Improvement of the Diagnostic Performance of Facial Neuritis Using Contrast-Enhanced 3D T1 Black-Blood Imaging: Comparison with Contrast-Enhanced 3D T1-Spoiled Gradient-Echo Imaging

This study aims to investigate the diagnostic ability of the contrast-enhanced 3D T1 black-blood fast spin-echo (T1 BB-FSE) sequence compared with the contrast-enhanced 3D T1-spoiled gradient-echo (CE-GRE) sequence in patients with facial neuritis. Forty-five patients with facial neuritis who underwent temporal bone MR imaging, including T1 BB-FSE and CE-GRE imaging, were examined. Two reviewers independently assessed the T1 BB-FSE and CE-GRE images in terms of diagnostic performance, and qualitative (diagnostic confidence and visual asymmetric enhancement) and quantitative analysis (contrast-enhancing lesion extent of the canalicular segment of the affected facial nerve (LEC) and the affected side-to-normal signal intensity ratio (rSI)). The AUCs of each reviewer, and the sensitivity and accuracy of T1 BB-FSE were significantly superior to those of CE-GRE (p < 0.05). Regarding diagnostic confidence and visual asymmetric enhancement, T1 BB-FSE tended to be rated greater than CE-GRE (p < 0.05). Additionally, in quantitative analysis, LEC and rSI of the canalicular segment on T1 BB-FSE were larger than those on CE-GRE (p < 0.05). The T1 BB-FSE sequence was significantly superior to the CE-GRE sequence, with more conspicuous lesion visualization in terms of both qualitative and quantitative aspects in patients with facial neuritis.

CT-like images based on T1 spoiled gradient-echo and ultra-short echo time MRI sequences for the assessment of vertebral fractures and degenerative bone changes of the spine

Objectives To evaluate the performance of 3D T1w spoiled gradient-echo (T1SGRE) and ultra-short echo time (UTE) MRI sequences for the detection and assessment of vertebral fractures and degenerative bone changes compared with conventional CT. Methods Fractures (n = 44) and degenerative changes (n = 60 spinal segments) were evaluated in 30 patients (65 ± 14 years, 18 women) on CT and 3-T MRI, including CT-like images derived from T1SGRE and UTE. Two radiologists evaluated morphological features on both modalities: Genant and AO/Magerl classifications, anterior/posterior vertebral height, fracture age; disc height, neuroforaminal diameter, grades of spondylolisthesis, osteophytes, sclerosis, and facet joint degeneration. Diagnostic accuracy and agreement between MRI and CT and between radiologists were assessed using crosstabs, weighted κ, and intraclass correlation coefficients. Image quality was graded on a Likert scale. Results For fracture detection, sensitivity, specificity, and accuracy were 0.95, 0.98, and 0.97 for T1SGRE and 0.91, 0.96, and 0.95 for UTE. Agreement between T1SGRE and CT was substantial to excellent (e.g., Genant: κ, 0.92 [95% confidence interval, 0.83–1.00]; AO/Magerl: κ, 0.90 [0.76–1.00]; osteophytes: κ, 0.91 [0.82–1.00]; sclerosis: κ, 0.68 [0.48–0.88]; spondylolisthesis: ICCs, 0.99 [0.99–1.00]). Agreement between UTE and CT was lower, ranging from moderate (e.g., sclerosis: κ, 0.43 [0.26–0.60]) to excellent (spondylolisthesis: ICC, 0.99 [0.99–1.00]). Inter-reader agreement was substantial to excellent (0.52–1.00), respectively, for all parameters. Median image quality of T1SGRE was rated significantly higher than that of UTE (p < 0.001). Conclusions Morphologic assessment of bone pathologies of the spine using MRI was feasible and comparable to CT, with T1SGRE being more robust than UTE. Key Points • Vertebral fractures and degenerative bone changes can be assessed on CT-like MR images, with 3D T1w spoiled gradient-echo–based images showing a high diagnostic accuracy and agreement with CT. • This could enable MRI to precisely assess bone morphology, and 3D T1SGRE MRI sequences may substitute additional spinal CT examinations in the future. • Image quality and robustness of T1SGRE sequences are higher than those of UTE MRI for the assessment of bone structures.

Volumetría hipocampal: análisis comparativo de los métodos de evaluación en enfermedad de Alzheimer

Objetivo La atrofia hipocampal es uno de los biomarcadores radiológicos más sensibles de la enfermedad de Alzheimer (EA) y existen diferentes métodos para evaluarla: análisis subjetivo visual (ASV), análisis objetivo manual (AOM) y análisis objetivo automático (AOA). Nos proponemos comparar esos métodos, y evaluar si el AOA presenta una confiabilidad cercana al AOM (método de referencia) y superior al ASV. Materiales y Métodos Se seleccionaron retrospectivamente imágenes de resonancia magnética (RM) fast spoiled gradient-echo (FSPGR) de 28 sujetos (14 con deterioro cognitivo leve, 7 con EA y 7 controles). El ASV fue realizado por 10 radiólogos, clasificando la atrofia hipocampal en: nula, leve, moderada o severa. El AOM se basó en la segmentación manual de los hipocampos por dos operadores. El AOA fue realizada por medio del software FreeSurfer 5.3. Se calcularon coeficientes de correlación rho de Spearman para las variables discretas y coeficientes de correlación intraclase para las variables continuas. Resultados Los coeficientes de correlación entre los dos operadores que realizaron el AOM fueron de 0,88 (p < 0,0001) para los hipocampos izquierdos y de 0,86 (p < 0,0001) para los hipocampos derechos. El coeficiente de correlación entre todos los ASV (promediados) y AOM fue de -0,81 (IC 95% -0,96- -0,66). Los coeficientes de correlación entre el AOA y el AOM fue de 0,54 (p < 0,0001) para los hipocampos izquierdos y de 0,61 (p < 0,0001) para los hipocampos derechos. Conclusión Si bien el AOA tiene moderada correlación con el método de referencia, no es superior al ASV promedio y se deberían tomar recaudos antes de ser implementado en la práctica asistencial.