Repeat Magnetic Resonance Imaging Scan Research Articles

Nonoperative Treatment of Isolated Posterior Glenohumeral Instability in an Active Military Population: Effect of Glenoid and Acromial Morphology.

Nonoperative management of posterior shoulder instability is common. However, limited data are available to assess the pathomorphologic factors associated with its failure. The purpose of this study was 2-fold: (1) to determine glenohumeral pathomorphologic features predictive of nonoperative management failure of posterior instability; and (2) to determine the relationship between nonoperative management failure and posterior glenoid bone loss (pGBL) progression. It was hypothesized that greater posterior acromial height (PAH) would adversely affect nonoperative survivorship and that shoulders treated nonoperatively would have pGBL progression compared with those undergoing surgical stabilization. Case-control study; Level of evidence, 3. This was a retrospective review of a consecutive series of patients with isolated posterior shoulder instability, defined as isolated posterior labral tear on magnetic resonance imaging (MRI) with corresponding physical examination findings, who underwent nonoperative management for 6 months and had no previous related surgical history. The primary outcome of interest was the failure of nonoperative management, defined as the inability to return to full military duty or requiring surgical intervention. The morphologic features assessed for association with nonoperative management failure included pGBL, glenoid version, acromial morphology, and posterior humeral head subluxation. We secondarily sought to determine the progression of pGBL on serial MRI scans. Cox proportional hazard analysis was used to evaluate risk factors for failure. In this study, 42 of 90 (46.7%) patients had failed nonoperative management and went on to receive an arthroscopic stabilization procedure. The group with failed treatment demonstrated a greater humeral head subluxation ratio than those with successful nonoperative management (0.65 ± 0.2 vs 0.62 ± 0.2; P = .038). Cox proportional hazard analysis identified pGBL, greater PAH, less posterior acromial coverage, and posterior humeral subluxation as significant risk factors for failure. Of those with failed nonoperative management, 17 had repeat MRI scans at a mean of 488.2 ± 87 days after index MRI for comparison, demonstrating a statistically significant progression of pGBL (index MRI, 2.68% ± 1.71%) versus after nonoperative treatment failure (6.54% ± 1.59%; P = .003). Failure occurred 47% of the time in patients who underwent nonoperative management for isolated posterior glenohumeral instability for a minimum of 6 months, and it was associated with a greater posterior humeral head subluxation, less posterior acromial coverage, greater PAH, and greater amounts of glenoid retroversion on index MRI. Additionally, those who had repeat MRI approximately 1 year after the index MRI demonstrated greater pGBL compared with the index MRI.

Minimizing unnecessary brain magnetic resonance imaging in pediatric endocrinology: a retrospective cohort analysis.

Brain magnetic resonance imaging (MRI) is mandatory or highly recommended in many pediatric endocrinological conditions to detect causative anatomic anomalies and rule out neoplastic lesions. However, MRI can also show findings associated with the underlying clinical condition, as well as unrelated "incidentalomas". These latter findings are often abnormalities with a high incidence in the general population for which there is no clear literature regarding their management, especially in pediatric patients. The present study aimed to evaluate the number of unnecessary performed MRIs in pediatric endocrinology. Retrospective analysis on 584 MRI scans performed in 414 patients (254 growth hormone deficiency, 41 other causes of short stature, 116 central precocious puberty). The MRI scans were completely normal in 67% of the individuals, and the prevalence of individuals who underwent more than one MRI was 18%, with no significant differences among the groups. The overall prevalence of incidentalomas was 17%. Among 170 repeated MRI scans, 147 (86%) were not required according to a dedicated protocol. Only five patients (four GHD, one Noonan) correctly repeated the MRI. All the repeated MRI scans did not reveal any progression in the findings. If we include the MRIs performed in cases of OCSS other than Noonan syndrome (n=32) and girls with CPP older than 6 years (n=89), an additional 121 MRIs could have been avoided, leading to a total number of unnecessary MRIs to 268 (46%). Only a few specific neuroimaging findings in endocrinologic pediatric patients warrant further investigation, while too often repeated imaging is carried out unnecessarily. We advocate the importance of guidelines to reduce costs for both the healthcare system and patients' families, as well as to alleviate physical and psychological distress for patients and caregivers.

Early experience with the use of Cissus quadrangularis and Dalbergia sissoo therapy on bone marrow edema and knee pain associated with degenerative medial compartment knee osteoarthritis

Background: Bone marrow edema (BME) refers to the accumulation of excess fluid in the bone marrow, often indicative of injury or inflammation. Some studies suggest that incorporating plant-based therapies, rich in anti-inflammatory compounds and nutrients, may contribute to alleviating BME and promoting overall bone health. Aims and Objective: The study aims to evaluate the effect of Cissus quadrangularis and Dalbergia sissoo therapy on BME and knee pain associated with degenerative medial compartment knee osteoarthritis (OA). Materials and Methods: This retrospective study examined seven individuals with medial tibial condyle BME associated with medial compartment OA. These patients were treated with initial 10 days of non-steroidal anti-inflammatory drugs along with once-a-day tablet containing C. quadrangularis (500 mg) and D. sissoo (400 mg). Visual analogue scores (VAS) and Oxford knee score (OKS) were noted at the beginning of the therapy and at 12 weeks of completion of therapy. Before treatment, BME (percentage of the medial tibial condyle) and presence/absence of subtle subchondral fracture were diagnosed with T2-weighted magnetic resonance imaging (MRI) images, and subsequently, its resolution was confirmed with a repeat MRI scan at 12 weeks. Results: At the end of 12 weeks of therapy, there was a statistically significant improvement in the mean VAS score (baseline 8.14±0.90 improved to 2.00±0.58 at 12 weeks, [P<0.0001]), OKS (baseline 25.71±1.80 improved to 36.57±1.51 at 12 weeks, [P=0.0001]), and there was statistically significant decrease in mean BME (baseline 37.86±10.35% decreased to 14.29±4.50% at the end of 12 weeks, [P=0.0001]). Conclusion: Our early experience shows that the combination therapy of C. quadrangularis + D. sissoo is effective in relief of pain, improvement in knee function, and resolution of BME associated with medial compartment knee OA. This combination is safe, effective, and well-tolerated by patients’ population.

ACCURACY OF A FRAMELESS OPTICAL STEREOTACTIC NEURONAVIGATION SYSTEM FOR BRAIN BIOPSY IN CATS: A CADAVERIC STUDY

Image-guided stereotactic techniques can display the locations of surgical instruments and biopsy targets in real time, allowing minimally invasive brain biopsies with reduced risk. This study aimed to assess the accuracy of an optical frameless neuronavigation system in feline cadavers and describe potential influencing factors. Phantom lesions were created in different brain regions and depths in 15 feline cadavers. After installing eight fiducial markers in the frontal bone and zygomatic arches, magnetic resonance imaging (MRI) was performed, and the images were imported into the neuronavigation system. Following patient and instrument registration, diluted gadolinium was injected into the phantom lesion (target), guided by the neuronavigation system. The coordinates of the target and contrast points were determined on repeated MRI scans and the distance between them was defined as the targeting error. The time from target selection to the completion of gadolinium injection was recorded as the required time. The targeting error and required time were compared between the initial 30% and final 30% of the collected data to assess the influence of operator experience. Among 76 lesions, the mean targeting error was [Formula: see text][Formula: see text]mm (95% confidence interval 2.76–3.15[Formula: see text]mm). Lesion location, lesion depth, and operator experience did not affect the accuracy; however, operator experience reduced the required time. This frameless optical neuronavigation system is potentially feasible for feline brain biopsy. The demonstrated accuracy substantiates its clinical utility for feline brain lesions [Formula: see text][Formula: see text]mm, and is comparable to that of other neuronavigation systems described in dogs.

Clinical Application of the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation Score for Reporting Magnetic Resonance Imaging in Men on Active Surveillance for Prostate Cancer.

The Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) score has been developed to standardise prostate magnetic resonance imaging (MRI) reporting in men on active surveillance (AS) for prostate cancer (PCa). To evaluate the feasibility of PRECISE scoring and assess its diagnostic accuracy. All PCa patients on AS with a baseline MRI and at least one follow-up MRI scan between January 2008 and September 2022 at a single tertiary referral centre were included in a database. The follow-up protocol of the Prostate Cancer International Active Surveillance (PRIAS) study was used. All scans were retrospectively re-reported by a dedicated uroradiologist and appointed a Prostate Imaging Reporting and Data System (version 2.1) and PRECISE score. Clinically significant progression was defined by histopathological upgrading (on biopsy or radical prostatectomy) to grade group ≥3 and/or evolution to T3 stage. A survival analysis was performed to assess differential progression-free survival (PFS) according to the PRECISE score. A total of 188 patients were included for an analysis with a total of 358 repeat MRI scans and 144 repeat biopsies. The median follow-up was 46 mo (interquartile range 21-74). Radiological progression (PRECISE 4-5) had sensitivity, specificity, negative predictive value, and positive predictive value of, respectively, 78%, 70%, 90%, and 49% for clinically significant progression. Four-year PFS was 91% for PRECISE 1-3 versus 66% for PRECISE 4-5 (p<0.001). In total, 137 patients underwent a confirmation MRI scan within 18 mo after diagnosis. Four-year PFS in this group was 81% for PRECISE 1-3 versus 43% for PRECISE 4-5 (p<0.001). Limitations include retrospective design and no strict adherence to AS protocol. Implementation of PRECISE scoring for PCa patients on AS is feasible and offers a prognostic value. Patients with PRECISE score 4-5 on confirmation MRI within 18 mo after diagnosis have a three-fold higher risk of clinically significant progression after 4 yr. Patients with low-risk prostate cancer can be followed up carefully. In this study, we evaluate the standardised reporting of repeat magnetic resonance imaging scans (using the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation [PRECISE] recommendations). PRECISE scoring is feasible and helps identify patients in need of further treatment.

Adaptive Training: A New Method to Improve the Image Quality of Abdominal Magnetic Resonance Imaging.

In abdominal magnetic resonance imaging (MRI), the late hepatic arterial phase is particularly important for the diagnosis of hepatocellular carcinoma (HCC). However, poor patient compliance with breath-hold imaging acquisition protocols and the administration of the liverspecific contrast agent gadolinium ethoxybenzyl-diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) increases the motion artifacts that degrade the quality of the images making it more difficult to interpret the images. This study aimed to evaluate the role of adaptive respiratory training in improving the quality of the MRI by reducing the motion artifacts and improving the signal intensity from the regions of interest (ROI) in the late hepatic arterial phase. A total of 120 patients who underwent an abdominal MRI between 2021 to 2022 to assess for the liver disease were included in the study. These patients were divided into two groups: the experimental group and the control group. The patients in the experimental group received adaptive training. The incidence of motion artifacts and the signal intensity in the late hepatic arterial phase within the abdominal aorta, hepatic artery, splenic artery, and hepatic parenchyma between the experimental group and the control group were compared. The incidence of motion artifacts in the experimental group was significantly reduced by 28.3% (p = 0.001, Chi-square value = 12.079). In the late hepatic arterial phase, the signal intensity of the abdominal aorta, the hepatic artery, the splenic artery, and the hepatic parenchyma increased by 7.3%, 27.4%, 29.5%, and 6.9%, respectively. Adaptive respiratory training reduced the incidence of motion artifacts and improved the signal intensity for various ROI. The improved image quality could potentially facilitate image interpretation and reduce the number of repeat MRI scans.

The Resolution of Kaplan Fiber Injuries Is Observed in a Majority of Cases at 9 Months After Acute Primary Anterior Cruciate Ligament Reconstruction: A Radiological Study

Background: The natural history of Kaplan fiber (KF) injuries after acute primary anterior cruciate ligament (ACL) reconstruction (ACLR) remains unknown. Purpose/Hypothesis: The purpose of this study was to evaluate the temporal change in the magnetic resonance imaging (MRI) appearance of the KF complex after acute primary ACLR. It was hypothesized that KF injuries would resolve with time. Study Design: Case series; Level of evidence, 4. Methods: A retrospective MRI analysis was conducted on 89 patients with ACL-injured knees to assess the change in the radiological appearance of KFs after primary ACLR. Patients who had undergone index MRI and ACLR within 90 days of the injury and further MRI at 9 months after surgery were included. Diagnostic criteria to identify radiological evidence of a KF injury and its subsequent resolution were applied, including the presence of high signal intensity on fluid-sensitive sequences, which is indicative of a pathological process radiologically. The proximity of KFs to the femoral cortical suspensory device (CSD) was noted on MRI scans and quantified in millimeters. Results: A KF injury was identified in 30.3% (27/89) of patients, with isolated high signal intensity observed in an additional 18.0% (16/89). At 9 months, MRI evidence of the reconstitution of the KF complex was found in 51.9% (14/27) of patients, with persistent discontinuity in the remaining patients (13/27). All patients (16/16) with isolated high signal intensity had complete resolution on repeat MRI scans. KF thickening was observed in 26.1% (12/46) of patients with previously healthy KFs and in 25.0% (4/16) with isolated high signal intensity. The CSD was positioned in close proximity (≤6 mm) to the center of the KF attachment in 61.8% (55/89) of patients, and this was associated with increased rates of KF thickening. Conclusion: The KF injury resolved radiologically in over half of the patients at 9 months after acute primary ACLR. High signal intensity in the region of the KFs on index MRI scans resolved in all cases, with evidence of residual KF thickening in only one-quarter of cases on repeat MRI scans, equivalent to the rate in those with healthy KFs. As such, it is not advisable to use high signal intensity on preoperative MRI scans as the sole criterion for the diagnosis of a KF injury. The position of the CSD after ACLR was intimately related to the KF attachment in the majority of patients, which was associated with KF thickening on postoperative MRI scans.

Cervical cord infarction mimicking migraine in a patient with vertebral artery dissection.

Cervical cord infarction mimicking migraine in a patient with vertebral artery dissection.

Diagnostic challenges of an incidental finding: case report of definitely-congenital glioblastoma multiforme in a very preterm infant

BackgroundCongenital brain tumors are extremely rare in the neonatal population, and often associated with a poor prognosis. The diagnostic suspicion is often aroused at antenatal scans or postnatally, if clinical signs and symptoms of increased intracranial pressure become evident. We present a case of definitely congenital glioblastoma multiforme incidentally diagnosed in a preterm infant, aiming to raise clinical awareness on this condition and to highlight the challenges of the related diagnostic work-up.Case presentationThis female infant was born at 31 weeks’ gestation after an uneventful pregnancy. No abnormalities were detected at antenatal ultrasound scans and genetic tests. Head circumference at birth was on the 25th centile. A routine brain ultrasound scan performed on day 1 revealed a large, inhomogeneous lesion in the right cerebral hemisphere, with contralateral midline shift, which was confirmed by brain magnetic resonance imaging (MRI). Eye fundus and routine blood exams, including platelets count, coagulation screening and C-reactive protein, were normal.Given the high risk of complications, surgical biopsy of the lesion was temporarily hold and a daily sonographic follow-up was undertaken. Although head circumference growth was steady on the 25th centile, progressive changes of the lesion were detected by cranial ultrasound.The repeat MRI scans showed a significant enlargement of the mass, with contralateral midline shift and signs of intralesional and intraventricular bleeding. In view of this worsening, surgical resection was performed. The histological examination of the lesion biopsy documented a GFAP+ highly cellular neoplasm, with no mutation on SMARCB1 gene. At the molecular analysis, mutations on IDH and H3F3A genes were absent, whereas MGMT promoter was unmethylated. The diagnosis was grade IV glioblastoma IDH wild-type.ConclusionsCongenital glioblastoma multiforme is an extremely rare but highly aggressive neoplasm. Since intralesional biopsy is not often feasible in affected neonates, knowledge of the associated clinical and neuroradiological features is particularly important, as they can also add useful information on the neoplasm behavior. Specimens from open surgical resection allow to perform a definite histological analysis and an extended molecular characterization, with relevant prognostic implications.

A detailed analysis of anatomical plausibility of crossed and uncrossed streamline rendition of the dentato-rubro-thalamic tract (DRT(T)) in a commercial stereotactic planning system

BackgroundAn increasing number of neurosurgeons use display of the dentato-rubro-thalamic tract (DRT) based on diffusion weighted imaging (dMRI) as basis for their routine planning of stimulation or lesioning approaches in stereotactic tremor surgery. An evaluation of the anatomical validity of the display of the DRT with respect to modern stereotactic planning systems and across different tracking environments has not been performed.MethodsDistinct dMRI and anatomical magnetic resonance imaging (MRI) data of high and low quality from 9 subjects were used. Six subjects had repeated MRI scans and therefore entered the analysis twice. Standardized DICOM structure templates for volume of interest definition were applied in native space for all investigations. For tracking BrainLab Elements (BrainLab, Munich, Germany), two tensor deterministic tracking (FT2), MRtrix IFOD2 (https://www.mrtrix.org), and a global tracking (GT) approach were used to compare the display of the uncrossed (DRTu) and crossed (DRTx) fiber structure after transformation into MNI space. The resulting streamlines were investigated for congruence, reproducibility, anatomical validity, and penetration of anatomical way point structures.ResultsIn general, the DRTu can be depicted with good quality (as judged by waypoints). FT2 (surgical) and GT (neuroscientific) show high congruence. While GT shows partly reproducible results for DRTx, the crossed pathway cannot be reliably reconstructed with the other (iFOD2 and FT2) algorithms.ConclusionSince a direct anatomical comparison is difficult in the individual subjects, we chose a comparison with two research tracking environments as the best possible “ground truth.” FT2 is useful especially because of its manual editing possibilities of cutting erroneous fibers on the single subject level. An uncertainty of 2 mm as mean displacement of DRTu is expectable and should be respected when using this approach for surgical planning. Tractographic renditions of the DRTx on the single subject level seem to be still illusive.

Early-phase vascular involvement is associated with acute pancreatitis severity: a magnetic resonance imaging study.

Although a number of studies have reported on the vascular abnormalities detected by magnetic resonance imaging (MRI) in patients with late-phase acute pancreatitis (AP), few have studied those occurring in the early phase of the disease. The aim of this research was to investigate the MRI findings of early vascular abnormalities in AP and to analyze the correlation of the prevalence of vascular involvement with the severity of AP based on the MR severity index (MRSI) and Acute Physiology and Chronic Health Evaluation (APACHE) II scores. A retrospective analysis was conducted of 301 consecutive AP patients who were admitted to our institution between March 2013 and June 2019. All patients underwent initial MRI during the early phase of pancreatitis and one or more repeat MRI scans in the late phase. Peripancreatic vascular conditions and pancreatitis were assessed using T1-/T2-weighted imaging and dynamic-enhanced MRI. The association between the prevalence of vascular involvement and AP severity graded according to the MRSI or APACHE II score was analyzed using Spearman's rank correlation. Among 301 AP patients, 75 (24.9%) had at least one MRI-detected vascular abnormality. Overall, vascular involvement on MRI was higher in necrotizing pancreatitis than in edematous pancreatitis [43.2% (54/125) vs. 11.9% (21/176), χ2=38.2, P<0.001]. In the early phase of AP, the prevalence of splenic vein phlebitis, portal vein phlebitis, and splenic arterial arteritis was 24.9% (75/301), 22.3% (67/301), and 19.9% (60/301), respectively. Splenic vein phlebitis was seen on initial MRI in 55.6% (15/27) of patients who had splenic vein thrombosis on repeat MRI. The MRSI scores showed that the prevalence of splenic vein phlebitis, portal vein phlebitis, and splenic arterial arteritis, respectively, was correlated with the severity of pancreatitis (r=0.532, 0.487, and 0.456; all P<0.01). The APACHE II scores showed that the prevalence of MRI-detected vascular involvement was significantly correlated with AP severity (r=0.335, P<0.05). Vascular abnormalities, including splenic vein phlebitis and splenic arterial arteritis, are commonly seen on MRI in patients with early-phase AP, and they may be supplementary indicators that can reflect the severity of pancreatitis.

Multiscale wavelet-based regularized reconstruction algorithm for three-dimensional compressed sensing magnetic resonance imaging

Nowadays, the most dynamic and safe imaging technique used in hospitals to diagnose is magnetic resonance imaging (MRI). In clinical applications, such as follow-up of patients with planning surgery, radiation therapy, therapy response in bone metastases assessment and treatment for brain disorders, repeated MRI scans are performed. Unfortunately, the slow acquisitions of MRI drive cost high by limiting patient throughput as well as limiting the potential indications for use. A mathematical framework called compressed sensing (CS) to accelerate MRI acquisition is used for generating undersampled measurements. Then, the iterative nonlinear numerical method is required for perfect reconstruction from highly undersampled measurements. In this work, the multiscale wavelet domain regularization prior-based iterative reconstruction algorithm is developed to address the above-mentioned reconstruction problem, in which multiscale wavelet domain generalized Gaussian mixture model is utilized for the regularization prior. The regularization-based algorithm is applied to generate three-dimensional (3D) high-quality MRI volume from multichannel k-space measurements in a compressed sensing framework. Several experiments using one synthetic and one real 3D CS multichannel k-space data were used to evaluate and validate the performance of the proposed algorithm. The total variation (TV)-based and soft-thresholding (ST) based-reconstruction methods were implemented to compare with the proposed algorithm. Extensive experimental results demonstrated that the proposed method has improved results in terms of visual quality and quantitative measurements compared to the existing methods.

Q&amp;A: Rating an Adductor Longus Tendon Tear

Q&amp;A: Rating an Adductor Longus Tendon Tear

MarkVCID cerebral small vessel consortium: II. Neuroimaging protocols.

MarkVCID cerebral small vessel consortium: II. Neuroimaging protocols.

Spontaneous Resolution of Primary Hypercortisolism of Cushing Disease After Pituitary Hemorrhage

To describe a case of spontaneous resolution of primary hypercortisolism from Cushing disease (CD) due to pituitary apoplexy (PA). Clinical, laboratory, and pathologic information are described. A 59-year-old female presented with a headache, a 2.3 cm sellar mass with a questionable hemorrhagic component, and clinical signs of hypercortisolism. On further evaluation, she had an increased 24-hour urine free cortisol, abnormal serum cortisol during a low dose dexamethasone suppression test, and an elevated plasma adrenocorticotropic hormone (ACTH), consistent with pituitary CD. As she was being prepared for surgical resection, she was noted to have spontaneous biochemical remission associated with resolution of her symptoms of hypercortisolism, and a repeat magnetic resonance imaging scan showed shrinkage of the sellar mass. She has been managed conservatively since and remains in clinical/biochemical remission until present time, 18 months following her initial presentation. We report a case of spontaneous resolution of CD from symptomatic hemorrhage within an ACTH-secreting pituitary adenoma, or PA. This has been rarely reported in the medical literature. The fact that she did not pass through a phase of adrenal withdrawal, makes us suspect a residual functional adenoma within or around the sella which may eventually grow, causing her disease to recur, as has been reported. Hence, continued monitoring will be required.

MRI Bone Marrow Edema Signal Intensity: A Reliable and Valid Measure of Lumbar Bone Stress Injury in Elite Junior Fast Bowlers.

Comparative reliability and prospective validity. First, to evaluate the reliability of four methods of assessing magnetic resonance imaging (MRI) bone marrow edema (BMO) of the posterior vertebral arch of the lumbar vertebrae of elite junior fast bowlers. Second, to evaluate the validity of the most reliable method for the early detection of lumbar bone stress injury. MRI has demonstrated utility in identifying BMO in lumbar vertebrae. Methods to grade the severity of BMO may provide valuable insight to inform clinical management, particularly in elite athletes where detection of early-stage bone stress may prevent progression to more severe and costly bone stress injury. Sixty-five male elite junior fast bowlers had repeat MRI scans during a cricket season. A subset of 19 bowlers' images were reassessed by experienced musculoskeletal radiologists to determine intra- and inter-rater reliability. All images were aligned with independent medical records of lower back symptoms and diagnosed bone stress injuries to establish the relationship of BMO and lumbar bone stress injury. Clinical detection of abnormal BMO, whether the pars region of the vertebra was considered in its entirety or subdivided into regions, had fair-to-moderate inter-rater reliability, and fair-to-almost perfect intra-rater reliability. Measurement of BMO signal intensity using an imaging software tool had excellent intra-rater and inter-rater reliability (ICC = 0.848, 0.837). BMO signal intensity was positively associated with subsequent LBSI (P < 0.001), and differentiated between asymptomatic and symptomatic bowlers (P < 0.001). Measurement of BMO signal intensity using an imaging software tool proved a reliable and valid measure of the severity of lumbar bone stress injury in elite junior fast bowlers. 2.

Robotically assisted long bone biopsy under MRI: cadaver study results.

We have designed and constructed an MR-safe robot made entirely of nonmetallic components with pneumatic actuators and optical encoders. The robot was developed to enable bone biopsies to be performed under magnetic resonance imaging (MRI) guidance in pediatric patients. The purpose of this study was to show the feasibility of using the robot for biopsy of the femur and tibia in a cadaver leg. Our long-term goal is to eliminate radiation exposure during bone biopsy procedures and provide more timely and accurate diagnosis for children with bone cancers and bone infections. The MR-safe robot was mounted on the MRI table. A cadaver leg was procured from an anatomy supply house and placed on the MRI table. All required hospital precautions for infection control were taken. A total of 10 biopsy targets were sampled using MRI guidance: five from the femur and five from the tibia. A handheld, commercially available battery-powered bone drill was used to facilitate drilling through the cortex. After the study, the leg was scanned with CT to better visualize and document the bone biopsy sites. Both the MRI and CT images were used to analyze the results. All of the targets were successfully reached with an average targeting accuracy of 1.43mm. A workflow analysis showed the average time for the first biopsy was 41min including robot setup time and 22min for each additional biopsy including the time for the repeat MRI scan used to confirm accurate targeting. The robot was shown to be MRI transparent, as no image quality degradation due to the use of the robot was detected. The results showed the feasibility of using an MR-safe robotic system to assist the interventional radiologist in performing precision bone biopsy under MRI guidance. Future work will include developing an MR-safe drill, improving the mounting of the robot and fixation of the leg, and moving toward first in child clinical trials.

Autoimmune encephalitis positive for both anti-γ-aminobutyric acid B receptor and anticollapsin response-mediator protein 5 antibodies

Rationale:Autoimmune encephalitis (AE) is a heterogeneous group of recently identified disorders. Despite severe and even prolonged neurologic deficits, dramatic improvements may occur with proper immunotherapy in some patients with AE. Antineuronal antibodies have been discovered in patients’ serum and cerebrospinal fluid (CSF). However, AE with multiple antineuronal antibodies is rare. To date, there are no published reports of AE with both anti-γ-aminobutyric acid B receptor (GABABR) and anticollapsin response-mediator protein 5 (CV2) antibodies.Patient concerns:We describe a 46-year-old man who presented with seizures, working memory deficits, and visual hallucinations. We detected anti-CV2 and anti-GABABR antibodies in his serum and CSF. Brain magnetic resonance imaging (MRI) revealed patchy abnormal signals in his left temporal lobe and hippocampus. The patient's symptoms improved after receiving intravenous immunoglobulin injections and glucocorticoids, but his condition relapsed within 4 months, and he was readmitted to our hospital. Repeated MRI scans revealed new lesions in his right temporal lobe and hippocampus.Diagnosis:The AE diagnosis was established from the results of the preliminary physical examination, the laboratory tests, and the imaging findings.Interventions:The patient received intravenous immunoglobulins and glucocorticoids.Outcomes:We followed the patient for 9 months from the date of the patient's second hospital discharge. He experienced no seizures during this period, but his short-term memory deficits and visual hallucinations were not completely alleviated.Lessons:Coexisting anti-CV2 and anti-GABABR antibodies may have synergistic effects and worsen the clinical syndrome. AE with multiple antineuronal antibodies may be relapse-prone. Further studies investigating the relationship between anti-CV2 and anti-GABABR antibodies are warranted.

Short-term Repeat Magnetic Resonance Imaging Scans in Suspected Early Axial Spondyloarthritis Are Clinically Relevant Only in HLA-B27-positive Male Subjects.

Our study investigated the natural history of magnetic resonance imaging (MRI)-determined bone marrow edema over a 12-week period in individuals with suspected axial spondyloarthritis. There were 109 MRI scans performed on 30 patients who fulfilled the Assessment of Spondyloarthritis international Society inflammatory back pain criteria at baseline and at 4, 8, and 12 weeks. There were 29 patients who completed the study. Only 4 (14%) patients changed from MRI-negative to MRI-positive (all HLA-B27-positive, OR 2.74). Three of 7 (43%) male HLA-B27-positive patients, 1 of 8 (12.5%) HLA-B27-positive female patients, and no HLA-B27-negative patients changed from MRI- negative to -positive. Repeat MRI scans within a 12-week period should be considered in HLA-B27-positive males.

Orbital cellulitis as the initial presentation of Langerhans cell histiocytosis in an adult patient

A 28-year-old woman presented with 3 weeks of right-sided blurry vision, proptosis, orbital pain, and upper eye lid swelling. She also complained of progressively worsening intermittent headaches. She had been evaluated in the emergency department multiple times for the same complaint, and had received multiple courses of intravenous antibiotics with minimal improvement. Physical examination revealed significant proptosis of the right eye although visual acuity was preserved in both eyes. Initial laboratory studies including complete blood count, basic metabolic panel, and thyroid functioning tests were within normal limits. An infectious workup including blood and fungal cultures were negative. A non-contrast computed tomography (CT) scan of the head demonstrated a mass on the right orbital rim which was concerning for right periorbital and orbital cellulitis, with the post septal component present along the superior and lateral aspects of the right orbit (Figure 1A). Broad spectrum antibiotics were initiated and a repeat magnetic resonance imaging scan performed ten days later showed partial improvement of the inflammatory changes associated with orbital cellulitis. However, there was an interval increase in the size of a more discrete mass-appearing lesion which was now eroding into the adjacent bony structures (Figure 1B). A biopsy of the lesion showed an infiltrate which stained strongly positive for CD1a and S100 (Figure 1C-F). A diagnosis of Langerhans cell histiocytosis (LCH) was considered. CT scans of the chest and abdomen-pelvis and a bone marrow biopsy did not show evidence of systemic LCH disease. She declined therapy and her prognosis is unknown. CNS imaging findings for Langerhans cell histiocytosis (LCH). A: CT head without contrast showed right periorbital edema with underlying, focal cortical destruction of the right superior orbital rim consistent with periorbital cellulitis. B: A MR of the orbits performed 2 weeks later showed an enlargement of the mass with invasion into the orbital rim. The mass is delineated by a yellow star. Subsequent pathology obtained from biopsy of the mass revealed Langerhans's histiocytosis (eosinophilic granuloma). C: Low power view; (E) High power view (cells are medium to large size, with folded/convoluted nuclei, fine chromatin, abundant eosinophilic cytoplasm in a background of eosinophils, neutrophils and small lymphocytes; (D) CD1a positive; (F) S100 positive LCH, previously known as histiocytosis X, describes a spectrum of proliferation of Langerhans cells that may manifest as a single system or multiple system disease. Although solitary ocular manifestations of LCH without evidence of systemic LCH are documented in children, they are rare in adults. The location of the infiltrate within the orbit largely determines the patient's presenting complaints.1 Most orbital manifestations of LCH in adults have been in the context of systemic LCH disease with only a handful of cases of solitary orbital LCH presenting as orbital cellulitis documented. The diagnosis is primarily determined by a biopsy of the presenting lesion, where immunohistochemical staining with S100 and CD1a is characteristic of Langerhans cells.2 Treatment strategies for orbital LCH depend on “case-by-case basis” and surgical resection and radiation is reserved for solitary lesions in children. Given its rarity, ideal management strategies are unclear, however solitary orbital LCH can spread to the central nervous system, and these patients can develop diabetes insipidus and systemic LCH. Aggressive prolonged multi-drug regimens including combinations of vincristine, prednisolone, etoposide, and methotrexate are used for treatment, with routine surveillance for recurrence with history, examination, and imaging. None. Not Applicable Obtained AD drafted and revised the manuscript. AG provided care for the patient and conceptualized the report. AG and HN revised and edited the manuscript for intellectual content.