Diagnostic Value of SusceptibilityWeighted MRI in Differentiating Cerebellopontine Angle Schwannoma from Meningioma

Background@#Differentiation of cerebellopontine angle (CPA) schwannoma from meningioma is often a difficult process to identify.Purpose: To identify imaging features for distinguishing CPA schwannoma from meningioma and to investigate the usefulness of susceptibility-weighted imaging (SWI) in differentiating them. @*Materials and Methods@#Between March 2010 and January 2015, this study pathologically confirmed 11 meningiomas and 20 schwannomas involving CPA with preoperative SWI were retrospectively reviewed. Generally, the following MRI features were evaluated: 1) maximal diameter on axial image, 2) angle between tumor border and adjacent petrous bone, 3) presence of intratumoral dark signal intensity on SWI, 4) tumor consistency, 5) blood-fluid level, 6) involvement of internal auditory canal (IAC), 7) dural tail, and 8) involvement of adjacent intracranial space. On CT, 1) presence of dilatation of IAC, 2) intratumoral calcification, and 3) adjacent hyperostosis were evaluated. All features were compared using Chi-squared tests and Fisher’s exact tests. The univariate and multivariate logistic regression analysis were performed to identify imaging features that differentiate both tumors. @*Results@#The results noted that schwannomas more frequently demonstrated dark spots on SWI (P = 0.025), cystic consistency (P = 0.034), and globular angle (P = 0.008); schwannomas showed more dilatation of internal auditory meatus and lack of calcification (P = 0.008 and P = 0.02, respectively). However, it was shown that dural tail was more common in meningiomas (P < 0.007). In general, dark spots on SWI and dural tail remained significant in multivariate analysis (P = 0.037 and P = 0.012, respectively). In this case, the combination of two features showed a sensitivity and specificity of 80% and 100% respectively, with an area under the receiver operating characteristic curve of 0.9. @*Conclusion@#In conclusion, dark spots on SWI were found to be helpful in differentiating CPA schwannoma from meningioma. It is noted that combining dural tail with dark spots on SWI yielded strong diagnostic value in differentiating both tumors.

Artificial Intelligence in Health Care: Current Applications and Issues

In recent years, artificial intelligence (AI) technologies have greatly advanced and become a reality in many areas of our daily lives. In the health care field, numerous efforts are being made to implement the AI technology for practical medical treatments. With the rapid developments in machine learning algorithms and improvements in hardware performances, the AI technology is expected to play an important role in effectively analyzing and utilizing extensive amounts of health and medical data. However, the AI technology has various unique characteristics that are different from the existing health care technologies. Subsequently, there are a number of areas that need to be supplemented within the current health care system for the AI to be utilized more effectively and frequently in health care. In addition, the number of medical practitioners and public that accept AI in the health care is still low;moreover, there are various concerns regarding the safety and reliability of AI technologyimplementations. Therefore, this paper aims to introduce the current research and application status of AI technology in health care and discuss the issues that need to be resolved.

Seed-Based Resting-State Functional MRI for Presurgical Localization of the Motor Cortex: A Task-Based Functional MRI-Determined Seed Versus an Anatomy-Determined Seed

OBJECTIVE: For localization of the motor cortex, seed-based resting-state functional MRI (rsfMRI) uses the contralateral motor cortex as a seed. However, research has shown that the location of the motor cortex could differ according to anatomical variations. The purpose of this study was to compare the results of rsfMRI using two seeds: a template seed (the anatomically expected location of the contralateral motor cortex) and a functional seed (the actual location of the contralateral motor cortex determined by task-based functional MRI [tbfMRI]). MATERIALS AND METHODS: Eight patients (4 with glioma, 3 with meningioma, and 1 with arteriovenous malformation) and 9 healthy volunteers participated. For the patients, tbfMRI was performed unilaterally to activate the healthy contralateral motor cortex. The affected ipsilateral motor cortices were mapped with rsfMRI using seed-based and independent component analysis (ICA). In the healthy volunteer group, both motor cortices were mapped with both-hands tbfMRI and rsfMRI. We compared the results between template and functional seeds, and between the seed-based analysis and ICA with visual and quantitative analysis. RESULTS: For the visual analysis, the functional seed showed significantly higher scores compared to the template seed in both the patients (p = 0.002) and healthy volunteers (p < 0.001). Although no significant difference was observed between the functional seed and ICA, the ICA results showed significantly higher scores than the template seed in both the patients (p = 0.01) and healthy volunteers (p = 0.005). In the quantitative analysis, the functional seed exhibited greater similarity to tbfMRI than the template seed and ICA. CONCLUSION: Using the contralateral motor cortex determined by tbfMRI as a seed could enhance visual delineation of the motor cortex in seed-based rsfMRI.

Clinical Features of Late-Onset Circulatory Collapse in Preterm Infants

PURPOSE: This study aimed to investigate the incidence and clinical features of late-onset circulatory collapse (LCC) in preterm infants. METHODS: Medical records of 327 preterm infants (born before 32 gestational weeks) admitted to the neonatal intensive care unit of Seoul National University Bundang Hospital between January 2014 and December 2017 were reviewed. LCC was defined as sudden onset of refractory hypotension occurring after 7 days of life without obvious causes, which responded to glucocorticoid administration. Clinical characteristics and outcomes in infants with LCC were compared with those in infants with hypotension associated with identifiable causes, which developed after 7 days of life. RESULTS: Among 327 preterm infants who enrolled in this study, 65 infants developed hypotension with oliguria after 7 days of life. Among these 65 infants, 35 (53.8%) met the criteria for LCC and 30 (46.2%) were diagnosed with hypotension associated with other identifiable causes. No statistically significant differences were observed in the baseline pre- and perinatal characteristics between infants with LCC and those with hypotension associated with other causes. Infants with hypotension associated with other causes showed a higher mortality rate than those with LCC (33.3% vs. 5.7%, P=0.004). The mean gestational age and birth weight of infants with LCC were 27+5±2+1 weeks and 963±245 g, respectively. LCC occurred at a mean postnatal age of 18 days. The median body weight at the time of diagnosis of LCC was 1,200 g. No association was observed between LCC and gestational age. CONCLUSION: Among preterm infants born before 32 gestastional weeks who developed hypotension after 7 days of life, nearly 50% were diagnosed with LCC without apparent identifiable causes. Infants with LCC showed a lower mortality rate than those with hypotension associated with other causes.

Three Korean patients with Cantú syndrome caused by mutations in ABCC9 and their clinical manifestations

Cantú syndrome (CS, OMIM 239850) is a very rare autosomal dominantly inherited genetic disease characterized by congenital hypertrichosis, neonatal macrosomia, a distinct facial features such as macrocephaly, and cardiac defects. Since the first description by Cantú et al. in 1982, about 50 cases have been reported to date. Recently, two causative genes for CS has been found by using exome sequencing analyses: ABCC9 and KCNJ8 . Most cases of clinically diagnosed CS have resulted from de novo mutations in ABCC9. In this study, we report three independent Korean children with CS resulting from de novo ABCC9 mutations. Our patients had common clinical findings such as congenital hypertrichosis, distinctive facial features. One of them showed severe pulmonary hypertension and hypertrophic cardiomyopathy, which require medical treatment. And, two patients had a history of patent ductus arteriosus. Although two of our patients had shown early motor developmental delay, it was gradually improved during follow-up periods. Although CS is quite rare, there are the concerns about development of various cardiac problems in the lifetime. Therefore, an accurate diagnosis followed by appropriate management and genetic counseling should be provided to CS patients.

The Association between Admission Hypothermia and Neonatal Outcomes in Very Low Birth Weight Infants

PURPOSE: We aimed to evaluate the effect of admission hypothermia on neonatal outcomes in very low birth weight infants (VLBWIs). METHODS: Medical records of 153 preterm infants, with birth weights <1,500 g and gestational ages <32 weeks, were retrospectively reviewed. The clinical characteristics and neonatal outcomes in infants who experienced moderate hypothermia during the first hour of life (Group I) were compared to those in infants with mild hypothermia or normothermia (Group II). RESULTS: Fifty of 153 infants experienced moderate hypothermia after birth. Group I had lower birth weight than Group II (867.8±304.4 g vs. 1,140.3±247.5 g, P<0.001), and were younger than Group II (27.6±2.6 weeks vs. 29.1±1.9 weeks, P<0.001). Adjusted proportion of moderate to severe bronchopulmonary dysplasia (BPD) and persistent pulmonary hypertension of newborn (PPHN) were higher in Group I than in Group II (56% vs. 21.8%, P=0.005), (9.1% vs. 1.5%, P=0.019). Multiple logistic regression analysis that did not control for PPHN (model II) showed that gestational age (Odds ratio [OR] 0.93, P=0.001), moderate hypothermia (OR 4.07, P=0.013), and surgical patent ductus arteriosus (OR 4.96, P=0.023) were associated with moderate to severe BPD. Association of moderate hypothermia with moderate to severe BPD was invalid when further multiple logistic regression analysis adjusting for PPHN (model I), which had a strong association with moderate to severe BPD (OR=15.46, P=0.039), was performed. CONCLUSION: Moderate hypothermia after birth in VLBWIs was associated with PPHN and moderate to severe BPD. The association between moderate hypothermia and moderate to severe BPD might be mediated by PPHN.

Clinical Utility of Prominent Hypointense Signals in the Draining Veins on Susceptibility-Weighted Imaging in Acute Cerebral Infarct: As a Marker of Penumbra and a Predictor of Prognosis

PURPOSE: A relative increase in deoxyhemoglobin levels in hypoperfused tissue can cause prominent hypointense signals in the draining veins (PHSV) within areas of impaired perfusion in susceptibility-weighted imaging (SWI). The purpose of this study is to evaluate the usefulness of SWI in patients with acute cerebral infarction by evaluating PHSV within areas of impaired perfusion and to investigate the usefulness of PHSV in predicting prognosis of cerebral infarction. MATERIALS AND METHODS: In 18 patients with acute cerebral infarction who underwent brain MRI with diffusion-weighted imaging and SWI and follow-up brain MRI or CT, we reviewed the presence and location of the PHSV within and adjacent to areas of cerebral infarction qualitatively and measured the signal intensity difference ratio of PHSVs to contralateral normal appearing cortical veins quantitatively on SWI. The relationship between the presence of the PHSV and the change in the extent of infarction in follow-up images was analyzed. RESULTS: Of the 18 patients, 10 patients showed progression of the infarction, and 8 patients showed little change on follow-up imaging. On SWI, of the 10 patients with progression 9 patients showed peripheral PHSV and the newly developed infarctions corresponded well to area with peripheral PHSV on initial SWI. Only one patient without peripheral PHSV showed progression of the infarct. The patients with infarction progression revealed significantly higher presence of peripheral PHSV (p=0.0001) and higher mean signal intensity difference ratio (p=0.006) comparing to the patients with little change. CONCLUSION: SWI can demonstrate a peripheral PHSV as a marker of penumbra and with this finding we can predict the prognosis of acute infarction. The signal intensity difference of PHSV to brain tissue on SWI can be used in predicting prognosis of acute cerebral infarction.

Small Bowel Volvulus Induced by Mesenteric Lymphangioma in an Adult: a Case Report

Mesenteric lymphangiomas are rare abdominal masses that are seldom associated with small bowel volvulus, and especially in adult patients. We report here on an unusual case of small bowel volvulus that was induced by a mesenteric lymphangioma in a 43-year-old man who suffered from repeated bouts of abdominal pain. At multidetector CT, we noticed whirling of the cystic mesenteric mass and the adjacent small bowel around the superior mesenteric artery. Small bowel volvulus induced by the rotation of the mesenteric lymphangioma was found on exploratory laparotomy. Lymphangioma should be considered as a rare cause of small bowel volvulus in adult patients.

Imaging Assessment of Primary Prostate Cancer, Focused on Advanced MR Imaging and PET/CT

Imaging assessment of prostate cancer is one of the most difficult sections of oncology imaging. Detecting, localizing and staging of the primary prostate cancer by preoperative imaging are still challenging for the radiologist. Magnetic resonance (MR) imaging provides excellent soft tissue contrast and is widely used for solid organ imaging, but results of preoperative imaging of the prostate gland with conventional MR imaging is unsatisfactory. Positron emission tomography and computed tomography (PET/CT) is the cornerstone in oncology imaging, but some limitations prohibit the assessment of primary prostate cancer with PET or PET/CT. Recent studies to overcome these insufficient accuracies of imaging evaluation of primary prostate cancers with advanced MR techniques and PET and PET/CT are reported. In this article, we review the imaging findings of prostate cancer on variable modalities, focused on MR imaging and PET/CT.

High-intensity Focused Ultrasound Treatment (HIFU) for the Advanced Pancreatic Cancer

PURPOSE: We wanted to evaluate the levels of effect and safety of high-intensity focused ultrasound ablation (HIFU) for treating patients with advanced pancreatic cancer. MATERIALS AND METHODS: Nineteen sessions of HIFU, with the patients under general anesthesia, were performed in 18 patients with advanced pancreatic cancer. The change of the gray-scale of the target lesion was analyzed during HIFU, and MRI was performed before and after HIFU. We assessed the extent of coagulative necrosis, the change of pain and the complications after HIFU. The change of tumor size and the survival of patients were also evaluated. RESULTS: The average size of tumor was 4 cm in diameter. Eighty nine percent of the target tumors showed increased echogenicity. On MRI, necrosis of the entire target tumor occurred in 79% of the patients. After treatment, effective pain relief was noted in 89% of the patients. There were no major complications. No size increase of the treated tumor was noted during 24 weeks of follow-up for 10 patients. Six patients among 12 patients who were available for follow-up are still alive and they are receiving chemotherapy. Six patients expired due to other disease or progression of metastasis. CONCLUSION: HIFU is a safe method without any major complications, and it is effective for inducing tumor necrosis and achieving pain control for patients with advanced pancreatic cancer.