Isolated Congenital Middle Ear Malformations: Comparison of Preoperative 0.1-mm Ultra-High-Resolution CT and Conventional High-Resolution CT.

ObjectivesThis study was conducted in order to compare the effect of field of view (FOV) size on image quality between ultra-high-resolution CT (U-HRCT) and conventional high-resolution CT (HRCT).MethodsEleven cadaveric lungs were scanned with U-HRCT and conventional HRCT and reconstructed with five FOVs (40, 80, 160, 240, and 320 mm). Three radiologists evaluated and scored the images. Three image evaluations were performed, comparing the image quality with the five FOVs with respect to the 160-mm FOV. The first evaluation was performed on conventional HRCT images, and the second evaluation on U-HRCT images. Images were scored on normal structure, abnormal findings, and overall image quality. The third evaluation was a comparison of the images obtained with conventional HRCT and U-HRCT, with scoring performed on overall image quality. Quantitative evaluation of noise was performed by setting ROIs.ResultsIn conventional HRCT, image quality was improved when the FOV was reduced to 160 mm. In U-HRCT, image quality, except for noise, improved when the FOV was reduced to 80 mm. In the third evaluation, overall image quality was improved in U-HRCT over conventional HRCT at all FOVs. Noise of U-HRCT increased with respect to conventional HRCT when the FOV was reduced from 160 to 40 mm. However, at 240- and 320-mm FOVs, the noise of U-HRCT and conventional HRCT showed no differences.ConclusionsIn conventional HRCT, image quality did not improve when the FOV was reduced below 160 mm. However, in U-HRCT, image quality improved even when the FOV was reduced to 80 mm.Key Points• Reducing the size of the field of view to 160 mm improves diagnostic imaging quality in high-resolution CT.• In ultra-high-resolution CT, improvements in image quality can be obtained by reducing the size of the field of view to 80 mm.• Ultra-high-resolution CT produces images of higher quality compared with conventional HRCT irrespective of the size of the field of view.

EP1.11-08 Ultra-High-Resolution CT to Project the Detailed Components in Nodules; Fat Components in Pulmonary Hamartomas

Objective: To conclude the clinical features and the postoperative efficacy of congenital middle ear malformation treated with Malleostapedotomy (MS), and to explore the security and effectiveness of MS surgery. Methods: The clinical data of 17 patients (18 ears) with congenital middle ear malformation undergoing MS procedure were analyzed. There were 10 males (11 ears) and 7 females (7 ears), aged from 7 to 48 years. The imaging examination, pure-tone audiometry, intraoperative findings and postoperative hearing improvement of these patients were analyzed and summarized, and software SPSS23.0 was used for statistical analysis. Rusults All the 17 patients (18 ears) presented with hearing loss since childhood on the affected sides. Preoperative high resolution CT (HRCT) of the temporal bone revealed definite malformations in 9 ears (6 ears with incus long process dysplasia and 3 ears with anterior and posterior crus dysplasia). Before surgery, the mean bone conductive hearing threshold at 500, 1 000, 2 000 and 4 000 Hz was (15.6±10.2) dB HL, the mean air conductive hearing threshold was (60.6±9.7) dB HL, and the mean air-bone gap was (45.0±8.9) dB. During the surgery, all 18 ears were found to be accompanied by absence or hypoplasia of incus long process. 12 ears had stapes fixation, 6 ears had oval window atresia. All patients were treated with MS procedure by using Piston. The patients were followed up for 3 months to 1 year. The mean bone conductive hearing threshold was (14.7±8.8) dB HL. The mean air conductive hearing threshold was (37.7±11.6) dB HL, and the mean air-bone gap was (23.0±8.0) dB. There were statistically significant differences in the mean air conductive hearing threshold and mean air-bone gap before and after surgery (P<0.05). While there were no statistically significant differences in the mean bone conductive hearing threshold before and after surgery (P=0.550). Conclusions: MS procedure is safe and reliable in patients with congenital middle ear malformation of incus long process dysplasia, stapes fixation or oval window atresia. HRCT is useful in evaluating the major deformity of ossicular chain and facial nerve deformity. However, it is not enough to evaluate the joint of incus-stapes and oval window atresia. MS surgery in middle ear malformation requires advanced surgical experience and skills. The hearing improvement can be significant, even though some air-bone gap after surgery exist.

Objective To explore the clinical value of ultra high resolution CT in the diagnosis of pulmonary nodules. Methods From January 2014 to December 2016, 120 cases with small pulmonary nodules and confirmed by pathology(maximum diameter less than or equal to 2cm) in the Fifth People's Hospital of Datong were included in the study.The 120 patients received high resolution CT scan(512×512 matrix), ultra high resolution CT scan(1 024×1 024 matrix). The images of two kinds of resolution CT were observed and analyzed, compared with high-resolution CT scan, ultra high resolution CT scanning for detection of small pulmonary nodules, CT signs detection situation, qualitative diagnosis, image quality. Results Compared with the high resolution CT scan, ultra high resolution CT scan had no statistically significant differences in the detective rate of maximum diameter of 0.5~2cm small pulmonary nodules (χ2=0.695, P>0.05), but the maximum diameter of the ultra high resolution CT scan less than or equal to 0.5cm small lung nodules detected more than that of the high resolution CT scan(χ2=6.021, P 0.05). The diagnostic accordance rates of the ultra high resolution CT scan for pulmonary malignant nodules and benign nodules were 98.08%, 97.06%, respectively, which were higher than those of the high resolution CT scan(86.54%, 85.29%, χ2=4.875, 5.850, all P 0.05). Conclusion Compared with the conventional high resolution CT scan, ultra high resolution CT scan is better for small pulmonary nodules image quality, and can accurately diagnose small pulmonary nodules, with high diagnostic accuracy, especially for the maximum diameter of less than 0.5cm of small pulmonary nodules. Key words: Solitary pulmonary nodule; Tomography, X-ray computed; Diagnosis

Objective: To summarize the clinical features and postoperative efficacy of patients with oval window atresia accompanied by facial nerve aberration. Methods: The clinical data of patients with congenital middle ear malformation with facial nerve aberration admitted to our hospital from January 2015 to March 2023 were retrospectively analyzed. There were 97 cases (133 ears) in total. Among them, 39 patients (44 ears) had complete follow-up data, including 27 male patients and 12 females, aged 7-48 years old, with an average age of 17.8 years old. Of these, 14 cases (16 ears) were patients combined with facial nerve aberration, and 25 cases (28 ears) were without facial nerve aberration. The results of imaging examination, pure-tone audiometry, selection of surgical strategy, intraoperative findings and postoperative hearing improvement were summarized and analyzed. The malformations of malleus, incus, stapes, oval window and facial nerve were recorded. Prism 9 software was used to statistically analyze the mean bone conductance and air-bone gap of patients before and after surgery. Results: All the 14 patients (16 ears) with middle ear malformation accompanied by facial nerve aberration and oval window atresia showed poor hearing and no facial palsy since childhood. High resolution CT (HRCT) examination of temporal bone, pure tone audiometry and Gelle test were performed before surgery. The malformations of malleus, incus, stapes, oval window and facial nerve were recorded. Preoperative high-resolution CT (HRCT) examination of temporal bone found 12 ears with 4 or more deformities, accounting for 75.00%, in the group of patients with facial nerve malformation. The preoperative average bone conductive threshold was (15.3±10.4) dB and the average air-bone gap was (46.3±10.6) dB in pure-tone audiometry (0.5, 1, 2, 4kHz). According to the different degrees of facial nerve and ossicle malformation, we performed three different hearing reconstruction strategies for the 14 patients (16 ears) with facial nerve aberration and oval window atresia, including 7 ears of incus bypass artificial stape implantation, 7 ears of Malleostapedotomy (MS) and 2 ears of Malleus-cochlear-prothesis (MCP). After 3 months to 18 months of follow-up, all patients showed no facial paralysis. The postoperative mean bone conductive threshold was (15.7±7.9) dB and air-bone gap was (19.8±8.5) dB. There were significant differences in mean air-bone gap before and after operation (t=7.766, P<0.05), and there was no significant difference between the mean bone conductive threshold before and after surgery (t=0.225, P=0.824). There was no significant difference of mean reduction of air-bone gap between patients with and without facial nerve aberration (t=1.412, P=0.165). There was no significant difference between the three hearing reconstruction strategies. There was no significant displacement of the Piston examined by U-HRCT. Conclusion: For patients of middle ear malformation whose facial nerve cover the oval window partially, incus bypass artificial stape implantation or Malleostapedotomy (MS) can be selected according to the specific condition of auditory ossis malformation, and for patients whose facial nerve completely covers the oval window area, Malleus-cochlear-prothesis (MCP) can be selected. Three types of stapes surgery are safe and reliable for patients with oval window atresia accompanied by facial nerve aberration. There was no significant difference in efficacy between them. Preoperative HRCT assessment of middle ear malformation is effective. There is no significant difference of surgical effect with or without facial nerve aberration. The U-HRCT can be used to evaluate the middle ear malformation before surgery and the Piston implantation status after surgery. Due to the risks of surgery, those who do not want to undergo surgery can choose artificial hearing AIDS, such as hearing aid, vibrating soundbridge, bone bridge or bone-anchored hearing aid.

PurposeTo compare the diagnostic sensitivity of ultra-high-resolution computed tomography (U-HRCT) and HRCT in isolated fenestral otosclerosis (IFO).MethodsA retrospective analysis was conducted on 85 patients (85 ears) diagnosed with IFO between October 2020 and November 2022. U-HRCT (0.1 mm thickness) was performed for 20 ears, HRCT (0.67 mm thickness) for 45 ears, and both for 20 ears. The images were evaluated by general radiologists and neuroradiologists who were blinded to the diagnosis and surgical information. The diagnostic sensitivity of U-HRCT and HRCT for detecting IFO was compared between the two groups.ResultsExcellent inter-observer agreement existed between the two neuroradiologists (Cohen’s κ coefficient 0.806, 95% CI 0.692–0.920), with good agreement between the general radiologists (Cohen’s κ coefficient 0.680, 95% CI 0.417–0.943). U-HRCT had a sensitivity of 100% (40/40 ears) for neuroradiologists and 87.5% (35/40 ears) for general radiologists, significantly higher than HRCT (89.2% [58/65 ears] for neuroradiologists; 41.5% [27/65 ears] for general radiologists) (p = 0.042, p′ < 0.000). General radiologists’ sensitivity with HRCT was significantly lower compared to neuroradiologists (p < 0.000), but no significant difference was observed when general radiologists switched to U-HRCT (p = 0.152). Among the 20 ears that underwent both examinations, U-HRCT detected lesions smaller than 1 mm in 5 ears, whereas HRCT’s sensitivity for neuroradiologists was 40% (2/5 ears), significantly lower than for lesions larger than 1 mm (93.3%, 14/15 ears, p = 0.032).ConclusionU-HRCT exhibits higher sensitivity than HRCT in diagnosing IFO, suggesting its potential as a screening tool for suspected otosclerosis patients.Critical relevance statementUltra-high-resolution computed tomography has the potential to become a screening tool in patients with suspected otosclerosis and to bridge the diagnostic accuracy gap between general radiologists and neuroradiologists.Key points• U-HRCT exhibits higher sensitivity than HRCT in the diagnosis of IFO.• U-HRCT has a significant advantage in the detection of less than 1 mm IFO.• U-HRCT has the potential to be used for screening of patients with suspected otosclerosis.Graphical

The purpose of this study was to compare conventional high-resolution CT (HRCT) with helical 16-MDCT in the detection of bronchiectasis. We retrospectively evaluated 80 patients including 61 with bronchiectasis (mean age, 64 years; range, 22-87 years) and a control group of 19 patients with normal MDCT of the chest. Two sets of images were blindly, randomly analyzed by two observers: contiguous 1-mm slices (MDCT set) and 1-mm slices every 10 mm (HRCT set) derived from the MDCT set. Images were scored independently for presence, extent, and severity of bronchiectasis, followed by a consensus interpretation. Kappa analysis assessed inter- and intraobserver agreement. MDCT was the radiologic gold standard. Of the 61 patients with bronchiectasis diagnosed with MDCT, 56 (92%) were positive for bronchiectasis on conventional HRCT. Seven patients had positive MDCT scans only, and two patients had positive HRCT scans only. Of 479 lobes, 59 were positive for bronchiectasis on MDCT and negative on HRCT, and 19 lobes were positive for bronchiectasis on HRCT and negative on MDCT (p < 0.0001). MDCT showed 25 more lobes with cylindric, 11 more lobes with varicose, and four more lobes with cystic bronchiectasis than did HRCT. Sensitivity, specificity, and positive and negative predictive values of HRCT in detecting bronchiectasis were 71%, 93%, 88%, and 81%, respectively. Interobserver agreement for presence, extent, and severity of bronchiectasis ranged from moderate to good for MDCT (kappa values, 0.64, 0.5, and 0.48, respectively) and poor to good for HRCT (kappa values, 0.65, 0.46, and 0.25, respectively). Contiguous helical 16-MDCT with 1-mm collimation is superior to HRCT at 10-mm intervals in showing the presence and extent of bronchiectasis.

The aim of this study was to determine whether there is superior diagnostic accuracy for the detection and exclusion of bronchiectasis using 16-slice CT of the chest (1 mm) compared with conventional high-resolution CT (HRCT) of the chest (10 mm). A prospective study was carried out in patients who were referred for chest CT by a chest physician for the investigation of bronchiectasis over a 1-year period. All scans were performed using a 16-slice CT scanner. In addition to contiguous 1 mm slices, conventional HRCT images (1 mm slice every 10 mm) were prepared. Both datasets were dual read. There were 53 patients with a median age of 62 years (range, 51.5-71.5 years), comprising 14 males and 39 females. 10 of 53 scans had no bronchiectasis in either dataset. 36 patients had bronchiectasis diagnosed on both HRCT and 1 mm scans. Two patients had tubular bronchiectasis on the HRCT scans, which was not confirmed on the 1 mm scans. Five patients had confirmed tubular bronchiectasis on the 1 mm scans, which was not identified on HRCT scans. 40 extra lobes demonstrated bronchiectasis on the 1 mm vs the HRCT scans; of these, half were labelled as definite bronchiectasis on the 1 mm scan. There was a 32% increased confidence with the 1 mm scans compared with conventional HRCT of the chest in the diagnosis of bronchiectasis (p < 0.001). In conclusion, there is improved diagnostic accuracy and confidence for diagnosis and exclusion of bronchiectasis using 16-slice chest CT (1 mm cuts) compared with conventional HRCT of the chest.

PurposeThe 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 methodsUHR-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. ResultsWith 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. ConclusionUHR-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.

PurposeThe image noise and image quality of a prototype ultra-high-resolution computed tomography (U-HRCT) scanner was evaluated and compared with those of conventional high-resolution CT (C-HRCT) scanners.Materials and MethodsThis study was approved by the institutional review board. A U-HRCT scanner prototype with 0.25 mm x 4 rows and operating at 120 mAs was used. The C-HRCT images were obtained using a 0.5 mm x 16 or 0.5 mm x 64 detector-row CT scanner operating at 150 mAs. Images from both scanners were reconstructed at 0.1-mm intervals; the slice thickness was 0.25 mm for the U-HRCT scanner and 0.5 mm for the C-HRCT scanners. For both scanners, the display field of view was 80 mm. The image noise of each scanner was evaluated using a phantom. U-HRCT and C-HRCT images of 53 images selected from 37 lung nodules were then observed and graded using a 5-point score by 10 board-certified thoracic radiologists. The images were presented to the observers randomly and in a blinded manner.ResultsThe image noise for U-HRCT (100.87 ± 0.51 Hounsfield units [HU]) was greater than that for C-HRCT (40.41 ± 0.52 HU; P < .0001). The image quality of U-HRCT was graded as superior to that of C-HRCT (P < .0001) for all of the following parameters that were examined: margins of subsolid and solid nodules, edges of solid components and pulmonary vessels in subsolid nodules, air bronchograms, pleural indentations, margins of pulmonary vessels, edges of bronchi, and interlobar fissures.ConclusionDespite a larger image noise, the prototype U-HRCT scanner had a significantly better image quality than the C-HRCT scanners.

Diagnostic and neurosurgical procedures require the precise localization of small intracranial arteries, but this may be difficult using conventional computed tomography angiography (CTA). This study was conducted to evaluate the quality of CTA images acquired using a prototype ultra-high-resolution computed tomography (U-HRCT) system compared with those acquired using a conventional computed tomography (C-CT) system. From July through September 2015, 10 adult patients (6 women and 4 men) previously scanned by C-CT were examined using U-HRCT to locate and assess cerebral aneurysms. The bilateral ophthalmic artery (Opth A), anterior choroidal artery (Acho A), and thalamoperforating arteries (TPAs) were visually evaluated in randomly presented CTA images. Images were graded on a 5-point scale, and differences in scores between U-HRCT and C-CT were evaluated by the Wilcoxon signed-rank test. A p value < 0.05 was considered statistically significant. Visual evaluation scores for images of the Opth A, Acho A, and TPAs were significantly higher for U-HRCT than for C-CT. U-HRCT images achieved good visualization (score > 3) for C-CT images with poor visualization (score < 3) in 66.7-100% of all the small arteries. U-HRCT is superior to C-CT for detecting and evaluating clinically significant small intracranial arteries.

To compare preoperative temporal bone high-resolution computed tomography (HRCT) readings to intraoperative findings during exploratory tympanotomy for suspected cases of isolated congenital middle ear malformations (CMEMs) and summarize the malformations that can and cannot be diagnosed with HRCT. A retrospective study was conducted. All cases were confirmed as isolated CMEMs during surgery. Detailed clinical records were reviewed, with a focus on imaging and surgical findings. One hundred and thirty-two patients and 145 ears were reviewed. Ninety cases (62.1%) could be identified as isolated CMEMs and at least one as middle ear anomaly using preoperative HRCT. Fifty-five cases (37.9%) were reported to be completely normal and the patients underwent exploratory tympanotomy to determine the final diagnosis. Stapes fixation, either alone or associated with other ossicular chain anomalies, contributed to 53.1% of the cases. Most cases of aplasia or dysplasia of the ossicular chain, for example, aplasia/dysplasia of the long process of the incus, aplasia of the stapes' superstructure, and atresia of the oval window were easily identified in preoperative HRCT. However, fixation of the ossicular chain can be elusive in HRCT, and exploratory tympanotomy is needed for a definitive diagnosis. HRCT provides helpful preoperative clinical information in CMEM and may obviate the need for middle ear exploration in some cases. The negative findings (anomalies that are difficult to identify through preoperative HRCT) and the positive findings (anomalies that are relatively easy to identify through preoperative HRCT) were summarized.

SummaryOtosclerosis is a primary otodystrophy that impacts the osseous architecture of the otic capsule within the temporal bone, resulting in progressive hearing loss. High-resolution computed tomography (HRCT) has traditionally been the gold standard imaging modality in otosclerosis, providing critical information in both diagnosis and surgical planning. However, its sensitivity varies widely. Recent advancements in imaging technology, such as ultra-high-resolution CT (UHRCT), provide higher spatial resolution and lower doses of radiation but, especially if based on cone beam CT (CBCT), face challenges in standardising bone density and are often limited by beam-hardening artefacts in the presence of metallic prostheses. Photon-counting detector CT (PCDCT) represents a promising UHRCT technology that directly converts photons into electrical signals, enhancing dose efficiency and image quality while reducing beam-hardening artefacts. Initial findings seem to indicate that PCDCT offers superior visualisation of otosclerotic foci and prosthesis positioning compared to traditional HRCT. Furthermore, PCDCT allows for less radiation exposure. This review examines the roles that HRCT and UHRCT, based both on CBCT and PCDCT, as well as magnetic resonance imaging, currently have in the imaging evaluation of otosclerosis. The findings highlight that while HRCT remains the standard, UHRCT and particularly PCDCT significantly improve the assessment capabilities, overcoming many limitations of previous technologies. Incorporating PCDCT imaging into routine clinical practice could lead to more precise diagnosis of otosclerosis, better surgical planning, and improved patient outcomes, ultimately granting more tailored and effective treatment strategies for otosclerosis, in line with the goals of precision medicine to optimise patient care.

ObjectiveTo evaluate radiologist agreement on the quantification of bronchiectasis by high-resolution computed tomography (HRCT).Materials and MethodsThe HRCT scans of 43 patients with bronchiectasis were analyzed by two radiologists, who used a scoring system to grade the findings. Kappa (κ) values and overall agreement were calculated.ResultsFor the measurement and appearance of bronchiectasis, the interobserver agreement was moderate (κ = 0.45 and κ = 0.43, respectively), as was the intraobserver agreement (κ = 0.54 and κ = 0.47, respectively). Agreement on the presence of mucous plugging was fair, for central distribution (overall interobserver agreement of 68.3% and κ = 0.39 for intraobserver agreement) and for peripheral distribution (κ = 0.34 and κ = 0.35 for interobserver and intraobserver agreement, respectively). The agreement was also fair for peribronchial thickening (κ = 0.21 and κ = 0.30 for interobserver and intraobserver agreement, respectively). There was fair interobserver and intraobserver agreement on the detection of opacities (κ = 0.39 and 71.9%, respectively), ground-glass attenuation (64.3% and κ = 0.24, respectively), and cysts/bullae (κ = 0.47 and κ = 0.44, respectively). Qualitative analysis of the HRCT findings of bronchiectasis and the resulting individual patient scores showed that there was an excellent correlation between the observers (intraclass correlation coefficient of 0.85 and 0.81 for interobserver and intraobserver agreement, respectively).ConclusionIn the interpretation of HRCT findings of bronchiectasis, radiologist agreement appears to be fair. In our final analysis of the findings using the proposed score, we observed excellent interobserver and intraobserver agreement.

To compare the value of conventional CT (CCT) and high-resolution CT (HRCT) to detect benign asbestos-related diseases, 159 exposed workers with a normal chest radiography were imaged by both techniques. Pleural plaques were detected in a total of 59 cases (37.1%). Ten cases (16.9%) were detected by CCT only and one case (1.7%) by HRCT only. Pulmonary lesions compatible with parenchymal asbestosis were detected by HRCT in 20 cases, whereas CCT showed abnormalities in 45% of these. Rounded atelectasis was equally recognized by both techniques. The results confirm that in a subject with a normal chest radiography, HRCT is a better diagnostic tool to demonstrate lesions of asbestosis. On the other hand, HRCT is insufficient to exclude the presence of pleural plaques. When HRCT does not reveal pleural abnormalities, CCT should be performed.