In patients with the clinical suspicion of intracranial hypotension, we found that cutoff values of 5.5 mm or less for the mamillopontine distance and 50° or less for the pontomesencephalic angle were sensitive and specific in strengthening the qualitative MRI findings. Therefore, quantitative assessments may provide a more accurate diagnosis.

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SUMMARY: Unexplained SDH in infants and children is an accepted marker for AHT. It has been proposed that IVT may be the initiating event leading to the development of acute SDH, mimicking the appearance of traumatic SDH. Our study aims to investigate if nontraumatic IVT causes SDH in the pediatric population. We retrospectively identified 36 patients with IVT and reviewed neuroimaging studies for the concurrent presence of SDH. In our 36 patients with IVT, no associated SDH was observed. Even with extensive IVT, no SDH was present. Three false-positive diagnoses of IVT were identified in the setting of mastoiditis and traumatic SDH, demonstrating pitfalls in imaging. In conclusion, our findings do not support the previous AHT literature stating that IVT is associated with, or leads to, SDH in neonates, infants, or children.ABBREVIATIONS: AHT ϭ abusive head trauma; CECT ϭ contrast-enhanced CT; CI ϭ confidence interval; CVT ϭ cortical vein thrombosis; FOV ϭ field of view; GRE ϭ gradient recalled echo; ICV ϭ internal cerebral veins; IVT ϭ intracranial venous thrombosis; MIP ϭ maximum intensity projection; SDH ϭ subdural hematoma/hemorrhage; SPGR ϭ spoiled gradient-recalled; TOF ϭ time-of-flight I VT, which is defined as CVT and/or dural venous sinus thrombosis, is relatively rare in children and young adults. It is often associated with underlying disease states that predispose a patient to a thrombotic event. SDH is also rare in the neonate, infant, and young child, and is usually associated with trauma, infection, thrombogenic states, and less often with other causes.1 IVT occurs with an estimated prevalence of 0.67/100,000 among infants in the first year of life.2 Neonates account for a significant number of pediatric cases. Risk factors for neonatal IVT include polycythemia, other prothrombotic states, and perinatal complications such as head trauma, asphyxia, sepsis, and meningitis. Spontaneous IVT has been described in infants and children, and is frequently due to an underlying condition such as infection, shock, dehydration, hypercoagulable states, iron deficiency anemia, and tumors. 3 However, in a review of the literature, very few cases of IVT were associated with SDH.AHT in neonates, infants, and young children is a complex diagnosis, requiring the interaction of pediatrics, radiology, ophthalmology, and the child protection team. Commonly, young infants present for medical care with unexplained neurologic symptoms, and the diagnosis of a SDH is made based upon imaging. The diagnosis of AHT is then subsequently established through a process that ties medical opinions with history, assessment of other injuries, and investigative results. Patients with AHT may develop IVT as a consequence of intracranial injury. Most such patients also often have other indicators of abusive injury such as fractures, bruises, and retinal hemorrhages. Only recently has IVT been proposed as the initiating event for extra-axial hemorrhage, such as SDH and subarachnoid hemorrhage, in the pediatric population. The theory sugge...

A series of 20 cases from 2 academic institutions is presented with a characteristic imaging triad of asymmetric ventriculomegaly, a large interhemispheric cyst, and partial or complete agenesis of the corpus callosum. Most cases were initially referred as aqueduct stenosis and hydrocephalus or focal porencephaly. We describe the imaging findings that identify an abnormal or absent corpus callosum associated with a type 1 interhemispheric cyst in fetuses initially thought to have hydrocephalus attributable to aqueductal stenosis. We suggest that the acronym AVID (asymmetric ventriculomegaly, interhemispheric cyst, and dysgenesis of the corpus callosum) may be useful in recognition of these cases. All cases presented with markedly asymmetric ventriculomegaly on initial sonography, with progressive hydrocephalus throughout gestation. Fetal magnetic resonance imaging was performed in 15 of 20 cases. Thirteen of 20 cases were identified in male fetuses. Associated fetal and postnatal abnormalities are also reported. Technological improvements in sonography and fetal magnetic resonance imaging allow improved characterization of associated intracranial anomalies in the setting of hydrocephalus. Accurate diagnosis can aid parental counseling, especially because isolated aqueductal stenosis suggests a better prognosis than hydrocephalus with anomalies. Markedly asymmetric ventriculomegaly in this series was the key to excluding isolated aqueductal stenosis and was associated with callosal malformation with a type 1a interhemispheric cyst.

Introduction: The hyperdense MCA sign has been used as a marker of an underlying large vessel occlusion (LVO)/thrombus in the non-contrast head CT of acute stroke patients. However, due its low sensitivity, it has not been used routinely for definitive diagnosis of LVO. Furthermore, clinicians also have the ability to obtain further imaging with CT angiography to better visualize the vessels in most patients. However, this further imaging can take on average up to an additional 30 minutes due to delays in acquisition, patient cooperation, processing and image transmission time. We wanted to look for a simple sign on the early imaging (non-contrast HCT) to determine if we could activate the neuro interventional suite faster. Hypothesis: When present, the hyperdense MCA sign can accurately predict presence of a LVO and identify patients eligible for endovascular therapy sooner than vessel imaging. Methods: We retrospectively looked at all initial non-contrast head CTs for all consecutive stroke patients presenting to our facility in 2017 (n=86), with a last known well time (LKW) < 6 hours and NIHSS > 4, for the presence of a hyperdense MCA sign. We then reviewed subsequent imaging (CTA) to determine if LVO was actually present. Results: The hyperdense MCA sign was present in 17 (out of 86) cases, all of which had an LVO on CTA. The positive predictive value (PPV) was 100% indicating that there was a high probability that subjects with a positive hyperdense MCA sign will have a LVO. There were 12 cases with an LVO on CTA did not have a hyperdense MCA sign showing a sensitivity of 58.6%, thus the absence of a hyperdense MCA sign does not exclude LVO. Conclusion: Quick delivery of appropriate treatments for acute stroke patients have been linked to better outcomes. Given our analysis of cases with NIHSS > 4 and LKW < 6 hours, it seems that presence of a hyperdense MCA sign on the initial non-contrast HCT leads to a high level of certainty that an LVO is present. Perhaps this sign, in combination of LKW and NIHSS, can be used to activate the neuro interventional team while additional imaging is being obtained.

277 Background: MRI/US guided biopsy (fusion biopsy) is increasingly utilized over systemic 12-core transrectal ultrasound biopsy (12-core biopsy) for men with MRI-visible prostate lesions. Methods: Patients with MRI visible prostate lesions who underwent fusion and 12-core biopsy from 2016-2020 in the Intermountain Healthcare (IHC) system were consecutively analyzed. This was in the setting of a continuous quality assurance initiative among the reading radiologists. Primary outcome was PCa detection defined by Gleason grade group (GGG) 1 or higher. Clinically significant cancer (CSC) was defined as GGG 2 or higher. Patients were stratified by date biopsy was performed, 2016-2017 and 2018-2020, and lesions were stratified by PI-RADS v2 category. For men with multiple lesions, the highest PI-RADS v2 category lesion was used. Results: A total of 142 men with 254 MRI-detectable lesions underwent both fusion and 12-core biopsies in the IHC system from 2016 to 2020. CSC was detected in 21.6% (55/254) of fusion biopsies. Comparing PI-RAD v2 categories 1-3 to PI-RADS v2 categories 4-5, the PPV for detecting CSC was 9% (15/162) compared to 44% (40/92) respectively. Fusion and 12-core biopsies were concordant for any PCa in 79% of men (112/142) and CSC in 83% (118/142). Fusion biopsy detected any PCa in 22/84 (26%) and CSC in 15/103 (15%) of men in whom 12-core biopsy was negative. 12-core biopsy detected any PCa in 8/70 (11%) and CSC in 9/97 (9%) of men in whom fusion was negative. In total, 15 patients (11%) had a CSC that would have been missed if fusion biopsy was omitted while 9 (6%) had a CSC that would have been missed without 12-core biopsy. Conclusions: Omitting fusion or 12-core biopsy for PI-RADS v2 lesions would have resulted in a missed CSC in 11% or 6% of patients from 2016-20, respectively. The combination of MRI/US-guided fusion biopsy and systematic 12-core biopsy increased detection rate of CSC. These results are in the setting of a continuous, multi-disciplinary quality assurance program and results are not necessarily applicable to other healthcare systems. [Table: see text]

e17604 Background: MRI-targeted biopsy is increasingly utilized over standard 12-core transrectal ultrasound (TRUS) biopsy for men with MRI-visible prostate lesions. Some clinicians defer biopsy for PI-RADS v2 category 1 and 2 lesions per the PRECISION Study (Kasivisvanathan et. Al, NEJM, 2018). The aim of this study was to independently validate the accuracy of PI-RADS v2 in detecting prostate cancer (PCa) when applied to MRI/US fusion-guided biopsies in an independent cohort of 156 patients from a large integrated community health system. Methods: Men undergoing MRI/US fusion-guided biopsy from 2016-2020 in the Intermountain Healthcare system were consecutively analyzed in this retrospective study. MRI were interpreted from four abdominal fellowship trained radiologists all with at least 5 years of experience. Fusion biopsies were performed by two urologists. Men were stratified into groups based on their PI-RADS v2 category 1-5. Biopsies were considered positive when Gleason ≥3+3. Results: A total of 156 men had 258 lesions for which they underwent MRI/US fusion-guided biopsies in the Intermountain Healthcare system from 2016 to 2020. The PCa detection rate for PIRADSv2 category 1-2 was 29.8%, category 3 32.6%, and category 4-5 37.6%. PIRADS v2 category 1, 2, 3, 4, and 5 yielded any PCa in 25, 15.9, 23.8, 53.1, and 66.7%, respectively (Table). PIRADS v2 category 1-2, 3, and 4-5 yielded any PCa in 16.8%, 23.8%, and 57.7%, respectively. Conclusions: PI-RADS v2 categories generally correlate with PCa detection rates, however, to avoid biopsy, the test must be both sensitive and specific, with low false negative rates. In our institution, we show that PI-RADS 1, 2, and 3 do not rule out the presence of PCa, and therefore should not be used as the sole factor in determining the need for prostate lesion biopsy. [Table: see text]

Methods and Results:Retrospective case note analysis of ultrasound and MRI diagnosed morbidly adherent placenta praevias were obtained. In the first case, an elective Cesarean section was done for major degree placenta praevia, antenatal diagnosis of morbidly adherent placenta praevia was not made. Patient had a Cesarean hysterectomy, ureteric stenting and repair of the urinary bladder. All other cases had antenatal diagnoses of morbidly adherent placenta praevias made. Colour Doppler ultrasound scan had a 100% sensitivity. In five out of six cases MRI confirmed morbidly adherent placenta praevia giving a sensitivity of 83%. Three out of seven cases (3/7) have had Cesarean hysterectomies. In four out of seven cases, uterus was preserved. Surgical haemostatic procedures undertaken include; interventional radiological procedures, bilateral internal iliac artery occlusion and B-lynch suture. Complications of internal iliac artery occlusion includes one patient suffering from popliteal arterial occlusion and subsequent vascular surgery. Conclusion: Six out of seven cases reported were antenatally diagnosed as having morbidly adherent placenta praevias by colour Doppler ultrasound and MRI. Detailed management and care plans were outlined in each case and patients and their families were briefed about the care pathways. These six cases will highlight the necessity of multidisciplinary involvement with high quality diagnostic modalities by colour Doppler ultrasound and MRI. This will have an impact on reduced maternal mortality and morbidity in this very complex and challenging clinical situation in Obstetric surgery.