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Öğe Contribution of fetal magnetic resonance imaging in the evaluation of neurosonographically detected cases of isolated mild and moderate cerebral ventriculomegaly(Wiley, 2022) Adıyaman, Duygu; Öztekin, Özgür; Kuyucu, Melda; Atakul, Bahar K.; Toklu, Gizem; Aykut, Ismail; Yıldırım, Alkım G. S.Aim This study aimed to present the contribution of prenatal magnetic resonance imaging (MRI) in the diagnosis of fetuses that were previously identified as isolated mild and moderate cerebral ventriculomegaly (VM) by ultrasound (US). Methods The data between February 2013 and August 2020 were collected for women who were diagnosed with isolated mild or moderate fetal VM by US and subsequently underwent a fetal MRI. Results Among 321 women, 21 (6.5%) had a clinically important additional finding after MRI. Twelve of 276 (4.3%) fetuses with mild VM and 9 of 45 (20%) with moderate VM had turned out to have additional central nervous system abnormalities. Additional findings were detected more in fetuses with moderate VM, mothers with an anterior-located placenta, and mothers with higher body mass indexes (BMIs) with statistical significance (p = 0.001, p = 0.013, p = 0.036, respectively). The most common additional MRI finding was grade 3 or 4 germinal matrix hemorrhage, which was detected in 11 of 21 fetuses (52.3%). Conclusions Considering the countries' health policies, prenatal MRI would contribute mostly to the diagnosis of fetuses with moderate VM, pregnancies with anterior-located placenta, and mothers with high BMIs. According to our data, we believe that MRI will be valuable, especially in the diagnosis of grade 3 and 4 intracranial hemorrhage group.Öğe Do fetal isolated mild venticulomegaly make any difference in regional ADC values at magnetic resonans imaging?(Dr Behcet Uz Cocuk Hastaliklari Ve Cerrahisi, 2021) Öcal, Zeynep Ayvat; Öztekin, Özgür; Öztekin, DenizObjective: Ventriculomegaly may not only develop secondary to a process,but it may also be in the form of isolated ventriculomegaly with no specific reason. MRI is performed to show the presence of accompanying pathologies.In this study, we measured ADC values in mild ventriculomegaly cases and aimed to investigate the role of ADC value measurements in predicting neurological prognosis in isolated mild ventriculomegaly during MRI. Methods: In our study, ADC values were measured of 37 patients detected to be present with mild ventriculomegaly and 17 fetuses in the control group who had no additional central nervous system patology. For the measurement, ROI was placed in differtent brain regions (frontal lobe white matter,occipital lobe white matter, basal ganglia, thalamus, cerebellum and pons). The analysis of the data obtained was performed using the SPSS (20th version) program. MannWhitney U test was applied. Statistical significance level was set as p<0.05. Results: There was no statistically significant difference between the isolated mild ventriculomegaly and the control group in terms of the mean maternal age (p=0.160). Also, no statistically significant difference was observed between the mean gestational age in the ventriculomegaly group and the control group (p=0.890). There was also no statistically significant difference between ADC measurements in different brain regions in the isolated mild ventriculomegaly and the control group (p=0.807). Conclusion: In order to determine the prognosis in isolated mild ventriculomegaly, other quantitative parameters such as ADC measurement, beyond morphological evaluation and diameter measurement should be determined, and also we need more studies comprising more cases in this field.Öğe Evidence of disrupted rhombic lip development in the pathogenesis of Dandy-Walker malformation(Springer, 2021) Haldipur, Parthiv; Bernardo, Silvia; Aldinger, Kimberly A.; Sivakumar, Tarika; Millman, Jake; Sjoboen, Alexandria H.; Millen, Kathleen J.; Öztekin, ÖzgürDandy-Walker malformation (DWM) and Cerebellar vermis hypoplasia (CVH) are commonly recognized human cerebellar malformations diagnosed following ultrasound and antenatal or postnatal MRI. Specific radiological criteria are used to distinguish them, yet little is known about their differential developmental disease mechanisms. We acquired prenatal cases diagnosed as DWM and CVH and studied cerebellar morphobiometry followed by histological and immunohistochemical analyses. This was supplemented by laser capture microdissection and RNA-sequencing of the cerebellar rhombic lip, a transient progenitor zone, to assess the altered transcriptome of DWM vs control samples. Our radiological findings confirm that the cases studied fall within the accepted biometric range of DWM. Our histopathological analysis points to reduced foliation and inferior vermian hypoplasia as common features in all examined DWM cases. We also find that the rhombic lip, a dorsal stem cell zone that drives the growth and maintenance of the posterior vermis is specifically disrupted in DWM, with reduced proliferation and self-renewal of the progenitor pool, and altered vasculature, all confirmed by transcriptomics analysis. We propose a unified model for the developmental pathogenesis of DWM. We hypothesize that rhombic lip development is disrupted through either aberrant vascularization and/or direct insult which causes reduced proliferation and failed expansion of the rhombic lip progenitor pool leading to disproportionate hypoplasia and dysplasia of the inferior vermis. Timing of insult to the developing rhombic lip (before or after 14 PCW) dictates the extent of hypoplasia and distinguishes DWM from CVH.Öğe Radiomic phenotypes distinguish atypical teratoid/rhabdoid tumors from medulloblastoma(Amer Soc Neuroradiology, 2021) Zhang, M.; Wong, S. W.; Lummus, S.; Han, M.; Radmanesh, A.; Ahmadian, S. S.; Yeom, K. W.; Öztekin, ÖzgürBACKGROUND AND PURPOSE: Atypical teratoid/rhabdoid tumors and medulloblastomas have similar imaging and histologic features but distinctly different outcomes. We hypothesized that they could be distinguished by MR imaging?based radiomic phenotypes. MATERIALS AND METHODS: We retrospectively assembled T2-weighted and gadolinium-enhanced T1-weighted images of 48 posterior fossa atypical teratoid/rhabdoid tumors and 96 match-paired medulloblastomas from 7 institutions. Using a holdout test set, we measured the performance of 6 candidate classifier models using 6 imaging features derived by sparse regression of 900 T2WI and 900 T1WI Imaging Biomarker Standardization Initiative?based radiomics features. RESULTS: From the originally extracted 1800 total Imaging Biomarker Standardization Initiative?based features, sparse regression consistently reduced the feature set to 1 from T1WI and 5 from T2WI. Among classifier models, logistic regression performed with the highest AUC of 0.86, with sensitivity, specificity, accuracy, and F1 scores of 0.80, 0.82, 0.81, and 0.85, respectively. The top 3 important Imaging Biomarker Standardization Initiative features, by decreasing order of relative contribution, included voxel intensity at the 90th percentile, inverse difference moment normalized, and kurtosis?all from T2WI. CONCLUSIONS: Six quantitative signatures of image intensity, texture, and morphology distinguish atypical teratoid/rhabdoid tumors from medulloblastomas with high prediction performance across different machine learning strategies. Use of this technique for preoperative diagnosis of atypical teratoid/rhabdoid tumors could significantly inform therapeutic strategies and patient care discussions.Öğe The role of the fetal MRI to predict the postnatal survival in fetuses with congenital diaphragmatic hernia(Dr Behcet Uz Cocuk Hastaliklari Ve Cerrahisi, 2021) Sarioğlu, Fatma Ceren; Sarıoğlu, Orkun; Yılmaz İnci Turkan; Atakul, Bahar Konuralp; Öztekin, Deniz; Öztekin, ÖzgürObjective: To assess the role of the magnetic resonance imaging (MRI) to predict the postnatal survival in patients with congenital diaphragmatic hernia (CDH). Method: 25 patients with CDH who had fetal MRI between 2015 and 2020 were enrolled in this retrospective study. Patients were divided into two groups according to the postnatal survival at 30 days of age: alive and dead. The fetal MRI images were assessed to calculate the lung-to-liver signal intensity ratio (LLSIR), and the total lung volume (TLV). In addition, the site of the defect (right or left), accompanying liver herniation (present or absent), detectable-ipsilateral lung parenchyma at the apex (present or absent) were also recorded. MRI images were evaluated by two pediatric radiologists. A p value lesser than 0.05 was considered statistically significant. Results: Among 25 fetuses, 6 were alive and 19 were dead within 30 days after birth. The detectable lung parenchyma had a relationship with the alive group (p = 0.023). Observed-to-expected TLV (p = 0.001) and LLSIR (p = 0.023) were significantly lower in the dead group. Using the cutoff values for the observed-to-expected TLV as 0.27 (a sensitivity of 84%, a specificity of 84%) and for the LLSIR as 2.02 (a sensitivity of 89%, a specificity of 67%) were found as predictors for death. Conclusion: The postnatal survival in CDH may be predicted using the observed-to-expected TLV and LLSIR on the fetal MRI. The presence of the detectable-ipsilateral lung parenchyma at the apex may also be associated with the postnatal survival.
