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Purpose: To compare image quality and radiation exposure between super- and ultra-high-resolution helical and super-high-resolution volumetric CT of the temporal bone. Methods: Six cadaveric temporal bone specimens were used to evaluate key temporal bone structures using the following CT reconstruction and acquisition modes: helical and single-volume acquisition modes in super-high resolution (0.25-mm slice thickness, 10242 matrix), and helical mode in ultra-high resolution (0.25-mm slice thickness, 20482 matrix). Two observers performed 5 previously described preoperative measurements, measured noise and signal-to-noise ratios for air, and noise for bone, and rated the visualization of 5 anatomical structures on a 4-point scale, for each reconstruction mode. Radiation dose exposure was recorded for each examination. Results: There was no significant difference between any of the quantitative or qualitative measurements in any of the reconstruction and acquisition modes. There was a slight increase in noise and a decrease in signal-to-noise ratio in the air using the single-volume mode (115 ± 13.1 HU and 8.37 ± 0.91, respectively) compared to the helicoidal super-high-resolution (92.4 ± 11.8 HU and 10.8 ± 1.26, respectively) and helicoidal ultra-high-resolution (91.1 ± 10.7 HU and 10.9 ± 1.39, respectively) modes (P < .002). The volumic CT dose index was 50.9 mGy with helical acquisition and 29.8 mGy with single-volume acquisition mode (P < .0001). Conclusion: The single-volume super-high-resolution acquisition mode allows a reduction in radiation dose exposure without compromising image quality compared to helical scanning, but with a slightly lower signal-to-noise ratio in air with the single-volume mode, while there was no difference in image quality between the helical super- and ultra-high-resolution modes.
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Cadáver , Dosis de Radiación , Relación Señal-Ruido , Hueso Temporal , Humanos , Hueso Temporal/diagnóstico por imagen , Hueso Temporal/anatomía & histología , Tomografía Computarizada Espiral/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Tomografía Computarizada por Rayos X/métodosRESUMEN
PURPOSE: The purpose of this study was to identify potential association between transverse sinus stenosis (TSS) and temporal bone thinning downstream of TSS on computed tomography (CT). MATERIALS AND METHODS: Clinical and radiological data of patients with venous pulsatile tinnitus due to TSS (TSS group) and treated with stenting from 2019 to 2022 were retrospectively collected. An age-matched control group of patients with venous or neutral pulsatile tinnitus (control group) was built. CT measurements of temporal bone thickness were performed at the level of transverse-sigmoid sinus junction (E1) and the occipitomastoid suture (E2). E1; E2 and E1/E2 ratios obtained in TSS and control groups were compared. RESULTS: A total of 122 patients with venous pulsatile tinnitus were included. There were 56 patients with TSS (TSS group; 56 women; mean age, 35.5 ± 11.3 [standard deviation] years) and 66 patients without TSS (control group; 54 women; mean age, 37.7 ± 10.5 [standard deviation] years). E1 measurements and E1/E2 ratios on the symptomatic and dominant sides were significantly lower in the TSS group by comparison with the contralateral side of the same group (P < 0.05) and the ipsilateral side of the control group (P < 0.05). There were no differences in median E2 values between the TSS group (6.8 mm; range: 3.5-10.8 mm) and the control group (7.1 mm; range: 2.9-11.2 mm) (P = 0.098). E1 = 0 mm was found only in the TSS group. At receiver operating characteristic (ROC) analysis, an E1/E2 ratio threshold of 0.562 maximized the ability to predict presence of TSS. An E1/E2 ratio < 0.562 was predictive of symptomatic TSS with an accuracy of 74% (95% confidence interval: 65-82%). The AUC for the diagnosis of TSS was 0.807 (95% CI: 0.729-0.885). CONCLUSION: Temporal bone thickness is significantly reduced downstream of the stenosis on the pulsatile tinnitus side and may be a good indicator of symptomatic TSS.
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PURPOSE: The purpose of this study was to evaluate the achievable radiation dose reduction of an ultra-high resolution computed tomography (UHR-CT) scanner using deep learning reconstruction (DLR) while maintaining temporal bone image quality equal to or better than high-resolution CT (HR-CT). MATERIALS AND METHODS: UHR-CT acquisitions were performed with variable tube voltages and currents at eight different dose levels (volumic CT dose index [CTDIvol] range: 4.6-79 mGy), 10242 matrix, and 0.25 mm slice thickness and reconstructed using DLR and hybrid iterative reconstruction (HIR) algorithms. HR-CT images were acquired using a standard protocol (120 kV/220 mAs; CTDI vol, 54.2 mGy, 5122 matrix, and 0.5 mm slice thickness). Two radiologists rated the image quality of seven structures using a five point confidence scale on six cadaveric temporal bone CTs. A global image quality score was obtained for each CT protocol by summing the image quality scores of all structures. RESULTS: With DLR, UHR-CT at 120 kV/220 mAs (CTDIvol, 50.9 mGy) and 140 kV/220 mAs (CTDIvol, 79 mGy) received the highest global image quality scores (4.88 ± 0.32 [standard deviation (SD)] [range: 4-5] and 4.85 ± 0.35 [range: 4-5], respectively; P = 0.31), while HR-CT at 120 kV/220 mAs and UHR-CT at 120 kV/20 mAs received the lowest (i.e., 3.14 ± 0.75 [SD] [range: 2-5] and 2.97 ± 0.86 [SD] [range: 1-5], respectively; P = 0.14). All the DLR protocols had better image quality scores than HR-CT with HIR. CONCLUSION: UHR-CT with DLR can be performed with up to a tenfold reduction in radiation dose compared to HR-CT with HIR while maintaining or improving image quality.
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BACKGROUND, AIMS: Stapes footplate thickness measurement using ultra-high-resolution CT has been described only in the lateral semicircular canal plane. The purpose of this study was to compare stapes footplate thickness between the lateral semicircular canal and stapes axial planes in patients with otosclerosis compared to controls. MATERIAL AND METHODS: We performed a retrospective single-center study of patients undergoing high-resolution temporal bone CT. Two radiologists measured stapes footplate thickness in both the lateral semicircular canal and stapes axial planes. RESULTS: Between February 2020 and October 2022, we collected 81 ears from 49 patients (75% of women; mean age 51.22 ± 16.6 years, 17 otosclerosis, and 64 controls). In the stapes axial plane, there was a significant anterior thickening in otosclerosis patients (Reader 1: 0.52 ± 0.12 [0.3-0.7] vs. 0.41 ± 0.08 [0.3-0.6], p = 0.001; Reader 2: 0.54 ± 0.06 [0.5-0.7] vs. 0.39 ± 0.08 [0.2-0.6], P < 0.001) compared to controls. These differences were not significant using the lateral semicircular canal plane. CONCLUSION: The stapes footplate was thickened at its AC in otosclerosis patients using only the stapes axial plane. SIGNIFICANCE: We propose to use the stapes axial plane instead of the lateral semicircular canal plane when analyzing the stapes.
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Otosclerosis , Canales Semicirculares , Estribo , Tomografía Computarizada por Rayos X , Humanos , Otosclerosis/diagnóstico por imagen , Femenino , Persona de Mediana Edad , Masculino , Estudios Retrospectivos , Canales Semicirculares/diagnóstico por imagen , Canales Semicirculares/patología , Estribo/diagnóstico por imagen , Estribo/patología , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Hueso Temporal/diagnóstico por imagen , Estudios de Casos y ControlesRESUMEN
PURPOSE: To describe the reliability of ultra-high-resolution computed tomography (UHR-CT) in the measurement of titanium stapes prostheses using manufacturer data as a reference. MATERIALS AND METHODS: This retrospective study included patients treated by stapedectomy with titanium prostheses who underwent UHR-CT between January 2020 and October 2023. Images were acquired using an ultra-high-resolution mode (slice thickness: 0.25 mm; matrix, 1024 × 1024). Two radiologists independently evaluated the length, diameter, and intra-vestibular protrusion of the prosthesis. Post-operative air-bone gaps (ABGs) were recorded. RESULTS: Fourteen patients were enrolled (mean age, 44.3 ± 13.8 [SD] years, 9 females), resulting in 16 temporal bone UHR-CTs. The exact length was obtained in 81.3 % (n = 13/16) and underestimated by 0.1 to 0.3 mm in the remaining 18.7 % (n = 3/16) CT scans for both readers (mean misestimation: -0.02 ± 0.06 [SD] mm, overall underestimation of 0.43 %). The exact diameter was reported in 75 % (n = 12/16) and 87.5 % (n = 14/16) of the CT scans for readers 1 and 2, respectively, and was off by 0.1 mm in all discrepancies (mean misestimation: 0.01 ± 0.04 [SD] mm, overall overestimation of 2.43 %). Intravestibular prosthesis protrusion was of 0.5 ± 0.43 [SD] mm (range: 0-1) and 0.49 ± 0.44 [SD] mm (range: 0-1.1) for readers 1 and 2, respectively, and did not correlate with ABGs (r = 0.25 and 0.22; P = 0.39 and 0.47 for readers 1 and 2, respectively). Intra and interobserver agreements were excellent. CONCLUSION: UHR-CT provides 99.6 % and 97.6 % accuracy for prosthesis length and diameter measurements, respectively.
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Hueso Temporal , Tomografía Computarizada por Rayos X , Humanos , Femenino , Masculino , Adulto , Hueso Temporal/diagnóstico por imagen , Estudios Retrospectivos , Tomografía Computarizada por Rayos X/métodos , Reproducibilidad de los Resultados , Prótesis Osicular , Cirugía del Estribo , Persona de Mediana Edad , Titanio , Diseño de PrótesisRESUMEN
PURPOSE: The purpose of this study was to evaluate the ability of ultra-high-resolution computed tomography (UHR-CT) to assess stapes and chorda tympani nerve anatomy using a deep learning (DLR), a model-based, and a hybrid iterative reconstruction algorithm compared to simulated conventional CT. MATERIALS AND METHODS: CT acquisitions were performed with a Mercury 4.0 phantom. Images were acquired with a 1024 × 1024 matrix and a 0.25 mm slice thickness and reconstructed using DLR, model-based, and hybrid iterative reconstruction algorithms. To simulate conventional CT, images were also reconstructed with a 512 × 512 matrix and a 0.5 mm slice thickness. Spatial resolution, noise power spectrum, and objective high-contrast detectability were compared. Three radiologists evaluated the clinical acceptability of these algorithms by assessing the thickness and image quality of the stapes footplate and superstructure elements, as well as the image quality of the chorda tympani nerve bony and tympanic segments using a 5-point confidence scale on 13 temporal bone CT examinations reconstructed with the four algorithms. RESULTS: UHR-CT provided higher spatial resolution than simulated conventional CT at the penalty of higher noise. DLR and model-based iterative reconstruction provided better noise reduction than hybrid iterative reconstruction, and DLR had the highest detectability index, regardless of the dose level. All stapedial structure thicknesses were thinner using UHR-CT by comparison with conventional simulated CT (P < 0.009). DLR showed the best visualization scores compared to the other reconstruction algorithms (P < 0.032). CONCLUSION: UHR-CT with DLR results in less noise than UHR-CT with hybrid iterative reconstruction and significantly improves stapes and tympanic chorda tympani nerve depiction compared to simulated conventional CT and UHR-CT with iterative reconstruction.
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Aprendizaje Profundo , Fantasmas de Imagen , Hueso Temporal , Tomografía Computarizada por Rayos X , Hueso Temporal/diagnóstico por imagen , Humanos , Tomografía Computarizada por Rayos X/métodos , Estribo/diagnóstico por imagen , Nervio de la Cuerda del Tímpano/diagnóstico por imagen , Algoritmos , Procesamiento de Imagen Asistido por Computador/métodosRESUMEN
OBJECTIVES: Consequences of COVID-19 on olfactory functions remained unclear during the pandemic. We assessed the efficacy of local budesonide in addition to olfactory rehabilitation when managing non-severe COVID-19 patients with persistent hyposmia. METHODS: A multicentric, randomized, superiority trial was conducted (ClinicalTrials.gov NCT04361474). The experimental group (EG) received budesonide and physiological saline nasal irrigations administered via three syringes of 20 ml in each nasal cavity in the morning and evening for 30 days. The control group (CG) received a similar protocol without budesonide. Patients were included if they were >18 years old, with a SARS-CoV-2 infection and presenting an isolated hyposmia persisting 30 days after symptom onset. The primary endpoint was the percentage of patients with improvement of more than two points on the ODORATEST score after 30 days of treatment. RESULTS: In total, 123 patients were included and randomized (EG: 62 vs CG: 61). Two patients from the EG met the primary endpoint with no statistical difference between the two groups (P = 0.5). CONCLUSION: To our knowledge, this is the first study evaluating local budesonide for COVID-19 related hyposmia treatment even though previous trials were performed with other local corticosteroids. Local budesonide efficacy was not demonstrated for persistent hyposmia related to COVID-19.
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Budesonida , COVID-19 , Humanos , Adolescente , Budesonida/uso terapéutico , COVID-19/complicaciones , SARS-CoV-2 , Anosmia/tratamiento farmacológico , Anosmia/etiología , Corticoesteroides , Resultado del TratamientoRESUMEN
Inflammatory labyrinthitis is defined as a fluctuant vestibulo-cochlear syndrome associated with an impairment of the blood-labyrinthine barrier (BLB) on delayed FLAIR MRI sequences. Systemic and intratympanic corticosteroids are the gold standard treatment but their effect is frequently insufficient. The objective is here to determine whether infliximab could be of value in the treatment of bilateral inflammatory labyrinthitis. A retrospective monocentric study was conducted between January 2013 and December 2021. All patients included in the study were affected with a bilateral vestibulo-cochlear syndrome associated with bilateral blood-labyrinthine barrier impairment. Patients were administered infliximab at the dose of 5 mg/kg every 6 weeks for 6 months. Audiometry, MRI with delayed FLAIR sequences on the labyrinth, and corticosteroid doses still required were assessed both before and after treatment with infliximab was completed. Pure-tone average (PTA) was the primary outcome. The secondary outcomes were the speech recognition threshold (SRT), the Dizziness Handicap Inventory (DHI) score, and the corticosteroid (CS) dose. A total of nine patients including five men and four women were enrolled in the study. Thirteen ears were analyzed. After a 6-month period of treatment, the mean PTA (54 ± 24 db versus 66 ± 22 db; p = 0.027), SRT (54 ± 37 db versus 66 ± 32 db; p = 0.041) and DHI score (27 ± 15 versus 9 ± 2; p = 0.032) significantly improved. After the 6-month treatment period, the mean CS dose decreased from 38 ± 33 to 6 ± 5 mg/day (p = 0.003). We conclude that infliximab substantially improves the vestibulo-cochlear function in patients with bilateral inflammatory labyrinthitis and could be of value in corticosteroid-dependent cases.
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BACKGROUND: The surgical treatment of otosclerosis consists of the replacement of the stapes using a piston. AIMS/OBJECTIVES: The objective of this study is to assess the audiometric results and quality of life (QOL) of patients who underwent surgery for otosclerosis by stapedectomy with fascia interposition (STIP) or by stapedotomy using CO2 laser (SLaser) without fascia interposition. MATERIAL AND METHODS: Ninety-one patients operated on for otosclerosis by STIP (40 patients) and by SLaser (51 patients) were included. Audiometric results were graphically displayed using the Amsterdam Hearing Evaluation Plot and were compared to the Common Otology Database (COD) comprising 660 patients. The patients' QOL was assessed with an otological validated survey. The significance level was p < .05. RESULTS: There was no significant difference in hearing improvement between SLaser and STIP-operated patients. There was no significant difference between our results and that of COD. QOL was significantly improved (+3.5/10) postoperatively for both STIP and SLaser in both social and professional fields. CONCLUSIONS AND SIGNIFICANCE: By comparing QOL and hearing gain of STIP and SLaser, our results suggest that both surgical techniques are a safe and successful treatment for otosclerotic stapes fixation. Further studies aiming at comparing larger series may confirm and refine these results.
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Audiometría , Láseres de Gas , Otosclerosis , Cirugía del Estribo , Humanos , Dióxido de Carbono/uso terapéutico , Láseres de Gas/uso terapéutico , Prótesis Osicular , Otosclerosis/complicaciones , Otosclerosis/diagnóstico , Otosclerosis/cirugía , Calidad de Vida , Estudios Retrospectivos , Cirugía del Estribo/métodos , Resultado del Tratamiento , Audiometría/métodos , Pérdida Auditiva/diagnóstico , Pérdida Auditiva/etiología , Pérdida Auditiva/cirugíaAsunto(s)
Síndrome Branquio Oto Renal , Oído Interno , Oído Interno/diagnóstico por imagen , Humanos , Riñón , LinajeRESUMEN
OBJECTIVES: The aim of this study was to shorten the 4-h delay between the intravenous administration of gadolinium and MRI acquisition for hydrops evaluation using an optimized 3D-FLAIR sequence in patients with Menière's disease. METHODS: This was a single-center prospective study including 29 patients (58 ears), recruited between November 2020 and February 2021. All patients underwent a 3-T MRI with an optimized 3D-FLAIR sequence without contrast then at 1 h, 2 h, and 4 h after intravenous administration of gadobutrol. The signal intensity ratio was quantitatively assessed with the region of interest method. We also evaluated the volume of endolymphatic structures (saccule, utricle) then the presence of endolymphatic hydrops and blood-labyrinthine barrier impairment at each acquisition time. RESULTS: For all ears, the signal intensity ratio was significantly non-inferior at 2 h compared to 4 h, with a mean geometric signal intensity ratio at 0.83 (95% CI: 0.76 to 0.90, one-sided p < .001 for non-inferiority at -30% margin). Mean volume equivalence of saccule and utricle between 2 and 4 h was proven at a ± 0.20 standardized deviation equivalence margin. Intra-rater agreements (Cohen's kappa) were all greater than 0.90 for all endolymphatic hydrops location and blood-labyrinthine-barrier impairment between the 2- and 4-h assessments. CONCLUSIONS: We demonstrated that using an optimized 3D-FLAIR sequence we could shorten the acquisition from 4 to 2 h with a high reliability for the diagnosis of endolymphatic hydrops and blood-labyrinthine-barrier impairment. CLINICAL TRIAL REGISTRATION: Clinical trial no: 38RC15.173 KEY POINTS: ⢠Magnetic resonance imaging with delayed 3D-FLAIR sequences allows the diagnosis of endolymphatic hydrops in patients with definite Menière's disease. ⢠An optimized 3D-FLAIR sequence with a long TR of 16000 ms and a constant flip angle allows for reducing the delay between intravenous injection of gadobutrol and MRI acquisition from 4 to 2 h to diagnose endolymphatic hydrops. ⢠Reducing this delay between intravenous injection and MRI acquisition could have implications for clinical practice for both patients and imaging departments.
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Hidropesía Endolinfática , Enfermedad de Meniere , Administración Intravenosa , Medios de Contraste , Hidropesía Endolinfática/diagnóstico , Gadolinio , Humanos , Imagenología Tridimensional , Imagen por Resonancia Magnética/métodos , Enfermedad de Meniere/diagnóstico por imagen , Compuestos Organometálicos , Estudios Prospectivos , Reproducibilidad de los ResultadosRESUMEN
PURPOSE: Endovascular treatment (EVT) has become a major option in management of infectious intracranial aneurysms (IIAs) complicating infective endocarditis. We report a retrospective, single-center series of consecutive patients with IIAs treated by EVT. METHODS: Patients were included from January 2009 to July 2020. IIAs were diagnosed on DSA. Each patient underwent a neurological assessment before and after EVT and was followed up by imaging within 15 days of EVT. Safety was assessed on the evolution of NIHSS score. A minor stroke was defined as a worsening of NIHSS < 4 points. Efficacy was defined as the absence of hemorrhagic event during cardiac surgery and the exclusion of the IIA on control imaging. RESULTS: Sixty-two IIAs (30 ruptured) were diagnosed in 31 patients. Fifty-six IIAs were diagnosed on the first DSA and 6 on the early control exploration. EVT was achieved in 55 IIAs by parent artery occlusion with glue in 52 distal IIAs and coils in 3 proximal IIAs. IIAs were located in 90.9% of cases on a fourth-division branch of a cerebral artery. The neurological examination remained unchanged in 29 patients (93.5%), and 2 patients suffered minor stroke. EVT was performed before cardiac surgery in 20/22 patients. All treated IIAs were excluded on follow-up imaging. No hemorrhage was observed during cardiac surgery or in the aftermath. Seven (11.3%) unruptured IIAs were not embolized. CONCLUSION: EVT of IIAs by occlusion of the parent artery is effective in preventing rupture and carries no significant neurological risk.
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Aneurisma Infectado , Aneurisma Roto , Embolización Terapéutica , Endocarditis , Procedimientos Endovasculares , Aneurisma Intracraneal , Aneurisma Infectado/diagnóstico por imagen , Aneurisma Infectado/cirugía , Aneurisma Roto/complicaciones , Aneurisma Roto/diagnóstico por imagen , Aneurisma Roto/cirugía , Endocarditis/complicaciones , Endocarditis/diagnóstico por imagen , Humanos , Aneurisma Intracraneal/complicaciones , Aneurisma Intracraneal/diagnóstico por imagen , Aneurisma Intracraneal/cirugía , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
PURPOSE: The purpose of this study was to describe the MRI characteristics of intralabyrinthine schwannoma (ILS) on post contrast three-dimensional (3D) fluid-attenuation-inversion-recovery (FLAIR) images obtained four hours after intravenous administration of a gadolinium-based contrast agent (4h-3D-FLAIR). MATERIALS AND METHODS: This IRB-approved retrospective multi-center study included patients presenting with typical ILS from January 2016 to October 2020. All medical charts were systematically collected. All MRI examinations, including 4h-3D-FLAIR images, were reviewed by two board-certified neuroradiologists. Main outcome measures were location, signal intensity and associated anomalies of ILS. RESULTS: Twenty-seven out of 8730 patients (0.31%) referred for the investigation of a cochleovestibular disorder had a final diagnosis of ILS. There were 13 men and 14 women with a mean age of 52 ± 17 (SD) years (age range: 20-86 years). The most common clinical presentation was unilateral progressive sensorineural hearing loss (16/27; 59%). All ILS were unilateral and 15 (15/27; 55%) were intracochlear. All ILS presented as a hypointense filling defect within the labyrinth on T2-weighted images that enhanced on post-contrast T1-weighted images. On 4h-3D-FLAIR images, all ILS presented as a hypointense filling defect, associated with diffuse perilymphatic hyperintensity. Two patients (2/27; 7%) presented with ipsilateral endolymphatic hydrops. CONCLUSION: ILS displays consistent features on post-contrast 4h-3D-FLAIR images. ILS should not be confused with endolymphatic hydrops and requires a systematic analysis of the corresponding T2-weighted images.
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Hidropesía Endolinfática , Neurilemoma , Adulto , Anciano , Anciano de 80 o más Años , Medios de Contraste , Femenino , Humanos , Imagenología Tridimensional/métodos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Neurilemoma/diagnóstico por imagen , Estudios Retrospectivos , Adulto JovenRESUMEN
PURPOSE: The purpose of this study was to compare the degree of perilymphatic enhancement between 4 hour post-contrast constant flip angle three-dimensional fluid attenuated inversion recovery (3D-FLAIR) images obtained with short repetition time (TR) and those obtained with long TR. MATERIALS AND METHODS: This single-center, prospective study included patients who underwent MRI of the inner ear with heavily T2-weighted sequence, 3D-FLAIR sequence with a "short" TR of 10,000 ms (s3D-FLAIR) and with a "long" TR of 16,000 ms (l3D-FLAIR). Signal intensity ratio (SIR) and contrast-to-noise ratio (CNR) obtained with s3D-FLAIR and l3D-FLAIR were quantitatively assessed using region of interest (ROI) method and compared. The morphology of the endolymphatic space on both sequences was also evaluated. RESULTS: From March 2020 to July 2020, 20 consecutive patients were enrolled (9 women and 11 men; mean age, 52.1 ± 14.5 [SD] years; age range: 29-75 years). On l3D-FLAIR images, mean SIR (21.1 ± 8.8 [SD]; range: 7.6-46.1) was significantly greater than that on s3D-FLAIR images (15.7 ± 6.7 [SD]; range: 5.9-33.4) (P < 0.01). On l3D-FLAIR images, mean CNR (17 ± 8.5 [SD]; range: 2-40) was significantly greater than that on s3D-FLAIR images (12 ± 6.3 [SD]; range: 3.2-29.8) (P < 0.01). Kappa value for inter-rater agreement for endolymphatic hydrops, vestibular atelectasis and perilymphatic fistula were 0.93 (95% CI: 0.74-1), 1 (95% CI: 0.85-1) and 1 (95% CI: 0.85-1) respectively. CONCLUSION: This study demonstrates that the sensitivity of 3D-FLAIR sequences to low concentration gadolinium in the perilymphatic space is improved by elongation of the TR, with SIR and CNR increased by +34.4% and +41.3% respectively.
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Oído Interno , Gadolinio DTPA , Adulto , Anciano , Medios de Contraste , Oído Interno/diagnóstico por imagen , Femenino , Humanos , Imagenología Tridimensional , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
PURPOSE: The purpose of this study was to prospectively evaluate image quality of three-dimensional fluid attenuated inversion recovery (3D-FLAIR) sequence acquired with a high acceleration factor and reconstructed with iterative denoising (ID) for brain magnetic resonance imaging (MRI) at 3-T. MATERIAL AND METHODS: Patients with brain tumor who underwent brain MRI were consecutively included. Two 3D-FLAIR sequences were successively performed for each patient. A first conventional FLAIR acquisition (conv-FLAIR) was performed with an acceleration factor of 6. The second acquisition was performed with an increased acceleration factor of 9. Two series one without ID (acc-FLAIR) and one with ID (acc-FLAIR-ID) were reconstructed. Two neuroradiologists independently assessed image quality, deep brain nuclei visualization and white matter/gray matter (WM/GM) differentiation on a 4-point scale. RESULTS: Thirty patients with brain tumor were consecutively included in this study. There were 16 women and 14 men with a mean age of 54 ± 17 (SD) years (range: 22-78 years). Scanning time of Acc-FLAIR-ID and Acc-FLAIR (4 min 40 sec) was 37% shorter than that of conv-FLAIR (2 min 50 sec) (P < 0.01). Improved image quality score was significantly different for both conv-FLAIR and acc-FLAIR-ID compared to acc-FLAIR (P < 0.01 for both). WM/GM differentiation score of conv-FLAIR was not significantly different compared to acc-FLAIR-ID (P = 0.10). Improved WM/GM differentiation score was different for both sequences compared to acc-FLAIR (P = 0.017 and P < 0.001). Deep brain nuclei visualization score was not different between conv-FLAIR and acc-FLAIR-ID (P = 0.71). However, the improved deep brain nuclei visualization score was significantly different for both sequences compared to acc-FLAIR (P < 0.001 for both). CONCLUSION: Scanning time of 3D-FLAIR sequence using a high acceleration factor reconstructed with ID algorithm can be reduced by 37% while preserving image quality for brain MRI.
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Encéfalo , Imagen por Resonancia Magnética , Adulto , Anciano , Algoritmos , Encéfalo/diagnóstico por imagen , Femenino , Humanos , Imagenología Tridimensional , Masculino , Persona de Mediana EdadRESUMEN
PURPOSE: The aim of this study was to assess the rate of endolymphatic hydrops (EH) on MRI and the rate of otolithic dysfunction with cVEMP and oVEMP, in patients with recurrent vertigo such as Menière's disease (MD), vestibular migraine (VM) and vestibular Menière's disease (vMD). METHODS: In this retrospective study, we performed 3D-FLAIR sequences with delayed acquisition in 20 MD, 20 VM and 20 vMD patients. Each subject was then assessed for the presence of EH on MRI. All patients underwent pure-tone audiometry, cVEMP and oVEMP. RESULTS: In MD patients, EH was observed in 18 (90%) out of 20 patients while EH was observed in only 1 MV (5%) and 1 vMD (5%) patients. We found significant differences between groups for the presence of EH on MRI (p = 0.001). MD patients had significant higher PTA level (p < 0.001) and oVEMP impairment than MV and vMD (p = 0.08 and p = 0.06, respectively). However, no significant differences were observed for cVEMP impairment, either asymmetric ratio (p = 0.36) and 1000/500 ratio (p = 0.20). CONCLUSIONS: Concerning cVEMP, we observed no significant differences between VM, vMD and MD. However, we observed higher oVEMP impairment, PTA level and EH on MRI in MD patients. We believe that MRI could be used to differentiate MD from VM patients with cochlear symptoms. However, in cases of migraine associated with recurrent vertigo and without cochlear symptoms, we believe that MRI is not a useful tool to differentiate between VM and vMD.
Asunto(s)
Oído Interno , Hidropesía Endolinfática , Enfermedad de Meniere , Trastornos Migrañosos , Potenciales Vestibulares Miogénicos Evocados , Neuronitis Vestibular , Hidropesía Endolinfática/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética , Enfermedad de Meniere/diagnóstico por imagen , Trastornos Migrañosos/diagnóstico por imagen , Estudios Retrospectivos , Vértigo/diagnóstico , Vértigo/etiologíaRESUMEN
OBJECTIVE: Part of the recent progress in the labyrinth imaging has been made possible by the rise of contrast-free T2-weighted and delayed (1h) FLAIR sequences. The aim of this article is to review evidence for the use of these two sequences to image the inner ear, especially the posterior membranous labyrinth. MATERIAL AND METHODS: We analyzed MRI-based papers (2007-2020)using high-resolution T2-weighted or contrast-enhanced FLAIR (1h) sequences to image the inner ear. RESULTS: T2-weighted sequences (3T MRI)enabled the visualization of the posterior membranous labyrinth with good correlation when compared to corresponding histological slices.Significant progress has been made, especially in terms of scanning time, aiming at reducing it, in order to decrease motions artifacts. The saccule is visible on a 3T MRI without significant motion artifacts. Its shape is ovoid, with a maximum height and width of 1.6 and 1.4âmm, respectively. An enlarged saccule was observed in 84%of patients with unilateral Meniere's disease, in 28%of patients with vestibular schwannomas (VS) and 47%of patients with intralabyrinthine schwannomas. VS obstructing the internal auditory canal caused a decrease of the perilymphatic signal (more moderate decrease in meningiomas) on T2 gradient-echo images. Contrast-enhanced FLAIR sequences are useful to image vestibular/facial neuritis and inflammatory inner ear diseases. CONCLUSION: Precise analysis of the posterior membranous labyrinth, in terms of size, shape and signal intensity, is possible on a 3T MRI using high-resolution gradient-echo T2-weighted sequences. Such sequences are an interesting add-on to delayed (4h30) FLAIR-based protocols for labyrinth imaging.