• Environmental Mutagens and Carcinogens
• /
• v.25 no.1
• /
• pp.25-31
• /
• 2005

The objective was to use MR imaging to provide a template of posterior fossa development during the late stages in the chick embryos. The MR findings were then correlated with histological data. Fourteen normal formalin-fixed embryonic specimens with a gestational age of 14 to 20 days were examined with 1.5 Tesla unit MRl using a conventional clinical magnet and pulse sequences. The MR findings were correlated with the whole-mount histological specimens. Resolution of the morphological features of posterior fossa development in embryos greater than 14 days gestational age was possible. Development of cerebellum, brain stem, 4th ventricle and bony posterior fossa was documented. In the 14-day-old embryos, a premordial cerebellum was visualized in the enlarged bony posterior fossa, and it covered the the roof of the primitive fourth ventricle. The bony posterior fossa grows at the same rate along the supratentorial skull. The supratentorial skull and the rostral part of the brain grows at the same rate. The cerebellum begins to grow later than the rostral part of the brain. In the 19- to 20-day-old embryos, MRl revealed the rapid development of the cerebellar hemispheres, along with an increase in volume manifested by the more typical mushroom-shaped configuration observed in the newly hatched. At this stage, the cerebellum almost completely filled the posterior fossa and covered the entire fourth ventricle. The brain stem grew steadily, but the volume change was too subtle to evaluate. Features of cerebellar histogeneis were beyond the resolution of MRl. However, there were lots of artifacts in the features of the bony posterior fossa. An MR template of normal posterior fossa development would be useful to avoid confusion of normal development with abnormal development and to identify the expected developmental features when provided the estimated gestational age of a embryo.

• Radiation Oncology Journal
• /
• v.21 no.1
• /
• pp.94-99
• /
• 2003

Purpose : To explore a 3D conformal radiotherapy technique for a posterior fossa boost, and the potential advantages of a prone position for such radiotherapy. Materials and Methods :A CT simulator and 3D conformal radiotherapy Planning system was used for the posterior fossa boost treatment on a 13-year-old medulloblastoma patient. He was placed In the prone position and Immobilized with an aquaplast mask and immobilization mold. CT scans were obtained of the brain from the top of the skull to the lower neck, with IV contrast enhancement. The target volume and normal structures were delineated on each slice, with treatment planning peformed using non-coplanar conformal beams. Results : The CT scans, and treatment In the prone position, were peformed successfully. In the prone position, the definition of the target volume was made easier due to the well enhanced tentorium, In audition, the posterior fossa was located anteriorly, and with the greater choice of beam arrangements, more accurate treatment planning was possible as the primary beams were not obstructed by the treatment table. Conclusion : .A posterior fossa boost, in the prone position, Is feasible in cooperating patients, but further evaluation is needed to define the optimal and most comfortable treatment positions.

• Korean Journal of Otorhinolaryngology-Head and Neck Surgery
• /
• v.61 no.12
• /
• pp.710-713
• /
• 2018

A congenital cholesteatoma is a benign mass formed from the keratinizing stratified squamous epithelium. It usually occurs in young children's anterosuperior part of the middle ear. A congenital cholesteatoma which originates from mastoid temporal bone or expands to posterior cranial fossa is rare. Standard treatment of an intracranial cholesteatoma is surgical removal with craniotomy. A 69-year-old woman was diagnosed with a congenital cholesteatoma of mastoid temporal bone that expanded to the posterior cranial fossa, which was successfully treated with transmastoid marsupialization without craniotomy. This is a first documented case of a congenital cholesteatoma of mastoid temporal bone that expanded to posterior cranial fossa, which was successfully treated with transmastoid marsupialization without craniotomy.

• Radiation Oncology Journal
• /
• v.6 no.2
• /
• pp.183-194
• /
• 1988

Twenty five patients with histologically proven medulloblastoma received craniospinal radiotherapy (CSRT) at the Seoul National University Hospital from 1979 to 1984. The extent of tumor removal was biopsy only in 2 patients, partial in 18, and near total in 5. With orthogonal technique of CSRT, mainly 55Gy was delivered to the posterior fossa (PF), 40Gy to whole brain (WB), and 30Gy to whole spine (WS). And with AP; PA technique, 50Gy to PF, 45-50Gy to WB, and 36 Gy to WS. Complete remission was obtained in $84\%$ of patients. Among 21 CR's 10 failures were observed, thus total failure rate was $56\%$ (14/25). Of 14 faiure 13 had the primary failure, 11 failed in primary site alone, 1 failure was combined with ventricular seeding, and another 1 was combined with neck node metastasis. There was 1 isolated spinal failure. Actuarial overall survival rates at 3 and 5 years were $75\%$ and $54\%$, and disease-free survival rates were $58\%$ and $36\%$, respectively. Better 5 year disease-free survival was noted in patients with 55 Gy to the posterior fossa than those with 50Gy $(62\%\;vs\;17\%,\;p<0.05)$, in patients treated with orthogonal technique than those treated with AP:PA technique $(87\%\;vs\;12\%,\;p<0.05)$, and in patients with near total removal than those with partial or less removal of tumor $(56\%\;vs\;30\%,\;N.S.)$ Re-irradiation was not satisfactory No severe late sequelae was noted among the survivors. For the higher control of medulloblastoma, dose to posterior fossa should be at least 55Gy with orthogonal CSRT to small tumor burden. And dose reduction in the subarachnoidal spaces might be safe, but optimal dose to the subarchnoidal spaces should be determined by the thorough tumor staging before radiotherapy.

• Journal of Korean Neurosurgical Society
• /
• v.29 no.6
• /
• pp.744-747
• /
• 2000

Objectives : The purpose of this study was to evaluate the clinical features of the epidermoid tumor of posterior fossa and to assess the surgical outcome. Methods : We reviewed the clinicoradiological records of 10 epidermoid tumor of posterior fossa, treated surgically at our hospital between 1991 and 1996. Results : The mean age of onset was 36 years old and mean duration of symptom was 5.2 years. Six were men and four were women. The location of tumors were cerebellopontine angle(CPA) 5 cases, cerebellum(Cbll)& 4th ventricle 3 cases, foramen magnum 1 case, and pineal region extended to Cbll and 4th ventricle 1 case. Common clinical features were trigeminal neuralgia in 3 cases, cerebellar signs 2 case, headache 2 cases, hemifacial spasm with deafness 1 case, cbll signs and multiple cranial nerve dysfunctions 1 case. One CPA epidermoid had no clinical symptom and sign associated with the tumor. The surgical approaches were suboccipital approach in 9 cases and one transcallosal approach to the tumor of pineal region. The extent of surgical removal was gross total resection in 5 cases and near total or subtotal resection in 5. Two patients with CPA tumor were complicated with facial paresis. One patient with tumor located in cerebellum extended into cisterna magna had postoperative vocal cord paresis. All complicated cases had severe adhesion of tumor capsule with brainstem or cranial nerve. The mean duration of follow up was 26 months. The overall outcome was improvement of symptoms and signs in 6 cases and stationary 4 cases. During follow up, imaging study was done in 7 patients and none of them had finding of tumor recurrence. Conclusion : We conclude that recurrence of tumor is rare in both total and subtotal resected cases, but long-term follow-up is required. Aggressive removal of tumor capsule that adhesed to brianstem or cranial nerve is avoided for preventing severe postoperative complication.

• Clinical and Experimental Pediatrics
• /
• v.51 no.12
• /
• pp.1363-1367
• /
• 2008

Cavernous hemangioma can occur in the entire brain but rarely in cerebellum, especially in the pediatric age group. Headache, seizure, gait disturbance, recurrent bleeding may be seen. This tumor is a relatively benign condition but if the lesion located in the posterior fossa or the brain stem bleeds, irreversible brain damage may occur because of its restrictive space. Moreover, it must be differentiated from malignant tumors. We report 12.6 year-old boy who represented posterior neck myalgia as the presenting symptom. The pain continued for about a month despite analgesic medications. Brain MRI showed intracranial hemorrhage in the left cerebellum (4.5 cm) representing repeated hemorrhages at different times and originated from the cavernous hemangioma accompanied by mild hydrocephalus. The lesion was surgically removed successfully and the cavernous hemangioma was confirmed by pathologic findings. After the follow-up period of 14 months, he is in good condition without any complications.

• Journal of the Korean Society of Radiology
• /
• v.81 no.4
• /
• pp.979-984
• /
• 2020

Cri-du-chat syndrome is a rare genetic disorder in which the patient presents with a characteristic high-pitched monotonous cry and recurrent aspiration pneumonia, attributed to abnormalities in the larynx, epiglottis, and nervous system. The most prominent brain MRI findings are the presence of pontine and cerebellar hypoplasia, which primarily involve posterior cranial fossa structures. Although atrophy of supratentorial structures were also a common radiological finding, it was considered to be a secondary change due to pontine hypoplasia. Here, we present the case of a three-month-old patient presenting with cri-du-chat at our institution. The patient also showed the presence of prominent pontine hypoplasia similar to previously reported cases; however, contrary to other cases, there was a general delayed myelination of brain instead of decreased myelination of anterior limb of internal capsule. Since the larynx, pons, and cerebellum all originated from similar notochord level, which suggests anomaly in early stage of development, laryngeal, and brain anomaly characteristically observed in the cridu-chat syndrome.

• Investigative Magnetic Resonance Imaging
• /
• v.5 no.2
• /
• pp.149-154
• /
• 2001

Purpose : Our aim was to evaluate the usefulness of fluid-attenuated inversion recovery (FLAIR) MR imaging for detection of acute subarachnoid hemorrhage (SAH) compared with unenhanced CT. Materials and methods ; We compared FLAIR MR images with unenhanced CT scans in 28 patients with acute SAH. Findings of SAH on CT and MR images were graded as 0 (absence), 1 (suspicious), 2 (definite) in the cerebral sulci, sylvian fissure, basal cistern, and cisterns of the posterior fossa. We also compared FLAIR MR images of 28 patients with those of 35 normal subjects, and then the sensitivity, specificity, and diagnostic accuracy of FLAIR MR image for detection of acute SAH were calculated. Results : FLAIR MR image was superior to CT in detecting SAH in the posterior fossa ($1.41{\pm}0.74{\;}vs{\;}0.78{\pm}0.80$; p<0.05) and cortical sulci ($1.11{\pm}0.80{\;}vs{\;}0.70{\pm}0.83$; p<0.05). There was no significant difference between FLAIR MR image and CT in detecting SAH in the basal cistern and sylvian fissure. The sensitivity, specificity, and diagnostic accuracy of FLAIR MR image for detection of SAH were 100% in all. Conclusion : FLAIR MR image is useful in detecting acute SAH, especially in patients with small amount of SAH or SAH in the posterior fossa.

• Journal of Korean Neurosurgical Society
• /
• v.30 no.2
• /
• pp.211-216
• /
• 2001

Hemorrhage due to capillary telangiectasia is rare. We report a case of capillary telangiectasia presenting with repeated cerebellar hemorrhage in a 38-year-old male. To our knowledge this is the first case of repeated cerebellar hemorrhage from the capillary telangiectasia. At the first operation, we removed hematoma only, but rebleeding occurred repeatedly in the same area. Finally, we evacuated the recurrent hematoma and vascular mass of capillary telangiectasia at the second operation under surgical microscope. Based on the findings of this case and a review of the literature, we conclude that capillary telangiectasia can be the cause of the massive repeated hemorrhage.