Evaluation of image quality of diffusion weighted readout segmentation of long variable echo-trains MR pulse sequence for lumbosacral nerve imaging at 3T.

Background: Limited magnetic resonance (MR) pulse sequences facilitate lumbosacral nerve imaging with acceptable image quality. This study aimed to evaluate the impact of parameter modification for Diffusion Weighted Image (DWI) using Readout Segmentation of Long Variable Echo-trains (RESOLVE) sequence with opportunities for improving the visibility of lumbosacral nerves and image quality. Methods: Following ethical approval and acquisition of informed consent, imaging of an MR phantom and twenty healthy volunteers (n=20) was prospectively performed with 3T MRI scanner. Acquired sequences included standard two-dimensional (2D) turbo spin echo sequences and readout-segmented echo-planar imaging (EPI) DWI-RESOLVE using three different b-values b-50, b-500 and b-800 s/mm2. Signal-to-noise ratio (SNR), apparent diffusion coefficient (ADC) and nerve size were measured. Two musculoskeletal radiologists evaluated anatomical structure visualisation and image quality. Quantitative and qualitative findings for healthy volunteers were investigated for differences using Wilcoxon signed-rank and Friedman tests, respectively. Inter and intra-observer agreement was determined with κ statistics. Results: Phantom images revealed higher SNR for images with low b-values with 206.1 (±10.9), 125.1 (±45.2) and 59.2 (±17.8) for DWI-RESOLVE images acquired at b50, b500 and b800, respectively. Comparable results were found for SNR, ADC and nerve size across normal right and left sided for healthy volunteer images. The SNR findings for b-50 images were higher than b-500 and b-800 images for healthy volunteer images. The qualitative findings ranked images acquired using b-50 and b-500 images significantly higher than corresponding b-800 images (P<0.05). Inter and intra-observer agreements for evaluation across all b-values ranged from 0.59 to 0.81 and 0.83 to 0.92, respectively. Conclusions: The modified DWI-RESOLVE images facilitated visualization of the normal lumbosacral nerves with acceptable image quality, which support the clinical applicability of this sequence.

Agreement Between International Radiologists on the Appropriateness and Urgency in Lumbar Spine MRI Referrals.

Purpose: To determine how radiologists across health-care jurisdictions internationally assess the appropriateness and urgency levels of lumbar spine Magnetic Resonance Imaging MRI referrals. Patients and Methods: Clinical information was extracted from 203 lumbar spine MRI referrals. Texts were divided into 10 datasets and embedded into a software to facilitate the classification process. Participant radiologists were recruited at the Image Perception Lab, at the Radiological Society of North America Congress, 2019 and through the institution radiology network. Radiologists were asked if they use referral guidelines in their practices. Radiologists assigned appropriateness and urgency levels based on the referral text. Appropriateness level descriptors were: indicated, indicated but needs more information or not indicated. Urgency levels were categorized: urgent, semi-urgent, or not urgent. All cases containing neurological symptoms with/without red flags were extracted and exact agreement between radiologists' responses on the indication status was calculated. Results: Seventy radiologists from 25 countries participated; 42% of participants indicated non-use of referral guidelines. Poor-moderate radiology agreements were recorded for appropriateness and referral urgency level decisions. 79.6% of responses indicated that cases containing neurological symptoms with/without red flags were indicated for scanning. Conclusion: Despite referral guidelines promotion, nearly half of participants stated non-usage. Subsequently, a varied agreement levels were found in assigning the appropriateness of the referrals. Appropriateness of referrals with neurological symptoms (with/without red flags) recorded good agreement.

Cardiac MRI in arrhythmogenic right ventricular cardiomyopathy.

OBJECTIVE: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a cause of sudden cardiac death in otherwise healthy young adults. This article outlines the spectrum of MRI findings in ARVC using a combination of static and cine images. CONCLUSION: The detection of right ventricular enlargement, fatty infiltration, fibrosis, and wall motion abnormalities at MRI is useful in the diagnosis of ARVC.

Validation of the educational effectiveness of a mobile learning app to improve knowledge about MR image quality optimisation and artefact reduction.

AIM: The aim was to design an app-based eLearning tool to provide radiographers with information about the physical basis of MR artefacts and practical elimination or/and minimisation strategies to optimise image quality, and to evaluate the impact of a smartphone app on radiographers' knowledge. METHODS: The study used the comparison-experimental approach (pre- and post-test). Thirty-five MR radiographers independently reviewed a prepared series of MR images (n = 25). The participants were requested to identify image quality related errors, to specify error-correction strategies and to score how confident they were in their responses. Participants were then divided into experimental (n = 19) and control cohorts (n = 16). The app was provided to the experimental cohort for 3 months; after this period both cohorts re-reviewed the MR image datasets and repeated their identification of image quality errors. RESULTS: The results showed a statistically significant difference between control and experimental cohorts relative to participants' pre- to post-test knowledge level. For the experimental cohort, years of experience, qualification and type of hospital were not associated with radiographer knowledge level and confidence in recognising the presence of an image quality error, naming the error and specifying appropriate correction strategies (p > 0.05). CONCLUSION: The study identified the potential of the smartphone app as an effective educational tool to support MR radiographers' knowledge in recognising and characterising MR image quality errors. KEY POINTS: • A high level of knowledge to optimise MR image quality is crucial. • Ongoing education in image quality optimisation is required. • The potential role of app as an effective educational tool is identified.

Impact of sensory design interventions on image quality, patient anxiety and overall patient experience at MRI.

OBJECTIVE: This study aimed to assess the effect of sensory stimulation on patient MRI experience and to assess whether sensory stimulation has a significant effect on MR image quality. METHODS: A case-control study was conducted over 4 months, involving patients undergoing MRI brain, cervical spine, breast and prostate. The study involved 106 patients, 64 cases and 42 controls. Cases underwent sensory stimulation during the scan in the form of a scented cotton pad placed in the scanner near their head and/or calming bird noises were played over headphones. Post-scan, participants completed a questionnaire regarding their experience of MRI. Scanning radiographers completed a questionnaire regarding patient tolerance of the scan. All studies were evaluated by two radiologists for the presence of movement artefact. RESULTS: 39% of cases and 38% of controls reported anxiety in the days preceding MRI. 6.2% of cases required coaching during image acquisition, while 9.7% of controls required coaching. 4.7% of cases and 4.8% controls required sequence repetition owing to movement artefact. Mean patient experience score (as graded by the patient) for controls was 1.74 ± 0.63 standard deviation (SD) and for cases, it was 1.67 ± 0.60 SD. (Lower assigned scores equated to a better experience). Mean patient experience score based on comments on a 5-point scale as graded by two observers was 2.81 ± 0.70 SD for controls, 2.42 + 0.94 SD for sound intervention and 2.46 ± 1.01 SD for scent intervention. Mean motion artefact score graded by the two radiologists was 1.13 ± 0.53 SD for controls and 1.08 ± 0.36 SD for cases. (A lower score equated to less movement artefact). We demonstrated a trend towards a relaxing experience in those patients undergoing MRI for the first time who underwent sensory intervention. Participant positive ratings of the smell pleasantness were associated with a reduced likelihood of experiencing anxiety (p = 0.13). Results were not statistically significant. CONCLUSION: This study demonstrated a subjectively improved experience of MRI for some patients with the intervention of sound and smell. The study failed to show a significant decrease in patient movement during MRI investigations. This may relate to the small study size and a low level of patient movement in the case group. Advances in knowledge: Sound and olfactory sensory environment interventions at MRI can improve the patient experience. These low-cost interventions are well tolerated, may improve acceptance of MRI in patients with anxiety and offer a competitive advantage to imaging centres.

Steady-state free-precession (SSFP) cine MRI in distinguishing normal and bicuspid aortic valves.

PURPOSE: To assess the diagnostic sensitivity and specificity of double-oblique true fast imaging with steady-state precession (SSFP) cine MRI in distinguishing normal and bicuspid aortic valves. MATERIALS AND METHODS: Echocardiograms on patients referred for MRI of the heart and thoracic aorta over a four-year period were reviewed retrospectively. A total of 17 patients with bicuspid aortic valve were identified and compared to 21 randomly chosen control patients. All patients had double-oblique SSFP (True FISP) cine MRI of the aortic valve independently assessed by two radiologists in a blinded fashion, and graded as bicuspid or normal. Image quality was graded as 1, 2, or 3. Discordance was resolved by consensus. RESULTS: A total of 38 cases were reviewed (27 men, 11 women; age range = 15-67 years, mean = 25.33 years). Interobserver agreement was 0.97 (36/38 cases). One case of normal tricuspid valve was reported as bicuspid by both readers (false-positive). All cases in which disparity arose were rated suboptimal by both readers (grade 2 or 3). Consensus review yielded sensitivity = 100%, specificity = 95.2%, positive predictive value = 94.4%, and negative predictive value = 100%; overall diagnostic accuracy was 97.36%. Interobserver agreement was 0.97. CONCLUSION: Double-oblique True FISP cine MR imaging of the aortic valve is 100% sensitive and 95% specific in distinguishing normal and bicuspid aortic valves.

MR venography with true fast imaging with steady-state precession for suspected lower-limb deep vein thrombosis.

PURPOSE: To compare true fast imaging with steady-state precession (FISP) magnetic resonance (MR) venography for suspected deep vein thrombosis (DVT) with contrast agent-enhanced venography. MATERIALS AND METHODS: This was a prospective study of randomly selected patients with a clinical suspicion of DVT of the lower limb. Standard contrast venography was performed and compared with MR venography from the inferior vena cava to the feet in 24 patients with use of true FISP sequences (repetition time, 3.74 msec; echo time, 1.8 msec). Two radiologists independently read the MR venography and contrast venography studies. Segment visibility, secondary signs of DVT, and additional diagnoses were noted. RESULTS: MR venography demonstrated all venous segments in the pelvis and thigh. When results were analyzed on a per-patient basis, there was good agreement between contrast venography and MR venography (kappa = 0.64; 95% CI, 0.33-0.94; P = .0001). When the venous system was analyzed on a segmental basis, there was very good agreement between contrast venography and MR venography (kappa = 0.81; 95% CI, 0.68-0.94; P = .0001). The sensitivity and specificity for DVT detection were 100% for the iliac and popliteal segments and 100% and 98%, 68% and 94%, and 87% and 98%, respectively, for the femoral, below-knee, and all veins. Eleven of 14 patients without DVT had an alternative diagnosis suggested by MR venography. CONCLUSIONS: MR venography with axial true FISP allows noninvasive rapid diagnosis of acute DVT in the iliac, femoral, popliteal, and calf muscle veins. MR venography is much less reliable in the tibial or peroneal veins. It may demonstrate a nonvenous cause of a patient's symptoms.