Growth Rates in Pediatric Diagnostic Imaging and Sedation

MRI safety-developing the right culture

In recent years, magnetic resonance imaging (MRI) among pediatric populations has risen, requiring strict adherence to MRI safety protocols for patient care. Children often face more complex safety risks compared to adult populations due to several challenges, such as increased need for sedation, and the limited data and testing on implant safety in pediatric patients. Our aim is to examine the key features of MRI safety and how safety culture impacts important aspects of MRI processes, including patient and staff screening, physical barriers, zoning regulations, emergency response protocols, and adverse event management. This article also explores the cornerstone of MRI safety, the Just Culture approach, which emphasizes transparency, accountability, and improvement of processes over punishment. Key efforts towards building and maintaining safety culture focus on raising awareness, outlining escalation procedures, and instilling a safety-first mindset. Given MRI safety's critical importance in pediatric patient care and staff well-being, the development of a culture that supports these goals is an imperative for every imaging center.

Reducing Sedation for Pediatric Thoracic CT Imaging Using Volumetric Target-mode EKG Gating

Introduction

Many children require sedation for imaging. We aimed to reduce sedation for thoracic (chest and cardiac) computed tomography (CT) scans in children 0-4 years old from 65% to 20% by December 2018 and to sustain.

Methods

We counted baseline, intervention, and a follow-up period thoracic CT scans performed with sedation in children 0-4 years old. We developed a new volumetric target-mode electrocardiogram-gated CT imaging protocol to reduce scan time and control for factors that decrease image quality. Additional interventions included technologist training, communication to radiologists and clinicians, and eliminating a default request for sedation accompanying the electronic order for most thoracic CT scans. A statistical process control chart tracked data to study process changes over time.

Results

During the baseline and intervention periods, 232 of 357 and 217 of 794 scans required sedation. Interventions created 2 centerline shifts. Overall, thoracic CT scans in children 0-4 years old requiring sedation decreased from 65% to 24% and was sustained 5 years later. No patients during the baseline period, one (1 of 794, 0.1%) during the intervention period and 2 (2 of 480, 0.4%) during the audit period 5 years later, initially had nondiagnostic nonsedated scans that required an additional scan with sedation.

Conclusions

We developed a volumetric target-mode electrocardiogram-gated CT protocol, eliminated default sedation ordering, and trained and educated staff to reduce sedation in young children undergoing thoracic CT scans. The frequency of sedation for thoracic CT in children 0-4 years old decreased from 65% to 24% and was sustained after revising imaging parameters and eliminating a default sedation order.

Sedation and anesthesia for imaging of the infant and neonate-a brief review

Sedation and anesthesia are often required in order to facilitate collection of high-quality imaging studies free of significant motion artifact for infants and neonates. Provision of safe sedation and anesthesia requires good communication between the ordering provider, radiologist, and anesthesiologist, careful pre-procedural evaluation of the patient, and availability of appropriate and sufficient equipment, drugs, personnel, and facilities. There are many additional factors to be considered for provision of safe sedation or anesthesia for infants and neonates-it is ideal to involve a fellowship-trained pediatric anesthesiologist in the planning and carry-out of these plans. In this review, we discuss some of the basic definitions of sedation and anesthesia, requirements for safe sedation and anesthesia, and many of the germane risks and additional considerations that factor into the delivery of a safe sedation or anesthesia plan for the imaging of an infant or neonate.

A survey of non-sedate practices when acquiring pediatric magnetic resonance imaging examinations

BACKGROUND

Improving access to magnetic resonance imaging (MRI) in childhood can be facilitated by making it faster and cheaper and reducing need for sedation or general anesthesia (GA) to mitigate motion. Some children achieve diagnostic quality MRI without GA through the use of non- practices fostering their cooperation and/or alleviating anxiety. Employed before and during MRI, these variably educate, distract, and/or desensitize patients to this environment.

OBJECTIVE

To assess current utilization of non-sedate practices in pediatric MRI, including variations in practice and outcomes.

MATERIALS AND METHODS

A survey-based study was conducted with 1372 surveys emailed to the Society for Pediatric Radiology members in February 2021, inviting one response per institution.

RESULTS

Responses from 50 unique institutions in nine countries revealed 49/50 (98%) sites used ≥ 1 non-sedate practice, 48/50 (96%) sites in infants < 6 months, and 11/50 (22%) for children aged 6 months to 3 years. Non-sedate practices per site averaged 4.5 (range 0-10), feed and swaddle used at 47/49 (96%) sites, and child life specialists at 35/49 (71%). Average success rates were moderate (> 50-75%) across all sites and high (> 75-100%) for 20% of sites, varying with specific techniques. Commonest barriers to use were scheduling conflicts and limited knowledge.

CONCLUSION

Non-sedate practice utilization in pediatric MRI was near-universal but widely variable across sites, ages, and locales, with room for broader adoption. Although on average non-sedate practice success rates were similar, the range in use and outcomes suggest a need for standardized implementation guidelines, including patient selection and outcome metrics, to optimize utilization and inform educational initiatives.

Nonpharmacological Interventions to Reduce Sedation and General Anesthesia in Pediatric MRI: A Meta-analysis

CONTEXT

Nonpharmacological strategies are increasingly used in pediatric procedures, but in pediatric MRI, sedation and general anesthesia are still commonly required.

OBJECTIVES

To evaluate the effectiveness of nonpharmacological interventions in reducing use of sedation and general anesthesia in pediatric patients undergoing MRI, and to investigate effects on scan time, image quality, and anxiety.

DATA SOURCES

We searched Ovid Medline, CINAHL, Embase, and CENTRAL from inception through October 10, 2022.

STUDY SELECTION

We included randomized controlled trials and quasi-experimental designs comparing the effect of a nonpharmacological intervention with standard care on use of sedation or general anesthesia, scan time, image quality, or child and parental anxiety among infants (<2 years), children, and adolescents (2-18 years) undergoing MRI.

DATA EXTRACTION

Standardized instruments were used to extract data and assess study quality.

RESULTS

Forty-six studies were eligible for the systematic review. Limited to studies on children and adolescents, the meta-analysis included 20 studies with 33 873 patients. Intervention versus comparator analysis showed that nonpharmacological interventions were associated with reduced need for sedation and general anesthesia in the randomized control trials (risk ratio, 0.68; 95% confidence interval, 0.48-0.95; l2 = 35%) and nonrandomized studies (risk ratio, 0.58; 95% confidence interval, 0.51-0.66; l2 = 91%). The effect was largest among children aged 3 to 10 years when compared with older children and adolescents aged 11 to 18 years.

LIMITATIONS

There was substantial heterogeneity among nonrandomized studies.

CONCLUSIONS

Nonpharmacological interventions must be considered as standard procedure in infants, children, and adolescents undergoing MRI.

Perioperative management and drug selection for sedated/anesthetized patients undergoing MRI examination: A review

In recent years, magnetic resonance imaging (MRI) technology has become an indispensable imaging tool owing to significant improvements in MRI that have opened up new diagnostic perspectives. Due to the closed environment, long imaging time, and need to remain still during the examination process, the examiner may cannot cooperate with the completion of the examination of the procedure, which increases the need for deep sedation or anesthesia. Achieving this can sometimes be challenging, especially in the special nontraditional environment of MRI equipment (unfamiliar and narrow spaces, away from patients, strong magnetic fields) and in special populations requiring sedation/anesthesia during examinations, which pose certain challenges for the perioperative anesthesia management of MRI. A simple "checklist" is necessary because it allows the anesthesiologist to become familiar with the particular environment and human and material resources as quickly as possible. For the choice of sedative/anesthetic, the traditional drugs, such as midazolam and ketamine, are still used due to the ease of administration despite their low sedation success rate, prolonged recovery, and significant adverse events. Currently, dexmedetomidine, with respiratory drive preservation, propofol, with high effectiveness and rapid recovery, and sevoflurane, which is mild and nonirritating, are preferred for sedation/anesthesia in children and adults undergoing MRI. Therefore, familiarity with the perioperative management of patient sedation and general anesthesia and drug selection in the MRI environment is critical for successful surgical completion and for the safe and rapid discharge of MRI patients receiving sedation/anesthesia.

Variability in Resource Utilization in the Evaluation and Management of Simple Febrile Seizures Inpatients in US Children's Hospitals

OBJECTIVE

To characterize resource utilization in the evaluation and treatment of hospitalized simple febrile seizure (SFS) patients in US tertiary pediatric hospitals.

METHODS

This is a retrospective cohort study using the Pediatric Health Information System from 2010 to 2015. Children 6 months to 5 years of age who were inpatients with a diagnosis of SFS. Children who had brain magnetic resonance imaging (MRI), electroencephalography (EEG), or received anticonvulsants were compared with those who did not have testing or anticonvulsant treatment. Hospital-level variation in the utilization rates of MRI, EEG, or treatment with anticonvulsants was also evaluated.

RESULTS

In Pediatric Health Information System-participating institutions, 8.4% (n=3640) of children presenting to the emergency department with SFS were hospitalized. Among these SFS inpatients, 57.8% (n= 2104) did not receive further evaluation with MRI/EEG or treatment with anticonvulsants. There was evidence of wide inter-hospital variation in resource utilization rates. The median (interquartile range) utilization rate was 6.2% (3.0 to 11.0%) for MRI, 28.5% (16.0 to 46.3%) for EEG and 17.1% (10.9 to 22.3%) for treatment with anticonvulsants.

CONCLUSION

No specific hospital-level factors were identified that contributed to the variation in resource utilization in the evaluation and management of hospitalized SFS patients.

Needle-free pharmacological sedation techniques in paediatric patients for imaging procedures: a systematic review and meta-analysis

BACKGROUND

Sedation techniques and drugs are increasingly used in children undergoing imaging procedures. In this systematic review and meta-analysis, we present an overview of literature concerning sedation of children aged 0-8 yr for magnetic resonance imaging (MRI) procedures using needle-free pharmacological techniques.

METHODS

Embase, MEDLINE, Web of Science, and Cochrane databases were systematically searched for studies on the use of needle-free pharmacological sedation techniques for MRI procedures in children aged 0-8 yr. Studies using i.v. or i.m. medication or advanced airway devices were excluded. We performed a meta-analysis on sedation success rate. Secondary outcomes were onset time, duration, recovery, and adverse events.

RESULTS

Sixty-seven studies were included, with 22 380 participants. The pooled success rate for oral chloral hydrate was 94% (95% confidence interval [CI]: 0.91-0.96); for oral chloral hydrate and intranasal dexmedetomidine 95% (95% CI: 0.92-0.97); for rectal, oral, or intranasal midazolam 36% (95% CI: 0.14-0.65); for oral pentobarbital 99% (95% CI: 0.90-1.00); for rectal thiopental 92% (95% CI: 0.85-0.96); for oral melatonin 75% (95% CI: 0.54-0.89); for intranasal dexmedetomidine 62% (95% CI: 0.38-0.82); for intranasal dexmedetomidine and midazolam 94% (95% CI: 0.78-0.99); and for inhaled sevoflurane 98% (95% CI: 0.97-0.99).

CONCLUSIONS

We found a large variation in medication, dosage, and route of administration for needle-free sedation. Success rates for sedation techniques varied between 36% and 98%.

Using intranasal dexmedetomidine with buccal midazolam for magnetic resonance imaging sedation in children: A single-arm prospective interventional study

OBJECTIVE

Although numerous intravenous sedative regimens have been documented, the ideal non-parenteral sedation regimen for magnetic resonance imaging (MRI) has not been determined. This prospective, interventional study aimed to investigate the efficacy and safety of buccal midazolam in combination with intranasal dexmedetomidine in children undergoing MRI.

METHODS

Children between 1 month and 10 years old requiring sedation for MRI examination were recruited to receive buccal midazolam 0.2 mg⋅kg^-1 with intranasal dexmedetomidine 3 μg⋅kg^-1. The primary outcome was successful sedation following the administration of the initial sedation regimens and the completion of the MRI examination.

RESULTS

Sedation with dexmedetomidine-midazolam was administered to 530 children. The successful sedation rate was 95.3% (95% confidence interval: 93.5-97.1%) with the initial sedation regimens and 97.7% (95% confidence interval: 96.5-99%) with a rescue dose of 2 μg⋅kg^-1 intranasal dexmedetomidine. The median sedation onset time was 10 min, and a significant rising trend was observed in the onset time concerning age (R = 0.2491, P < 0.001). The wake-up and discharge times significantly correlated with the duration of the procedure (R = 0.323, P < 0.001 vs. R = 0.325, P < 0.001). No oxygen deficiency nor medication intervention due to cardiovascular instability was observed in any of the patients. History of a prior failed sedation was considered a statistically significant risk factor for failed sedation in the multivariate logistic regression model [odds ratio = 4.71 (95% confidence interval: 1.24-17.9), P = 0.023].

CONCLUSION

In MRI examinations, the addition of buccal midazolam to intranasal dexmedetomidine is associated with a high success rate and a good safety profile. This non-parenteral sedation regimen can be a feasible and convenient option for short-duration MRI in children between 1 month and 10 years.

Incidence and Causes of Adverse Events in Diagnostic Radiological Studies Requiring Anesthesia in the Wake-Up Safe Registry

OBJECTIVES

General anesthesia or sedation can facilitate the completion of diagnostic radiological studies in children. We evaluated the incidence, predictors, and causes of adverse events (AEs) when general anesthesia is provided for diagnostic radiological imaging.

METHODS

Deidentified data from 24 pediatric tertiary care hospitals participating in the Wake-Up Safe registry during 2010-2015 were obtained for analysis. Children 18 years or younger receiving general anesthesia for radiological procedures were identified using Current Procedural Terminology codes, and reported AEs were analyzed if they were associated with anesthetic care at magnetic resonance imaging or computed tomography locations. Logistic regression was used to determine predictors of AE occurrence in cases with complete covariate data.

RESULTS

We identified 175,486 anesthetics for diagnostic radiological exams, compared with 83 AEs in magnetic resonance imaging or computed tomography locations (AE incidence of 0.05%). In multivariable analysis, AEs were more likely among patients with American Society of Anesthesiologists physical status IV compared with American Society of Anesthesiologists physical status I patients (adjusted odds ratio, 8.9; 95% confidence interval, 2.8-28.0; P < 0.001). Twenty-three AEs resulted in harm to the patient, whereas 32 AEs required unplanned hospital or intensive care unit admission. Anesthetic complications or issues were the most common cause of AEs (n = 52).

CONCLUSIONS

Anesthesia provided for pediatric radiological studies is very safe and with an overall low AE incidence. The contribution of anesthetic complications to reported AEs suggests opportunities for further process improvement in this setting.

Trust-Based Partnerships Are Essential - and Achievable - in Health Care Service

When people think about trust in the context of health care, they typically focus on whether patients trust the competence of doctors and other health professionals. But for health care to reach its full potential as a service, trust must also include the notion of partnership, whereby patients see their clinicians as reliable, caring, shared decision-makers who provide ongoing "healing" in its broadest sense. Four interrelated service-quality concepts are central to fostering trust-based partnerships in health care: empathetic creativity, discretionary effort, seamless service, and fear mitigation. Health systems and institutions that prioritize trust-based partnerships with patients have put these concepts into practice using several concrete approaches: investing in organizational culture; hiring health professionals for their values, not just their skills; promoting continuous learning; attending to the power of language in all care interactions; offering patients "go-to" sources for timely assistance; and creating systems and structures that have trust built into their very design. It is in the real-world implementation of trust-based partnership that health care can reclaim its core mission.

Motion estimation and correction in SPECT, PET and CT

Patient motion impacts single photon emission computed tomography (SPECT), positron emission tomography (PET) and X-ray computed tomography (CT) by giving rise to projection data inconsistencies that can manifest as reconstruction artifacts, thereby degrading image quality and compromising accurate image interpretation and quantification. Methods to estimate and correct for patient motion in SPECT, PET and CT have attracted considerable research effort over several decades. The aims of this effort have been two-fold: to estimate relevant motion fields characterizing the various forms of voluntary and involuntary motion; and to apply these motion fields within a modified reconstruction framework to obtain motion-corrected images. The aims of this review are to outline the motion problem in medical imaging and to critically review published methods for estimating and correcting for the relevant motion fields in clinical and preclinical SPECT, PET and CT. Despite many similarities in how motion is handled between these modalities, utility and applications vary based on differences in temporal and spatial resolution. Technical feasibility has been demonstrated in each modality for both rigid and non-rigid motion, but clinical feasibility remains an important target. There is considerable scope for further developments in motion estimation and correction, and particularly in data-driven methods that will aid clinical utility. State-of-the-art machine learning methods may have a unique role to play in this context.

A Case Report of B-cell Lymphoblastic Leukemia/Lymphoma Presenting as Isolated Torticollis in a 2-year-old Female

Introduction

Malignancy is a rare cause of acquired torticollis in children, and spinal cord involvement from hematolymphoid malignancies is similarly unusual. Neurologic abnormalities may not be present on initial evaluation, and delayed diagnosis and treatment is associated with increased risk of permanent paralysis.

Case Report

The author describes a case of isolated torticollis in a 2-year-old evaluated multiple times in the emergency department (ED) and outpatient settings. For her first three presentations, the patient had no associated neurologic abnormalities. She was discharged with return precautions and a presumptive diagnosis of viral infection/lymphadenitis. She later developed weakness of her left arm and was diagnosed with a B-cell lymphoblastic leukemia/lymphoma causing spinal cord compression.

Conclusion

This case highlights the importance of continued comprehensive and meticulous physical examination in patients with repeat ED visits, as well as the value of detailed discharge instructions in mitigating diagnostic delays in these patients.

Drug selection for sedation and general anesthesia in children undergoing ambulatory magnetic resonance imaging

The demand for drug-induced sedation for magnetic resonance imaging (MRI) scans have substantially increased in response to increases in MRI utilization and growing interest in anxiety in children. Understanding the pharmacologic options for deep sedation and general anesthesia in an MRI environment is essential to achieve immobility for the successful completion of the procedure and ensure rapid and safe discharge of children undergoing ambulatory MRI. For painless diagnostic MRI, a single sedative/anesthetic agent without analgesia is safer than a combination of multiple sedatives. The traditional drugs, such as chloral hydrate, pentobarbital, midazolam, and ketamine, are still used due to the ease of administration despite low sedation success rate, prolonged recovery, and significant adverse events. Currently, dexmedetomidine, with respiratory drive preservation, and propofol, with high effectiveness and rapid recovery, are preferred for children undergoing ambulatory MRI. General anesthesia using propofol or sevoflurane can also provide predictable rapid time to readiness and scan times in infant or children with comorbidities. The selection of appropriate drugs as well as sufficient monitoring equipment are vital for effective and safe sedation and anesthesia for ambulatory pediatric MRI.

Head Motion Correction Based on Filtered Backprojection in Helical CT Scanning

Head motion may unexpectedly occur during a CT scan. It thereby results in motion artifacts in a reconstructed image and may lead to a false diagnosis or a failure of diagnosis. To alleviate this motion problem, as a hardware approach, increasing the gantry rotation speed or using an immobilization device is usually considered. These approaches, however, cannot completely resolve the motion problem. Hence, motion estimation (ME) and compensation for it have been explored as a software approach instead. In this paper, adopting the latter approach, we propose a head motion correction algorithm in helical CT scanning, based on filtered backprojection (FBP). For the motion correction, we first introduce a new motion-compensated (MC) reconstruction scheme based on FBP, which is applicable to helical scanning. We then estimate the head motion parameters by using an iterative nonlinear optimization algorithm, or the L-BFGS. Note here that an objective function for the optimization is defined on reconstructed images in each iteration, which are obtained by using the proposed MC reconstruction scheme. Using the estimated motion parameters, we then obtain the final MC reconstructed image. Using numerical and physical phantom datasets along with simulated head motions, we demonstrate that the proposed algorithm can provide significantly improved quality to MC reconstructed images by alleviating motion artifacts.

Feed and Swaddle: An Alternative to Infant Sedation for Craniofacial Imaging

Objective:

The gold standard for diagnosis of craniosynostosis is a clinical examination and motionless head computed tomography (CT). Computed tomography sedation is associated with increased cost, resource utilization, medical, and possible developmental risks. This study investigates whether a “feed and swaddle” protocol can be used to achieve diagnostic quality craniofacial imaging without the use of infant sedation.

Design:

Prospective cohort study.

Setting:

Tertiary academic medical center.

Patients:

Ninety patients <18 months of age undergoing evaluation for craniosynostosis from 2012 to 2018.

Interventions:

A feed and swaddle protocol.

Main Outcome Measures:

Diagnostic level imaging without the use of infant sedation.

Results:

Eighty-five (94%) achieved a diagnostic quality craniofacial CT scan using the “feed and swaddle” method. Mean patient age was 24.0 ± 10.0 weeks. Craniosynostosis was diagnosed in 74% of patients. Mean age of patients with successful completion of a CT scan was 23.7 ± 9.6 weeks, compared to 27.2 ± 17.1 weeks for unsuccessful completion. Mean weight for the successful group was 15.6 ± 2.9 pounds and 15.9 ± 2.5 pounds for the unsuccessful group. Mean travel distance was 59.2 ± 66.5 miles for successful patients and 66.5 ± 61.5 miles for unsuccessful patients. For the unsuccessful patients, there were no delays in surgical planning or scheduling.

Conclusion:

The “feed and swaddle” protocol described here is an effective alternative to infant sedation for motionless craniofacial CT imaging.

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

Objective Anesthesia 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 methods The 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%. Results No 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. Conclusion A 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.

The Effects of Anesthesia on the Pediatric Developing Brain: Strategies to Reduce Anesthesia Use in Pediatric MRI and Nursing's Role in Driving Patient Safety

PURPOSE

To describe the physiological and biological principles of anesthesia for children; nonanesthesia practices; the state of the evidence of patient- and family-centered care strategies to reduce anesthesia use; and role of nursing in ensuring patient safety through reducing anesthesia use for pediatric magnetic resonance imaging (MRI).

DESIGN

Integrative literature review.

METHODS

Review and synthesis of experimental and nonexperimental literature.

FINDINGS

Anesthesia use in pediatric MRI: 20 studies met inclusion criteria. Physiological and biological side effects of anesthesia in children are substantial. Of significance is the developing research on the extent to which anesthesia affects the developing brain of children. Nonanesthesia in pediatric MRI: 16 studies met inclusion criteria. Common themes were noted between patient- and family-centered care strategies and reducing anesthesia use in children requiring MRI.

CONCLUSIONS

There are significant risks associated with anesthesia on the developing brain. Nurses play an important role in using patient-centered strategies to reduce pediatric anesthesia use and advocate for patient safety.

General anesthesia / sedation requirement influences the way MRI brain scans are ordered in a tertiary pediatric hospital

BACKGROUND

MRI guidelines have been created to help clinicians order scans appropriately. Some scans in children are carried out under general anesthesia (GA) / sedation.

PURPOSE

To evaluate if the requirement for GA/sedation influences the way MRI brain scans are ordered.

STUDY TYPE

Retrospective.

POPULATION

Children with MRI brain scans in 2015 to 2017.

FIELD STRENGTH

3T, 1.5T.

ASSESSMENT

Institutional Review Board approval for waiver of consent was obtained. Clinical MRI brain reports for children were classified into whether they conformed to the American College of Radiology (ACR) 2013 guidelines by research assistants under supervision of a pediatric radiologist. Scans were sorted into those with normal brains or abnormality.

STATISTICAL TEST

The statistical difference between groups was assessed using t-test for continuous variables and chi-square test for categorical variables with IBM SPSS 19.

RESULTS

Of the total 1893 MRI scans, 431 were performed under GA and six under sedation. Of the 431 cases performed under GA/sedation, 383 (87.6%) were ordered according to guidelines. Of the 1456 cases that did not require GA/sedation, 710 (48.8%) conformed to guidelines. The percentage of scans ordered according to guidelines was 38.8% higher in those who had scans performed under GA/sedation (P < 0.001). MRI scans were normal in 635 (58.0%) out of the 1093 cases ordered according to guidelines and normal in 638 (79.8%) out of the 800 cases that did not follow guidelines. Scans not ordered according to guidelines had higher proportion of normal scans (21.8%) compared with those ordered according to guidelines (P < 0.001).

DATA CONCLUSION

Higher adherence to imaging guidelines is seen in younger patients who were exposed to the risks of GA/sedation for the MRI. Scans not adhering to guidelines had a higher percentage of having no brain abnormality detected.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 6 J. Magn. Reson. Imaging 2019;49:e250-e255.

A modified CO2/O2 Guedel airway improves capnographic accuracy compared with a CO2/O2 nasal cannula: An infant manikin study

BACKGROUND

Capnography via a CO2/O2 nasal cannula is commonly used for respiratory monitoring during sedation. However, signal disturbances are frequently encountered, especially in young children.

OBJECTIVE

Sampling ports placed closer to the trachea have been shown to result in improved signal quality. In a manikin model of a 6-month-old infant we compared capnography from a modified Guedel airway with a CO2 port located at the tip with that from a CO2/O2 nasal cannula.

DESIGN

A comparison study using an artificial model of a breathing 6-month-old infant.

SETTING

Department of Paediatrics, Inselspital Bern, Switzerland, from March 2016 to June 2016.

MATERIAL

Modified CO2/O2 Guedel airway.

INTERVENTIONS

Capnography using a modified CO2/O2 Guedel airway or a CO2/O2 nasal cannula was performed for tidal volumes of 20 to 80 ml (in steps of 20 ml), respiratory rates of 20 to 60 min (in steps of 10 min) and with different O2 flows (0 to 2 l min, in steps of 0.5 l).

MAIN OUTCOME MEASURES

Comparison of differences between tracheal and device CO2. Secondary outcomes included the effect of various respiratory settings and O2 flows on the CO2 difference.

RESULTS

The tracheal to device CO2 difference was significantly smaller when using a modified CO2/O2 Guedel airway vs. a CO2/O2 nasal cannula: Mean ± SD, 16.8 ± 4.9 vs. 24.1 ± 5.9 mmHg, P less than 0.0001. An O2 flow of 0.5 to 2 l min did not influence the tracheal to device CO2 difference with the modified CO2/O2 Guedel airway in contrast to the CO2/O2 nasal cannula where there were significant differences (P < 0.0001). The effect of various tidal volumes and respiratory rates proved to be similar in both devices.

CONCLUSION

Capnography traces derived from a sample port at the tip of a modified CO2/O2 Guedel airway were more accurate than those obtained from a CO2/O2 nasal cannula.

TRIAL REGISTRATION

Not applicable.

The Utility of the Modified Yale Preoperative Anxiety Scale for Predicting Success in Pediatric Patients Undergoing MRI Without the Use of Anesthesia

PURPOSE

MRI is a common modality for diagnostic imaging. In children, general anesthesia is often required to complete MRI examinations. Simulation training can reduce the need for anesthesia in some children. Reliable screening tools to select who could benefit from practice MRI sessions are lacking. This study evaluates the use of the modified Yale Preoperative Anxiety Scale (mYPAS) in effectively identifying patients who may benefit from simulation-based training.

METHODS

Children aged 5 and older who were originally scheduled for MRI with anesthesia in 2015 to 2016 were prospectively recruited for simulation-based training. The mYPAS assessment was performed by trained certified child life specialists before and after practice MRI sessions. The primary outcome was whether mYPAS could predict completing an MRI examination without anesthesia.

RESULTS

Eighty patients (43 boys and 37 girls, age 8.5 ± 3.0 years) were enrolled in the study. Eleven subjects (14%) required general anesthesia to complete the MRI examination despite participating in the simulation. In the overall cohort, mYPAS scores improved after simulation from 31 ± 11 to 27 ± 9 (95% confidence interval of difference, -6, -2; P < .001 by paired t test). Receiver operating characteristic curve analysis found that presimulation mYPAS had good utility for predicting anesthesia requirement for MRI completion (area under the curve = 0.81). A presimulation mYPAS score > 33 predicted need for anesthesia with 82% sensitivity and 78% specificity.

CONCLUSIONS

The mYPAS is a quick screening tool to identify pediatric patients who could benefit from simulation training by being able to complete an MRI examination without anesthesia.

Pediatric anesthesia and neurotoxicity: what the radiologist needs to know

The use of cross-sectional imaging in the pediatric population continues to rise, particularly the use of MRI. Limiting motion artifact requires cooperative subjects who do not move during imaging, so there has been an increase in the need for pediatric sedation or anesthesia. Over the last decade, concern has increased that exposure to anesthesia might be associated with long-term cognitive deficits. In this review we report current understanding of the effects of anesthesia on the pediatric population, with special focus on long-term developmental and cognitive outcomes, and suggest how radiologists can use new technologies or imaging strategies to mitigate or minimize these potential risks.

Pediatric providers and radiology examinations: knowledge and comfort levels regarding ionizing radiation and potential complications of imaging

BACKGROUND

Pediatric providers should understand the basic risks of the diagnostic imaging tests they order and comfortably discuss those risks with parents. Appreciating providers' level of understanding is important to guide discussions and enhance relationships between radiologists and pediatric referrers.

OBJECTIVE

To assess pediatric provider knowledge of diagnostic imaging modalities that use ionizing radiation and to understand provider concerns about risks of imaging.

MATERIALS AND METHODS

A 6-question survey was sent via email to 390 pediatric providers (faculty, trainees and midlevel providers) from a single academic institution. A knowledge-based question asked providers to identify which radiology modalities use ionizing radiation. Subjective questions asked providers about discussions with parents, consultations with radiologists, and complications of imaging studies.

RESULTS

One hundred sixty-nine pediatric providers (43.3% response rate) completed the survey. Greater than 90% of responding providers correctly identified computed tomography (CT), fluoroscopy and radiography as modalities that use ionizing radiation, and ultrasound and magnetic resonance imaging (MRI) as modalities that do not. Fewer (66.9% correct, P<0.001) knew that nuclear medicine utilizes ionizing radiation. A majority of providers (82.2%) believed that discussions with radiologists regarding ionizing radiation were helpful, but 39.6% said they rarely had time to do so. Providers were more concerned with complications of sedation and cost than they were with radiation-induced cancer, renal failure or anaphylaxis.

CONCLUSION

Providers at our academic referral center have a high level of basic knowledge regarding modalities that use ionizing radiation, but they are less aware of ionizing radiation use in nuclear medicine studies. They find discussions with radiologists helpful and are concerned about complications of sedation and cost.

MRI Utilization and the Associated Use of Sedation and Anesthesia in a Pediatric ACO

BACKGROUND AND OBJECTIVES

MRI is commonly used in the pediatric population and often requires sedation or general anesthesia to complete. This study used data from a pediatric accountable care organization (ACO) to investigate trends in MRI utilization and in the requirement for anesthesia to complete MRI examinations.

METHODS

The Partners for Kids (PFK) ACO claims database was queried for MRI examination encounters involving patients 0 to 18 years old from 2009 to 2014, with utilization expressed as encounters per 10,000 PFK members-months. Data were limited to 2011 to 2014 to ensure consistent billing of anesthesia services. Encounters were classified according to the presence of procedure codes for anesthesia or sedation.

RESULTS

MRI utilization was approximately constant over the study period at 11 to 12 encounters per 10,000 member-months. The need for anesthesia increased from 21% to 28% of encounters over 2011 to 2014. The latter increase was shared across 1- to 6-year-old, 7- to 12-year-old, and 12- to 18-year-old subgroups. In multivariable regression analysis of monthly utilization, increasing need for anesthesia could not be attributed to secular trends in patient demographics or types of examinations ordered. Paid cost data were available for outpatient MRIs, and MRIs with sedation accounted for an increasing share of these costs (from 22% in 2011 to 33% in 2014).

CONCLUSION

There was an increasing need for anesthesia services to complete MRI examinations in this pediatric population, resulting in increasing cost of MRI examinations and presenting a challenge to ACO cost containment.

Translational motion correction algorithm for truncated cone-beam CT using opposite projections

BACKGROUND

Cone-beam computed tomography (CBCT) is widely used in various medical imaging applications, including dental examinations. Dental CBCT images often suffer from motion artifacts caused by involuntary rigid motion of patients. However, earlier motion compensation studies are not applicable for dental CBCT systems using truncated detectors.

OBJECTIVE

This study proposes a novel motion correction algorithm that can be applied for truncated dental CBCT images.

METHODS

We propose a two-step method for motion correction. First, we estimate the relative displacement of each pair of opposite projections by finding the motion vector that maximizes the two-dimensional correlation coefficients of the opposite projections. Second, we convert the relative displacement into the absolute coordinate motion that yields the highest image sharpness of the reconstruction image. Using the motion vectors in the absolute coordinate system, motion artifacts are then compensated by modifying the trajectory of the source and detector during the back-projection step of the image reconstruction process.

RESULTS

In simulation, the proposed method successfully estimated the true relative displacement. After converting to the absolute coordinate motions, the motion-compensated image was close to the ground-truth image and exhibited a lower mean-square-error than that of the uncompensated image. The results from the real data experiment also confirmed that the proposed method successfully compensated for the motion artifacts.

CONCLUSIONS

The experimental results confirmed that the proposed method was applicable to most dental CBCT systems using a truncated detector without any use of an additional motion tracking system nor prior knowledge.

Use of Anesthesia for Imaging Studies and Interventional Procedures in Children

Ongoing investigation from the Pediatric Anesthesia NeuroDevelopment Assessment (PANDA) study hopes to examine the long-term effect on cognitive and language development of a single anesthetic exposure in children undergoing inguinal hernia repair. The fifth PANDA Symposium, held in April 2016, continued the mission of previous symposia to examine evidence from basic science and clinical studies on potential neurotoxic effects of anesthetics on developing brain. At the 2016 Symposium, a panel of specialists from nonsurgical pediatric disciplines including anesthesiology, radiology, neurology, gastroenterology, oncology, cardiology, and critical care reviewed use of anesthesia in their practices, including how concern over possible neurodevelopmental effects of early childhood anesthetic exposure has changed discussion with patients and families regarding risks and benefits of imaging studies and interventional procedures involving sedation or anesthesia. This paper summarizes presentations from nonsurgical pediatric specialists at the 2016 PANDA Symposium.

A quality improvement project to reduce hypothermia in infants undergoing MRI scanning

BACKGROUND

Hypothermia prevention strategies during MRI scanning under general anesthesia in infants may pose a challenge due to the MRI scanner's technical constraints. Previous studies have demonstrated conflicting results related to increase or decrease in post-scan temperatures in children. We noted occurrences of post-scan hypothermia in anesthetized infants despite the use of routine passive warming techniques.

OBJECTIVE

The aims of our quality improvement project were (a) to identify variables associated with post-scan hypothermia in infants and (b) to develop and implement processes to reduce occurrence of hypothermia in neonatal intensive care unit (NICU) infants undergoing MRI.

MATERIALS AND METHODS

One hundred sixty-four infants undergoing MRI scanning were prospectively audited for post-scan body temperatures. A multidisciplinary team identified potential variables associated with post-scan hypothermia and designed preventative strategies: protocol development, risk factor identification, vigilance and use of a vacuum immobilizer. Another audit was performed, specifically focusing on NICU infants.

RESULTS

In the initial phase, we found that younger age (P = 0.002), lower weight (P = 0.005), lower pre-scan temperature (P < 0.01), primary anesthetic technique with propofol (P < 0.01), advanced airway devices (P = 0.02) and being in the NICU (P < 0.01) were associated with higher odds for developing post-scan decrease in body temperature. Quality improvement processes decreased the occurrence of hypothermia in NICU infants undergoing MRI scanning from 65% to 18% (95% confidence interval for the difference, 26-70%, P < 0.001).

CONCLUSION

Several variables, including being in the NICU, are associated with a decrease in post-scan temperature in infants undergoing MRI scanning under sedation/general anesthesia. Implementation of strategies to prevent hypothermia in infants may be challenging in the high-risk MRI environment. We were able to minimize this problem in clinical practice by applying quality improvement principles.

Growth in an Anesthesiologist- and Nurse Anesthetist-Supervised Sedation Nurse Program Using Propofol and Dexmedetomidine

In 2007, the Department of Anesthesia at the University of Iowa established an anesthesiologist-supervised nurse-managed sedation program. In 2008, the use of propofol and dexmedetomidine by nurses was approved in Iowa. We reviewed 11,038 elective sedation cases done between January 1, 2007, and June 30, 2014. Caseload increased from 170 to 470 cases/quarter. Propofol use increased from 0% to approximately equal to 70% of cases and dexmedetomidine from 0% to approximately equal to 25% of cases. There were no safety issues. The number of nurses working each day (on average) increased from 2.2 to 4.7, but supervising providers remained at 1/day. There were no changes in general anesthesia or monitored anesthesia care cases performed for comparable procedures. Trained, supervised nurses can safely administer propofol or dexmedetomidine to selected patients for a wide variety of procedures.

Comparison of rescue techniques for failed chloral hydrate sedation for magnetic resonance imaging scans--additional chloral hydrate vs intranasal dexmedetomidine

BACKGROUND

Chloral hydrate, a commonly used sedative in children during noninvasive diagnostic procedures, is associated with side effects like prolonged sedation, paradoxical excitement, delirium, and unpleasant taste. Dexmedetomidine, a highly selective α-2 agonist, has better pharmacokinetic properties than chloral hydrate. We conducted this prospective, double-blind, randomized controlled trial to evaluate efficacy of intranasal dexmedetomidine with that of a second oral dose of chloral hydrate for rescue sedation during magnetic resonance imaging (MRI) studies in infants.

METHODS

One hundred and fifty infants (age group: 1-6 months), who were not adequately sedated after initial oral dose of 50 mg · kg(-1) chloral hydrate, were randomly divided into three groups with the following protocol for each group. Group C: second oral dose chloral hydrate 25 mg · kg(-1); Group L and Group H: intranasal dexmedetomidine in a dosage of 1 and 2 mcg · kg(-1), respectively. Status of sedation, induction time, time to wake up, vital signs, oxygen saturation, and recovery characteristics were recorded.

RESULTS

Successful rescue sedation in Groups C, L, and H were achieved in 40 (80%), 47 (94%), and 49 (98%) of infants, respectively, on an intention to treat analysis, and the proportion of infants successfully sedated in Group H was more than that of Group L (P ˂ 0.01). There were no significant differences in sedation induction time; however, the time to wake up was significantly shorter in Group L as compared to that in Group C or H (P < 0.01). No significant adverse hemodynamic or hypoxemic effects were observed in the study.

CONCLUSION

Intranasal dexmedetomidine induced satisfactory rescue sedation in 1- to 6-month-old infants during MRI study, and appears to cause sedation in a dose-dependent manner.

Correction for human head motion in helical x-ray CT

Correction for rigid object motion in helical CT can be achieved by reconstructing from a modified source-detector orbit, determined by the object motion during the scan. This ensures that all projections are consistent, but it does not guarantee that the projections are complete in the sense of being sufficient for exact reconstruction. We have previously shown with phantom measurements that motion-corrected helical CT scans can suffer from data-insufficiency, in particular for severe motions and at high pitch. To study whether such data-insufficiency artefacts could also affect the motion-corrected CT images of patients undergoing head CT scans, we used an optical motion tracking system to record the head movements of 10 healthy volunteers while they executed each of the 4 different types of motion ('no', slight, moderate and severe) for 60 s. From these data we simulated 354 motion-affected CT scans of a voxelized human head phantom and reconstructed them with and without motion correction. For each simulation, motion-corrected (MC) images were compared with the motion-free reference, by visual inspection and with quantitative similarity metrics. Motion correction improved similarity metrics in all simulations. Of the 270 simulations performed with moderate or less motion, only 2 resulted in visible residual artefacts in the MC images. The maximum range of motion in these simulations would encompass that encountered in the vast majority of clinical scans. With severe motion, residual artefacts were observed in about 60% of the simulations. We also evaluated a new method of mapping local data sufficiency based on the degree to which Tuy's condition is locally satisfied, and observed that areas with high Tuy values corresponded to the locations of residual artefacts in the MC images. We conclude that our method can provide accurate and artefact-free MC images with most types of head motion likely to be encountered in CT imaging, provided that the motion can be accurately determined.

Contrast-enhanced magnetic resonance imaging in pediatric patients: review and recommendations for current practice

Magnetic resonance imaging (MRI), frequently with contrast enhancement, is the preferred imaging modality for many indications in children. Practice varies widely between centers, reflecting the rapid pace of change and the need for further research. Guide-line changes, for example on contrast-medium choice, require continued practice reappraisal. This article reviews recent developments in pediatric contrast-enhanced MRI and offers recommendations on current best practice. Nine leading pediatric radiologists from internationally recognized radiology centers convened at a consensus meeting in Bordeaux, France, to discuss applications of contrast-enhanced MRI across a range of indications in children. Review of the literature indicated that few published data provide guidance on best practice in pediatric MRI. Discussion among the experts concluded that MRI is preferred over ionizing-radiation modalities for many indications, with advantages in safety and efficacy. Awareness of age-specific adaptations in MRI technique can optimize image quality. Gadolinium-based contrast media are recommended for enhancing imaging quality. The choice of most appropriate contrast medium should be based on criteria of safety, tolerability, and efficacy, characterized in age-specific clinical trials and personal experience.

Magnetic resonance imaging: Clinical experience with an open low-field-strength scanner in a resource challenged African state

INTRODUCTION

Despite the fact that an magnetic resonance imaging (MRI) has been in clinical use for over 20 years, its use and availability in Nigeria, a West African state, is still extremely low. Hence, only few publications are available on the clinical experience with MRI from Nigeria. We set out to evaluate our initial clinical experience with a low-field-strength MRI in a Nigeria's foremost university hospital.

MATERIALS AND METHODS

A retrospective review of all studies, performed with an open 0.2 Tesla MAGNETOM Concerto (Siemens Medical) MRI scanner over a 5-year period (2006 - 2010) was conducted. All patients with complete records were evaluated for their clinical and demographic characteristics.

RESULTS

The records of 799 MRI studies were available. Patients' ages ranged from 1 day to 90 years, with a mean of 40.1 years (± 20.7 SD). There were 463 (57.9%) males and 336 (42.1%) females. Over 90% of the studies were requested to evaluate brain or spine lesions. Low back pain represented the commonest (161/799, 20.7%) clinical indication for MRI. The largest number of patients was referred by physicians from surgical specialties (65.6%).

CONCLUSION

The awareness and competence for proper use of MRI in Nigeria appears high. Low back pain is the commonest indication for MRI in our institution, and surgeons make a greater use of the facility. The provision of high-signal strength MRI may be beneficial in making a wider range of applications available to clinicians.

Oral chloral hydrate vs. intranasal midazolam for sedation during computerized tomography

We conducted this single blind randomized clinical trial to compare the efficacy and safety of oral chloral hydrate and intranasal midazolam for induction of sedation for computerized tomography scan of brain in children. Participants aged 1-10 years (n=60) were randomized to receive 100 mg/kg chloral hydrate orally with intra nasal normal saline OR intranasal midazolam 0.2 mg/kg with oral normal saline. Adequate sedation (Ramsay sedation score of four) was obtained and CT scan completed successfully in 76.7% of chloral hydrate group and in 40% of midazolam group (P=0.004). No significant difference was seen for side effects frequency between the two drugs (10% in chloral hydrate, 3.3% in midazolam group; P=0.34). We conclude that oral chloral hydrate can be considered as a safe and effective drug for sedation in children undergoing CT scan of brain.

Sedation and anesthesia for CT: emerging issues for providing high-quality care

During the past decades, the use of CT to diagnose conditions and monitor treatment in the pediatric setting has increased. Infants and children often require procedural sedation to maintain a motionless state to ensure high-quality imaging. Various medication regimens have been recommended to achieve satisfactory sedation for this painless procedure. While the incidence of adverse events remains low, procedural sedation carries the risk of serious morbidity and mortality. The use of evidence-based, structured approaches to procedural sedation should be used to reduce variation in clinical practice and improve outcomes.

Variability in imaging utilization in U.S. pediatric hospitals

BACKGROUND

Use of medical imaging is under scrutiny because of rising costs and radiation exposure. We compare imaging utilization and costs across pediatric hospitals to determine their variability and potential determinants.

MATERIALS AND METHODS

Data were extracted from the Pediatric Health Information System (PHIS) database for all inpatient encounters from 40 U.S. children's hospitals. Imaging utilization and costs were compared by insurance type, geographical region, hospital size, severity of illness, length of stay and type of imaging, all among specific diagnoses.

RESULTS

The hospital with the highest utilization performed more than twice as many imaging studies per patient as the hospital with the lowest utilization. Similarly, imaging costs ranged from $154 to $671/patient. Median imaging-utilization rate was 1.7 exams/patient on the ward and increased significantly in the PICU (11.8 exams/patient) and in the NICU (17.7 exams per patient, (P < 0.001). Considerable variability in imaging utilization persisted despite adjustment for case mix index (CMI, range in variation 16.6-25%). We found a significant correlation between imaging utilization and both CMI and length of stay, P < 0.0001). However, only 36% of the variation in imaging utilization could be explained by CMI.

CONCLUSION

Diagnostic imaging utilization and costs vary widely in pediatric hospitals.

National incidence of use of monitored anesthesia care

BACKGROUND

Sedation or monitored anesthesia care (MAC), alone or after peripheral regional nerve block, is currently administered by anesthesiologists and/or certified registered nurse anesthetists. Some of this care may be at risk for substitution by other providers or by reductions in reimbursement.

METHODS

Data from the 2006 United States of America National Survey of Ambulatory Surgery were analyzed to determine national rates for the percentage of total ambulatory anesthesia operating room (OR) time that was either (1) sedation and/or MAC, or (2) peripheral regional nerve block with/without sedation or MAC.

RESULTS

MAC cases alone comprised 29%± 2% of OR time with an anesthesiologist and/or certified registered nurse anesthetist. MAC and/or peripheral block comprised 34% ± 2% of OR time. Percentages by cases were larger than by OR time (P < 0.0001). Among cases with anesthesia, 42% ± 3% were MAC and 47% ± 2% were MAC with/without peripheral block. Percentages of American Society of Anesthesiologists' Relative Value Guide units for MAC would be intermediate between the 29% and 42%, and for MAC and/or peripheral block between the 34% and 47%.

CONCLUSIONS

MAC alone or after peripheral nerve block accounts for a relatively high percentage of ambulatory anesthetics nationwide.

Impact of anesthesiologists on the incidence of vaginal birth after cesarean in the United States: role of anesthesia availability, productivity, guidelines, and patient safety

The rate of vaginal birth after cesarean delivery (VBAC) has been steadily decreasing in the United States. What is not clear, however, is what part the availability of anesthesia personnel has played in this reduction. We review the role of anesthesia services in the trend of the decreasing rates of VBAC. Three areas of particular interest to anesthesiology services are addressed: (1) the current ability of anesthesiologists in the United States to provide "immediate" availability for VBAC at all delivery locations; (2) the workforce estimates for anesthesiology staffing in the future; and (3) the barriers to the immediate availability of anesthesiologists in all hospitals that provide obstetrical care. The concept of "immediate availability" is discussed, and examples of ways to reduce the risks to patients are provided. Finally, possible solutions that may improve patient safety without a dramatic increase in number of anesthesiologists available to work on labor and delivery units are highlighted.