Background Pilocytic astrocytoma, medulloblastoma, and ependymoma are the most common pediatric CNS tumors seen at posterior cranial fossa and final diagnosis obtained by histopathology after surgical excision. Routine MRI study gives an idea about site and extension of the tumors but provide a little information about type and grade of tumors. ADC ratio had high sensitivity and specificity in differentiation between these tumors as regard type and grade according to tumor cellularity. Patients and methods Prospective study conducted on thirty pediatric patients (11 males and 19 females) with CNS posterior fossa masses, their ages ranged from 2 to 17 years (mean age of 8.7 years), conventional MRI, DWI, ADC value, and ADC ratio were done for all patients. Results ADC values were significantly different between pilocytic astrocytomas (1.43 ± 0.28 × 10−3) and medulloblastomas (0.71 ± 0. 21 × 10−3) with a P value < 0.001, also there was a significant difference when comparing medulloblastomas (0.71 ± 0.21 × 10−3) with ependymomas (1.04 × 10−3 ± 0.21) with a P value < 0.001. ADC ratio at a cutoff > 1.7 showed significant good power of discrimination of astrocytoma (AUC = 0.85) from ependymoma with 87.5% sensitivity and 93.3% specificity. Similarly, at cutoff ≤ 1.6-> 1.2 was a significant good predictor of ependymoma (AUC = 0.85) with 87.8% sensitivity and 99.5% specificity. While, ADC ratio ≤ 1.2 was significant excellent discriminator of medulloblastoma (AUC = 0.99) with 100% sensitivity and 90% specificity. Conclusion ADC ratio is a simple way used in distinguishing juvenile pilocytic astrocytoma, ependymoma, and medulloblastoma, which are the most frequent pediatric posterior fossa tumors. Cutoff ADC ratio of more than 1.7 characteristic of JPA with 87.5% sensitivity and 93.3% specificity, ADC ratio less than 1.1 characteristic of medulloblastoma with 100% sensitivity and 90% specificity. ADC ratios more than 1.1 and less than 1.7 characteristic of ependymoma with 87.8% sensitivity and 99.5% specificity. We recommended ADC ratio as a routine study in evaluation of pediatric CNS posterior fossa tumors.

Gastric volvulus (GV) is a rare condition in infants. The aim of this study was to define the management strategies of infants with GV based on their clinical and radiologic features. The medical records of 13 infants with a radiologically confirmed diagnosis of GV were retrospectively reviewed. Patients were divided into two groups according to the type of treatment (surgical vs conservative). Abdominal radiographs and upper gastrointestinal contrast studies allowed an unequivocal diagnosis in both groups. Group 1 included 3 infants with acute GV and 2 with chronic, intermittent secondary GV. Three patients had associated diaphragmatic defects, 1 had an ileocolic intussusception, and 1 had hypertrophic pyloric stenosis. The main presenting symptoms were vomiting, dehydration, respiratory distress, and abdominal pain and distention in acute cases and vomiting and failure to thrive in chronic cases. A laparotomy was required in all 5 infants with no recurrence of symptoms. Group 2 included 8 infants with idiopathic chronic GV, who were managed nonoperatively with gradual improvement of symptoms over 12 months. Based on our study, we conclude that: (1) laparotomy can be reserved for patients with either acute or chronic secondary GV; (2) conservative treatment is both safe and effective in infants with chronic idiopathic GV; and (3) routine gastropexy for all patients with a radiologic diagnosis of GV appears to be overtreatment.

The aim of this work is to evaluate the role of Doppler US and MRI in the diagnosis of placenta accreta. Patients and methods: During period between 2012 to 2013, 120 pregnant patients with previous cesarean section were investigated by ultrasound and Doppler and then in suspected cases MRI was obtained (10 cases). The Sonographic and MRI diagnoses were compared with the final pathologic or operative findings or with both. Results: The mean age of this study group was 29 years ranging from 20 to 40. Among patients with confirmed placenta accreta, the mean age was 32.25 ranging from 25 to 40 years. The mean parity of patients ranged from 1 to 6 with a mean of 1.6. Among patients with placenta accreta, the mean parity ranged from 2 to 6 with a mean of 3.75. The total number of cases with placenta accreta in this study was 4, all of which were previa. This was out of a total of 25 cases of placenta previa. Transabdominal US features were the presence of intraplacental lacunae (sonolucencies), loss of retroplacental clear zone and disruption of bladder-uterine serosa interface with smallest myometrial thickness <1 mm over site of placental implantation by using color Doppler ultrasonography, the most prominent color Doppler feature in this study was the presence of intraplacental lacunar flow. Magnetic resonance imaging accurately predicted placenta accreta in 4 of 4 cases with placenta accreta and correctly ruled out placenta accreta in the rest six cases. Conclusion:In conclusion, data of the present study show that the use of transabdominal color Doppler ultrasonography complemented by MRI in suspected cases improves the diagnostic accuracy in prediction of placenta accreta in patients with previous cesarean delivery.

Background: Cutaneous malignant melanoma (CMM) is a highly aggressive tumor with high tendency of return despite complete surgical removal. It has a high risk of dissemination to regional lymph nodes and visceral organs. The prognosis is highly dependent on lymph node involvement and distant metastases. Positron Emission Tomography with Computed Tomography (PET/CT) is a valuable non-invasive tool for the diagnosis and staging of patients with MM. The purpose of the present study was to evaluate the role of integrated (PET/CT) in staging, restaging, prognosis, and prediction of recurrence in patients with malignant melanoma. Results: Fifty malignant melanoma patients with age ranged from 28 to74 years (mean age 55.94 + 13.40 years) were 28 males (mean age 56.71 + 12.82) and 22 females (mean age 54.95 + 14.34). All our patients were histopathologically proven to have malignant melanoma. Twenty-one patients came for initial staging by 18F-FDG PET/CT. Their findings were compared with the reference standards and showed the sensitivity of 93.33%, specificity of 60%, and accuracy of 85.71% for primary staging. 18F-FDG PET/CT scan in 11 clinical suspicion patients of relapse after treatment showed the sensitivity of 100%, specificity of 66.66%, positive predictive value of 88.88%; negative predictive value of 100%; and accuracy of 90.90%. FDG-PET/CT of whole body scan in 18 cases of stage IV melanoma showed sensitivity of 100%, specificity of 66.66%, and overall accuracy of 94.44% for detection of distant metastases. SUVmean and SUVmax in all studied groups were significantly higher in true positive more than true negative or false-positive patients diagnosed by PET/CT with high sensitivity (82.88-100%). Conclusion: PET/CT imaging enhanced diagnostic performance in detection of the primary malignancy, in followup of high-risk patients and patients with suspected or known local or distant recurrence, and in restaging of patients with known distant metastatic disease to assess tumor response.

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