indicated if linear or dot-like structures with high attenuation accompanied spheno-occipital synchondrosis. RESULTS: CT indicated that within a certain age range, various kinds of foramina, pseudoforamina, and ossification centers were frequent. The anterior presphenoidal foramen was most commonly seen in infants aged 1-12 months (16/17, 94 %); the posterior presphenoidal foramen in children less than 2 years old(27/37, 73 % ) ; the rostro-orbital pseudoforamen in children aged 2 -5 years (9/17, 53%); intrapostsphenoidal pseudoforamen in children 6 -12 years old(20/37, 54%) and spheno-occipital pseudoforamen and intrasynchondral ossified bodies in children aged 13 -16 years. The canalis basilaris medianus was identified in about 20 % of all subjects regardless of age. CONCLUSION: Development of the minute central skull base foramina varied greatly according to age. Knowledge of the CT appearances of such embryologic variants of the central skull base should not only help Provide an understanding of complex skull base anatomy but also identify abnormal skull base development.

CT Diagnosis of Intestinal Obstruction: Findings and Usefulness

PURPOSE: To present the findings of intestinal obstruction and evaluate the value of CT in the diagnosis of intestinal obstruction. MATERIALS AND METHODS: We prospectively analyzed CT scans of twenty-two patients who were suspected to have intestinal obstruction. All 22 patients were confirmed with surgery:10 patients with adhesion, four with primary intestinal tumor, one with metastatic intestinal tumor, two with inflammatory bowel disease, two with intussusception, two with extrinsic compression by ovarian tumor, and one with inguinal hernia. The CT scans were evaluated with special attention to their causes, locations, and CT findings of intestinal obstruction. CT diagnosis and findings were compared with surgical results. RESULTS: Their causes were diagnosed correctly on CT scans in seventeen of 22 cases(77.3%). Locations of the intestinal obstruction were diagnosed correctly in 16 cases(72.7% ). The CT findings of intestinal obstruction were categorized into dilated proximal bowel loops with normal distal loops, thickening of the affected bowel wall, presence of the transitional zone, and no detectable abnormalities. The associated extraluminal findings were fat infiltration around the dilated bowel loops, ascites, and mesenteric lymphnodes enlargement. There were two limitations of CT in our study:first, no detectable differences between jejunum and ileum on CT scans, and second, difficulty in differential diagnosis between thickened bowel wall mimicking normal non-dilated segment and mechanical obstruction from tumors or inflammatory bowel diseases. CONCLUSION: We conclude that CT is useful method in the evaluation of causes and locations of intestinal obstruction and the demonstration of the associated extraluminal abnormalities.

CT findings of cervical lymphadenopathy: morphological analysis

To evaluate the effectiveness of computed tomography for the differential diagnosis of cervical lymphadenopathy, we reviewed CT scans of 26 patients with cervical lymphadenopathy retrospectively. These included 10 patients with tuberculous lymphadenitis, 11 patients with metastasis and 5 patients with lymphoma, We evaluated the CT scans with a special attention to internal nodal density, feature of contrast enhancement and location of lymphadenopathy. Tuberculous lymphadenitis involved multiple nodes unilaterally and showed central low density with even or uneven rim enhancement, usually occurring in young patients (mean: 31.6 years). Two cases with tuberculous lymphadenitis showed calcifications within the lymph nodes. Lymphoma involved unilateral or bilateral nodes and appeared as conglomerated isodense mass with even rim enhancement. Metastasis involved multiple nodes unilaterally and showed focal, diffuse of mixed pattern of central low density with variable rim enhancement, usually occurring in old patients (mean: 59.4 years). Locations of most frequent lymph node involvements were internal jugular group (76%), spinal accessory group (54%) and retropharyngeal group(12%).