Anesthesia for magnetic resonance imaging

Fourier-transform infrared spectroscopy: a universal optical sensing technique with auspicious application prospects in the diagnosis and management of autoimmune diseases

Autoimmune diseases (AIDs) are poorly understood clinical syndromes due to breakdown of immune tolerance towards specific types of self-antigens. They are generally associated with an inflammatory response mediated by lymphocytes T, autoantibodies or both. Ultimately, chronic inflammation culminates in tissue damages and clinical manifestations. AIDs affect 5% of the world population, and they represent the main cause of fatality in young to middle-aged females. In addition, the chronic nature of AIDs has a devastating impact on the patient's quality of life. It also places a heavy burden on the health care system. Establishing a rapid and accurate diagnosis is considered vital for an ideal medical management of these autoimmune disorders. However, for some AIDs, this task might be challenging. Vibrational spectroscopies, and more particularly Fourier-transform infrared (FTIR) spectroscopy, have emerged as universal analytical techniques with promising applications in the diagnosis of various types of malignancies and metabolic and infectious diseases. The high sensitivity of these optical sensing techniques and their minimal requirements for test reagents qualify them to be ideal analytical techniques. The aim of the current review is to explore the potential applications of FTIR spectroscopy in the diagnosis and management of most common AIDs. It also aims to demonstrate how this technique has contributed to deciphering the biochemical and physiopathological aspects of these chronic inflammatory diseases. The advantages that can be offered by this optical sensing technique over the traditional and gold standard methods used in the diagnosis of these autoimmune disorders have also been extensively discussed.

Retrospective features of cases with cranial magnetic resonance imaging

Aim: In this study, we aimed to reveal the diagnostic profiles of 0-18 years aged patients, for whom cranial magnetic resonance imaging is requested in outpatient settings, and to evaluate the cranial imaging results according to gender and age groups. Materials and Methods: The files of patients aged 0-18 years who were requested cranial magnetic resonance imaging for various indications, between August 2019 and March 2021, in Balikesir University, Faculty of Medicine pediatric neurology and pediatric health and diseases outpatient clinics were reviewed retrospectively. Age, gender, main complaint and neuroradiological imaging results were obtained from hospital records. Data were divided for three different age groups (0-6, 7-12, 13-18). Results: Cranial magnetic resonance imaging of 313 cases were analyzed. The mean age of the patients was 9.35±4.89 (4 months-17 years) years. There were 164 (52.4%) boys and 149 (47.6%) girls. There were 82 (26.2%) cases in the 0-6 years age group, 104 (33.2%) in the 7-12 years age group and 127 (40.6%) in the 13-18 years age group. The most common reasons for requesting cranial magnetic resonance imaging were as; seizure/epilepsy in 106 (33.9%) cases, headache in 65 (20.8%) cases, and neuromotor retardation in 28 (8.9%) cases. While the cranial imaging of 200 (63.9%) cases was normal, the results of 113 (36.1%) cases were evaluated as abnormal. The most common abnormal findings were intracranial mass (2.5%), nonspecific white matter lesion (5.1%), intracranial cyst (5.7%), sinusitis (9.2%) and hydrocephalus/hydrancephaly (2.6%). When age groups were compared in terms of showing normal or abnormal cranial imaging findings, no statistically significant difference was found (p=0.73), but a statistically significant difference was found between the genders in the same respect (p=0.007). Conclusion: Our study is important for including cranial MRI request indications and results in pediatric practice and it creating a diagnostic profile in these patients.

The effect of "multiphase sedation" in the course of computed tomography and magnetic resonance imaging on children, parents and anesthesiologists

BACKGROUND AND OBJECTIVES

We aimed to investigate the effect on children undergoing Computed Tomography (CT) or Magnetic Resonance Imaging (MRI), their parents and attending anesthesiologist of "multiphase sedation" which we define as "the intended sedation level achieved with one or more agents through the same or different routes with more than one administration".

MATERIAL AND METHODS

One hundred children and their parents were randomly allocated to one of two study groups. In phase 1; in Group I the patients were given midazolam (0.5mg.kg(-1)) in 5 mL fruit juice, and the ones in control group (Group II) were given only fruit juice. After intravenous (iv) cannulation; in phase II, boluses of propofol were given to achieve the adequate sedation for imaging. Anxiety scores of children and their parents were recorded using Oucher scale and STAI, respectively, and parental satisfaction was evaluated by visual analogue scale (VAS). The number of attempts for iv cannulation, length of time for preparation, and amount of hypnotics were recorded.

RESULTS

Anxiety state of children was similar between groups before premedication, but later it was lower in Group I. Before procedure, STAI score of parents was similar and later it was lower in Group I. Parental satisfaction in Group I was higher. The number of attempts for iv cannulation and required propofol dose was less in Group I.

CONCLUSION

"Multiphase sedation" procedure provides children to feel less pain and anxiety, and decreases parental anxiety while increasing their satisfaction. It supplies a comfortable and safe sedation, as it provides a short and problem-free preparation process for the attending anesthetist as well.

Impact of psychological interventions on reducing anxiety, fear and the need for sedation in children undergoing magnetic resonance imaging

Children undergoing magnetic resonance imaging examination frequently experience anxiety and fear before and during the scanning. The aim of the present study was to assess: i) whether and to what extent psychological interventions might reduce anxiety and fear levels; ii) whether the intervention is related to a decrease in the need for sedation. The interventions consisted of three activities: a clown show, dog interaction and live music. The emotional status (anxiety and fear) of the children was evaluated before and after the activities through a rating scale questionnaire. The results showed that the activities had high effectiveness in reducing the level of anxiety and fear and decreased the need for sedation in the experimental group compared to the control group. This approach proved to be a positive patient experience, helping to alleviate children's anxiety and fear, decreasing the need for sedation, and was cost-effective.

Practical planning to maintain premature infants' safety during magnetic resonance imaging: a systematic review

BACKGROUND

Magnetic resonance imaging (MRI) makes a significant contribution to diagnose brain injury in premature infants and is a diagnostic procedure that requires the infant to be taken out of the controlled environment established for growth and development. To ensure safe procedures for these vulnerable patients, practical planning and surveillance are paramount.

PURPOSE

This systematic review summarizes and evaluates the literature reporting on practical planning to maintain required safety for premature infants undergoing MRI.

METHODS

Literature identified through various search strategies was screened, abstracted, appraised, and synthesized through a descriptive analysis. Thirteen research studies, 2 quality improvement projects, and 10 other documents, including practice guidelines, general reviews and articles, a book chapter, and an editorial article, were retained for in-depth review.

CONCLUSIONS

Various procedures and equipment to ensure the safety of premature infants during MRI have been developed and tested. Although the results are promising and increasingly consistent, our review suggests that more research is needed before conclusive recommendations for the use of magnetic resonance-compatible incubators, the "feed-and-sleep" approach to avoid sedation, or the specific noise-cancelling ear protection for the premature infants' safety during MRI can be established.

Frequency of choroidal abnormalities in pediatric patients with neurofibromatosis type 1

PURPOSE

To investigate the frequency of choroidal abnormalities in pediatric patients with neurofibromatosis type 1 detected by infrared reflectance imaging.

METHODS

The fundus of 38 eyes of 19 patients with neurofibromatosis type 1 was examined using infrared reflectance imaging with optical coherence tomography. Forty eyes of 20 age-matched controls were examined similarly. Each patient was evaluated for the presence and the number of choroidal abnormalities. The correlation between the total number of choroidal abnormalities and the patient's age was studied.

RESULTS

A total of 19 patients (11 females, 8 males) were included. The mean age of the neurofibromatosis group was 8.63 ± 3.15 years (range: 4 to 16 years) and that of the control group was 9.05 ± 3.27 years (range: 4 to 15 years). Choroidal nodules appearing as bright patchy nodules were detected in 15 (78.9%) of 19 patients with neurofibromatosis type 1 and 1 (5%) of 20 control subjects. In terms of the frequency of choroidal abnormalities, the difference was significant between the patients with neurofibromatosis type 1 and the controls (P < .001). There was a positive correlation between the number of choroidal abnormalities in both eyes and the patient's age (r = 0.701, P = .001).

CONCLUSIONS

Choroidal abnormalities are frequent in neurofibromatosis type 1. Choroidal abnormalities detected by infrared reflectance imaging with optical coherence tomography can be used to diagnose neurofibromatosis type 1.

Magnetic Resonance Imaging in Children under Anesthesia: The Relationship between the Degree of Information Provided to Parents and Parents’ Anxiety Scores

Background. We aimed to investigate the correlation between the anxiety scores of parents whose children are administered anesthesia for magnetic resonance imaging (MRI) and the level of information provided to them before the MRI. The study included 146 children and their parents. The demographic information of the children and their parents was recorded. The parents were divided into two groups. In Group I, the patient's medical history and physical exam findings were recorded on a standard consultation form by an anesthesiologist. In Group II, the parents were additionally provided with more detailed information on how the anesthesia would be administered and the drugs to be used and their side effects and complications. The anxiety scores of the parents were found to be lower in Group II. A higher level of education was associated with higher anxiety scores. Intergroup comparison detected lower anxiety scores for Group II parents whose education levels were up to high school. However, no change upon receiving detailed information was detected in the anxiety scores of parents with higher education levels. In conclusion, this may lower the anxiety scores in parents informed about details of anesthesia administration and may raise parents' sense of confidence in the doctor.

Propofol drip infusion anesthesia for MRI scanning: two case reports

The magnetic resonance imaging (MRI) room is a special environment. The required intense magnetic fields create unique problems with the use of standard anesthesia machines, syringe pumps, and physiologic monitors. We have recently experienced 2 oral maxillofacial surgery cases requiring MRI: a 15-year-old boy with developmental disability and a healthy 5-year-old boy. The patients required complete immobilization during the scanning for obtaining high-quality images for the best diagnosis. Anesthesia was started in the MRI scanning room. An endotracheal intubation was performed after induction with intravenous administration of muscle relaxant. Total intravenous anesthesia via propofol drip infusion (4-7 mg/kg/h) was used during the scanning. Standard physiologic monitors were used during scan pauses, but special monitors were used during scanning. In MRI scanning for oral maxillofacial surgery, general anesthesia, with the added advantage of having a secured airway, is recommended as a safe alternative to sedation especially in cases of patients with disability and precooperative chidren.

Role of MRA in the detection of intracranial aneurysm in the acute phase of subarachnoid hemorrhage

BACKGROUND

Magnetic resonance angiography (MRA) has been evaluated for the detection of unruptured intracranial aneurysms with favorable results at 3 Tesla (3T) and with similar diagnostic accuracy as both 3D time-of-flight (3D-TOF) and contrast-enhanced (CE-MRA) MRA. However, the diagnostic value and place of MRA in the detection of ruptured aneurysms has been little evaluated. Thus, the goal of this prospective single-center series was to assess the feasibility and diagnostic value of 3T 3D-TOF MRA and CE-MRA for aneurysm detection in acute non-traumatic subarachnoid hemorrhage (SAH).

METHODS

From March 2006 to December 2007, all consecutive patients admitted to our hospital with acute non-traumatic SAH (≤10 days) were prospectively included in this study evaluating MRA in the diagnostic workup of SAH. Feasibility of MRA and sensitivity/specificity of 3D-TOF and CE-MRA were assessed compared with gold standard DSA.

RESULTS

In all, 84 consecutive patients (45 women, 39 men; age 23-86 years) were included. The feasibility of MRA was low (43/84, 51.2%). The reasons given for patients not undergoing magnetic resonance imaging (MRI) examination were clinical status (27 patients), potential delay in aneurysm treatment (11 patients) and contraindications to MRI (three patients). In patients explored by MRA, the sensitivity of CE-MRA (95%) was higher compared with 3D-TOF (86%) with similar specificity (80%). Also, 3D-TOF missed five aneurysms while CE-MRA missed two.

CONCLUSION

The value of MRA in the diagnostic workup of ruptured aneurysms is limited due to its low feasibility during the acute phase of bleeding. Sensitivity for aneurysm detection was good for both MRA techniques, but tended to be better with CE-MRA.

Anesthesia in the intraoperative MRI environment

Intraoperative MRI (iMRI) can be applied in several surgical settings. The incorporation of MRI technology into the operating room requires special considerations. The size and design of the operating room, including the equipment introduced into this setting, must be MR safe and allow adequate anesthesia monitoring and care. There are general restrictions and perils that may present in an operating room setting because of the MRI technology involving the monitoring equipment, anesthesia machine, and infusion devices. Incorporating the MRI technology into the operating room presents a new challenge in a transdisciplinary environment. The use of the iMRI technology has provided revolutionary tools for the new generation of medical practice.

Magnetic resonance imaging and proton magnetic resonance spectroscopy of the brain in the diagnostic evaluation of developmental delay

AIM

To assess the contribution of MRI and proton spectroscopy (1HMRS) in establishing an etiological diagnosis in children with developmental delay (DD) and to assess whether the chance of finding specific abnormalities correlates with the presence of neurological signs and/or abnormal head circumference (HC).

METHODS

Patients were derived from a cohort of 325 consecutive patients with DD receiving structured multidisciplinary evaluation in our centre. Patients had MRI/1HMRS if a diagnosis could not be made clinically and if additional neurological signs and/or abnormal HC and/or an IQ below 50 were present. The MRI protocol consisted of axial IR, T2, FLAIR, sagittal T1 and coronal T2 sequences. Multivoxel 1HMRS was located in a plane superior to the lateral ventricles with voxels in both grey matter and white matter.

RESULTS

One hundred and nine children were scanned, 80 of them because of neurological signs and/or abnormal HC. Although minor abnormalities were noted in the vast majority of patients, MRI and/or 1HMRS really contributed to an etiological diagnosis in only 10 (9%) patients, all of whom were scanned because of neurological signs. In these 10 patients, 1HMRS was diagnostic in one patient and of additional value to MRI findings in 3 patients.

CONCLUSIONS

MRI and 1HMRS may contribute to the diagnostic evaluation of DD, especially if applied specifically to patients with neurological signs, whereas its role is very limited in children without these signs.

Transport, monitoring, and successful brain MR imaging in unsedated neonates

Neonatal cerebral MR imaging is a sensitive technique for evaluating brain injury in the term and preterm infant. In term encephalopathic infants, MR imaging reliably detects not only the pattern of brain injury but might also provide clues about the timing of injury. In premature infants, MR imaging has surpassed US in the detection of white matter injury, a common lesion in this population. Concerns remain about the safety and transport of sedated neonates for MR examination to radiology suites, which are usually located at a distance from neonatal intensive care units. We present our own institutional experience and guidelines used to optimize the performance of cerebral MR examinations in neonates without sedation or anesthesia.

A comprehensive analysis of MRI research risks: in support of full disclosure

Magnetic resonance imaging (MRI) procedures have been used for over 20 years. This modality is considered relatively safe and holds great promise. Yet, MRI has a number of risks. In order for MRI research to meet the Canadian standard of disclosure, the investigator must communicate and make note of all risks in their research protocols and consent forms. Those creating and reviewing research protocols and consent forms must take notice of the different circumstances under which MRI poses a risk. First, this paper will describe the current standard of disclosure in Canada for research participants. Second, the paper will provide a comprehensive synthesis of the known physical and psychological risks associated with MRI. Third, the paper will provide recommendations concerning areas for further investigation and risk reduction strategies. This information will thus equip researchers and research ethics boards (REBs) with the criteria needed for the composition of research protocols that meet the Canadian disclosure standard.