ALADA Dose Optimization in the Computed Tomography of the Temporal Bone: The Diagnostic Potential of Different Low-Dose CT Protocols

Objective: Repeated computed tomography (CT) is essential for diagnosis, surgical planning and follow-up in patients with middle and inner ear pathology. Dose reduction to “as low as diagnostically acceptable” (ALADA) is preferable but challenging. We aimed to compare the diagnostic quality of images of subtle temporal bone structures produced with low doses (LD) and reference protocols (RP). Methods: Two formalin-fixed human cadaver heads were scanned using a 64-slice CT scanner and cone-beam CT (CBCT). The protocols were: RP (120 kV, 250 mA, CTDIvol 83.72 mGy), LD1 (100 kV, 80 mA, CTDIvol 26.79 mGy), LD2 (100 kV, 35 mA, CTDIvol 7.66 mGy), LD3 (80 kV, 40 mA, CTDIvol 4.82 mGy), and CBCT standard protocol. Temporal bone structures were assessed using a 5-point scale. Results: A median score of ≥2 was achieved with protocols such as the tendons of m. tensor tympani (RP/LD1/LD2/CBCT) and m. stapedius (CBCT), the incudostapedial joint (RP/LD1/CBCT), the incudomalleolar joint (RP/LD1/LD2/CBCT), the stapes feet (RP/LD1/CBCT), the stapes head (RP/LD1/LD2/CBCT), the tympanic membrane (RP/LD1/LD2/CBCT), the lamina spiralis ossea (none), the chorda tympani (RP/LD1/CBCT), and the modiolus (RP/LD1/LD2/CBCT). Adaptive statistical iterative reconstructions did not show advantages over the filtered back projection. Conclusions: LD protocols using a CTDIvol of 7.66 mGy may be sufficient for the identification of temporal bone structures.

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Association between multimodality measures of aortic stenosis severity and quality-of-life improvement outcomes after transcatheter aortic valve replacement

European Heart Journal - Quality of Care and Clinical Outcomes ◽

10.1093/ehjqcco/qcab017 ◽

2021 ◽

Author(s):

Michael A Catalano ◽

Shahryar G Saba ◽

Bruce Rutkin ◽

Greg Maurer ◽

Jacinda Berg ◽

...

Keyword(s):

Quality Of Life ◽

Computed Tomography ◽

Aortic Valve ◽

Transcatheter Aortic Valve Replacement ◽

Multivariable Analysis ◽

Calcium Score ◽

Post Intervention ◽

Transcatheter Aortic Valve

Abstract Aims Up to 40% of patients with aortic stenosis (AS) present with discordant grading of AS severity based on common transthoracic echocardiography (TTE) measures. Our aim was to evaluate the utility of TTE and multi-detector computed tomography (MDCT) measures in predicting symptomatic improvement in patients with AS undergoing transcatheter aortic valve replacement (TAVR). Methods and results A retrospective review of 201 TAVR patients from January 2017 to November 2018 was performed. Pre- and post-intervention quality-of-life was measured using the Kansas City Cardiomyopathy Questionnaire (KCCQ-12). Pre-intervention measures including dimensionless index (DI), stroke volume index (SVI), mean transaortic gradient, peak transaortic velocity, indexed aortic valve area (AVA), aortic valve calcium score, and AVA based on hybrid MDCT-Doppler calculations were obtained and correlated with change in KCCQ-12 at 30-day follow-up. Among the 201 patients studied, median KCCQ-12 improved from 54.2 pre-intervention to 85.9 post-intervention. In multivariable analysis, patients with a mean gradient >40 mmHg experienced significantly greater improvement in KCCQ-12 at follow-up than those with mean gradient ≤40 mmHg (28.1 vs. 16.4, P = 0.015). Patients with MDCT-Doppler-calculated AVA of ≤1.2 cm2 had greater improvements in KCCQ-12 scores than those with computed tomography-measured AVA of >1.2 cm2 (23.4 vs. 14.1, P = 0.049) on univariate but not multivariable analysis. No association was detected between DI, SVI, peak velocity, calcium score, or AVA index and change in KCCQ-12. Conclusion Mean transaortic gradient is predictive of improvement in quality-of-life after TAVR. This measure of AS severity may warrant greater relative consideration when selecting the appropriateness of patients for TAVR.

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Surgical considerations during cochlear implantation: the utility of temporal bone computed tomography

The Journal of Laryngology & Otology ◽

10.1017/s0022215121000232 ◽

2021 ◽

pp. 1-8

Author(s):

Beomcho Jun ◽

Sunwha Song

Keyword(s):

Computed Tomography ◽

Temporal Bone ◽

Cochlear Implantation ◽

Round Window ◽

Three Dimensional ◽

Electrode Placement ◽

Posterior Tympanotomy ◽

Electrode Insertion ◽

Window Approach ◽

Bone Structures

Abstract Objective This paper describes the construction of portals for electrode placement during cochlear implantation and emphasises the utility of pre-operative temporal bone three-dimensional computed tomography. Methods Temporal bone three-dimensional computed tomography was used to plan portal creation for electrode insertion. Results Pre-operative temporal bone three-dimensional computed tomography can be used to determine the orientation of temporal bone structures, which is important for mastoidectomy, posterior tympanotomy and cochleostomy, and when using the round window approach. Conclusion It is essential to create appropriate portals (from the mastoid cortex to the cochlea) in a step-by-step manner, to ensure the safe insertion of electrodes into the scala tympani. Pre-operative three-dimensional temporal bone computed tomography is invaluable in this respect.

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NEUMATIZACIÓN DEL TUBÉRCULO ARTICULAR Y DISCONTINUIDAD DE LA FOSA MANDIBULAR DEL TEMPORAL: ESTUDIO MEDIANTE TOMOGRAFÍA COMPUTARIZADA

Revista Facultad de Odontología ◽

10.17533/udea.rfo.v31n1-2a3 ◽

2019 ◽

Vol 31 (1-2) ◽

Author(s):

Rosa Ferrer ◽

Adalsa Hernández-Andara ◽

Ana Isabel Ortega Pertuz

Keyword(s):

Computed Tomography ◽

Temporal Bone ◽

Temporomandibular Joints ◽

High Prevalence ◽

Mandibular Fossa ◽

Bone Expansion ◽

Bone Structures ◽

Minimal Resistance ◽

Air Cells ◽

Ct Studies

Introduction: air cells in the articular tubercle and the discontinuity of the cortical mandibular fossa are sites of minimal resistance, favoring the extension of various pathologies, which should be differentiated from similar processes involving bone expansion/destruction. The aim of this study was to assess pneumatized articular tubercle (PAT) and discontinuity of the temporal bone’s mandibular fossa (DMF) through computed tomography (CT), focusing on its distribution by age, sex, and laterality. Methods: 200 CT studies including both temporomandibular joints (TMJ) were selected, recording age, sex, presence/absence of PAT and DMF and their laterality. Results: 19% of patients had some anatomical variants. PAT was seen in 15.5% of cases (n = 31), 21 females (67.74%) and 10 males (32.26%). DMF was seen in seven cases (3.5%), all in females. 51.62% of PAT were bilateral, and 85.71% of DMF were unilateral. Conclusions: the sample under study has a high prevalence of PAT. DMF should be considered in the evaluation of TMJ by CT, with this being the method of choice to assess bone structures and air spaces in temporal bone.

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THE IMPACT OF HEAD POSITIONING ON THE IMAGE QUALITY OF MULTI-DETECTOR COMPUTED TOMOGRAPHY

Biomedical Engineering Applications Basis and Communications ◽

10.4015/s1016237221500502 ◽

2021 ◽

pp. 2150050

Author(s):

Yang-Ting Hsu ◽

Jo-Chi Jao

Keyword(s):

Computed Tomography ◽

Image Quality ◽

Control Group ◽

Ct Scanner ◽

Head Ct ◽

Radiologic Technologists ◽

Head Positioning ◽

The Impact ◽

Multi Detector Computed Tomography

Radiologic technologists face various types of patients during multi-detector computed tomography (CT) examinations. In emergency departments, it is common to have patients who cannot follow instructions for the examinations. The asymmetric axial view of the head CT might affect the correctness of the clinician’s diagnosis. This study aimed to assess the impact of head positioning on the image quality of head CT using two phantoms. All scans were performed on a 16-slice CT scanner. In the control group, the tilted angle of the phantoms was 0[Formula: see text], and no multiplanar reconstruction (MPR) was performed. In the experimental groups, the tilted angles of the phantoms were 5[Formula: see text], 10[Formula: see text] and 15[Formula: see text], respectively, and MPR was performed afterwards. The results showed that if the head was tilted during the head CT examinations, image asymmetry and artifacts appeared without MPR. After MPR, one phantom showed that there were significant differences and the other phantom showed no significant differences quantitatively in image symmetry and artifacts between experimental groups and the control group, while both phantoms showed no significant differences qualitatively in image symmetry and artifacts between experimental groups and the control group. Although MPR can correct the image asymmetry and artifacts caused by tilted head positioning to some extent, it consumes time. Therefore, technologists should position the head as exactly as possible when performing head CT examinations.

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Imaging Techniques

Interventional Radiology ◽

10.1093/med/9780190276249.003.0008 ◽

2018 ◽

pp. 75-88

Author(s):

Daniel C. O’Brien ◽

Junjuian Huang ◽

Scott A. Resnick

Keyword(s):

Computed Tomography ◽

Magnetic Resonance ◽

Magnetic Resonance Angiography ◽

Multidetector Ct ◽

Imaging Techniques ◽

Cone Beam Ct ◽

Digital Subtraction ◽

Interventional Radiologist ◽

Multidetector Ct Angiography

Minimally invasive interventional radiographic procedures rely on many of the same imaging techniques as are used in diagnostic studies. This chapter describes the imaging modalities most commonly utilized by the interventional radiologist intraprocedurally. These include fluoroscopy, digital subtraction angiography (DSA), sonographic techniques for percutaneous interventions and intravascular ultrasound, and computed tomography (CT) and cone beam CT (CBCT). Imaging techniques used adjunctively in the procedure planning and follow-up phases are also briefly reviewed, including multidetector CT angiography, magnetic resonance angiography (MRA), and sonographic vascular evaluation. Specific interventions are mentioned throughout as a means of illustrating the clinical utilities of these imaging techniques, although specific procedural considerations are discussed more thoroughly elsewhere.

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Management of the Temporal Bone Fibrous Dysplasia With External Auditory Canal Stenosis and Secondary Cholesteatoma in an Asian Population: A 11-Case Series

Ear Nose & Throat Journal ◽

10.1177/0145561320927922 ◽

2020 ◽

pp. 014556132092792

Author(s):

Kun Zhang ◽

Peng Qu ◽

Bing Wang ◽

Endong Zhang ◽

Bing Chen

Keyword(s):

Hearing Loss ◽

Fibrous Dysplasia ◽

Temporal Bone ◽

External Auditory Canal ◽

Perioperative Complications ◽

Case Series ◽

Asian Population ◽

Canal Stenosis

Objective: This article summarizes the experience of diagnosis and treatment of temporal bone fibrous dysplasia (FD) with external auditory canal (EAC) stenosis and secondary cholesteatoma in the Chinese population, in order to improve the quality of life of patients in the future. Methods: Eleven patients with FD of the temporal bone who underwent surgery were retrospectively reviewed. Results: All lesions originated from the temporal bone, and all involved of the EAC. There were 11 cases of cholesteatoma in the EAC, 4 cases of cholesteatoma in the middle ear. The most common symptoms were hearing loss (100%), tinnitus (36.4%), and otorrhea (36.4%). Two patients were severe-profound sensorineural hearing loss, and one patient was complicated with subperiosteal abscesses. All 11 patients underwent surgery. There were no perioperative complications in this series and median follow-up time was 4.2 years. Conclusion: Temporal bone FD remains a rare diagnosis, especially in the Asian population. The lesions mainly lead to stenosis of the EAC, especially at the osteochondral junction. Cholesteatoma is the main complication of this disease, which is secondary to occlusion of the EAC with the growth of the lesion. Canaloplasty of EAC combined with wide meatoplasty can provide excellent prognosis in most cases.

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Monostotic fibrous dysplasia of the temporal bone

The Journal of Laryngology & Otology ◽

10.1017/s0022215100145177 ◽

1999 ◽

Vol 113 (8) ◽

pp. 772-774 ◽

Cited By ~ 3

Author(s):

J. Xenellis ◽

A. Bibas ◽

L. Savy ◽

P. Maragoudakis ◽

P. Nomicos

Keyword(s):

Computed Tomography ◽

Fibrous Dysplasia ◽

Temporal Bone ◽

Symptomatic Disease ◽

Normal Bone ◽

Limited Surgery

AbstractFibrous dysplasia is a slowly progressive bony disorder where normal bone is replaced by abnormal fibroosseous tissue. Its monostotic variety in the temporal bone is very rare and such a case is presented here. Computed tomography (CT) may be adequate for the diagnosis and follow-up of these patients. Limited surgery should only be considered in cases of symptomatic disease.

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Visualizing patterns of intervertebral disc damage with dual-energy computed tomography: assessment of diagnostic accuracy in an ex vivo spine biophantom

Acta Radiologica ◽

10.1177/02841851211025863 ◽

2021 ◽

pp. 028418512110258

Author(s):

Julian Pohlan ◽

Carsten Stelbrink ◽

Niklas Tuttle ◽

Felix Kubicka ◽

Ho Jung Kwon ◽

...

Keyword(s):

Computed Tomography ◽

Intervertebral Disc ◽

Diagnostic Accuracy ◽

Ex Vivo ◽

Dual Energy ◽

Detection Accuracy ◽

Single Source ◽

Ct Scanner ◽

Dual Energy Computed Tomography ◽

Diagnostic Potential

Background Previously, dual-energy computed tomography (DECT) has been established for imaging spinal fractures as an alternative modality to magnetic resonance imaging (MRI). Purpose To analyze the diagnostic accuracy of DECT in visualizing intervertebral disc (IVD) damage. Material and Methods The lumbar spine of a Great Dane dog was used as an ex vivo biophantom. DECT was performed as sequential volume technique on a single-source CT scanner. IVDs were imaged before and after an injection of sodium chloride solution and after anterior discectomy in single-source sequential volume DECT technique using 80 and 135 kVp. Chondroitin/Collagen maps (cMaps) were reconstructed at 1 mm and compared with standard CT. Standardized regions of interest (ROI) were placed in the anterior anulus fibrosus, nucleus pulposus, and other sites. Three blinded readers classified all images as intact disc, nucleus lesion, or anulus lesion. Additionally, clinical examples from patients with IVD lesions were retrospectively identified from the radiological database. Results Interrater reliability was almost perfect with a Fleiss kappa of 0.833 (95% confidence interval [CI] 0.83–0.835) for DECT, compared with 0.780 (95% CI 0.778–0.782) for standard CT. For overall detection accuracy of IVD, DECT achieved 91.0% sensitivity (95% CI 83.6–95.8) and 92.0% specificity (95% CI 80.8–97.8). Standard CT showed 91.0% sensitivity (95% CI 83.6–95.8) and 78.0% specificity (95% CI 64.0–88.5). Conclusion DECT reliably identified IVD damage in an ex vivo biophantom. Clinical examples of patients with different lesions illustrate the accurate depiction of IVD microstructure. These data emphasize the diagnostic potential of DECT cMaps.

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Cone-beam CT image quality improvement using Cycle-Deblur consistent adversarial networks (Cycle-Deblur GAN) for chest CT imaging in breast cancer patients

Scientific Reports ◽

10.1038/s41598-020-80803-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hui-Ju Tien ◽

Hsin-Chih Yang ◽

Pei-Wei Shueng ◽

Jyh-Cheng Chen

Keyword(s):

Computed Tomography ◽

Deep Learning ◽

Image Quality ◽

Cone Beam Ct ◽

Cone Beam ◽

Breast Cancer Patients ◽

Image Guided Radiotherapy ◽

Image Quality Improvement ◽

Image Pairs

AbstractCone-beam computed tomography (CBCT) integrated with a linear accelerator is widely used to increase the accuracy of radiotherapy and plays an important role in image-guided radiotherapy (IGRT). For comparison with fan-beam computed tomography (FBCT), the image quality of CBCT is indistinct due to X-ray scattering, noise, and artefacts. We proposed a deep learning model, “Cycle-Deblur GAN”, combined with CycleGAN and Deblur-GAN models to improve the image quality of chest CBCT images. The 8706 CBCT and FBCT image pairs were used for training, and 1150 image pairs were used for testing in deep learning. The generated CBCT images from the Cycle-Deblur GAN model demonstrated closer CT values to FBCT in the lung, breast, mediastinum, and sternum compared to the CycleGAN and RED-CNN models. The quantitative evaluations of MAE, PSNR, and SSIM for CBCT generated from the Cycle-Deblur GAN model demonstrated better results than the CycleGAN and RED-CNN models. The Cycle-Deblur GAN model improved image quality and CT-value accuracy and preserved structural details for chest CBCT images.

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