Seizure-induced reversible magnetic resonance imaging abnormalities: A retrospective cohort study.

PURPOSE: Seizure-induced reversible magnetic resonance imaging (MRI) abnormalities (SRMA) present challenges in seizure management. We sought to investigate the frequency, risk factors, evolution and prognostic value of SRMA. METHODS: A retrospective observational cohort study of consecutive seizure patients investigated with an MRI of the brain was conducted. Clinical and MRI data were reviewed to determine the clinical characteristics and imaging findings of SRMA. Outcomes (seizure freedom versus uncontrolled seizures and deaths) were assessed upon the last clinic follow-up. Mann-Whitney U test and chi-square test for independence with Bonferroni correction were used to explore the statistical significance of predictive factors. RESULTS: The study included 483 consecutive seizure patients with 7.6% developing SRMA. Patients with SRMA were older (median age 57 years, interquartile range-IQR 52-66, p < 0.001) and experienced longer seizures (median 5 minutes, IQR 2-15, p = 0.002) compared with seizure patients with normal MRI. Seizure type (provoked versus unprovoked), recurrence (first versus recurrent) and epileptiform EEG changes did not demonstrate a significant association. Diffusion restriction and ADC reduction observed in SRMA resolved earlier, while T2, FLAIR hyperintensities and temporal lobes changes persisted longer on follow-up scans. The median time interval from seizure to complete resolution of SRMA was 87 days (IQR 45-225). No statistical difference in outcomes was seen between patients with SRMA and normal MRIs (p = 0.19). CONCLUSIONS: SRMA is an uncommon finding following seizures. It is not associated with poor seizure control or mortality. Risk factors associated with SRMA include older age and longer seizure duration including status epilepticus.

Prevalence and location of acetabular sublabral sulci at hip arthroscopy with retrospective MRI review.

OBJECTIVE: The objective of this prospective study was to determine the prevalence and location of acetabular sublabral sulci diagnosed as variants at hip arthroscopy and to provide a retrospective MRI review. SUBJECTS AND METHODS: Two experienced hip arthroscopists noted the prevalence and location of acetabular labral sulci in 121 patients. The study population consisted of 57 males and 64 females with an average age of 43 years (range, 16-70 years). Of the 121 hip arthroscopies that showed sulci (22% of patients), correlation with the relevant MR studies (n = 27) was performed. Two radiologists who were aware of the arthroscopic findings reviewed the MR studies retrospectively, and agreement on imaging appearances was reached by consensus. RESULTS: Arthroscopy revealed 30 sulci (25%) in 27 of the 121 patients. In those who had a single sulcus (25 patients), 11 (44%) were located anterosuperiorly, 12 (48%) posteroinferiorly, one (4%) anteroinferiorly, and one (4%) posterosuperiorly. The other two patients had more than one sulcus: one patient had one posterosuperior sulcus and one posteroinferior sulcus; and the other patient had one anterosuperior sulcus, one anteroinferior sulcus, and one posteroinferior sulcus. In total, of the 121 patients, the number and position of the sulci were 12 anterosuperior (10%), 14 posteroinferior (12%), two anteroinferior (2%), and two posterosuperior (2%). Of the 27 MR examinations, 24 were unenhanced and three studies were performed after intraarticular injection of gadolinium. In these 27 patients, a total of 30 sulci were detected at arthroscopy. On retrospective MR review of both the conventional and gadolinium-enhanced studies, nine (75%) of the 12 anterosuperior sulci could be visualized. Ten (71%) of the 14 posteroinferior sulci were also identified. Neither of the two anteroinferior sulci could be seen. Both of the posterosuperior sulci were evident. Of the conventional MR studies, of a potential of 27, 18 (70%) were identified on conventional imaging. CONCLUSION: Sulci of the hip exist (22% of patients) and can be found at all anatomic positions (i.e., anterosuperior, anteroinferior, posterosuperior, and posteroinferior) of the hip. These sulci can be visualized on MRI with an accuracy of 70% using a nongadolinium technique.

Magnetic resonance imaging in knee synovitis: clinical utility in differentiating asymptomatic and symptomatic meniscal tears.

It is well documented that meniscal tears may be found frequently by MRI as an incidental finding in asymptomatic knees. We aim to review the literature regarding the ability of MRI to differentiate between asymptomatic and symptomatic meniscal tears. Ovid MEDLINE, MEDLINE inProcess, Cochrane reviews, Web of Science, Embase and CINAHL were systematically searched. A total of 1251 publications were screened based on their titles, abstracts and full texts, of which 1213 publications were excluded because they did not address the relationship between synovitis and meniscal tears, were case reports or reviews, concerned atypical patient populations or reported surgical research. Of the 38 retained publications, only two reported results specific to perimeniscal synovitis, while 36 discussed less specific but relevant findings. The small number of heterogeneous results describing perimeniscal synovitis precluded meta-analysis. In the symptomatic knee, identification of the likelihood of a meniscal tear contributing to the patient's pain is of significance to the orthopaedic surgeon. In our literature review, we have identified that localised synovitis and displacement of the meniscus are two features that may assist in identifying the subgroup of patients that may benefit from meniscal intervention.

Are extra-labral MR findings useful in the diagnosis of a labral tear?

OBJECTIVE: To determine diagnostic performance statistics of extra-labral magnetic resonance (MR) findings for detection of labral tears in a population of patients with clinical suspicion of this diagnosis. MATERIALS AND METHODS: Seventy-nine patients clinically suspected of having a labral tear (who underwent arthroscopy) had their MR studies retrospectively reviewed to determine the presence of lateral acetabular oedema-like marrow signal, ganglia, dysplastic femoral bumps, synovial herniation pits and geodes. These findings were then correlated with the arthroscopic presence (or absence) of a labral tear. RESULTS: All findings (lateral acetabular oedema-like marrow signal, ganglia, dysplastic femoral bumps, synovial herniation pits and geodes) had a specificity and positive predictive value (PPV) of 100%. Lateral acetabular oedema-like marrow signal had a sensitivity of 35% and 20% negative predictive value (NPV). This was the only statistically significant finding (P < 0.05). The sensitivity and NPV of ganglia were 12% and 16%, dysplastic femoral bumps (12%, 16%), synovial herniation pits (4%, 14%) and geodes (6%, 15%) respectively, (P > 0.05). CONCLUSION: Lateral acetabular oedema-like marrow signal is a useful sign (100% PPV) in the MR diagnosis of a labral tear, if one is clinically suspected. The other findings (ganglia, dysplastic femoral bumps, synovial herniation pits and geodes) were not statistically significant. Further studies are required to evaluate these.