Background: This study aimed to assess the diagnostic feasibility of radiomics analysis based on magnetic resonance (MR)-proton density fat fraction (PDFF) for grading hepatic steatosis in patients with suspected non-alcoholic fatty liver disease (NAFLD). Methods: This retrospective study included 106 patients with suspected NAFLD who underwent a hepatic parenchymal biopsy. MR-PDFF and MR spectroscopy were performed on all patients using a 3.0-T scanner. Following whole-volume segmentation of the MRPDFF images, 833 radiomic features were analyzed using a commercial program. Radiologic features were analyzed, including median and mean values of the multiple regions of interest and variable clinical features. A random forest regressor was used to extract the important radiomic, radiologic, and clinical features. The model was trained using 20 repeated 10-fold cross-validations to classify the NAFLD steatosis grade. The area under the receiver operating characteristic curve (AUROC) was evaluated using a classifier to diagnose steatosis grades. Results: The levels of pathological hepatic steatosis were classified as low-grade steatosis (grade, 0–1; n = 82) and high-grade steatosis (grade, 2–3; n = 24). Fifteen important features were extracted from the radiomic analysis, with the three most important being wavelet-LLL neighboring gray tone difference matrix coarseness, original first-order mean, and 90th percentile. The MR spectroscopy mean value was extracted as a more important feature than the MR-PDFF mean or median in radiologic measures. Alanine aminotransferase has been identified as the most important clinical feature. The AUROC of the classifier using radiomics was comparable to that of radiologic measures (0.94 ± 0.09 and 0.96 ± 0.08, respectively). Conclusion MR-PDFF-derived radiomics may provide a comparable alternative for grading hepatic steatosis in patients with suspected NAFLD.

Gastric metastasis from renal cell carcinoma (RCC) is extremely rare, occurring in 0.2% of all RCC cases. Owing to its low prevalence, metachronous gastric metastasis from RCC may be underdiagnosed, and the imaging findings have not been well-established. Herein we present a case of metastatic RCC manifesting as a gastric polyp in a 70-year-old female along with a literature review on the imaging findings of gastric metastases from RCC. In patients presenting with gastric hyper-enhancing polypoid masses, metastasis from RCC should be considered as a differential diagnosis.

Gastrointestinal tract involvement in undifferentiated pleomorphic sarcoma (UPS) is extremely rare. To the authors' knowledge, only 21 cases of primary small bowel UPS have been reported in the literature available in English. Reported CT findings in primary small bowel UPS have been nonspecific, and MRI findings have been reported in only one case. The present article describes a case involving a 72-year-old male with histologically confirmed primary UPS arising from the ileum, focusing on both CT and magnetic resonance enterography findings. On CT, primary small bowel UPS was noted as a heterogeneously enhanced small bowel mass without obstruction. Magnetic resonance enterography revealed heterogeneous intermediate T1 and T2 signal intensity, with hemorrhagic or necrotic foci within the mass and heterogeneous enhancement. The differential diagnosis included malignant gastrointestinal tumor; however, the prognosis of UPS is worse, with higher incidences of extra-abdominal metastasis.

Schwannoma is a benign nerve sheath tumor that involves Schwann cells mostly found in the head, neck, posterior mediastinum and extremities. Schwannoma develops rarely in the retroperitoneum; thus, renal schwannoma is extremely uncommon. Differentiation of renal schwannoma from renal cell carcinoma is difficult with radiologic analysis. A few cases of these tumors have been reported in literature, and little has been described regarding imaging appearances. In this study, we present a rare case of a renal schwannoma, resembling renal cell carcinoma, with radiological correlations.

Progressive transformation of germinal centers (PTGC) is an atypical feature seen in lymph nodes with unknown pathogenesis. PTGC most commonly presents in adolescent and young adult males as solitary painless lymphadenopathy with various durations. Cervical nodes are the most commonly involved ones while involvements of axillary and inguinal nodes are less frequent. PTGC develops extremely rarely in other locations. We report a rare case of solitary mass present in the presacral space. The mass as subsequently proven to be PTGC. To the best of our knowledge, PTGC in the presacral space has not been previously reported in the literature.
Adolescent ; Germinal Center* ; Humans ; Lymph Nodes ; Lymphatic Diseases ; Magnetic Resonance Imaging* ; Male ; Young Adult

Adenosarcoma of the uterus is a rare biphasic tumor containing benign glandular epithelial and malignant mesenchymal components. The tumor has been reported to be associated with antiestrogen therapy, particularly tamoxifen, but there have been a few case reports with MRI. We present two cases of MRI findings of uterine adenosarcoma after antiestrogen therapy, tamoxifen and toremifene in breast cancer patients. The tumor presents as a large polypoid mass occupying the endometrial cavity, and may protrude into the vagina. On MRI, the tumor typically shows solid components with scattered small cysts and heterogeneous enhancement. These findings are not significantly different from conventional adenosarcoma.
Adenosarcoma* ; Breast Neoplasms ; Estrogen Receptor Modulators ; Humans ; Magnetic Resonance Imaging* ; Tamoxifen ; Toremifene ; Uterus ; Vagina

Obstructed hemivagina and ipsilateral renal anomaly (OHVIRA) syndrome is an uncommon congenital abnormality of the female urogenital tract characterized by the triad of uterine didelphys, obstructed hemivagina, and ipsilateral renal agenesis. A 13-year-old female presented with acute lower abdominal pain. Magnetic resonance imaging (MRI) revealed uterine didelphys, hematometrocolpos, obstructed hemivagina, and right ipsilateral agenesis, consistent with OHVIRA syndrome. Also, a well-defined mass with fluid signal intensity, mimicking adnexal neoplasm was seen in the right lower pelvic cavity adjacent to the posterior wall of the bladder. Vaginal septotomy and drainage of hematometrocolpos were done initially, but unilateral hysterectomy was later performed to relieve the patient's symptoms. The cystic mass in the right lower pelvic cavity was also excised and confirmed as a blind megaureter.
Abdominal Pain ; Adolescent ; Congenital Abnormalities ; Drainage ; Female ; Humans ; Hysterectomy ; Magnetic Resonance Imaging* ; Urinary Bladder

PURPOSE: We wanted to estimate the prevalence and risk factors of overactive bladder(OAB) in Korean children who were 5-13 years of age, according to the definition of OAB. MATERIALS AND METHODS: A randomly selected cross-sectional study was conducted on 26 kindergartens and 27 elementary schools nationwide in Korea. There were 19,240 children; a parent was asked to complete the questionnaires, which included items about OAB and the children's voiding and defecating habits. OAB was defined as urgency with or without urge incontinence, and usually with an increased daytime frequency and nocturia(ICCS 2006, group A) or an increased daytime frequency(>8 times/day) and/or urge urinary incontinence with or without urgency (group B); its prevalence and associated factors were investigated. RESULTS: The response rate for the questionnaires was 85.84%. The overall prevalence of OAB was 16.59%(group A) and 18.79%(group B). For groups A and B, the prevalence of OAB decreased with age from 22.89% to 12.16% and from 40.44% to 9.60%, respectively(p=0.0001). The overall rate of wet and dry OAB was 26.97% and 73.03%, respectively. Compared to the normal group, the children with OAB had a higher prevalence of nocturnal enuresis(NE), constipation, fecal incontinence, a history of urinary tract infection and delayed bladder control in both groups A and B(p<0.05). The rate of increased daytime frequency and urge incontinence were 3.69% and 2.31%(p=0.009), and 26.97% and 14.78%(p=0.0001) in group A and for the non-OAB children, respectively; their prevalence in group A decreased with age from 5.04% to 3.06% and from 45.74% to 18.50%, respectively(p=0.0001). CONCLUSIONS: The overall prevalence of OAB in group A for Korean children 5-13 years of age was similar to that in group B. However, the range of prevalence in group B was much more variable than that in group A. NE, constipation, fecal incontinence, a history of urinary tract infection and delayed bladder control may be risk factors for OAB in children.
Child ; Constipation ; Cross-Sectional Studies ; Fecal Incontinence ; Humans ; Korea ; Parents ; Prevalence ; Risk Factors ; Urinary Bladder ; Urinary Bladder, Overactive ; Urinary Incontinence ; Urinary Incontinence, Urge ; Urinary Tract Infections

PURPOSE: To evaluate the immunogenicity of hepatitis B vaccine among very low birth weight infants(VLBWI) who were vaccinated at 0, 1, 6 months of chronological age and to determine the factors associated with antibody formations. METHODS: A total of 243 VLBWI admitted to Seoul and Gangneung Asan Medical Center neonatal intensive care units from 1997 to 2004 were included. Of 243, 13 infants were born to HBs Ag positive mother. All infants were given DNA recombinant vaccine at 0, 1, and 6 months of chronological age. Infants born to HBs Ag positive mothers received hepatitis B immunoglobulin at birth and a total of 4 doses of vaccinations. An antibody level over 10 mIU/mL, tested at 3-4 months after last vaccination, was regarded as a positive seroconversion. RESULTS: The seroconversion rates were 84.4 percent and 84.5 percent for VLBWI and extremely low birth weight infants(ELBWI), respectively. Of 28 seronegative infants who were given revaccinations, 60.7 percent seroconverted, resulting in 95.3 percent, 97.5 percent seroconversion rates for VLBWI and ELBWI, respectively. 76.9 percent of infants born to HBsAg positive mothers seroconverted and none became hepatitis B carriers. Factors such as gestational age, sex, various neonatal illness, and kinds of vaccinations did not influence the formation of the hepatits B antibody, however, the higher the weight at time of first vacciation yielded better seroconversion rate. CONCLUSION: Revaccination of seronegative VLBWI after 3 doses of hepatitis B vaccinaton is very effective. Therefore, testing the immune status after the hepatitis B vaccination, a practice not routinely done, is highly recommended.
Chungcheongnam-do ; DNA ; Gangwon-do ; Gestational Age ; Hepatitis B Surface Antigens ; Hepatitis B Vaccines ; Hepatitis B* ; Hepatitis* ; Humans ; Immunization, Secondary ; Immunoglobulins ; Infant ; Infant, Low Birth Weight ; Infant, Newborn ; Infant, Very Low Birth Weight* ; Intensive Care Units, Neonatal ; Mothers ; Parturition ; Seoul ; Vaccination*

The ultimate goal in treating zygomatic complex fracture is to obtain an accurate, stable reduction while minimizing external scars and functional deformity. The present authors present our experiences with a single transconjunctival incision and two-point (inferior orbital rim and frontozygomatic suture) fixation in 53 patients with zygomatic complex fracture which were not comminuted. All patients had transconjunctival approaches with lateral canthal extensions, and six out of 53 patients also had an additional small (about less than 2 cm) gingivobuccal incision to achieve an accurate reduction. There were 3 minor complications, and the overall esthetics and functional results were satisfactory with a long term follow-up. Our method has the following advantages in the reduction of zygomatic complex fracture; It leaves only an inconspicuous lateral canthal scar. In addition, it provides excellent simultaneous visualization of the inferior orbital rim and frontozygomatic suture area. Hence, twopoint fixation through a single incision can be performed with a satisfactory stability.
Zygomatic Fractures/*surgery ; Treatment Outcome ; Surgical Procedures, Minimally Invasive/instrumentation/methods ; Osteotomy/*instrumentation/*methods ; Middle Aged ; Male ; Humans ; Fracture Fixation, Internal/*instrumentation/*methods ; Female ; Conjunctiva/*surgery ; Bone Plates ; Aged, 80 and over ; Aged ; Adult ; Adolescent