PURPOSE: To describe the magnetic resonance (MR) findings of pigmented villonodular synovitis(PVNS) of the knee, and to evaluate the clinical value of MR in the diagnosis of PVNS. MATERIALS AND METHODS:MR imagings of seven patients with PVNS were studied. The type of lesion, presence of bony erosion, the signal intensity, and the relationship between contrast enhancement and signal intensity on T2-weighted images were analyzed, retrospectively. RESULTS: The lesion was mainly villous in three patients and nodular in four, and bony erosion was seen in one patient. On T2-weighted image, the signal intensity of the villous form was mixed iso- and hypointense in two, hypointense in one, and that of the nodular form was heterogeneous with hypo-, iso-, and hyperintensities. The hypointense portion on T2-weighted image showed poor contrast enhancement, which may suggest hemosiderin deposition or advanced fibrosis. The iso- or hyperintense portion on T2-weighted image showed strong enhancement, which suggest active cellular proliferation. CONCLUSION:MR imaging could be a very useful modality in the diagnosis as well as prediction of histological findings of the PVNS.
Cell Proliferation ; Diagnosis ; Fibrosis ; Hemosiderin ; Humans ; Knee* ; Magnetic Resonance Imaging* ; Retrospective Studies ; Synovitis, Pigmented Villonodular*

PURPOSE: To investigate MR imaging characteristics of the fracture healing process. MATERIALS AND METHODS: We performed MR-pathologic correlation of fractures experimentally produced by the three-point beding system inthe proximal tibias of 24 New Zealand white rabbits. Axial spin echo T1-weighted image(T1WI), T2-weighted image(T2WI) and T1WI after gadopentetate dimeglumine injection were obtained 1-28 days after fracture MR imaging was followed by freezing, sectioning along the MR imaging planes and histopathologic examinations. Changes in MR signal around the fractures were correlated with histopathologic findings. RESULTS: Hematomas and inflammatory tissue around the fractures, noted one day after fracture, showed slightly increased homogeneous signal intensityon T1WI, heterogeneous hyperintensity on T2WI and heterogeneous contrast enhancement. Granulation tissue,cartilage, and immature osteoid, noted 1-4 weeks after fracture, showed iso- or slight hyperintensity on T1WI, hyperintensity on T2WI and contrast enhancement. Hard callus containing ossified osteoid showed hypointensity onboth T1WI and T2WI without contrast enhancement. CONCLUSION: The characteristics of MR signal intensity and contrast enhancing pattern can explain the histopathology of the fracture healing process.
Bony Callus ; Fracture Healing ; Freezing ; Gadolinium DTPA ; Hematoma ; Magnetic Resonance Imaging* ; Rabbits ; Tibia*

PURPOSE: Acquired epileptic aphasia (AEA) accompanied by electroencephalogram (EEG) abnormality is a rare disease; therefore, there are few studies investigating the prognostic factors and treatment efficacy. We aimed to determine the therapeutic effects and prognostic factors for clinical seizure and neuropsychological function in acquired aphasia patients. METHODS: We retrospectively studied cases of AEA diagnosed at Severance Children's Hospital from January 2013 to October 2017. We evaluated the efficacy of antiepileptic drugs, steroids, and ketogenic diets (KD) in treating acquired aphasia. The EEG patterns and prognostic factors were predicted by the background EEG and frequency of spike and wave during sleep (SWS). RESULTS: The study analyzed 20 patients, 11 male and 9 female, with AEA. Aphasia most commonly occurred at 4 years of age, and clinical seizure was most likely to occur between 2 and 4 years of age and focal seizures were the most common seizure type. KD was shown to be the best treatment for clinical seizure in AEA patients. Patients with normal EEG background showed better responses to clinical seizure treatment and improvements in neuropsychological function. CONCLUSION KD and steroids generate the best therapeutic effects for clinical seizure in AEA patients. Improvements in neuropsychological function in AEA patients may be related to the EEG background and the SWS patterns. Additionally, the results suggest that the response of clinical seizure to antiepileptic drugs may also be related to the EEG background. However, the current study had some limitations and further research is needed.

To our knowledge, only one case of vaginal cavernous hemangioma in pregnancy has been reported all over the world and there is no report in Korea. The authors have experienced one case of vaginal cavernous hemangioma in pregnancy and report our case with a brief review of literature.
Hemangioma, Cavernous* ; Korea ; Pregnancy* ; Vagina

PURPOSE: The creation and maintainance of radiology teaching materials is both laborious and very time-consuming but at a teaching hospital is important. Through use of the technology offered by today's worldwide web, this problem can be efficiently solved, and on this basis, we divised a multimedia radiology self-learning course for abdominal ultrasound and CT. MATERIALS AND METHODS: A combination of video and audio tapes has been used as teaching material; the authors digitized and converted these to Hypertext Mark-up Language(HTML) format. Films were digitized with a digital camera and compressed to Joint Photographic Expert Group (JPEG) format, while audio tapes were digitized with a sound recorder and compressed to Real Audio format. RESULTS: The self-learning course for abdominal ultrasound consists of 14 steps, and that for abdominal CT, 19 steps. Both provide images, voice anrrations, and related texts and graphics. The learner can navigate the course at his/her own speed, repeating or skipping any part, as required. CONCLUSION: 'Multimedia on the Worldwide Web' will facilitate easy management and maintenauce of a self-learning course. To make this more suitable for practical use, continual upgrading on the basis of experience is needed.
Hospitals, Teaching ; Hypermedia ; Internet* ; Joints ; Multimedia* ; Teaching Materials ; Tomography, X-Ray Computed ; Ultrasonography ; Voice

PURPOSE: Mutations in the cyclin-dependent kinase-like 5 (CDKL5) gene are associated with epileptic encephalopathy and severe cognitive impairment. We aim to characterize the association between this gene and treatment efficacy. METHODS: We retrospectively analyzed 10 patients who were treated at Severance Children's Hospital for epileptic encephalopathy who were subsequently diagnosed with a CDKL5 mutation using next-generation sequencing. RESULTS: Electroencephalography (EEG) results showed generalized pattern abnormalities in 60% (6/10) of patients with CDKL5 mutations. We analyzed the effects of three treatments, namely antiepileptic drugs (AEDs), ketogenic diet (KD), and steroids. A more than 50% reduction in seizures was observed in 12% (1/8) of patients treated with clobazam. KD treatment proved ineffective in most cases. In addition, a more than 50% reduction in seizures was observed in 57% (4/7) of patients treated with steroids. EEG analysis of patients treated effectively with steroids revealed that 75% (3/4) showed hypsarrhythmia and 25% (1/4) showed focal epileptiform. CONCLUSION In this study, as in other studies, AEDs and KD did not effectively control seizures in most patients with a CDKL5 mutation. However, steroid therapy reduced the frequency of seizures in patients who also exhibited hypsarrhythmia. This suggests that steroid treatment is helpful in cases of hypsarrhythmia with CDKL5 mutations.

PURPOSE: Childhood absence epilepsy (CAE) is a common form of idiopathic generalized epilepsy with onset middle childhood and has typically a good prognosis, but remission rates vary. We aimed to analyze unfavorable prognostic factors in children initially diagnosed with CAE. METHODS: We retrospectively reviewed 48 patients under 13 years of age who were diagnosed with CAE at the Severance Children's Hospital, Seoul, Korea. We analyzed clinical information including comorbidity through neuropsychological test. RESULTS: Thirteen of the 48 patients (27%) showed an unfavorable prognosis, with clinical seizures or seizure waves on electroencephalogram persistent even after 12 months of anticonvulsant therapy. The mean age at absence seizure onset was 6.51±2.36 years. The most commonly used antiepileptic drug (AED) was ethosuximide, and the median duration of initial AEDs was 25.63±24.41 months. The presence of comorbidity and clinical absence seizures after 6 months of AEDs correlated with an unfavorable prognosis. Motor seizures were the most unfavorable prognostic factor during follow-up. CONCLUSION This study shows that clinical absence seizures after 6 months of AED, comorbidity, and motor seizure are the most important predictive factors of an unfavorable prognosis for absence epilepsy in childhood. This study suggests that when these factors are observed, early intervention needs to be considered.

Purpose: This study examined the characteristics and outcomes of resective epilepsy surgery following corpus callosotomy (CC) in children with Lennox-Gastaut syndrome (LGS). Methods: We retrospectively analyzed 17 children with LGS who underwent resective surgery (RS) after CC over a span of 10 years, with a minimum of 2 years of follow-up, at a single tertiary epilepsy center in Korea. Results: Of the 17 patients, 13 (73.5%) demonstrated favorable surgical outcomes (Engel class I or II) at 1 year after RS, and eight (47.1%) were ultimately free of seizures 2 years after surgery. A significantly larger decrease in the number of anti-seizure medications taken from before to 2 years after the final surgical procedure was observed in the group that became seizure-free than in the group with persistent seizures (P=0.062). Furthermore, a significantly greater decline in daily adaptive function was found in the persistent seizure group (P=0.059). The baseline characteristics, results of presurgical evaluation, and treatment-related factors assessed prior to surgery showed no significant differences between the seizure-free group and the group with persistent seizures. Conclusion In conclusion, RS may be a viable option for patients with LGS who exhibit lateralization and/or localization on presurgical evaluation after CC, as the procedure may reveal a concealed primary focus. The proactive implementation of two-stage epilepsy surgery could provide significant seizure reduction and preservation of cognitive function in carefully selected patients with LGS.

Background: For the first time in Korea, we aimed to study the efficacy and safety of cannabidiol (CBD), which is emerging as a new alternative in treating epileptic encephalopathies. Methods: This study was conducted retrospectively with patients between the ages of 2–18 years diagnosed with Lennox-Gastaut syndrome (LGS) or Dravet syndrome (DS) were enrolled from March to October 2019, who visited outpatient unit at 3 and 6 months to evaluate medication efficacy and safety based on caregiver reporting. Additional evaluations, such as electroencephalogram and blood tests, were conducted at each period also. CBD was administered orally at a starting dose of 5 mg/kg/day, and was maintained at 10 mg/kg/day. Results: We analyzed 34 patients in the LGS group and 10 patients in the DS group between the ages of 1.2–15.8 years. In the 3-month evaluation, the overall reduction of seizure frequency in the LGS group was 52.9% (>50% reduction in 32.3% of the cases), and 29.4% in the 6-month evaluation (more than 50% reduction in 20.6%). In DS group, the reduction of seizure frequency by more than 50% was 30% and 20% in the 3-month and 6-month evaluation, respectively. Good outcomes were defined as the reduction of seizure frequency by more than 50% and similar results were observed in both LGS and DS groups. Adverse events were reported in 36.3% of total patients of which most common adverse events were gastrointestinal problems. However, no life-threatening adverse event was reported in both LGS and DS during the observation period. Conclusion In this first Korean study, CBD was safe and tolerable for use and could be expected to potentially reduce the seizure frequency in pediatric patients with LGS or DS.