Magnetic resonance imaging brain sequences in pediatrics

There are various pediatric magnetic resonance imaging (MRI) protocols followed in institutes and by individual radiologists, determined by the disease process and the indication for imaging, to narrow down the differential diagnosis. Most times, it is beneficial to modify protocols when the scans are being done, based on the findings seen on initially acquired sequences. This is particularly useful in pediatric patients considering most of them are scanned either under sedation or general anesthesia, and repeat scans will be cumbersome. In this particular review article, we are going to discuss appropriate MRI sequences in scanning pediatric brains and the need for rapid MRI sequences. This is of immense importance as MRI in pediatric patients poses challenges both to radiologists and technologists. Consequently, appropriate MRI protocols should be set to avoid repeat studies.

Neuroimaging of Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) accounts for 10% to 20% of strokes worldwide and is associated with high morbidity and mortality rates. Neuroimaging is indispensable for rapid diagnosis of ICH and identification of the underlying etiology, thus facilitating triage and appropriate treatment of patients. The most common neuroimaging modalities include noncontrast computed tomography (CT), CT angiography (CTA), digital subtraction angiography, and magnetic resonance imaging (MRI). The strengths and disadvantages of each modality will be reviewed. Novel technologies such as dual-energy CT/CTA, rapid MRI techniques, near-infrared spectroscopy, and automated ICH detection hold promise for faster pre- and in-hospital ICH diagnosis that may impact patient management.

Design and implementation of outpatient-based rapid MRI protocols to rule out metastatic spinal cord compression and brain metastases.

e18307 Background: Metastatic spinal cord compression (MSCC) and symptomatic brain metastases (mets) are potential emergencies that demand coordinated multidisciplinary management. Patients (pts) with concerning symptoms are often referred to the Emergency Department (ED) for expedited imaging, but most do not require subsequent ED or inpatient management. Unnecessary ED visits incur substantial cost to the health system and patients, and cause psychosocial stress for patients often near the end-of-life. To improve access to expedited outpatient imaging for high-risk pts and reduce unnecessary ED visits, we developed outpatient rapid MRI protocols and pathways to rule out MSCC and brain mets. Methods: Tailored abbreviated MRI protocols were developed to allow rapid acquisition of brain ( < 13 minutes) and full spine ( < 25 minutes) exams. Dedicated appointments were reserved on the daily MRI schedule. Exams were immediately interpreted and reported by Radiology to the ordering clinician. This pathway was piloted within the Thoracic Oncology group beginning in 10/2018. Results: Referring specialties included Radiation Oncology (50%), Medical Oncology (36%), Pulmonology (7%), and Surgery (7%). For 6 pts who had outpatient rapid brain imaging, median time from order to exam start was 4.3 h (1.8-31) and order to final report 6.8 h (3.2-34.1). Brain mets were found in 4/6 patients. Only 1/4 positive studies required subsequent ED management. For 8 pts referred for rapid spine imaging, median time from order to exam start was 14.4 h (2.2-72.5) and order to final report 16.7 h (4.0-74.4). Only 1 patient was found to have cord compression and required ED/inpatient management. Overall, 86% of patients did not require ED or inpatient admission. 3 pts (all with negative imaging) died a median 13.4 d (1.4-28.3) after order placement. Conclusions: Outpatient rapid MRI protocols facilitate same-day imaging, interpretation, and management, improving care for thoracic oncology pts with new concerning neurologic symptoms and reducing unnecessary ED visits. Future work will expand access beyond Thoracic Oncology and further quantify improvements in cost savings and patient quality of life.

Recombinant Tissue-Type Plasminogen Activator Study of Wake-Up Ischemic Strokes Guided by Rapid MRI

Background: rt-PA intravenous thrombolytic therapy and its efficacy have been widely recognized and proved for strokes. However, for patients with wake-up ischemic stroke (WUIS), they lose the opportunity to receive rt-PA intravenous thrombolytic therapy because of the difficulty of determining the onset time window. Aim: This study is aimed at investigating the intravenous thrombolytic therapy of WUIS guided by rapid MRI. Methods: Data were collected from patients with acute ischemic stroke within 4.5 h and from WUIS patients with uncertain onset time window, who received the treatment of rt-PA intravenous thrombolytic therapy in our hospital from November 2006 to April 2018. The improved Rankin scale was used to evaluate neurological function recovery. According to the Rankin scale score, patients were divided into two groups: those with good prognosis (modified Rankin scale [mRS] score 0–1) and those with poor prognosis (mRS score 2–6). Results: A total of 253 patients received rt-PA intravenous thrombolysis after head MRI evaluation; this included 177 cases of acute ischemic stroke and 76 cases of WUIS (which contains 2 death cases, 0.8% mortality; 3 cases of symptomatic bleeding, 1.2% bleeding rate; and 5 cases of aggravation, 2.0% aggravation rate). There was no statistical difference between the baseline data from the acute ischemic stroke patients with 4.5 h onset time window and the baseline data from the WUIS patients with undetermined onset time window, when the treatment was guided by rapid MRI. There were also no significant statistical differences in National Institutes of Health Stroke Scale score, Rankin scale score, symptomatic bleeding, death and aggravation of the disease between the 2 groups at 24 h, 3 days, and 7 days after admission (p < 0.05). Conclusion: According to the characteristic of undetermined onset time window of WUIS, more WUIS patients would be benefited from the rt-PA intravenous thrombolytic treatment when it is conducted under the guidance of rapid MRI.

Prolonged Motor Block following Epidural Anaesthesia: A Proposed Pathway for Investigation and Management to Facilitate Rapid MRI Scanning to Exclude Vertebral Canal Haematoma

Vertebral canal haematoma following epidural anaesthesia is a rare but potentially devastating occurence, which can lead to permanent neurological damage. Early clinical identification and diagnosis using MRI imaging with surgical decompression of the haematoma can lead to full recovery (Kebaish 2004). However surgical patients often have metal clips or staples, which are left inside the body, some of which are not MRI compatible. Currently there is no process to document which surgical clips have been used and their MRI compatibility in an accessible format. This can lead to a delay in performing MRI imaging. We propose a clinical pathway to expedite diagnosis of vertebral canal haematoma to incorporate a system to allow rapid identification of MRI compatibility of surgical clips used during surgery.