The chosen case study is regarding a Magnetic Resonance Imaging MRI review

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The chosen case study is regarding a Magnetic Resonance Imaging (MRI) review of a 9-month-old diagnosed with right lateral ventriculomegaly. A brief history leading to the MRI scan will be discussed for a better comprehension of the case.Unobstructed circulation of CSF is necessary for the protection and nourishment of the brain (Marieb, 2016). Abnormal production of CSF or failure to drain out of the lateral ventricles can result in ventricular enlargement, a phenomenon known as Ventriculomegaly (Wyldes,2009). Ventriculomegaly (VM) is a rare congenital disorder which affects approximately 2 out of 1000 babies annually (Mikic et al., 2011). VM can be caused by several factors such as infection, genetic makeup, brain abnormality, haemorrhage or unknown aetiology in many cases. The earliest detection of VM is possible pre-birth from the antenatal scans (Chaveeva et al., 2015). These scans are also beneficial for timely interventional planning for diagnosis and treatment in complicated cases (Gaglioti et al., 2009). Unilateral VM was diagnosed at the 20-week antenatal scan in this case after abnormal measurements of the head circumference were obtained. The antenatal finding of VM is of significance as it can help elucidate other malformations of the central nervous system if present (Griffiths et al., 2010). Previous research has shown delayed development and brain abnormalities in infants diagnosed with VM but the prognosis of unilateral VM, where only one ventricle is enlarged, has shown better developmental outcomes in most cases (Zaki et al., 2009). Literature has demonstrated some ambiguity and interlinkage of terms ventriculomegaly and hydrocephalus. Research by Rekate (2009) explains that hydrocephalus is an abnormal increase in the volume of CSF that results in high intracranial pressure and ventricular distension whereas ventriculomegaly is the enlargement of lateral ventricles without any change in intracranial pressure. Recent research by Norton (2018) has proposed that if the widening of the atria of lateral ventricle is more than 10mm than it is considered as VM whereas measurement of atria greater than 15mm is an indication for hydrocephalus. Some of the reasons for the accumulation of CSF in the ventricles are excess production, infection, loss of cerebral tissue, obstruction and genetic or chromosomal abnormalities (Kahle et al., 2016). In this case, the excess accumulation of the CSF in the right lateral ventricle was due to the presence of a porencephalic cyst obstructing the foramen of Munro – an opening connecting each lateral ventrice with the third ventricle (Marieb, 2016). The porencephalic cyst is a hollow shaped structure that is filled up with CSF which significantly reduces or obstructs the flow of CSF between ventricles (Radiopaedia, 2019). Clinical history of the patient showed regular scans were conducted to assess the ventricles for any unexpected changes before birth (Fox et al., 2018). 2 days post birth, the patient was referred for MRI screening for carrying out surgical planning. MRI is the preferred modality of choice for interventional procedures due to its ability to produce images of high spatial resolution (Hugelshofer et al., 2016). Endoscopic fenestration was the surgical procedure performed which involves the insertion of a shunt and an endoscope through a small opening of the dilated ventricle which aids in the removal of the cyst and normalising the flow of CSF through ventricles. After the procedure, follow up imaging needs to be carried out regularly to check if the enlarged ventricle is reducing in size and accumulated fluid is being discharged from the ventricles at the predicted rate (Hugelshofer et al., 2016). Laskin et al. (2009) emphasise the need for follow-up imaging post-surgery to assess for developmental delays and genesis of any secondary conditions. The patient had an MRI review at three months of age preceding this follow-up MRI under General Anesthetic (GA). Computed Tomography (CT) and MRI are modalities that are preferred for brain pathologies and congenital abnormalities due to their ability to acquire high-resolution diagnostic images (Giedd and Rapoport, 2010). CT scans which involve ionising radiation are much faster scans with high sensitivity and specificity for pathologies associated with cortical bone and foreign bodies assessment, but despite these benefits, it is not the modality of choice for paediatric imaging (Giedd et al., 2010). Ionising radiation causes more biological damage to the developing cells in children which highly increases the risk of them developing cancer later in life (Miglioretti et al., 2013). Ultrasound is another modality that does not involve ionising radiation but is limited in paediatric head imaging as the diagnostic image acquisition is dependent on factors such as skills of the practitioner and access of acoustic window to soft tissue structures which are obstructed by narrowed or closed fontanelle in some cases (Rozovysky et al., 2013)MRI for paediatric imaging is favoured as it does not involve the use of ionising radiation which also makes it suitable for children requiring regular specialised scanning as a part of their treatment plans. MRI is equipped with the ability to capture high-resolution cross-sectional images which allows better evaluation and differentiation of soft tissue structures in children (Thukral, 2015). It is also beneficial for looking at vascularity and fast-paced neural changes in children. Even though it is the modality of choice, MRI has various risk factors associated with paediatric imaging. The transmission of radiofrequency pulses during the scan produces heat which can increase the body temperature. The children are more at risk of hyperthermia as compared to adults as the latter’s thermoregulation mechanism is still developing (Sammet, 2016). Additionally, the strong electromagnetic fields of the MRI scanner may cause short term sensory effects such as nausea, vertigo and flickering sensations (Gattringer et al., 2018). MRI is regulated by Control of Electro Magnetic Fields at Work regulations (CEMFAW), a legal entity formulated in 2016 to regulate the exposure of electromagnetic fields to the staff and patients (Keevil and Lomas, 2017). MRI scans are quite prolonged usually lasting for one or two hours, but for optimum image quality, patients are required to lie immobile during continuous imaging. As the patient is an infant, MRI under GA was recommended as it helps to deal with obstacles such as patient movement during the examination, fear of the equipment, unfamiliar environment, communication barrier, patient safety, claustrophobia, anxiety and nervousness (Berg and Cambell, 2016). However, GA does have significant risk factors associated with its application such as respiratory distress, cardiac problems, airway obstruction, and hypoventilation (Cote, 2016). A pre-procedural assessment following the RCR guidelines needs to be carried out before the appointment date to assess the patients’ health, weight, previous history and any contraindications to anaesthesia. This information is necessary for safe administration of the correct dose of GA attuned to individual patient needs (RCR, 2016). Constant supervision of the infant at all levels of the procedure by an experienced anaesthetist is required to deal with any complications timely and proficiently (Reddy, 2012). The patient was advised to fast 3 hours before the appointment as it helps to reduce the risk of nausea and vomiting afterwards due to GA (Arthurs and Sury, 2013). The patient arrived in the afternoon for the procedure and was seated in the paediatric waiting area after making the necessary Identification checks. As the patient is too young to consent for themselves, the consent was sought from the parents under the consent guidelines of the hospital (NHS, 2019). Under MRI protocols set by the trust, all people entering the MRI controlled area are required to fill out a screening form under the supervision of the imaging support worker fully trained in MRI safety and precautionary measures (Saunders et al., 2009). Patients and carers with pacemakers are contraindicated for MRI imaging as the magnetic fields can adversely affect the mechanisms of some pacemakers. Similarly, metallic implants and ferromagnetic objects need to be deemed MRI safe before letting the patient enter the controlled area as there is a possibility of them being pulled on due to strong magnetic fields (Allen et al., 2012). Previous screening checks had been performed, but as this was an outpatient, it was necessary to assure that there have been no changes in the information recently for safety reasons (Cahoon, 2014). The patient did not require changing and was in clothing considered safe for MRI screening, i.e. loose fitting with no metallic buttons and zips (Zimmerman and Gibby, 2013). The patient accompanied by the parents were taken into the control room-a restricted area accessible only to the departmental staff and patients deemed safe after the screening checks. This zone is separated from the waiting area to minimise the exposure of fringe fields to the general public (Grover et al., 2010). All the paediatric imaging performed under GA is considered a top priority, and a team briefing comprising of the anaesthetist, lead radiographer, anaesthetist nurse and support worker was conducted to discuss the patient history, clinical details, previous images, the need for contrast and any other areas of concern before the examination (Cahoon, 2014). A checklist, comprising of all the protective measures applied before, during and after the scanning, is completed at the end of the procedure. Permission was sought from the patient’s parents and the staff involved in the procedure by the student radiographer under the standards of paediatric imaging laid out by the society of radiographers (SOR, 2019).Anxiety and concerns of parents are understandable as sedation for paediatric is a high-risk examination (Reddy, 2012). The lead radiographer and anaesthetist explained the procedure to the parents in detail and professionally answered their queries with constant assurance and communication throughout the scanning. Empathising with the carers and acknowledging their emotional needs is necessary to gain trust and induce feelings of confidence and satisfaction regarding the examination (Cahoon, 2014). The patient was orally sedated by the anaesthetist administering the anaesthetic gas through an oxygen mask while monitoring the saturation levels (Isaacson et al., 2011). Oral sedation for children has shown a quicker recovery with none to minimal side effects as compared to intravenous sedation (Raschle et al., 2012). The patient after GA administration was taken off all the equipment which was non-MR compatible. The ‘pause and check’ protocol was conducted before the team entered the magnetic room by verbally ensuring everyone was safe to enter and had no have metallic or magnetic objects on them which can be hazardous. This safety pause is essential as it significantly reduces the possibility of harmful events (CQC, 2017). The patient was placed on the scanner in the magnet room, a more restricted zone situated inside the control room. The patient was connected to all the MR safe equipment monitoring the patient’s heart rate, saturation levels and respiratory rate. Care was taken to ensure that patients body parts were not superimposed on each other to avoid increased absorption of radiofrequency pulses (RF) which can cause tissue damage and excessive heating (Sammet, 2016). Ear plugs were plugged in to protect patients hearing from acoustic noise of the scanner. A head coil was placed on the head which will help in attaining high signal to noise ratio compensating for the small structural anatomy as compared to an adult. Care was taken to create insulation between the head coil and the patients head, so they were not in direct contact to avoid skin damage (Barkovich et al.,2018).The paediatric head protocol scans were performed on the Siemens MAGNETON Avanto 1.5 tesla scanner integrated with TIM coil which greatly reduces the acoustic noise and acquisition time without adversely affecting the imaging quality (Siemens, 2019). The water content in the paediatric brain is more than in an adult therefore paediatric MRI neuroimaging requires modified scans to compensate for smaller structures, high-water content and maturing myelin due to constant developmental growth in the first two years of life (Rashcle, 2012). The paediatric head protocol has a dedicated number of sequences which can be modified by the radiographer in case of incidental findings (Cahoon, 2014). Pule sequence parameters in MRI help in creating images with varying signal to noise ratio. The time duration taken to receive the signal back from the organ of interest after transmission of RF pulses constitutes time to echo (TE) and the period between consecutive RF pulses is called the repetition time (TR) (Grover et al., 2015).• LOCALISER The scanning was initiated by first carrying out a localiser scan in all three planes, sagittal, axial and coronal to ensure that the patient is correctly positioned and area of interest is fully covered. This scan is crucial as it mainly helps in planning for other scans (Bazzocchi et al., 2014).