Magnetic Resonance Imaging Procedures Research Articles

Safety and Functional Integrity of Continuous Glucose Monitoring Components After Simulated Radiologic Procedures.

Background:We investigated wearable components of the Dexcom G6 continuous glucose monitoring (CGM) System in simulated therapeutic and diagnostic radiologic procedures.Methods:G6 transmitters were loaded with simulated glucose data and attached to sensors. Sets of sensor/transmitter pairs were exposed to x-rays to simulate a radiotherapeutic procedure and to radiofrequency (RF) and magnetic fields to simulate diagnostic magnetic resonance imaging (MRI). The x-ray simulation provided a cumulative dose of 80 Gy. The MRI simulation used RF fields oscillating at 64 or 128 MHz and magnetic fields of 1.5 or 3 T. During the MRI simulation, displacement force, induced heating, and induced currents were measured. After the simulations, bench tests were used to assess data integrity on the transmitters and responsiveness of sensors to various concentrations of aqueous glucose.Results:Glucose concentrations reported by sensor/transmitter pairs after undergoing x-irradiation or a simulated MRI exam were similar to those from control (unexposed) devices. During the 3 T MRI simulation, the devices experienced a displacement force of 306 g, which was insufficient to dislodge the sensor/transmitter from the substrate, RF-induced heating of <2°C, and an induced current of <16 pA. Data stored on the transmitters prior to the MRI simulation remained intact.Conclusion:Wearable components of the G6 CGM System retain basic functionality and data integrity after exposure to simulated therapeutic and diagnostic radiologic procedures. The devices are unlikely to be affected by x-irradiation used in typical imaging studies. Simulated MRI procedures create displacement force, minimal heating, and current in sensor/transmitter pairs.

Presence of other rare earth metals in gadolinium-based contrast agents

Gadolinium-based contrast agents (GBCA) are widely used to enhance tissue contrast during magnetic resonance imaging (MRI) procedures. However, free Gadolinium (Gd) is undesirable as a drug substance, due to its high toxicity. Consequently, a coordinating ligand is required to keep it in solution and to increase tolerance. In order to achieve an adequate performance, GBCA must be administered in relatively large amounts. Chelate amounts are around 13–20 g and for Gd alone, this may amount to 3.3 g. Taking into account the route of administration, impurities in GBCA may be significant. Gadolinium occurs in nature along with 16 other elements known collectively as rare earth metals (RE), which are found throughout the earth's crust in minerals such as monazite. Gadolinium oxide corresponds to 0.7–4.0% of the RE present in minerals, and the sum concentration of RE in minerals is around 4%. Rare earth metals are difficult to separate, as the chemical and physical properties of one RE are significantly similar to those of others. In this study, the presence of other RE in GBCA formulations was investigated. Different lots of Magnevist®, Viewgam®, OptiMARK®, Omniscan®, Dotarem®, and Gadovist® were analyzed. Inductively-coupled plasma mass spectrometry and atomic absorption spectrometry were used for RE determination. Procedure optimization included sample decomposition and method validation for element determination. The results showed that Sc, Y, La, Ce, Pr, Nd, Eu, Tb, Tm, Dy, Ho, and Er were present in the 22 samples analyzed. Terbium, Thulium, Europium, and Lanthanum were, on average, found in the highest amounts, which were 0.42 mg/L, 0.17 mg/L, 0.17 mg/L, and 0.16 mg/L, respectively. These results could be attributed to the similarity among Europium, Gadolinium, and Terbium. They are in sequence in the periodic table and therefore present very close ionic radii, restricting their separation. Considering the sum of all RE, Viewgam® was the most contaminated formulation (mean of 2.16 mg/L) and Magnevist® the least (mean of 0.64 mg/L). Although the RE are chemically similar, the other RE do not perform as Gd as a contrast agent; therefore, their presence in formulations may be a matter of concern.

Visions of the Uterine Cavity

Advancements in modern imaging techniques such as ultrasound, magnetic resonance imaging, computer tomography and other radiological procedures have improved the diagnosis of gynecological conditions to a great extent. However, the establishment of a final diagnosis and the initiation of appropriate treatment requires direct viewing of the uterine cavity as in hysteroscopy. In many cases, the patient can be treated during the initial hysteroscopy.

Associations between Anterior Cruciate Ligament Injuries and Patella Alta and Trochlear Dysplasia in Adults Using Magnetic Resonance Imaging.

The aim of this study was to research the associations between anterior cruciate ligament (ACL) injuries and patella alta and trochlear dysplasia in adult patients using magnetic resonance imaging (MRI). This retrospective study included 221 adult patients: 110 with acute complete noncontact ACL tears and 111 without ACL injuries who underwent knee MRI procedures between May 2016 and July 2018. After the ACL injuries were verified using the sagittal proton density images, the patellar height and patellar tendon length were measured on the sagittal T1-weighted images, and the Insall-Salvati ratio (ISR) was calculated. In the axial proton density MRI scans, according to the Dejour and Le Coultre classification of trochlear dysplasia, the knees were classified as normal or as types A, B, C, or D. The patellar length was not significantly different between the patient and control groups (41.5 ± 3.3 vs. 41.0 ± 2.9 mm, respectively). An increased patellar tendon length (46.1 ± 3.9 vs. 44.5 ± 3.4 mm, respectively) and an increased ISR (1.11 ± 0.08 vs. 1.08 ± 0.06, respectively) were measured in the patient group (with the ACL tears). In the group with the ACL tears, the rate of trochlear dysplasia was higher (15.45%) than that in the healthy group (4.5%). Of the 17 trochlear dysplasia patients in the ACL group, 11 were type A (10%), 2 were type B (1.82%), 3 were type C (2.73%), and 1 was type D (0.91%). Results showed increased patellar tendon lengths, ISRs, and trochlear dysplasia in the patients with the ACL injuries when compared with the healthy control group. Although the causative relationship has not yet been clearly elucidated, one should keep in mind that these variations may be risk factors for ACL tears.

Resting State Functional Connectivity of the Thalamus in North Korean Refugees with and without Posttraumatic Stress Disorder

In posttraumatic stress disorder (PTSD), functional connectivity (FC) between the thalamus and other brain areas has yet to be comprehensively investigated. The present study explored resting state FC (rsFC) of thalamus and its associations with trauma-related features. The included subjects were North Korean refugees with PTSD (n = 23), trauma-exposed North Korean refugees without PTSD (trauma-exposed control [TEC] group, n = 22), and South Korean healthy controls (HCs) without traumatic experiences (HC group, n = 40). All participants underwent psychiatric evaluation and functional magnetic resonance imaging (fMRI) procedures using the bilateral thalamus as seeds. In the TEC group, the negative rsFC between each thalamus and its contralateral postcentral cortex was stronger relative to the PTSD and HC groups, while positive rsFC between the left thalamus and left precentral cortex was stronger in the HC group compared to the PTSD and TEC groups. Thalamo-postcentral rsFC was positively correlated with the CAPS total score in the TEC group, and with the number of traumatic experiences in the PTSD group. The present study identified the difference of thalamic rsFC alterations among traumatized refugees and HCs. Negative rsFC between the thalamus and somatosensory cortices might be compensatory changes after multiple traumatic events in refugees.

Comparison of the Effects of Midazolam-Ketamine or Midazolam-Propofol Combinations on Hemodynamic Stability, Patient Comfort, and Post-anesthesia Recovery in Children Undergoing Sedation for Magnetic Resonance Imaging Procedures

BackgroundMagnetic resonance imaging (MRI) requires complete immobility of the subject during the acquisition of each sequence, which is highly important for image quality. MRI may necessitate sedation, particularly in young children and in some adolescent and adult patients, although the ideal sedation procedure leading to minimal side effects with the highest patient comfort in children undergoing MRI procedures remains controversial. The aim of this study was to compare the effects of midazolam-ketamine and midazolam-propofol combinations on hemodynamic stability, patient comfort, and post-anesthesia recovery in pediatric patients undergoing sedation for MRI and also to determine the ideal sedation procedure with minimal side effects.Materials and MethodsThe retrospective study included 40 pediatric patients aged between 2 and 12 years with normal growth and an American Society of Anesthesiology physical status (ASA-PS) 1-2 who were sedated with a combination of midazolam-ketamin or midazolam-propofol for the MRI procedure. The 40 patients were divided into two groups based on the drug combination used for sedation: (I) midazolam-ketamine (M-K) (n = 20) and (II) midazolam-propofol (M-P) (n = 20). Demographic characteristics, duration of MRI procedure, total duration of procedure, MRI image quality, family satisfaction, peripheral capillary oxygen saturation (SpO2), systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), and Ramsay Sedation Score (RSS) scores were compared between the two groups.ResultsNo significant difference was detected between the groups with regard to gender, duration of MRI procedure, and total duration of procedure. The MRI scanning quality was very good in 14 (70%) and moderately good in 6 (30%) subjects in the M-K group, whereas the scanning quality was very good in 9 (45%) and moderately good in 11 (55%) subjects in the M-P group. There were significant differences between the two groups at different times in terms of SBP, DBP, and HR values. No complication was observed in any patient and no patient required additional sedation throughout the procedure.ConclusionThe midazolam-ketamine combination provided better hemodynamic stability than the midazolam-propofol combination, although the two combinations were similar with regard to patient comfort and post-anesthesia recovery.

Performing MRI Scans on Cochlear Implant and Auditory Brainstem Implant Recipients: Review of 14.5 Years Experience.

To assess the complication rate of magnetic resonance imaging (MRI) using 1.5 T scanners on cochlear implant (CI) and auditory brainstem implant (ABI) recipients over 14.5 years. Prospective study conducted in a tertiary referral center for cochlear and auditory brainstem implantation, including patients with neurofibromatosis 2. The primary outcome was complications related to MRI scanning in implant recipients, including failure to complete MRI sessions. The secondary outcome was magnet void size due to MRI scanning with magnet in situ. Ninety-seven patients (21 ABI recipients, 76 CI recipients of whom 23 were bilateral) underwent a total of 428 MRI sessions consisting of 680 MRI procedures, which generated 2,601 MRI sequences (excluding localizers). Of these, 28/428 (6.5%) MRI sessions were performed with magnet removed, and the remaining 400/428 (93.4%) with the magnet in situ. The overall complication rate per session was 15/428 (3.5%). The majority of complications were accounted for by patient discomfort, in some cases requiring abandoning the scan session, but 5 magnet dislocations were also recorded. There were no cases of implant device failure or excessive demagnetization of the receiver stimulator magnet.For CI and ABI recipients, the implant caused large voids of around 110 mm × 60 mm with the magnet in situ which reduced to 60 mm × 30 mm when the magnet was removed. However, it was usually possible to visualize the internal acoustic meatus and cerebellopontine angle by positioning the implant package higher and further forward compared with conventional positioning. MRI scanning in ABI and CI recipients is generally safe and well tolerated without magnet removal, and carries a low rate of complications. However, patients should be fully informed of the possibility of discomfort, and precautions such as local anesthetic injection and head bandaging may reduce the likelihood of adverse events.

Chapter 9 - Neuroimaging and radiation exposure in pregnancy

Physiologic changes occurring in pregnancy and postpartum can have secondary effects on the maternal nervous system. While most alterations to neurologic function during pregnancy are transient, there is an elevated risk for more serious complication in the peripartum period, such as cerebrovascular events or exacerbation of preexisting neurologic conditions. Due to the morbidity and mortality associated with these neurologic manifestations in some cases, timely diagnostic evaluation is essential. In the pregnant population, the use of diagnostic techniques such as computed tomography (CT) and magnetic resonance imaging (MRI), commonly employed to evaluate emergent neurologic abnormalities, requires special consideration of the potential risks associated with prenatal exposure. This review discusses several neurologic conditions affecting women during pregnancy for which diagnostic imaging may be warranted. Concerns relating to CT and MRI procedures, radiation exposure in utero, and exposure to intravenous contrast by placental transfer and breastfeeding are also reviewed.

Insular volume reduction in young male schizophrenia patients

Objective: Recent developments in neuroimaging have advanced the understanding of biological mechanisms underlying schizophrenia. Structural and functional abnormalities of the insular cortex have been reported in schizophrenia patients. Many studies have demonstrated that insula volume is lower in schizophrenia patients than healthy individuals. The present study aimed to compare insula volumes of young male schizophrenia patients with that of age-matched young healthy male subjects to eliminate age and gender bias. Methods: Twenty-three male schizophrenia patients meeting DSM-5 diagnostic criteria, who were at the age of 18-40 years, and age-matched 25 healthy male subjects were included into the study. All patients magnetic resonance imaging (MRI) procedure was completed. Insula volume of schizophrenia patients and healthy male volunteers was calculated using MRICloud method. Disease severity was assessed using Positive and Negative Symptom Scale (PANSS). Results: Volumes of both the left and the right insula were significantly lower in the patient group vs. the control group. Moreover, a positive correlation was determined between the right insula volume and the scores of positive symp-tom severity scale. Conclusion: Decreased insular volume is not a specific marker, but it may be a general marker regarding psychopathology. However, investigating whether the diagnostic specificity of insular cortex abnormalities in psychopathologies will be the focus of future studies.

Recommendations of the Polish Medical Society of Radiology and the Polish Society of Neurology for the routinely used magnetic resonance imaging protocol in patients with multiple sclerosis.

Magnetic resonance imaging (MRI) is a widely used method for the diagnosis of multiple sclerosis (MS) that is essential for the detection and follow-up of the disease. The Polish Medical Society of Radiology (PLTR) and the Polish Society of Neurology (PTN) present the second version of the recommendations for examinations routinely conducted in magnetic resonance imaging departments in patients with MS, which include new data and practical comments for electroradiology technicians and radiologists. The recommended protocol aims to improve the MRI procedure and, most importantly, to standardise the method of conducting scans in all MRI departments. This is crucial for the initial diagnostics that are necessary to establish a diagnosis as well as monitor patients with MS, which directly translates into significant clinical decisions.MS is a chronic idiopathic inflammatory demyelinating disease of the central nervous system (CNS), the aetiology of which is still unknown. The nature of the disease lies in the CNS destruction process disseminated in time and space. MRI detects focal lesions in the white and grey matter with high sensitivity (with significantly less specificity in the latter). It is also the best tool to assess brain atrophy in patients with MS in terms of grey matter volume and white matter volume as well as local atrophy (by measuring the volume of thalamus, corpus callosum, subcortical nuclei, hippocampus) as parameters that correlate with disability progression and cognitive dysfunctions. Progress in magnetic resonance techniques, as well as the abilities of postprocessing the obtained data, has become the basis for the dynamic development of computer programs that allow for a more repeatable assessment of brain atrophy in both cross-sectional and longitudinal studies.MRI is unquestionably the best diagnostic tool used to follow up the course of the disease and to treat patients with MS. However, to diagnose and follow up the patients with MS on the basis of MRI in accordance with the latest standards, an MRI study must meet certain quality criteria, which are the subject of this paper.

Imaging of psoriatic arthritis and aspects of radiographic progression

Psoriatic arthritis (PsA) is a heterogeneous multifactorial disease with musculoskeletal involvement, which can be manifested as monoarthritis, oligoarthritis or polyarthritis and in some patients can also affect the axial skeleton. The most frequent indications of inflammation are bone marrow edema and enthesitis. The early and differential diagnosis of PsA is a clinical challenge, particularly as a differential diagnosis from other inflammatory or degenerative diseases of joints. Inflammatory joint and tendon alterations in the region of the extremities and the spine can be visualized with high sensitivity by the use of magnetic resonance imaging (MRI), musculoskeletal sonography (US) and fluorescence optical imaging (FOI). The use of MRI has a prognostic value with respect to the further radiographic course of the disease, particularly in the initial stages of the disease. Structural damage can be specifically and also partially demonstrated 3‑dimensionally in peripheral joints and the spine by the use of computed tomography (CT) and conventional X‑ray imaging. High-resolution peripheral quantitative CT (HR-pQCT) in particular, can visualize pathophysiological processes and the morphological consequences even in early stages of the disease. The values of conventional X‑ray diagnostics, CT, MRI, musculoskeletal US and alternative imaging procedures are presented with respect to the diagnostics and prognosis of the progression of patients with PsA.

Introduction of a CMR-conditional cardiac phantom simulating cardiac anatomy and function and enabling training of interventional CMR procedures

Interventional magnetic resonance imaging (MRI) procedures promise to open-up new vistas regarding clinically relevant diagnostic and/or therapeutic procedures in the field of cardiology. However, a number of major limitations and challenges regarding interventional cardiovascular magnetic resonance (CMR) procedures still delay their translation from pre-clinical studies to human application. A CMR-conditional cardiac phantom was constructed using MR-safe or -conditional materials only that is based on a unique modular composition allowing quick replacement of individual components. A maximal flow of 76 ml/sec in the aorta and 111 ml/sec in the pulmonary artery were measured, whereas the maximal flow velocity was 56 cm/sec and 89 cm/sec, respectively. A conventional wedge-pressure catheter was advanced over a MRI-conditional guidewire into the right ventricle and thereafter positioned in the pulmonary artery. Pulmonary artery pressure was measured, obtaining the following values for our cardiac phantom: max/min/mean = 16/10/12 mmHg. The presented CMR-conditional cardiac phantom is the first of its kind that does not only mimic cardiac mechanics with adjustable fluid pressure in a four chamber setup that is closely adapted to that of the human heart, but also enables introduction and testing of interventional tools such as guidewires and catheters.

Assessment of a Novel 3T MRI Compatible Cochlear Implant Magnet: Torque, Forces, Demagnetization, and Imaging.

A novel cochlea implant (CI) device magnet providing alignment to the static field of a magnetic resonance imaging (MRI) will lead to reduced torque, longitudinal forces, and demagnetization effects. The image void and distortion will be comparable to those obtained with standard CI magnets. MRI investigations of CI users pose several challenges such as magnet dislocation, demagnetization, and may cause pain. The presence of a CI magnet within MRI field causes image distortions and may diminish the diagnostic value of an MRI procedure. Objective of this work is to evaluate magnetic forces and imaging properties of the novel CI magnet within 1.5 and 3T MRI. Forces and torque of the novel CI magnet were measured in both 1.5 and 3T MRI and compared with the standard magnet in 1.5T. One cadaver head was implanted with the CI devices containing the novel and standard magnets in different configurations reflecting clinical scenarios and imaging properties were assessed and compared. In particular the torque has been reduced with the novel CI magnet in comparison to the standard one. Both CI magnets have not shown any signs of demagnetization. The image void and distortion was comparable between the two magnets for the main MRI clinical scanning protocols in 1.5T MRI. The novel CI magnet is safe to use for MRI investigations of CI users in 3T MRI without a need for bandaging and has acceptable level of image artefacts.

Can virtual reality simulation prepare patients for an MRI experience?

IntroductionA Magnetic Resonance Imaging (MRI) examination is often described by patients as frightening and uncomfortable. To prepare patients for an MRI examination, this study explored the use of virtual reality (VR) simulation compared to a mock MRI scan (full-scale MRI machine replica, without internal magnets). MethodsTwenty participants underwent a VR and a mock MRI scan. Ratings of anxiety and how comfortable and relaxed the participants felt were recorded at five touchpoints during and after each simulation. Post-simulation questionnaires were used to gather responses on the experience and preferences. ResultsNo significant differences were found in participants’ ratings of how anxious they felt during or between the two simulations (χ2 (9) = 27.269, p = .126), or how relaxed they felt (χ2 (9) = 14.664, p = .101). There were also no significant differences in the reported levels of comfort between the two types of simulation (χ2 (9) = 20.864, p = .013, post hoc tests for all VR versus mock scan rankings p > .05). There were no significant differences in how real the participants thought each simulation felt, or how anxious, relaxed, and comfortable they felt following each type of simulation (p > .05). Although 65% of participants thought the mock simulation felt more real than the VR, 86% found VR simulation to be a helpful way to prepare for a real MRI exam. ConclusionVR could be a feasible and accessible alternative to mock scanning. It has the potential to improve patient experiences of potentially stressful MRI examinations. Implications for practiceVR offers clinicians a new cost-effective tool to prepare patients for an MRI examination. VR technology could be used at home, as a training tool, to familiarise clinicians and clinical trainees with the MRI procedure and better understand patients’ experiences.

Effect of Anesthesia Applied for Magnetic Resonance Imaging on the Body Temperature of Pediatric Patients.

ObjectiveAnesthesia may be required to ensure the immobility of the patient during a magnetic resonance imaging (MRI) scan, particularly in pediatric patients. An MRI scanner generates radiofrequency radiation (RFR) to obtain images of parts of the body. During an MRI procedure, an amount of RFR is transformed into heat by the body, thereby leading to increased body temperature. However, patients are at increased risk of hypothermia due to the impairment of thermoregulation by anesthesia and the cold and dry environment of the MRI room. The aim of this study was to investigate the effects of anesthesia on body temperature with regard to patient safety in pediatric patients undergoing an MRI scan.Materials and methodsThe study included a total of 40 children aged three to 10 years who underwent an MRI procedure. The patients were divided into two groups based on the administration of anesthesia: (I) non-sedated and (II) sedated. Prior to the procedure, non-sedated patients were informed about the procedure by a psychiatrist. Body temperature was measured from the tympanic membrane and skin in each patient. The MRI scan was performed at room temperature (20°C-22°C) with a relative humidity of 35%-40%.ResultsNo significant change was found between pre- and post-scan body temperatures in Group I, whereas a significant decrease was found between pre- and post-scan body temperatures in Group II. No complication occurred in any patient due to temperature change or anesthesia.ConclusionA significant decrease in body temperature was found in pediatric patients undergoing an MRI procedure under sedation. The results implicated that anesthesia has a remarkable effect on the balance between the temperature increase caused by RFR and the temperature decrease caused by anesthesia.

Experimental and numerical investigations of a small animal coil for ultra-high field magnetic resonance imaging (7T)

Abstract The purpose of this work was to develop and investigate a radiofrequency (RF) coil to perform image studies on small animals using the 7T magnetic resonance imaging (MRI) system, installed in the imaging platform in the autopsy room (Portuguese acronym PISA), at the University of Sao Paulo, Brazil, which is the unique 7T MRI scanner installed in South America. Due to a high demand to create new specific coils for this 7T system, it is necessary to carefully assess the distribution of electromagnetic (EM) fields generated by the coils and evaluate the patient/object safety during MRI procedures. To achieve this goal 3D numerical methods were used to design and analyse a 8-rungs transmit/receive linearly driven birdcage coil for small animals. Calculated magnetic field (B1) distributions generated by the coil were crosschecked with measured results, indicating good confidence in the simulated results. Electric field results were post-processed and predictions of local specific absorption rate (SAR) values were achieved for a spherical phantom filled with muscle-like tissue, indicating that the sample would not suffer any unsafe deposition of energy. Post mortem abdomen images obtained from a rat presented good image quality and no artifacts related to field non-homogeneity were observed.

Loss Path Influence on the MRI Radio Frequency Pulse Sequence: A Theoretical Evidence.

The RF pulse is initiated from either the loop or loopless MRI antenna. It has shown an increased advancement in recent times. Somehow, the concept has proven successful in the MR imaging procedure. Using the fundamental theories of the MRI concept, mathematical experimentation was carried out analytically to investigate the Loss Path Concept (LPC). The LPC was proposed to be one of the defects responsible for poor/blurred medical imaging of certain parts of the body. The LPC results obtain in this mathematical experimentation was found to be -56 dB and 6.7 dB. Theoretically, the LPC can be resolved mathematically by incorporating the molecular boundaries of the tissues. Practically, LPC can be resolved by introducing a detachable RF strip detector to synchronise-particles across different molecular boundaries and prevent patients from excess exposure to RF radiation.

JUSTIFICATION OF RADIOLOGICAL PROCEDURES ALGORITHM ADJUSTMENT IN DIAGNOSIS OF LOWER BACK PAIN CAUSE AT UNIVERSITY CLINICAL CENTER TUZLA

Introduction: Lower Back Pain (LBP) is one of the most frequent reasons for visiting physican. Authors of guidelines scrutinizing use of radiography and Computed tomography (CT) or Magnetic resonance imaging (MRI) in LBP diagnostic. Method of choice in the LBP diagnostic should be MRI except in cases where we should get diagnostic informations as soon as possible (traumas etc.) and in strict indications in bone structures where CT should be a method of choice. Increase of CT use and following icrease CT derived radiation dose in patients are very serious problems of last decades. Aim: To show the nessesary of procedure algorithm adjusment in LBP diagnostic. Reasons are: danger of overdiagnosis leading to chronifications, loosing time and money to get exact diagnose and leading to cumulate very high ionizing doses (10 mSv per person with average body weight from lumbar spine CT) that could couse a cancer if it is over 100 mSv (in some studies if it is over 50 mSv). Patients and methods: Sixty-nine patients, average age of 51.35 years, were included in the study. Lumbar spine CT was performed and repeated procedure at MRI in a very short time in Clinic for Radiology and Nuclear Medicine of University Clinical Centre Tuzla from January 1 2017 to February 9 2018. The sample of patients was formed consecutively. Referral diagnosis for CT procedures were: M51 in 36 patients (52.17%), N/A in 13 (18.84%), M05 in 4 (5.8%), G83.4 in 3 (4.35%) and other in 13 (18.84%). Results: 30 (83.33%) of patients were referred from CT to MRI procedure in time under 42 days (during acute phase). Relation of justified and unjustified undertaken CT procedures were: 71% unjustified, 10% justified and 19% N/A.Conclusion: Performed study showed unjustified undertaken CT procedures and high unnecessary radiation dose in 71% patients. There are justified reasons for procedure algorithm adjusment in LBP diagnostic. Key words: lower back pain, diagnostic procedure algorithm, CT, MRI

Control of the magnetic near-field pattern inside MRI machine with tunable metasurface

The metasurfaces concept allows developing and advancing the methods to control the near electromagnetic field pattern in almost arbitrary ways. This property, among other things, is making them an essential platform for useful applications, for example, to improve magnetic resonance imaging (MRI) characteristics through local enhancement of the transmit efficiency as well as the increase in the sensitivity of the radio frequency coils. In this letter, we investigate a compact metasurface-based resonator formed as an array of parallel copper wires with capacitive loads printed on the low-loss dielectric substrate. We demonstrate how to tailor the spectral characteristics of the metasurface eigenmode as well as to control precisely the homogeneity of the near-field pattern by changing the effective capacitance of the structure. We experimentally verify that by tuning the metasurface characteristics, it is possible to decrease the excitation power needed to provide the optimal transmit efficiency of the body coil, thus making the MRI procedure safer. Our approach offers a practical method to control the electromagnetic near-field pattern and has potential in various applications, such as MRI and wireless power transfer.

Training health professionals in patient-centered communication during magnetic resonance imaging to reduce patients’ perceived anxiety

ObjectiveWe examined how a patient-centered communication training program for magnetic resonance imaging (MRI) affected health professional (HP) practice and patients’ perceived anxiety (PA). MethodsWe implemented an intervention program. Six of the 17 eligible HPs completed the study. The proportion of observed desired behaviors (PODBs), including MRI procedure explanation (MRI-PE), communication, and MRI checking procedures was measured using an observation grid. We tested 182 patients (85 pre-, 58 post-, and 39 at follow-up) for PA pre- and post-MRI. ResultsThe Bayesian ANOVA effect size suggested moderate evidence of improvement in HP PODBs, pre- to post-intervention. Use of MRI-PE declined between post-intervention and follow-up (6 months later). Observed changes in PA, pre- to post-MRI, could be related to time constraints and perceived pressure to explain the exam in detail once institutional routines are reestablished. ConclusionIn MRI units, time constraints condition the performance of HPs who address patients’ PA. Practice implications“Real workplace” interventions that promote better patient-centered communication and provide each patient with a comprehensive explanation of MRI procedures also appear to improve HP PODBs.