Sensitive Detection of Infratentorial and Upper Cervical Cord Lesions in Multiple Sclerosis with Combined 3D FLAIR and T2-Weighted (FLAIR3) Imaging.

BACKGROUND AND PURPOSE: Infratentorial and spinal cord lesions are important for diagnosing and monitoring multiple sclerosis, but they are difficult to detect on conventional MR imaging. We sought to improve the detection of infratentorial and upper cervical cord lesions using composite FLAIR3 images. MATERIALS AND METHODS: 3D T2-weighted FLAIR and 3D T2-weighted images were acquired in 30 patients with MS and combined using the FLAIR3 formula. FLAIR3 was assessed against 3D T2-FLAIR by comparing the number of infratentorial and upper cervical cord lesions per subject using the Wilcoxon signed rank test. Intrarater and interrater reliability was evaluated using the intraclass correlation coefficient. The number of patients with and without ≥1 visible infratentorial/spinal cord lesion on 3D T2-FLAIR versus FLAIR3 was calculated to assess the potential impact on the revised MS diagnostic criteria. RESULTS: Compared with 3D T2-FLAIR, FLAIR3 detected significantly more infratentorial (mean, 4.6 ± 3.6 versus 2.0 ± 1.8, P < .001) and cervical cord (mean, 1.58 ± 0.94 versus 0.46 ± 0.45, P < .001) lesions per subject. FLAIR3 demonstrated significantly improved interrater reliability (intraclass correlation coefficient = 0.77 [95% CI, 0.63-0.87] versus 0.60 [95% CI, 0.40-0.76] with 3D T2-FLAIR, P = .019) and a tendency toward a higher intrarater reliability (0.86 [95% CI, 0.73-0.93] versus 0.79 [95% CI, 0.61-0.89], P = .23). In our cohort, 20%-30% (47%-67%) of the subjects with MS had ≥ 1 infratentorial (cervical cord) lesion visible only on FLAIR3. CONCLUSIONS: FLAIR3 provides higher sensitivity than T2-FLAIR for the detection of MS lesions in infratentorial brain parenchyma and the upper cervical cord.

Indentation and Transverse Diameter of the Meckel Cave: Imaging Markers to Diagnose Idiopathic Intracranial Hypertension.

BACKGROUND AND PURPOSE: Clinical and imaging manifestations of idiopathic intracranial hypertension should prompt early diagnosis and treatment to avoid complications. Multiple diagnostic imaging criteria are reported to suggest the diagnosis of idiopathic intracranial hypertension with questionable sensitivity and/or specificity. Increased intracranial pressure results in dilation of the perineural cisternal spaces such as the optic nerve sheaths and the Meckel cave. It may also cause protrusion of cisternal structures of the Meckel cave through the skull base foramina, which could result in indentation or a bilobed appearance of the Meckel cave. We investigated the changes in the Meckel cave in patients with proved idiopathic intracranial hypertension versus healthy controls. MATERIALS AND METHODS: We studied 75 patients with a diagnosis of idiopathic intracranial hypertension and 75 age-and sex-matched healthy controls. The transverse diameter of Meckel cave was measured in the axial and coronal planes of T2-weighted MR imaging sequences, and comparison was made between the 2 groups. RESULTS: The mean diameters of the Meckel cave on the coronal T2 plane in patients with idiopathic intracranial hypertension were 5.21 ± 1.22 mm on the right side and 5.16 ± 0.90 mm on the left side, while in the control group, they measured 3.89 ± 0.62 mm and 4.09 ± 0.68 mm, respectively (P value < .001). Of 75 patients with an approved diagnosis of idiopathic intracranial hypertension, 57 (76%) showed an indented Meckel cave as opposed to 21 (28%) in the control group. CONCLUSIONS: Our results confirm for the first time that the shape and size of the Meckel cave can be used as sensitive and specific diagnostic imaging markers for the diagnosis of idiopathic intracranial hypertension.

Signos básicos en ecografía pulmonar. Broncograma líquido y broncograma aéreo: Diferenciación / Basic sign in lung echography. Liquid and air bronchogram: Differentiation

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Imágenes del depósito de gadolinio en el sistema nervioso central / Images of gadolinio deposit in the central nervous system Abstract

Magnetic resonance imaging has been shown to be very useful in the diagnosis and monitoring of multiple diseases affecting the central nervous system. Gadolinium has been used extensively worldwide. It has been estimated that since its introduction more than two hundred million doses of GBCA have been administered globally. Gadolinium-based contrast agents (GBCAs) were long considered medicines with a high safety profile, the literature reports incidences of immediate adverse effects such as headache, dizziness, and altered sense of taste. Studies performed a few years after the introduction of GBCA showed that there were gadolinium deposits in the tissues but their clinical significance was not known. It wasn’t until 2006 when the first reports were published that associated the gadolinium ion tissue deposits from GBCA with a systemic inflammatory entity of the connective tissue similar to scleroderma known as Nephrogenic Systemic Fibrosis (NSF), in patients with chronic renal failure. In 2013, the association between the use of GBCAs and the progressive increase in the signal intensity of the dentate nucleus and the globus pallidus in T1-weighted MRI images without contrast medium, was described for the first time. This review describes the most relevant aspects of the pathophysiology of these findings taking into account their differential diagnosis.

Las imágenes por resonancia magnética han mostrado ser de gran utilidad en el diagnóstico y seguimiento de múltiples enfermedades que afectan el sistema nervioso central. El gadolinio se ha utilizado ampliamente a nivel mundial. Se estima que desde su introducción se han administrado más de doscientos millones de dosis de MCBG en el mundo. Los medios de contraste basados en Gadolinio (MCBG) fueron considerados por mucho tiempo medicamentos con un alto perfil de seguridad, la literatura reporta incidencia de efectos adversos inmediatos como cefalea, mareo y alteración del sentido del gusto. Estudios realizados pocos años después de la introducción de los MCBG mostraron que había depósitos de gadolinio en los tejidos, pero no se conocía su significancia clínica Fue hasta 2006 cuando se publicaron los primeros reportes que asociaban el depósito tisular del ion gadolinio proveniente de los MCBG con una entidad inflamatoria sistémica del tejido conectivo similar a la escleroderma conocida como Fibrosis Sistémica Nefrogénica (FSN) en pacientes con falla renal crónica. En 2013 se describió por primera vez la asociación entre el uso de los MCBG y el aumento progresivo de la intensidad de señal del núcleo dentado y los globos pálidos en las imágenes de RM ponderadas en T1 sin medio de contraste. En esta revisión se describen los aspectos más relevantes de la fisiopatología de estos hallazgos considerando su diagnóstico diferencial.

Corneal topography changes after vitreoretinal surgery.

The authors report the results of a prospective study to assess corneal topography changes after vitreoretinal surgery procedures. Computer-assisted videokeratography using a Topographic Modeling System-1 (TMS-1) were prospectively performed before and after vitreoretinal surgery (vitrectomy with or without scleral buckling) in 12 eyes (patients) with varied vitreoretinal pathology, including cytomegalovirus (CMV) retinitis, CMV-related retinal detachment, retinal detachment with and without proliferative vitreoretinopathy, trauma, acute retinal necrosis, and macular hole. Preoperative and postoperative surface regularity index (SRI), surface asymmetry index (SAI), and induced astigmatism were determined. Patients were followed for an average of 6 months (range: 2-15 months). Mean preoperative SRI was 0.52 (0.05-1.06) and postoperative SRI was 0.73 (0.25-1.36). Mean preoperative SAI was 0.43 (0.22-0.93) and postoperative SAI was 0.56 (0.21-0.99). Mean induced astigmatism was 0.7 diopters. Our study suggests that the central corneal optical quality (SRI) and the asymmetricity of the anterior corneal curvature (SAI) deteriorates after vitreoretinal surgery.