MRI Group Research Articles

Association of White Matter Hyperintensities With Serum Lipid Profile and Hematologic Parameters in Migraine Patients.

Introduction Migraine is one of the most common neurological diseases. Comorbidities, especially stroke, may be observed. White matter hyperintensities are common in migraine patients. Although many factors have been associated with white matter hyperintensities, such as age, gender, migraine type, frequency, and presence of aura, the etiology of white matter hyperintensities remains unclear. We aimed to study the relationship between the development of white matter hyperintensities and serum lipid profilesand hematologic parameters in migraine patients. Methods Demographic data, comorbidities, migraine types, presence of aura, and frequency of attacks were reviewed. Cranial MRI scans, hematologic profiles, and lipid profiles were analyzed. Results The study included 51 patients with white matter hyperintensity on cranial MRI and 76 migraine patients with normal cranial MRI. High-density lipoprotein cholesterol (HDL-c) was statistically significantly higher in the patients with white matter hyperintensity in the cranial MRI (WMH+) group. A statistically significant cut-off value was found for the PLR parameter in differentiating white matter hyperintensity on cranial MRI in migraine patients. Conclusion In our study, we examined the factors contributing to the development of white matter hyperintensity in migraine patients and observed the correlation between disease duration and white matter hyperintensity. While no correlation was observed between low-density lipoprotein cholesterol (LDL-c) and white matter hyperintensity, HDL-c was dramatically elevated in patients with white matter hyperintensity. Furthermore, our study shows that PLR is a useful, easily accessible, and practical parameter for detecting the development of white matter hyperintensity in migraine patients. Larger-scale randomized studies are needed for a clearer interpretation of these findings.

Neonatal Anthropometric Measurements: A Comparison of Neonates With 3-T Fetal MRI Exposure, With 1.5-T Fetal MRI Exposure, and Without In-Utero MRI Exposure.

Background: Fetal MRI is increasingly performed at 3 T. Nonetheless, safety concerns persist regarding potential increased risk of intrauterine growth restriction from in-utero 3-T MRI exposure. Objective: To compare neonatal anthropometric measurements between newborns who underwent 3-T fetal MRI, newborns who underwent 1.5-T fetal MRI, and newborns without in utero MRI exposure. Methods: This single-center retrospective study included gravid patients who underwent fetal ultrasound and possible 1.5-T or 3-T fetal MRI within 10 days from January 2017 to January 2022. For each included patient who also underwent 3-T fetal MRI, one matched patient who also underwent 1.5-T MRI and two matched patients without in-utero MRI exposure, were randomly selected. Matching was based on gestational age per the fetal ultrasound. Neonatal anthropometric characteristics were compared among groups. Results: The final sample included 416 patients (mean age, 32±5 years), 104 in the 3-T MRI group, 104 in the 1.5-T MRI group, and 208 in the MRI-unexposed group. Mean gestational age at the time of fetal ultrasound used for matching was 27 weeks 2 days in the 3-T group, 25 weeks 2 days in the 1.5-T group, and 26 weeks 0 days in the MRI-unexposed group (p=.07). The distribution of indications for fetal MRI was not significantly different between the 3-T and 1.5-T groups (p=.62). Mean gestational age at delivery was 37 weeks 5 days in the 3-T group, 38 weeks 0 day in the 1.5-T group, and 38 weeks 2 days in the unexposed group (p=.51). No significant difference (p=.09) was observed among groups in mean neonatal weight (3-T: 3120±753 g; 1.5-T: 3104±704 g; unexposed: 2967±614 g); neonatal weight percentile (3-T: 45±27; 1.5-T: 42±26; MRI: 41±24); neonatal head circumference (3-T: 34±3 cm; 1.5-T: 34±3 cm; unexposed: 34±2 cm), or neonatal head circumference percentile (3-T: 48±29; 1.5-T: 42±23; unexposed: 43±30). Conclusion: There were no significant differences in neonatal anthropometric measurements among newborns who underwent in-utero 3-T MRI, newborns who underwent in-utero 1.5-T MRI, and newborns without in-utero MRI exposure. Clinical Impact: The results support the safety of 3-T MRI with respect to growth of the developing fetus.

Synthetic lumbar MRI can aid in diagnosis and treatment strategies based on self-pix networks

CT and MR tools are commonly used to diagnose lumbar fractures (LF). However, numerous limitations have been found in practice. The aims of this study were to innovate and develop a spinal disease-specific neural network and to evaluate whether synthetic MRI of the LF affected clinical diagnosis and treatment strategies. A total of 675 LF patients who met the inclusion and exclusion criteria were included in the study. For each participant, two mid-sagittal CT and T2-weighted MR images were selected; 1350 pairs of LF images were also included. A new Self-pix based on Pix2pix and Self-Attention was constructed. A total of 1350 pairs of CT and MR images, which were randomly divided into a training group (1147 pairs) and a test group (203 pairs), were fed into Pix2pix and Self-pix. The quantitative evaluation included PSNR and SSIM (PSNR1 and SSIM1: real MR images and Pix2pix-generated MR images; PSNR2 and SSIM2: real MR images and Self-pix-generated MR images). The qualitative evaluation, including accurate diagnosis of acute fractures and accurate selection of treatment strategies based on Self-pix-generated MRI, was performed by three spine surgeons. In the LF group, PSNR1 and PSNR2 were 10.884 and 11.021 (p < 0.001), and SSIM1 and SSIM2 were 0.766 and 0.771 (p < 0.001), respectively. In the ROI group, PSNR1 and PSNR2 were 12.350 and 12.670 (p = 0.004), and SSIM1 and SSIM2 were 0.816 and 0.832 (p = 0.005), respectively. According to the qualitative evaluation, Self-pix-generated MRI showed no significant difference from real MRI in identifying acute fractures (p = 0.689), with a good sensitivity of 84.36% and specificity of 96.65%. No difference in treatment strategy was found between the Self-pix-generated MRI group and the real MRI group (p = 0.135). In this study, a disease-specific GAN named Self-pix was developed, which demonstrated better image generation performance compared to traditional GAN. The spine surgeon could accurately diagnose LF and select treatment strategies based on Self-pix-generated T2 MR images.

AB041. The morphological changes of paraspinal muscles in adult brachial plexus injury.

Traumatic brachial plexus injury (BPI) is a debilitating injury that has a devastating impact. However, management of BPI remains a complex challenge, not only in diagnosis but also in treatment strategies for reconstructive microsurgeons. The aim of this study was to develop an additional assessment tool for root avulsion based on the volume of paraspinal muscle (PM) prior to surgical intervention, making the preoperative diagnosis more precise. This retrospective study was centered on adult patients with BPI who underwent surgical exploration and treatment, postoperative follow-up at the Chang Gung Hospital. Labeling of PMs was aided by semi-automated segmentation using 3D Slicer 5.2.2. Slices spanning from the lower end of the upper vertebral body endplate to the upper end of the lower vertebral body. The ratio of muscle volume on the lesion side to that on the normal side (L/N ratio), indicating the volume proportion between the injured and healthy areas, serves as the primary parameter for assessing the relationship in root avulsion. The L/N ratio for the deepest layers of PMs consistently predicted the level of root injury across C4 to C7 levels, with all reaching statistical significance. In terms of partial and total root avulsion, the L/N ratio of layer 4th at 0.78 significantly outperforms other methods. Concerning the timing of MRI, both partial avulsion (PA) and total avulsion (TA) groups of merge roots showed a statistically significant decrease in the L/N ratio over time. In conclusion, the L/N volume ratio of 4th layer in PMs reliably predicts the functional severity of avulsed roots and surpasses the performance of traditional diagnostic tools under specific conditions.

MRCT and CT in the diagnosis of pediatric disease imaging: assessing imaging performance and clinical effects

ObjectiveThis study focused on analyzing the clinical value and effect of magnetic resonance imaging plus computed tomography (MRCT) and CT in the clinical diagnosis of cerebral palsy in children.MethodsFrom February 2021 to April 2023, 94 children diagnosed with cerebral palsy were selected from our hospital for study subjects. These patients were divided into CT and MRI groups, with CT examination given to the CT group and MRI examination given to the MRI group. The positive rate of the two examination methods in the diagnosis of cerebral palsy was compared, different imaging signs in two groups of children with cerebral palsy were compared, and the diagnostic test typing results between two groups were further analyzed.ResultsThe diagnostic positivity rate of the children in the MRI group was 91.49%, which was significantly higher than that of the children in the CT group (70.21%) (P < 0.05). In both groups, encephalomalacia, bilateral frontal subdural effusions, and gray-white matter atrophy of the brain were the main signs, and the difference in the proportion of these three imaging signs between the two groups was not significant (P > 0.05). Differences between the two groups examined for cerebral palsy subtypes were not significant (P > 0.05).ConclusionThe positive rate of pediatric cerebral palsy examined by MRI is higher than that of CT diagnosis, but the clinic should organically combine the two to further improve the detection validity and accuracy.

Intraoperative magnetic resonance imaging in glioma surgery: a single-center experience.

To investigate the effect of intraoperative magnetic resonance imaging (Io MRI) on overall and progression-free survival (OS and PFS), on the extent of resection (EOR) in patients with glioma, and impact of the radiological diagnosis on the decision to continue the surgery when a residual mass was detected on Io MRI. The study comprised 153 glioma patients who received surgical treatment between 2013 and 2023. One-hundred twenty-five of them had Io MRI guidance during surgery. The remainder 28 patients constituted the control group who did not undergo Io MRI. All patients' age at surgery, gender, initial radiological diagnosis, primary tumor localization, EOR, last histopathological diagnosis, and the follow-up periods were recorded. The rate of tumor recurrence in Io MRI cases was significantly lower compared to the cases in the control group (p < .0001). It was decided to continue the operation in 45 Io MRI applied cases. This raised the gross total resection (GTR) rate from 33.6% to 49.6% in the Io MRI group. The frequency of GTR was significantly higher in patients with an initial radiological diagnosis of low grade glioma than those with high grade glioma. The shortest OS was seen in occipital gliomas. In this study, the convenience provided by the high-field MRI device was explored and proven both in reducing the tumor burden, increasing the PFS, and providing the surgeon with a maximal resection in the first operation.

Comparison of Clinical Breast Exam to Breast MRI Surveillance in Patients Following Nipple-Sparing Mastectomy

BackgroundNipple sparing mastectomy (NSM) is increasingly being performed for patients with breast cancer. However, optimal postoperative surveillance has not been defined. MethodsA prospectively maintained database identified patients with in-situ and invasive cancer who underwent NSM between 2007-2021. Clinical data on postoperative breast surveillance and interventions were collected. Patients who had MRI surveillance versus clinical breast exam (CBE) alone were compared with respect to tumor characteristics, recurrence, and survival. ResultsA total of 483 NSMs were performed on 399 patients. 255 (63.9%) patients had invasive ductal carcinoma, 31 (7.8%) invasive lobular carcinoma, 92 (23.1%) DCIS, 6 (1.5%) mixed ductal and lobular carcinoma, 9 (2.3%) others, and 6 (1.5%) unknown. Postoperatively, 265 (66.4%) patients were followed with CBE alone and 134 (33.6%) had surveillance MRIs. At a median follow-up of 33 months, 20 patients (5.0%) developed in-breast recurrence, 6 patients had (1.5%) an axillary recurrence, and 28 with (7.0%) distant recurrence. 14 (53.8%) LRR were detected in the CBE group and 12 (46.2%) were detected in the MRI group (P = .16). Overall survival (OS) was 99%, with no difference in OS between patients who had CBE alone versus MRI (P = .46). MRI was associated with higher biopsy rates compared to CBE alone (15.8% vs. 7.8%, P = .01). ConclusionsCompared to CBE alone, the use of screening MRI following NSM results in higher rate of biopsy and no difference in overall survival.

Comparison of brain imaging and physical health between research and clinical neuroimaging cohorts of ageing.

To compare brain MRI measures between Adult Changes in Thought (ACT) participants who underwent research, clinical, or both MRI scans, and clinical health measures across the groups and non-MRI subjects. Retrospective cohort study leveraging MRI, clinical, demographic, and medication data from ACT. Three neuroradiologists reviewed MRI scans using NIH Neuroimaging Common Data Elements (CDEs). Total brain and white matter hyperintensity (WMH) volumes, clinical characteristics, and outcome measures of brain and overall health were compared between groups. 1166 MRIs were included (77 research, 1043 clinical, and 46 both) and an additional 3146 participants with no MRI were compared. Compared to the group with research MRI only, the clinical MRI group had higher prevalence of the following: acute infarcts, chronic haematoma, subarachnoid haemorrhage, subdural haemorrhage, haemorrhagic transformation, and hydrocephalus (each P < .001). Quantitative WMH burden was significantly lower (P < .001) and total brain volume significantly higher (P < .001) in research MRI participants compared to other MRI groups. Prevalence of hypertension, self-reported cerebrovascular disease, congestive heart failure, dementia, and recent hospitalization (all P < .001) and diabetes (P = .002) differed significantly across groups, with smaller proportions in the research MRI group. In ageing populations, significant differences were observed in MRI metrics between research MRI and clinical MRI groups, and clinical health metric differences between research MRI, clinical MRI, and no-MRI groups. This questions whether research cohorts can adequately represent the greater ageing population undergoing imaging. These findings may also be useful to radiologists when interpreting neuroimaging of ageing.

MRI evaluation of cranial pathologies in rapidly progressive early puberty cases aged 8-9.

The aim of this study was to investigate the frequency and distribution of intracranial pathologies in female patients between 8 and 9 years of age who were diagnosed with early puberty (rapidly progressive) through the evaluation of MRI images. A total of 74 female patients diagnosed with central precocious puberty (CPP) (6-8 years) and rapidly progressive early puberty (RPEP) (8-9 years) were included in the study. The patients were categorized into two groups, normal and abnormal, based on the findings from their MRI scans. Recent literature has classified abnormal MRI findings into three groups: pathological findings, findings with a questionable relationship to CPP, and incidental findings. Furthermore, the patients were divided into four groups based on their MRI findings and whether they had CPP or RPEP : CPP (6-8 years) +Normal MRI, RPEP (8-9 years) + Normal MRI, CPP (6-8 years) +Abnormal MRI, RPEP (8-9 years) +Abnormal MRI. Out of the 74 girls included in the study, 54% (n=40) showed normal MRI results, while abnormal MRI findings were detected in 46% (n = 34) of the cases. No malignant lesions were identified among cases with abnormal MRI findings. The occurrence of abnormal MRI findings was observed in 46% of the PP group and 45% of the RPEP group. Incidental findings were the most common MRI findings in both groups. The proportion of cases with pathological findings and findings with a questionable relationship to CPP was similar in both groups (p = 0.06). Basal luteinizing hormone (LH) concentration was found to be higher in the RPEP (8-9 years) +Abnormal MRI group compared to the CPP (6-8 years) +Normal MRI group (p = 0.01). Our study is the first to investigate MRI findings in cases of rapidly progressive early puberty in the age range of 8-9 years. Our study demonstrates that there is no difference in terms of intracranial findings between cases of precocious puberty at the age of 6-8 years and cases of rapidly progressive early puberty aged 8-9.

Rapid brain MRI for image-guided ventricular catheter placement in pediatric patients: protocol and preliminary clinical outcomes.

Neuronavigation is a useful adjunct for catheter placement during neurosurgical procedures for hydrocephalus or ventricular access. MRI protocols for navigation are lengthy and require sedation for young children. CT involves ionizing radiation. In this study, the authors introduce the clinical application of a 1-minute rapid MRI sequence that does not require sedation in young children and report their preliminary clinical experience using this technique in their pediatric population. All patients who underwent ventricular catheter placement at a children's hospital using a rapid noncontrast MRI protocol, standard MRI, or head CT from July 2021 to August 2023 were included. Type of procedure, etiology of hydrocephalus, ventricle configuration and size, morphology of ventricles, need for adjunctive intraoperative ultrasound, duration of procedure, accuracy of catheter placement, and need for proximal revision within 90 days were retrospectively recorded and compared across imaging modalities. Sixty-eight patients underwent 83 procedures: 21 underwent CT navigation, 29 standard MRI, and 33 rapid MRI. Patients who received standard MRI more often had tumor etiology, while those who underwent CT and rapid MRI had posthemorrhagic etiology (χ2 = 13.04, p = 0.042). Intraoperative ultrasound was required for 1 patient in the standard MRI group and 1 patient in the CT group. There was no difference in procedure time across groups (p = 0.831). On multivariable analysis, procedure time differed by procedure type, where external ventricular drain placement and proximal revision were faster (p < 0.001 and p < 0.028, respectively). Proximal revision due to obstruction within 90 days occurred in 3 cases (in the same patient with complex loculated hydrocephalus) in the rapid MRI group and 2 cases in the CT group. Although this study was not powered for statistical inference, the authors report on the clinical use of a 1-minute rapid MRI sequence for neuronavigation in hydrocephalus or ventricular access surgery. There were no instances in which intraoperative ultrasound was required as an adjunct for procedures navigated with rapid MRI, and intraoperative time did not differ from that of standard navigation protocols.

Cross‐Validation of Paranoid and Depressive Scales: Results From Functional MRI Group Independent Component Analysis

Cross‐Validation of Paranoid and Depressive Scales: Results From Functional MRI Group Independent Component Analysis

Preoperative breast MRI positively impacts surgical outcomes of needle biopsy–diagnosed pure DCIS: a patient-matched analysis from the MIPA study

ObjectivesTo investigate the influence of preoperative breast MRI on mastectomy and reoperation rates in patients with pure ductal carcinoma in situ (DCIS).MethodsThe MIPA observational study database (7245 patients) was searched for patients aged 18–80 years with pure unilateral DCIS diagnosed at core needle or vacuum-assisted biopsy (CNB/VAB) and planned for primary surgery. Patients who underwent preoperative MRI (MRI group) were matched (1:1) to those who did not receive MRI (noMRI group) according to 8 confounding covariates that drive referral to MRI (age; hormonal status; familial risk; posterior-to-nipple diameter; BI-RADS category; lesion diameter; lesion presentation; surgical planning at conventional imaging). Surgical outcomes were compared between the matched groups with nonparametric statistics after calculating odds ratios (ORs).ResultsOf 1005 women with pure unilateral DCIS at CNB/VAB (507 MRI group, 498 noMRI group), 309 remained in each group after matching. First-line mastectomy rate in the MRI group was 20.1% (62/309 patients, OR 2.03) compared to 11.0% in the noMRI group (34/309 patients, p = 0.003). The reoperation rate was 10.0% in the MRI group (31/309, OR for reoperation 0.40) and 22.0% in the noMRI group (68/309, p < 0.001), with a 2.53 OR of avoiding reoperation in the MRI group. The overall mastectomy rate was 23.3% in the MRI group (72/309, OR 1.40) and 17.8% in the noMRI group (55/309, p = 0.111).ConclusionsCompared to those going directly to surgery, patients with pure DCIS at CNB/VAB who underwent preoperative MRI had a higher OR for first-line mastectomy but a substantially lower OR for reoperation.Clinical relevance statementWhen confounding factors behind MRI referral are accounted for in the comparison of patients with CNB/VAB-diagnosed pure unilateral DCIS, preoperative MRI yields a reduction of reoperations that is more than twice as high as the increase in overall mastectomies.Key Points• Confounding factors cause imbalance when investigating the influence of preoperative MRI on surgical outcomes of pure DCIS.• When patient matching is applied to women with pure unilateral DCIS, reoperation rates are significantly reduced in women who underwent preoperative MRI.• The reduction of reoperations brought about by preoperative MRI is more than double the increase in overall mastectomies.

Value of Proximal Femur Geometry in Predicting Occult Hip Fracture.

Background and Objectives: Patients with occult hip fractures are a difficult subgroup to treat. MRI is the gold standard for diagnosing occult proximal femur fractures but is costly and may not be readily available in an emergency setting. The purpose of this study was to determine whether changes in the proximal femur geometry can predict the likelihood of an occult hip fracture in patients presenting with hip pain following a ground-level fall. Material and Methods: Patients admitted to the hospital with a clinical suspicion of a hip fracture but initial negative radiographs over a seven-year period were included. All patients were additionally investigated with an MRI scan, and retrospectively, six radiologic parameters were obtained on plain radiographs: The cortical thickness index (CTI), the canal to calcar ratio (CCR), the canal flare index (CFI), the morphological cortical index (MCI), the canal bone ratio (CBR) and the canal bone aria ratio (CBAR). Subsequently the result of the plain radiographic indices of the patients with a negative MRI (Group A, no occult fracture) were compared to those with a positive MRI (Group B, occult fracture). Results: A total of 78 patients (59 female, 19 male) could be included in the study. The mean age was 82 years. The univariate analyses revealed a poor predictive ability of all radiological parameters with AUC values ranging from 0.515 (CBR) to 0.626 (CTI), whereas a multivariate prognostic model demonstrated improved prognosis (AUC = 0.761) for the CTI (p = 0.024), CBAR (p = 0.074) and CRR (p = 0.081) as the most promising predictive radiological parameters. Conclusions: Single radiologic indices obtained from conventional X-rays of the proximal femur have a weak predictive value in detecting occult fractures of the hip and cannot be used as clinical decision-making factors.

Abstract 276: CT versus MR based imaging for ischemic stroke triage: effect on workflow during contrast shortage

Introduction We assessed the feasibility and effectiveness of using magnetic resonance (MR) imaging as a substitute for computed tomography (CT) angiography and perfusion for triaging ischemic stroke patients during the national shortage of iodinated contrast medium between May 4th to July 17th 2022. Methods We compared the rates of intravenous tissue plasminogen activator treatment (IVT) and endovascular thrombectomy (EVT), changes in treatment times, and patient outcomes (defined by modified Rankin Scores (mRS) at discharge) before (4 months period) and after (3 months period) transitioning from CT angiography (CTA) and perfusion (CTP) to Fast MRI imaging. Results We analyzed 241 patients in the CT‐based group and 166 patients in the MR‐based group. EVT was performed on almost twice as many patients in the CTA/CTP group (12%) compared to the Fast MRI group (6.6%), but this difference was not statistically significant (p=0.07). Workflow processing time showed no significant difference, with similar time intervals for door‐to‐needle, door‐to‐interventioanal radiology suite, door‐to‐puncture, and door‐to‐first pass. However, the CTA/CTP group exhibited a trend towards faster overall times. Both groups had similar rates of mRS 0‐2 at discharge (41.9% vs 43%, p=0.82). Conclusion We observed a non‐significant reduction in the rate of EVT during the period of MRI substitution secondary to the iodinated contrast medium shortage, although treatment times and patient outcomes were similar.

Effects of ultra-high field MRI environment on cognitive performance in healthy participants

IntroductionUltra-high field MRI (UHF MRI) is rapidly becoming an essential part of our toolbox within health care and research studies; therefore, we need to get a deeper understanding of the physiological effects of ultra-high field. This study aims to investigate the cognitive performance of healthy participants in a 7 T (T) MRI environment in connection with subjectively experienced effects. MethodsWe measured cognitive performance before and after a 1-h 7T MRI scanning session using a Digit Symbol Substitution Test (DSST) in 42 subjects. Furthermore, a computer-based survey regarding the subjectively experienced effects in connection with the MRI examination was distributed. Similarly, two DSSTs were also performed by a control group of 40 participants. ResultsEven though dizziness was the strongest sensory perception in connection to the MRI scanning, we did not find any correlation between dizziness and cognitive performance. Whilst the control group improved (p=<0.001) on their second DSST the MRI group showed no significant difference (p=0.741) in the DSST before and after MRI scanning. ConclusionTransient effect on cognition after undergoing MRI scanning can't be ruled out as the expected learning effect on the DSST was not observed. Implications for practiceIncreasing understanding of the possible adverse effects may guide operators in performing UHF MRI in a safe way and with person-centered care. Furthermore, it can guide researchers in setting up research protocols to minimize confounding factors in their fMRI studies due to the transient adverse effects of the UHF environment.

Preoperative Assessment of Perianal Fistulas with Combined Magnetic Resonance and Tridimensional Endoanal Ultrasound: A Prospective Study.

we designed a prospective study of diagnostic accuracy that compared pelvic MRI and 3D-EAUS with pelvic MRI alone in the preoperative evaluation and postoperative outcomes of patients with perianal fistulas. the sample size was 72 patients and this was divided into two imaging groups. MRI alone was performed on the first group. Both MRI and 3D-EAUS were performed in parallel on the second group. Surgical exploration took place after two weeks and was the standard reference. Park's classification, the presence of a concomitant abscess or a secondary tract, and the location of the internal opening were recorded. All patients were re-evaluated for complete fistula healing and fecal incontinence six months postoperatively. All of the collected data were subjected to statistical analysis. the MRI group included 36 patients with 42 fistulas. The MRI + 3D-EAUS group included 36 patients with 46 fistulas. The adjusted sensitivity and negative predictive value were 1.00 for most fistula types in the group that underwent combined imaging. The adjusted specificity improved for intersphincteric fistulas in the same group. The adjusted balanced accuracy improved for all fistula types except rectovaginal. The combination of imaging methods showed improved diagnostic accuracy only in the detection of a secondary tract. The healing rate at six months was 100%. Fecal incontinence at six months did not present a statistically significant difference between the two groups (Fisher's exact test p-value > 0.9). Patients with complex perianal fistulas had a statistically significant higher probability of undergoing a second surgery (x2 test p-value = 0.019). the combination of pelvic MRI and 3D-EAUS showed improved metrics of diagnostic accuracy and should be used in the preoperative evaluation of all patients with perianal fistulas, especially those with complex types.

Efficacy and Safety of MRI and CT Guided VX2 Hepatic Para-vascular Tumor Model in Rabbits.

To compare the efficacy and safety of 1.5 T MRI and CT-guided VX2 hepatic para-vascular tumor model in rabbits. Sixty New Zealand white rabbits were randomly and equally divided into MRI-guided group (n=30) and CT-guided group (n=30). Rabbit VX2 tumor fragments were implanted beside the rabbit hepatic great vessels under MRI and CT guidance in the MRI and CT group to evaluate the success rate of tumor model establishment, puncture needle display and tip peripheral vascular situation, operation time and safety. In the MRI-guided group, 29 rabbits (29/30, 96.7%) had a successful establishment of liver tumor model, and 1 rabbit had needle metastasis. In the CT-guided group, 24 rabbits (24/30, 80%) had a successful establishment of liver tumor model, while 2 rabbits had needle metastasis, 3 rabbits had metastases in other parts of the liver, and 1 had an unknown cause of death. The differences in tumor model establishment success rate between the two groups were statistically significant (χ2 = 4.043, P < 0.05). The fold number of artifacts at T1WI was 7.26±0.38 for the 20 G coaxial puncture needle in the MRI-guided group and 2.51±0.57 for the 20 G coaxial puncture needle in the CT-guided group, and the difference was statistically significant (t=36.76, P < 0.001), but star-shaped hypodense artifacts would appear around the needle tip. The operation time was longer in the MRI-guided group than in the CT-guided group (13.32±2.45 minutes in the MRI-guided group vs. 8.42±1.46 minutes in the CTguided group; t=9.252, P < 0.001). A small number of ascites occurred in 2 patients (2/30, 6.67%) in the CT-guided group; no serious complications such as liver abscess, jaundice or diaphragmatic perforation were observed in both groups. Compared with CT, MRI-guided hepatic para-vascular tumor implantation in rabbits might be a more effective modeling method. Although the needle tip pseudopacity of the puncture needle is large and the operation time is long, the incidence of complications is low.

Comparing the influence of mixed reality, a 3D viewer, and MRI on the spatial understanding of brain tumours

Background: Multiple 3D visualization techniques are available that obviates the need for the surgeon to mentally transform the 2D planes from MRI to the 3D anatomy of the patient. We assessed the spatial understanding of a brain tumour when visualized with MRI, 3D models on a monitor or 3D models in mixed reality.Methods: Medical students, neurosurgical residents and neurosurgeons were divided into three groups based on the imaging modality used for preparation: MRI, 3D viewer and mixed reality. After preparation, the participants needed to position, scale, and rotate a virtual tumour inside a virtual head of the patient in the same orientation as the original tumour would be. Primary outcome was the amount of overlap between the placed tumour and the original tumour to evaluate accuracy. Secondary outcomes were the position, volume and rotation deviation compared to the original tumour.Results: A total of 12 medical students, 12 neurosurgical residents, and 12 neurosurgeons were included. For medical students, the mean amount of overlap for the MRI, 3D viewer and mixed reality group was 0.26 (0.22), 0.38 (0.20) and 0.48 (0.20) respectively. For residents 0.45 (0.23), 0.45 (0.19) and 0.68 (0.11) and for neurosurgeons 0.39 (0.20), 0.50 (0.27) and 0.67 (0.14). The amount of overlap for mixed reality was significantly higher on all expertise levels compared to MRI and on resident and neurosurgeon level also compared to the 3D viewer. Furthermore, mixed reality showed the lowest deviations in position, volume and rotation on all expertise levels.Conclusion: Mixed reality enhances the spatial understanding of brain tumours compared to MRI and 3D models on a monitor. The preoperative use of mixed reality may therefore support the surgeon to improve spatial 3D related surgical tasks such as patient positioning and planning surgical trajectories.

Working from home: Changes in radiologist reporting behavior in response to the COVID-19 pandemic.

Remote reporting is an important preventive measure against coronavirus disease 2019 (COVID-19) for radiology departments; it reduces the chance of cross-infections between coworkers. The purpose of this study was to evaluate how the preferred locations that radiologists filed reports from changed in response to COVID-19 by measuring the use of internal teleradiology workstations. Data were obtained from the radiological information system (RIS) database at our institution, which recorded the reporting workstation for each radiological examination. The reporting activities in 2021 were divided into computed radiography (CR) and computed tomography (CT)/magnetic resonance imaging (MRI) groups. The Wilcoxon signed-rank test was used to measure differences in the use of off-site workstations in prepandemic, midpandemic, and postpandemic periods. There were statistically significant increases in the number of reports filed from off-site workstations for each attending physician from the prepandemic period to the midpandemic period in both the CR (15.1%-25.4%, p = 0.041) and CT/MRI (18.9%-28.7%, p = 0.006) groups. There was no significant difference noted between the prepandemic and postpandemic periods for either the CR (15.1% vs 18.4%, p = 0.727) or CT/MRI group (18.9% vs 23.3%, p = 0.236). In response to the COVID-19 outbreak, radiologists used internal teleradiology to report CR and CT/MRI examinations significantly more frequently. In contrast to the predictions of previous studies, the use of internal teleradiology returned to baseline levels after the pandemic was under control.

Paper 57: Can 2.0mm Diameter Operative Arthroscopy Predict Appropriate Surgical Management of Intra-Articular Shoulder Pathology More Accurately than MRI? A Prospective, Blinded Clinical Trial

Objectives: The purpose of this study was to compare the intra-articular diagnostic capability of a 2.0mm needle arthroscope to that obtained using MR imaging in patients scheduled to undergo shoulder arthroscopy and determine which was more effective at predicting the appropriate surgical procedure (as defined by CPT code) for patients with glenohumeral pathology. Methods: This study is a prospective, blinded, single-center trial performed with patients who were scheduled to undergo operative arthroscopy for intra-articular shoulder pathology. Thirty consecutive patients were included between May 2020 and July 2020. Each patient underwent an MRI pre- operatively and, on the day of surgery, two recorded diagnostic arthroscopies were performed: the first using a 2.0mm arthroscope, followed by a standard 4.0mm arthroscope. Both videos and MR images were then de-identified and blindly reviewed by two fellowship-trained orthopedic sports surgeons. Analysis included diagnostic agreement of the 2.0mm arthroscope and MRI as compared to the 4.0mm arthroscope which was considered the gold standard. The descriptive quality of the intra-articular pathology as well as the most appropriate treatment recommendation in the form of Current Procedural Terminology (CPT) was compared between the diagnostic modalities. Results: For all intra-articular pathologies except humeral head chondromalacia, the 2.0mm arthroscope had a higher percentage agreement and positive predictive value (PPV) compared to MRI. The 2.0mm arthroscope had a higher sensitivity, specificity, PPV and negative predictive value (NPV) when evaluating the long-head biceps (LHB), superior labrum, infraspinatus, subscapularis and glenoid cartilage. The 2.0mm arthroscope had the highest accuracy when identifying lesions of the LHB (Kappa 0.73) followed by tears of the subscapularis (Kappa 0.65), and articular-sided lesions of the supraspinatus (Kappa 0.62). MRI accuracy was highest when identifying lesions of the LHB (Kappa 0.52), followed by tears of the subscapularis (Kappa 0.31), and articular-sided supraspinatus lesions (Kappa 0.29) but these values were all lower in the MRI group when compared to the 2.0mm arthroscope group. When predicting the appropriate CPT codes for each shoulder, the 2.0mm group had a higher kappa value than the MRI group (kappa 0.87 v 0.56) and a higher agreement percentage (93.1% v 76.7%) (p=0.0003). When considering rotator cuff repair (CPT 29827), the 2.0mm arthroscopy was equally sensitive (93.3 and 93.8) but had a higher PPV as compared to MRI (100 and 83.3). There were no complications related to the use of the 2.0mm arthroscope in this series. Conclusions: 2.0mm arthroscopy is a safe and effective method of diagnosing intra-articular glenohumeral pathology. When diagnosing pathology within the shoulder, the 2.0mm arthroscopy had a higher positive predictive value than MRI when assessing all anatomic pathology except for humeral head chondromalacia. When compared to MRI, the 2.0mm arthroscope was able to more accurately predict which rotator cuff tears would require surgical repair (CPT 29827). When considering all CPT codes for the shoulders in this series, the 2.0mm arthroscope was more accurate at predicting the appropriate surgical procedure (CPT) than the MRI. [Table: see text][Table: see text]