Latest Magnetic Resonance Imaging Research Articles

Eighty-One Percent of Unrepaired Interportal Capsulotomies Showed Healed Capsules on Magnetic Resonance Imaging 5 Years After Primary Hip Arthroscopy

PurposeTo evaluate whether un-repaired interportal capsulotomy presents with capsular defect at MR imaging 5 years after primary hip arthroscopy, and to determine its effect on functional results and findings of osteoarthritis on a radiograph or MRI imaging. MethodsPatients with femoro-acetabular impingement (without arthritis, dysplasia) were retrospectively reviewed after arthroscopic labral repair or debridement and femoroplasty through interportal capsulotomy without closure. Patients were assessed preoperatively and a minimum of five years postoperatively using patient-reported outcomes (Hip Outcome Score Activities of Daily Living [HOS-ADL], modified Harris Hip Score [mHHS]), visual analogue scale scores, radiographic measures, and magnetic resonance imaging (MRI) ResultsForty patients (42hips) eligible for the study were evaluated and 81% of the hips had healed capsules, while there were 8 (19%) hips had capsule defects at the latest MR imaging. There were three hips with subchondral oedema in the defect group compared to one in the capsule healed group (p: 0.01) at the latest MRI, which were not present at preoperative MR imaging (still positive at the multivariate analysis when the preoperative alpha angle was also taken into consideration . Functional results did not differ between groups (p>0.05). ConclusionIn this study, 81% of interportal capsulotomies healed without repair at 5 years after primary hip arthroscopy.

Brainstem Surgery: Functional Surgical Anatomy with the Use of an Advanced Modern Intraoperative Neurophysiological Procedure.

Intraoperative neurophysiology (ION) in brainstem surgery evolved as brainstem surgery advanced.The original idea of brainstem mapping (BSM) is a neurophysiological procedure to locate cranial nerve motor nuclei (CNMN) on the floor of the fourth ventricle. With the introduction of various skull base approaches to the brainstem, BSM is carried out on any surface of the brainstem to expose the safe entry zone to the intrinsic brainstem lesion. It is the modern concept of BSM, a broader definition of BSM. BSM enables to avoid direct damage to the CNMN when approaching the brainstem through the negative mapping region.The corticobulbar tract (CBT) motor evoked potential (MEP) is another ION procedure in brainstem surgery. It enables monitoring of the functional integrity of the whole cranial motor pathway without interrupting surgical procedures. Combined application of both BSM and CBT-MEP monitoring is indispensable for the functional preservation of the CNMN and their supranuclear innervation during the brainstem surgery.In this paper, the neurophysiological aspect of BSM and the CBT-MEP was fully described. Normal anatomical background of the floor of the fourth ventricle and the detail of the CBT anatomy were demonstrated to better understand their clinical usefulness, limitations, and surgical implications derived from ION procedures. Finally, a future perspective in the role of ION procedures in brainstem surgery was presented. The latest magnetic resonance imaging (MRI) technology can allow surgeons to find an "on the image" safe entry zone to the brainstem. However, the role of BSM and the CBT-MEP monitoring in terms of safe brainstem surgery stays unshakable. Special attention was paid for the recent trend of management in diffuse intrinsic pontine gliomas. A new role of BSM during a stereotactic biopsy was discussed.It is the authors' expectation that the paper enhances the clinical application of a contemporary standard of the ION in brainstem surgery and supports safer brainstem surgery more than ever and in the future.

Clinical and Radiological Outcomes in Patients With Anterior Shoulder Instability and Glenoid Bone Loss after Arthroscopic Free Bone Block Combined With Dynamic Anterior Stabilization

Background: As an alternative to the Latarjet procedure, the arthroscopic free bone block (FBB) procedure combined with dynamic anterior stabilization (DAS) has been recently proposed to provide both glenoid augmentation and a tendon sling effect for treating anterior shoulder instability (ASI) with glenoid bone loss. Purpose: To evaluate the clinical and radiological outcomes of FBB-DAS for ASI with glenoid bone loss. Study Design: Case series; Level of evidence, 4. Methods: Patients who underwent arthroscopic FBB-DAS for ASI with >15% glenoid bone loss between February 2017 and March 2020 were screened and enrolled in this study. Clinical outcome measures were assessed preoperatively and at a minimum 2-year follow-up, including recurrence, complications, shoulder functional scores, range of motion, and return to sports. Postoperative computed tomography and magnetic resonance imaging were also performed. Results: Of a total of 65 patients with a mean follow-up of 46.1 ± 13.1 months, no patients experienced a recurrent dislocation or subluxation postoperatively, while 2 had a positive anterior apprehension test (3.1%). Additionally, 2 patients (3.1%) experienced complications of hematoma and shoulder stiffness, respectively. The mean visual analog scale score, American Shoulder and Elbow Surgeons score, Rowe score, and Oxford Shoulder Instability Score all improved significantly from 3.2 ± 2.4, 75.0 ± 18.9, 43.6 ± 27.3, and 33.8 ± 9.0 preoperatively to 1.3 ± 0.8, 95.1 ± 8.0, 95.5 ± 7.8, and 14.8 ± 3.5 at final follow-up, respectively (all P < .001). No difference was detected in range of motion except for 8.1° and 7.5° external rotation limitations in adduction and abduction, respectively. There were 62 patients (95.4%) who returned to sports, and 54 patients (83.1%) returned to the preinjury level. The transferred biceps tendon was intact in all 59 patients who completed radiological examination at the latest follow-up. Good bone healing was achieved in 98.3% of patients, and the glenoid bone defect decreased from 18.1% to 4.9%. Osseous and labral glenoids were significantly enlarged in width and depth on the latest magnetic resonance imaging (all P < .001). Conclusion: Arthroscopic FBB-DAS provided satisfactory clinical and radiological outcomes for ASI with glenoid bone loss. Despite slight external rotation restrictions, it achieved low recurrence and complication rates, excellent shoulder functional scores, a high return-to-sports rate, and favorable graft healing and remodeling.

Non-functioning pituitary microadenoma in children and adolescents: Is follow-up with diagnostic imaging necessary?

PurposeNo consensus exists regarding follow-up recommendations for suspected pituitary microadenoma in children. To address this knowledge gap, we investigated the growth potential of pituitary solid and cystic lesions <10 mm in children and evaluated the accuracy of magnetic resonance imaging (MRI) measurements.MethodsThe children included were <18 years at first pituitary MRI and radiologically diagnosed with a non-functioning microadenoma or cyst <10 mm. Lesion size at first and latest MRI as well as all individual MRI examinations were re-evaluated.ResultsIn total, 74 children, median age 12 years (range 3–17), had a non-functioning microadenoma, probable microadenoma, or cyst. Of these, 55 underwent repeated MRI (median 3, range 2–7) with a median follow-up of 37 months (range 4–189). None of the pituitary lesions without hormonal disturbances increased significantly during follow-up. Two radiologists agreed that no lesion could be identified in 38/269 (14%) MRI examinations, and in 51/231 (22%) they disagreed about lesion location. In 34/460 (7%) MRI measurements size differed >2 mm, which had been considered significant progression.ConclusionNon-functioning pituitary microadenoma in children has small size variations, often below the spatial resolution of the scanners. We suggest lesions <4 mm only for clinical follow-up, lesions 4–6 mm for MRI after 2 years and ≥7 mm MRI after 1 and 3 years, with clinical follow-up in between. If no progression, further MRI should only be performed after new clinical symptoms or hormonal disturbances.

Shedding light on excessive crying in babies.

Excessive and inconsolable crying behavior in otherwise healthy infants (a condition called infant colic (IC)) is very distressing to parents, may lead to maternal depression, and in extreme cases, may result in shaken baby syndrome. Despite the high prevalence of this condition (20% of healthy infants), the underlying neural mechanisms of IC are still unknown. By employing the latest magnetic resonance imaging (MRI) techniques in newborns, we prospectively investigated whether newborns' early brain responses to a sensory stimulus (smell) is associated with a subsequent crying behavior. In our sample population of 21 healthy breastfed newborns, those who developed IC at 6 weeks exhibited brain activation and functional connectivity in primary and secondary olfactory brain areas that were distinct from those in babies that did not develop IC. Different activation in brain regions known to be involved in sensory integration was also observed in colicky babies. These responses measured shortly after birth were highly correlated with the mean crying time at 6 weeks of age. Our results offer novel insights into IC pathophysiology by demonstrating that, shortly after birth, the central nervous system of babies developing IC has already greater reactivity to sensory stimuli than that of their noncolicky peers. Shortly after birth, the central nervous system of colicky infants has a greater sensitivity to olfactory stimuli than that of their noncolicky peers. This early sensitivity explains as much as 48% of their subsequent crying behavior at 6 weeks of life. Brain activation patterns to olfactory stimuli in colicky infants include not only primary olfactory areas but also brain regions involved in pain processing, emotional valence attribution, and self-regulation. This study links earlier findings in fields as diverse as gastroenterology and behavioral psychology and has the potential of helping healthcare professionals to define strategies to advise families.

Cortical Superficial Siderosis Evolution.

Background and Purpose- We investigated cortical superficial siderosis (cSS) progression and its clinical relevance for incident lobar intracerebral hemorrhage (ICH) risk, in probable cerebral amyloid angiopathy presenting with neurological symptoms and without ICH at baseline. Methods- Consecutive patients meeting modified Boston criteria for probable cerebral amyloid angiopathy from a single-center cohort who underwent magnetic resonance imaging (MRI) at baseline and during follow-up were analyzed. cSS progression was assessed by comparison of the baseline and follow-up images. Patients were followed prospectively for incident symptomatic ICH. cSS progression and first-ever ICH risk were investigated in Cox proportional hazard models adjusting for confounders. Results- The cohort included 118 probable cerebral amyloid angiopathy patients: 72 (61%) presented with transient focal neurological episodes and 46 (39%) with cognitive complaints prompting the baseline MRI investigation. Fifty-two patients (44.1%) had cSS at baseline. During a median scan interval of 2.2 years (interquartile range, 1.2-4.4 years) between the baseline (ie, first) MRI and the latest MRI, cSS progression was detected in 33 (28%) patients. In multivariable logistic regression, baseline cSS presence (odds ratio, 4.04; 95% CI, 1.53-10.70; P=0.005), especially disseminated cSS (odds ratio, 9.12; 95% CI, 2.85-29.18; P<0.0001) and appearance of new lobar microbleeds (odds ratio, 4.24; 95% CI, 1.29-13.9; P=0.017) were independent predictors of cSS progression. For patients without an ICH during the interscan interval (n=105) and subsequent follow-up (median postfinal MRI time, 1.34; interquartile range, 0.3-3 years), cSS progression independently predicted increased symptomatic ICH risk (hazard ratio, 3.76; 95% CI, 1.37-10.35; P=0.010). Conclusions- Our results suggest that cSS evolution may be a useful biomarker for assessing disease progression and ICH risk in cerebral amyloid angiopathy patients and a candidate biomarker for clinical studies and trials.

Significance of combined use of MRI and perfusion SPECT for evaluation of multiple system atrophy, cerebellar type.

Multiple system atrophy, cerebellar type (MSA-C) sometimes shows asymmetrical findings on magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT). To assess the frequency and clinical significance of asymmetrical MRI and (99m)Tc-ethyl cysteinate dimer perfusion (ECD) SPECT findings of the cerebellum, middle cerebellar peduncle (MCP), and pons in MSA-C patients. We retrospectively reviewed 28 patients with MSA-C who underwent MRI and (99m)Tc-ECD SPECT and evaluated laterality of atrophy and signal changes on MRI, and laterality of perfusion on (99m)Tc-ECD SPECT transversely and longitudinally. Laterality was identified for 64%, 61%, and 21% of atrophy in the cerebellum, MCP, and pons, respectively, on MRI and for 71% of atrophy in the cerebellum on perfusion SPECT. Concerning comparisons between the latest MRI and SPECT findings, laterality of cerebellar/MCP atrophy on MRI and decreased cerebellar perfusion on SPECT was matched in 57%, mismatched in 11%, and absent in 25% of patients. On past images, MRI and SPECT showed matched laterality in 33%, mismatched laterality in 27%, no laterality in 13%, and SPECT precedent laterality in 27% of patients. Including the latest and past images, asymmetrical changes were observed in 75% of patients. We could not identify any correlation between laterality of image findings and cerebellar symptoms in most patients. Asymmetrical changes on MRI and perfusion SPECT are common in MSA-C patients. Perfusion SPECT is useful for diagnosing MSA-C in the early stages from a functional perspective.

MRI in dementia-type diseases

Dementia-inducing conditions represent a leading cause of disability and are a major health concern in industrialized countries. The burden these conditions put on society is certain to rise in the context of an ever-increasing elderly population. As these conditions feature an insidious onset and overlapping clinical features, imaging is a powerful tool in refining the diagnosis and assessing the progression of dementing conditions. The radiologist needs to be aware of and be able to detect underlying pathologies which could be reversible. Furthermore, imaging is important not only in excluding other pathologies but also in improving diagnostic accuracy. This article presents the typical clinical presentations as well as magnetic resonance imaging (MRI) features of the degenerative and the non-degenerative causes of dementia. The focus is on the core knowledge for MRI diagnostics in dementing conditions and a brief presentation of the latest MRI techniques which may become a part of standard imaging protocols in the future.

Bipolar I Disorder Presaging X-Linked Adrenoleukodystrophy

Bipolar I Disorder Presaging X-Linked Adrenoleukodystrophy

Detecting plasma Epstein-Barr virus DNA to diagnose postradiation nasopharyngeal skull base lesions in nasopharyngeal carcinoma patients: a prospective study

The diagnosis of postradiation nasopharyngeal skull base lesions in petients with nasopharyngeal carcinoma (NPC) is still a tough problem in clinical practice. An early and accurate diagnosis is important for subsequent management. We prospectively evaluated the diagnostic value of plasma Epstein-Barr virus (EBV) DNA in detecting postradiation nasopharyngeal skull base lesions in NPC patients. From July 2006 to September 2010, 90 patients with postradiation NPC (34 women and 56 men; median age: 42 years) met the selection criteria and were recruited in this study. All postradiation nasopharyngeal skull base lesions were found in the latest magnetic resonance imaging (MRI) examinations before endoscopic surgery, and the nasopharyngeal cavity was normal under flexible nasopharyngoscopy. Plasma EBV DNA detection was performed within 2 weeks before endoscopic surgery. A total of 90 endoscopic operations were successfully performed without any postoperative complications. Recurrences confirmed by postoperative pathology were found in 30 patients. The specificity, positive and negative predictive values of plasma EBV DNA detection were better than those of MRI. In addition, combining plasma EBV DNA detection with MRI improved the specificity and positive predictive values of MRI. Plasma EBV DNA detection followed by MRI would help to diagnose recurrence whereas MRI was unable. These results indicate that plasma EBV DNA is an effective and feasible biomarker for detecting postradiation nasopharyngeal skull base lesions in NPC patients.

High Incidence of Radiation-Induced Cavernous Hemangioma in Long-Term Survivors Who Underwent Hematopoietic Stem Cell Transplantation with Radiation Therapy during Childhood or Adolescence

Radiation-induced cavernous hemangioma (RICH) is a late complication of cerebral radiation therapy. Long-term survivors of hematopoietic stem cell transplantation (HSCT) who underwent radiation therapy could be at increased risk for RICH. We investigated records of 68 patients who underwent HSCT during childhood or adolescence and were assessed by magnetic resonance imaging (MRI), including T2*-weighted imaging of the brain, annually for 5 years over a range of 6 to 29 years after HSCT. We developed a scoring and grading system for RICH to monitor the process and the progress of radiologic changes. Among the 68 patients investigated, 28 (41.2%) were diagnosed with CH. All 28 patients had received total body irradiation as a conditioning treatment for HSCT and/or cranial radiation therapy before HSCT as part of the treatment of their primary disease. RICH was diagnosed in none of the patients who did not receive radiation (n = 19), in 46.2% of those who received 6 to 12 Gy (n = 39), and in all of those who received 18 to 36 Gy (n = 10). Total RICH scores were correlated with higher radiation doses. Careful and long-term evaluation with MRI, including T2*-weighted imaging, is necessary for HSCT recipients who received radiation therapy before and/or during HSCT.

Ethics roundtable: 'Open-ended ICU care: Can we afford it?'

The patient is a 27-year-old previously healthy male with a diagnosis of viral encephalitis with a lymphocytic pleocytosis on cerebrospinal fluid examination. For 3 months, he has been in status epilepticus (SE) on high doses of barbiturates, benzodiazepines, and ketamine and a ketogenic feeding-tube formula. He remains in burst suppression on continuous electroencephalography (EEG). He is trached and has a percutaneous endoscopic gastrostomy (PEG) feeding tube. He has been treated several times for pneumonia, and he is on a warming blanket and is on vasopressors to maintain his blood pressure. His vitals are stable and his lab work is within limits. The sedation is decreased under EEG guidance every 72 hours, after which he goes back into SE and heavy sedation is resumed. The latest magnetic resonance imaging (MRI) shows edema but otherwise no obvious permanent cortical damage. The family wants a realistic assessment of the likely outcome. The neurologist tells them the literature suggests the outlook is poor but not 100% fatal. As long as all of his other organs are functioning on life support, there is always a chance the seizures will stop at some time in the future, and so the neurologist recommends an open-ended intensive care unit (ICU) plan and hopes for that outcome.

Temporomandibular Joint Soft-Tissue Pathology, II: Nondisc Abnormalities

The most important objective in a magnetic resonance imaging (MRI) study of the temporomandibular joint (TMJ) is to determine the location of disk, because the presence of a displaced disk is a critical sign of TMJ dysfunction. However, a high frequency of disk displacement appears in asymptomatic volunteers; thus, other MRI indirect signs of TMJ dysfunction can help in the diagnosis. Further studies using the latest MRI techniques allow a better understanding of the sources of joint pain and the discrepancy between imaging findings and patient symptoms. Evaluation of other MRI signs such as the presence of joint effusion, the rupture of retrodiscal ligaments, or the thickness of the attachment of the external pterygoid muscle can be used as indirect early signs of TMJ dysfunction, before osteoarthritic changes lead to a more advanced stage of the dysfunctional spectrum. In this article we show those MRI indirect signs of TMJ dysfunction, providing more reasons to separate anatomic variants of healthy individuals from a real internal derangement.

Accuracy of Quantitative MR Vessel Wall Imaging Applying a Semi?Automated Gradient Detection Algorithm?A Validation Study

Magnetic resonance imaging (MRI) is uniquely suited to study the pathophysiology of arteriosclerosis. So far, magnetic resonance (MR) measurements of vessel dimensions have mainly been done by manual tracing of vessel wall contours. However, such data postprocessing is very time-consuming and has limited accuracy due to difficulties in precise tracing of the thin vessel wall. To assess the accuracy and reproducibility of quantitative vascular MR imaging applying a data analysis method based on (1) vessel wall unwrapping, followed by (2) a gradient detection algorithm for MR data postprocessing. Vascular MR imaging studies were done both in vessel phantoms and in healthy volunteers (n=29) on a clinical 1.5 T MR scanner. A dark blood double-inversion turbo spin echo sequence with fat suppression was applied, with proton-density-weighted and breath-hold acquisition for aortic imaging and T2-weighted acquisition for carotid imaging. Intraobserver and interobserver variability were systematically evaluated by two independent observers. A repeat study within 10 days of the first MRI was performed in 10 of these subjects for assessment of interstudy reproducibility. The semiautomated edge detection software revealed a clear view of the inner and outer vessel wall boundaries both in the phantoms and in the volunteers studied. There was close agreement between MR-derived measurements and phantom dimensions (mean difference of 1.1+/-16.9 mm2, 8.0+/-19.9 mm2, 9.0+/-12.1 mm2 for vessel wall cross-sectional area, inner vessel area, and total vessel area, respectively). Quantification of vessel dimensions was feasible in all 29 healthy volunteers studied. Semiautomated quantification of cross-sectional vessel wall area (mean+/-SD, 253.6+/-208.4 mm2) revealed close correlation for repeated measurements by one or two observers (r=0.99 each). Both intraobserver and interobserver variability of vessel wall area MR measurements were low (mean difference 7.5+/-16.7 mm2 and 14.4+/-24.6 mm2 , respectively). In the repeat study of 10 volunteers, MRI with semiautomated postprocessing quantitation revealed a high correlation and agreement of vessel dimensions between the two scans (r=0.994, mean difference 2.6+/-25.1 mm2). Semiautomated analysis methods can provide approaches that benefit from the human understanding of the image and the computer's ability to measure precisely and rapidly. Thus, by combining the latest MRI methods and semiautomated image analysis methods, we are now able to reproducibly determine the geometric parameters of blood vessels.