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Tomography, Volume 9, Issue 6 (December 2023) – 21 articles

Cover Story (view full-size image): Quantitative imaging biomarkers (QIBs) from diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) MR imaging hold promise in characterizing tumor physiology. Limitations remain with the accessibility of quantitative DWI multi-b-value and DCE pharmacokinetic analysis tools for radiologists and researchers. We present Quantitative Analysis and Multiparametric Evaluation Routines for MRI (MRI-QAMPER) software for the extraction of QIBs from MRI data. MRI-QAMPER is MATLAB based (The Mathworks) with advanced routines for post-processing quantitative DWI, DCE, T1, and T2 data. MRI-QAMPER analyzes data from brain, pancreas, bladder, and other organs via customizable presets for non-linear fitting. MRI-QAMPER is approved with National Cancer Institute Quantitative Imaging Network Level 5 “Clinical Benchmark” status for use in clinical trials. View this paper
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9 pages, 10163 KiB  
Case Report
Exploring CNS Involvement in Pain Insensitivity in Hereditary Sensory and Autonomic Neuropathy Type 4: Insights from Tc−99m ECD SPECT Imaging
by Cheng-Chun Chiang, Yu-Che Wu, Chiao-Hsin Lan, Kuan-Chieh Wang, Hsuan-Ching Tang and Shin-Tsu Chang
Tomography 2023, 9(6), 2261-2269; https://doi.org/10.3390/tomography9060175 - 18 Dec 2023
Viewed by 1212
Abstract
Hereditary sensory and autonomic neuropathy type 4 (HSAN4), also known as congenital insensitivity to pain with anhidrosis (CIPA), is a rare genetic disorder caused by NTRK1 gene mutations, affecting nerve growth factor signaling. This study investigates the central nervous system’s (CNS) involvement and [...] Read more.
Hereditary sensory and autonomic neuropathy type 4 (HSAN4), also known as congenital insensitivity to pain with anhidrosis (CIPA), is a rare genetic disorder caused by NTRK1 gene mutations, affecting nerve growth factor signaling. This study investigates the central nervous system’s (CNS) involvement and its relation to pain insensitivity in HSAN4. We present a 15-year-old girl with HSAN4, displaying clinical signs suggestive of CNS impact, including spasticity and a positive Babinski’s sign. Using Technetium-99m ethyl cysteinate dimer single-photon emission computed tomography (Tc−99m ECD SPECT) imaging, we discovered perfusion deficits in key brain regions, notably the cerebellum, thalamus, and postcentral gyrus. These regions process pain signals, providing insights into HSAN4’s pain insensitivity. This study represents the first visualization of CNS perfusion abnormality in an HSAN4 patient. It highlights the intricate relationship between the peripheral and central nervous systems in HSAN4. The complexity of HSAN4 diagnosis, involving potential unidentified genes, underscores the need for continued research to refine diagnostic approaches and develop comprehensive treatments. Full article
(This article belongs to the Section Brain Imaging)
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14 pages, 6830 KiB  
Article
Non-A Non-B Acute Aortic Dissection: Is There Some Confusion in the Radiologist’s Mind?
by Tullio Valente, Giacomo Sica, Federica Romano, Gaetano Rea, Roberta Lieto, Marisa De Feo, Alessandro Della Corte, Salvatore Guarino, Candida Massimo, Mariano Scaglione, Emanuele Muto and Giorgio Bocchini
Tomography 2023, 9(6), 2247-2260; https://doi.org/10.3390/tomography9060174 - 15 Dec 2023
Cited by 1 | Viewed by 945
Abstract
Background: The aim of this study is to define and determine the rate of acute non-A–non-B aortic dissections, and to evaluate CT angiography findings and possible complications, as well as to discuss management strategies and currently available therapy. Non-A non-B type of aortic [...] Read more.
Background: The aim of this study is to define and determine the rate of acute non-A–non-B aortic dissections, and to evaluate CT angiography findings and possible complications, as well as to discuss management strategies and currently available therapy. Non-A non-B type of aortic dissection is still a grey area in the radiologist’s mind, such that it is not entirely clear what should be reported and completed in terms of this disease. Methods: A retrospective single-center study including 36 pre-treatment CT angiograms of consecutive patients (mean age: 61 years) between January 2012 and December 2022 with aortic dissection involving the aortic arch with/without the thoracic descending/abdominal aorta (type non-A non-B). Results: According to the dissection anatomy, we identified three modalities of spontaneous acute non-A–non-B anatomical configurations. Configuration 1 (n = 25) with descending-entry tear and retrograde arch extension (DTA entry). Configuration 2 (n = 4) with Arch entry tear and isolated arch involvement (Arch alone). Configuration 3 (n = 7) with Arch entry and anterograde descending (±abdominal) aorta involvement (Arch entry). CT angiogram findings, management, and treatment options are described. Conclusions: Acute non-A non-B dissection represents an infrequent occurrence of aortic arch dissection (with or without involvement of the descending aorta) that does not extend to the ascending aorta. The complete understanding of its natural progression, distinct CT angiography subtypes, optimal management, and treatment strategies remains incomplete. Within our series, patients frequently exhibit a complex clinical course, often necessitating a more assertive approach to treatment compared to type B dissections. Full article
(This article belongs to the Section Cardiovascular Imaging)
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14 pages, 3573 KiB  
Article
MSTAC: A Multi-Stage Automated Classification of COVID-19 Chest X-ray Images Using Stacked CNN Models
by Thanakorn Phumkuea, Thakerng Wongsirichot, Kasikrit Damkliang, Asma Navasakulpong and Jarutas Andritsch
Tomography 2023, 9(6), 2233-2246; https://doi.org/10.3390/tomography9060173 - 13 Dec 2023
Viewed by 1103
Abstract
This study introduces a Multi-Stage Automated Classification (MSTAC) system for COVID-19 chest X-ray (CXR) images, utilizing stacked Convolutional Neural Network (CNN) models. Suspected COVID-19 patients often undergo CXR imaging, making it valuable for disease classification. The study collected CXR images from public datasets [...] Read more.
This study introduces a Multi-Stage Automated Classification (MSTAC) system for COVID-19 chest X-ray (CXR) images, utilizing stacked Convolutional Neural Network (CNN) models. Suspected COVID-19 patients often undergo CXR imaging, making it valuable for disease classification. The study collected CXR images from public datasets and aimed to differentiate between COVID-19, non-COVID-19, and healthy cases. MSTAC employs two classification stages: the first distinguishes healthy from unhealthy cases, and the second further classifies COVID-19 and non-COVID-19 cases. Compared to a single CNN-Multiclass model, MSTAC demonstrated superior classification performance, achieving 97.30% accuracy and sensitivity. In contrast, the CNN-Multiclass model showed 94.76% accuracy and sensitivity. MSTAC’s effectiveness is highlighted in its promising results over the CNN-Multiclass model, suggesting its potential to assist healthcare professionals in efficiently diagnosing COVID-19 cases. The system outperformed similar techniques, emphasizing its accuracy and efficiency in COVID-19 diagnosis. This research underscores MSTAC as a valuable tool in medical image analysis for enhanced disease classification. Full article
(This article belongs to the Special Issue The Challenge of Advanced Medical Imaging Data Analysis in COVID-19)
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11 pages, 2935 KiB  
Article
Transnasal Endoscopic Pituitary Surgery—The Role of a CT Scan in Individual Tailoring of Posterior Septum Size Resection
by Jakub Lubojacký, Lenka Čábalová, Michaela Mladoňová, Viktória Hránková, Tomáš Krejčí, Jakub Mičaník, Maria Miklošová, Lačezar Ličev, Pavel Komínek and Petr Matoušek
Tomography 2023, 9(6), 2222-2232; https://doi.org/10.3390/tomography9060172 - 12 Dec 2023
Viewed by 962
Abstract
Objective: This study was designed to evaluate the possibility of predicting the minimum size of septal resection for safe tumor extraction in transnasal paraseptal pituitary adenoma resection from preoperative computed tomography scans. Methods: A retrospective CT scan analysis was performed on 20 patients [...] Read more.
Objective: This study was designed to evaluate the possibility of predicting the minimum size of septal resection for safe tumor extraction in transnasal paraseptal pituitary adenoma resection from preoperative computed tomography scans. Methods: A retrospective CT scan analysis was performed on 20 patients who underwent endoscopic pituitary surgery at the University Hospital in Ostrava. Virtual insertion of the straight instrument into the sphenoid cavity was simulated using a CT scan. The minimum septal resection size was predicted and compared to various diameters in the nasal cavity. The results were then compared with cadaveric dissections, in which septal resections were performed at 1 cm and 2 cm distances from the anterior sphenoid wall. The association between cadaver dissections and CT scan results was studied. Results: A total of 20 patients who underwent endoscopic transnasal surgery for pituitary adenoma between the years 2020 and 2021 were enrolled in the study. The mean virtual posterior septal size resection needed to reach the medial edge of the ICA with the straight instrument, without infracturing the nasal septum, was 13.2 mm. In cadavers with a 1 cm posterior septal resection, the medial edge of the ICA was reached with the straight instrument. In 2 cm resections, it was possible to reach beyond the lateral edge of the ICA. Conclusion: There is no significant correlation between the minimum septal size resection and measured diameters in the nasal cavity. According to our study, a 1 cm resection is sufficient for a non-extended pituitary tumor extraction. More extensive septal resections allow for better maneuverability and overview in the surgical field. Full article
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11 pages, 3274 KiB  
Article
Chest X-ray at Emergency Admission and Potential Association with Barotrauma in Mechanically Ventilated Patients: Experience from the Italian Core of the First Pandemic Peak
by Pietro Andrea Bonaffini, Francesco Stanco, Ludovico Dulcetta, Giancarla Poli, Paolo Brambilla, Paolo Marra, Clarissa Valle, Ferdinando Luca Lorini, Mirko Mazzoleni, Beatrice Sonzogni, Fabio Previdi and Sandro Sironi
Tomography 2023, 9(6), 2211-2221; https://doi.org/10.3390/tomography9060171 - 8 Dec 2023
Viewed by 893
Abstract
Barotrauma occurs in a significant number of patients with COVID-19 interstitial pneumonia undergoing mechanical ventilation. The aim of the current study was to investigate whether the Brixia score (BS) calculated on chest-X-rays acquired at the Emergency Room was associated with barotrauma. We retrospectively [...] Read more.
Barotrauma occurs in a significant number of patients with COVID-19 interstitial pneumonia undergoing mechanical ventilation. The aim of the current study was to investigate whether the Brixia score (BS) calculated on chest-X-rays acquired at the Emergency Room was associated with barotrauma. We retrospectively evaluated 117 SARS-CoV-2 patients presented to the Emergency Department (ED) and then admitted to the intensive care unit (ICU) for mechanical ventilation between February and April 2020. Subjects were divided into two groups according to the occurrence of barotrauma during their hospitalization. CXRs performed at ED admittance were assessed using the Brixia score. Distribution of barotrauma (pneumomediastinum, pneumothorax, subcutaneous emphysema) was identified in chest CT scans. Thirty-eight subjects (32.5%) developed barotrauma (25 pneumomediastinum, 24 pneumothorax, 24 subcutaneous emphysema). In the barotrauma group we observed higher Brixia score values compared to the non-barotrauma group (mean value 12.18 vs. 9.28), and logistic regression analysis confirmed that Brixia score is associated with the risk of barotrauma. In this work, we also evaluated the relationship between barotrauma and clinical and ventilatory parameters: SOFA score calculated at ICU admittance and number of days of non-invasive ventilation (NIV) prior to intubation emerged as other potential predictors of barotrauma. Full article
(This article belongs to the Section Artificial Intelligence in Medical Imaging)
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21 pages, 97789 KiB  
Review
Imaging of Pathologies of the Temporal Bone and Middle Ear: Inflammatory Diseases, Their Mimics and Potential Complications—Pictorial Review
by Christopher Kloth, Annika Beck, Nico Sollmann, Meinrad Beer, Marius Horger and Wolfgang Maximilian Thaiss
Tomography 2023, 9(6), 2190-2210; https://doi.org/10.3390/tomography9060170 - 8 Dec 2023
Viewed by 1797
Abstract
Imaging of the temporal bone and middle ear is challenging for radiologists due to the abundance of distinct anatomical structures and the plethora of possible pathologies. The basis for a precise diagnosis is knowledge of the underlying anatomy as well as the clinical [...] Read more.
Imaging of the temporal bone and middle ear is challenging for radiologists due to the abundance of distinct anatomical structures and the plethora of possible pathologies. The basis for a precise diagnosis is knowledge of the underlying anatomy as well as the clinical presentation and the individual patient’s otological status. In this article, we aimed to summarize the most common inflammatory lesions of the temporal bone and middle ear, describe their specific imaging characteristics, and highlight their differential diagnoses. First, we introduce anatomical and imaging fundamentals. Additionally, a point-to-point comparison of the radiological and histological features of the wide spectrum of inflammatory diseases of the temporal bone and middle ear in context with a review of the current literature and current trends is given. Full article
(This article belongs to the Section Neuroimaging)
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32 pages, 1271 KiB  
Review
A Systematic Literature Review of 3D Deep Learning Techniques in Computed Tomography Reconstruction
by Hameedur Rahman, Abdur Rehman Khan, Touseef Sadiq, Ashfaq Hussain Farooqi, Inam Ullah Khan and Wei Hong Lim
Tomography 2023, 9(6), 2158-2189; https://doi.org/10.3390/tomography9060169 - 5 Dec 2023
Cited by 2 | Viewed by 2332
Abstract
Computed tomography (CT) is used in a wide range of medical imaging diagnoses. However, the reconstruction of CT images from raw projection data is inherently complex and is subject to artifacts and noise, which compromises image quality and accuracy. In order to address [...] Read more.
Computed tomography (CT) is used in a wide range of medical imaging diagnoses. However, the reconstruction of CT images from raw projection data is inherently complex and is subject to artifacts and noise, which compromises image quality and accuracy. In order to address these challenges, deep learning developments have the potential to improve the reconstruction of computed tomography images. In this regard, our research aim is to determine the techniques that are used for 3D deep learning in CT reconstruction and to identify the training and validation datasets that are accessible. This research was performed on five databases. After a careful assessment of each record based on the objective and scope of the study, we selected 60 research articles for this review. This systematic literature review revealed that convolutional neural networks (CNNs), 3D convolutional neural networks (3D CNNs), and deep learning reconstruction (DLR) were the most suitable deep learning algorithms for CT reconstruction. Additionally, two major datasets appropriate for training and developing deep learning systems were identified: 2016 NIH-AAPM-Mayo and MSCT. These datasets are important resources for the creation and assessment of CT reconstruction models. According to the results, 3D deep learning may increase the effectiveness of CT image reconstruction, boost image quality, and lower radiation exposure. By using these deep learning approaches, CT image reconstruction may be made more precise and effective, improving patient outcomes, diagnostic accuracy, and healthcare system productivity. Full article
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10 pages, 2522 KiB  
Article
Automated High-Order Shimming for Neuroimaging Studies
by Jia Xu, Baolian Yang, Douglas Kelley and Vincent A. Magnotta
Tomography 2023, 9(6), 2148-2157; https://doi.org/10.3390/tomography9060168 - 1 Dec 2023
Viewed by 968
Abstract
B0 inhomogeneity presents a significant challenge in MRI and MR spectroscopy, particularly at high-field strengths, leading to image distortion, signal loss, and spectral broadening. Existing high-order shimming methods can alleviate these issues but often require time-consuming and subjective manual selection of regions [...] Read more.
B0 inhomogeneity presents a significant challenge in MRI and MR spectroscopy, particularly at high-field strengths, leading to image distortion, signal loss, and spectral broadening. Existing high-order shimming methods can alleviate these issues but often require time-consuming and subjective manual selection of regions of interest (ROIs). To address this, we proposed an automated high-order shimming (autoHOS) method, incorporating deep-learning-based brain extraction and image-based high-order shimming. This approach performs automated real-time brain extraction to define the ROI of the field map to be used in the shimming algorithm. The shimming performance of autoHOS was assessed through in vivo echo-planar imaging (EPI) and spectroscopic studies at both 3T and 7T field strengths. AutoHOS outperforms linear shimming and manual high-order shimming, enhancing both the image and spectral quality by reducing the EPI image distortion and narrowing the MRS spectral lineshapes. Therefore, autoHOS demonstrated a significant improvement in correcting B0 inhomogeneity while eliminating the need for additional user interaction. Full article
(This article belongs to the Section Brain Imaging)
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14 pages, 8127 KiB  
Article
The Role of Cone-Beam Computed Tomography CT Extremity Arthrography in the Preoperative Assessment of Osteoarthritis
by Marion Hamard, Marta Sans Merce, Karel Gorican, Pierre-Alexandre Poletti, Angeliki Neroladaki and Sana Boudabbous
Tomography 2023, 9(6), 2134-2147; https://doi.org/10.3390/tomography9060167 - 29 Nov 2023
Viewed by 2691
Abstract
Osteoarthritis (OA) is a prevalent disease and the leading cause of pain, disability, and quality of life deterioration. Our study sought to evaluate the image quality and dose of cone-beam computed tomography arthrography (CBCT-A) and compare them to digital radiography (DR) for OA [...] Read more.
Osteoarthritis (OA) is a prevalent disease and the leading cause of pain, disability, and quality of life deterioration. Our study sought to evaluate the image quality and dose of cone-beam computed tomography arthrography (CBCT-A) and compare them to digital radiography (DR) for OA diagnoses. Overall, 32 cases of CBCT-A and DR with OA met the inclusion criteria and were prospectively analyzed. The Kellgren and Lawrence classification (KLC) stage, sclerosis, osteophytes, erosions, and mean joint width (MJW) were compared between CBCT-A and DR. Image quality was excellent in all CBCT-A cases, with excellent inter-observer agreement. OA under-classification was noticed with DR for MJW (p = 0.02), osteophyte detection (<0.0001), and KLC (p < 0.0001). The Hounsfield Unit (HU) values obtained for the cone-beam computed tomography CBCT did not correspond to the values for multi-detector computed tomography (MDCT), with a greater mean deviation obtained with the MDCT HU for Modeled Based Iterative Reconstruction 1st (MBIR1) than for the 2nd generation (MBIR2). CBCT-A has been found to be more reliable for OA diagnosis than DR as revealed by our results using a three-point rating scale for the qualitative image analysis, with higher quality and an acceptable dose. Moreover, the use of this imaging technique permits the preoperative assessment of extremities in an OA diagnosis, with the upright position and bone microarchitecture analysis being two other advantages of CBCT-A. Full article
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18 pages, 3279 KiB  
Review
High-Resolution Phase-Contrast Tomography on Human Collagenous Tissues: A Comprehensive Review
by Michele Furlani, Nicole Riberti, Maria Laura Gatto and Alessandra Giuliani
Tomography 2023, 9(6), 2116-2133; https://doi.org/10.3390/tomography9060166 - 27 Nov 2023
Viewed by 1869
Abstract
Phase-contrast X-ray imaging is becoming increasingly considered since its first applications, which occurred almost 30 years ago. Particular emphasis was placed on studies that use this technique to investigate soft tissues, which cannot otherwise be investigated at a high resolution and in a [...] Read more.
Phase-contrast X-ray imaging is becoming increasingly considered since its first applications, which occurred almost 30 years ago. Particular emphasis was placed on studies that use this technique to investigate soft tissues, which cannot otherwise be investigated at a high resolution and in a three-dimensional manner, using conventional absorption-based settings. Indeed, its consistency and discrimination power in low absorbing samples, unified to being a not destructive analysis, are pushing interests on its utilization from researchers of different specializations, from botany, through zoology, to human physio-pathology research. In this regard, a challenging method for 3D imaging and quantitative analysis of collagenous tissues has spread in recent years: it is based on the unique characteristics of synchrotron radiation phase-contrast microTomography (PhC-microCT). In this review, the focus has been placed on the research based on the exploitation of synchrotron PhC-microCT for the investigation of collagenous tissue physio-pathologies from solely human samples. Collagen tissues’ elasto-mechanic role bonds it to the morphology of the site it is extracted from, which could weaken the results coming from animal experimentations. Encouraging outcomes proved this technique to be suitable to access and quantify human collagenous tissues and persuaded different researchers to approach it. A brief mention was also dedicated to the results obtained on collagenous tissues using new and promising high-resolution phase-contrast tomographic laboratory-based setups, which will certainly represent the real step forward in the diffusion of this relatively young imaging technique. Full article
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13 pages, 1048 KiB  
Article
Artificial Intelligence for Image-Based Breast Cancer Risk Prediction Using Attention
by Stepan Romanov, Sacha Howell, Elaine Harkness, Megan Bydder, D. Gareth Evans, Steven Squires, Martin Fergie and Sue Astley
Tomography 2023, 9(6), 2103-2115; https://doi.org/10.3390/tomography9060165 - 24 Nov 2023
Cited by 2 | Viewed by 2475
Abstract
Accurate prediction of individual breast cancer risk paves the way for personalised prevention and early detection. The incorporation of genetic information and breast density has been shown to improve predictions for existing models, but detailed image-based features are yet to be included despite [...] Read more.
Accurate prediction of individual breast cancer risk paves the way for personalised prevention and early detection. The incorporation of genetic information and breast density has been shown to improve predictions for existing models, but detailed image-based features are yet to be included despite correlating with risk. Complex information can be extracted from mammograms using deep-learning algorithms, however, this is a challenging area of research, partly due to the lack of data within the field, and partly due to the computational burden. We propose an attention-based Multiple Instance Learning (MIL) model that can make accurate, short-term risk predictions from mammograms taken prior to the detection of cancer at full resolution. Current screen-detected cancers are mixed in with priors during model development to promote the detection of features associated with risk specifically and features associated with cancer formation, in addition to alleviating data scarcity issues. MAI-risk achieves an AUC of 0.747 [0.711, 0.783] in cancer-free screening mammograms of women who went on to develop a screen-detected or interval cancer between 5 and 55 months, outperforming both IBIS (AUC 0.594 [0.557, 0.633]) and VAS (AUC 0.649 [0.614, 0.683]) alone when accounting for established clinical risk factors. Full article
(This article belongs to the Special Issue Artificial Intelligence in Breast Cancer Screening)
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14 pages, 2125 KiB  
Article
Potential for Dose Reduction in CT-Derived Left Ventricular Ejection Fraction: A Simulation Study
by Martin Weber Kusk, Søren Hess, Oke Gerke and Shane J. Foley
Tomography 2023, 9(6), 2089-2102; https://doi.org/10.3390/tomography9060164 - 15 Nov 2023
Viewed by 1813
Abstract
Background: Measuring left ventricular ejection fraction (LVEF) is important for detecting heart failure, e.g., in treatment with potentially cardiotoxic chemotherapy. MRI is considered the reference standard for LVEF, but availability may be limited and claustrophobia or metal implants still present challenges. CT has [...] Read more.
Background: Measuring left ventricular ejection fraction (LVEF) is important for detecting heart failure, e.g., in treatment with potentially cardiotoxic chemotherapy. MRI is considered the reference standard for LVEF, but availability may be limited and claustrophobia or metal implants still present challenges. CT has been shown to be accurate and would be advantageous, as LVEF could be measured in conjunction with routine chest–abdomen–pelvis oncology CT. However, the use of CT is not recommended due to the excessive radiation dose. This study aimed to explore the potential for dose reduction using simulation. Using an anthropomorphic heart phantom scanned at 13 dose levels, a noise simulation algorithm was developed to introduce controlled Poisson noise. Filtered backprojection parameters were iteratively tested to minimise differences in myocardium-to-ventricle contrast/noise ratio, as well as structural similarity index (SSIM) differences between real and simulated images at all dose levels. Fifty-one clinical CT coronary angiographies, scanned with full dose through end-systolic and -diastolic phases, were located retrospectively. Using the developed algorithm, noise was introduced corresponding to 25, 10, 5 and 2% of the original dose level. LVEF was measured using clinical software (Syngo.via VB50) with papillary muscles in and excluded from the LV volume. At each dose level, LVEF was compared to the 100% dose level, using Bland–Altman analysis. The effective dose was calculated from DLP using a conversion factor of 0.026 mSv/mGycm. Results: In the clinical images, mean CTDIvol and DLP were 47.1 mGy and 771.9 mGycm, respectively (effective dose 20.0 mSv). Measurements with papillary muscles excluded did not exhibit statistically significant LVEF bias to full-dose images at 25, 10 and 5% simulated dose. At 2% dose, a significant bias of 4.4% was found. With papillary muscles included, small but significant biases were found at all simulated dose levels. Conclusion: Provided that measurements are performed with papillary muscles excluded from the LV volume, the dose can be reduced by a factor of 20 without significantly affecting LVEF measurements. This corresponds to an effective dose of 1 mSv. CT can potentially be used for LVEF measurement with minimal excessive radiation. Full article
(This article belongs to the Section Cardiovascular Imaging)
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10 pages, 1144 KiB  
Article
Have Chest Imaging Habits Changed in the Emergency Department after the Pandemic?
by Cüneyt Arıkan, Ejder Saylav Bora, Efe Kanter and Fatma Nur Karaarslan
Tomography 2023, 9(6), 2079-2088; https://doi.org/10.3390/tomography9060163 - 7 Nov 2023
Viewed by 870
Abstract
The rate of patients undergoing tomography in the emergency department has increased in the last two decades. In the last few years, there has been a more significant increase due to the effects of the pandemic. This study aimed to determine the rate [...] Read more.
The rate of patients undergoing tomography in the emergency department has increased in the last two decades. In the last few years, there has been a more significant increase due to the effects of the pandemic. This study aimed to determine the rate of patients who underwent chest imaging in the emergency department, the preferred imaging method, and the demographic characteristics of the patients undergoing imaging during the pre-pandemic and post-pandemic periods. This retrospective cross-sectional study included patients admitted to the emergency department between January 2019 and March 2023. The number of female, male, and total emergency admissions, the rate of patients who underwent chest X-ray (CXR) and chest computed tomography (CCT), and the age and gender distribution of the cases who underwent chest imaging were compared according to the pre-pandemic (January 2019–February 2020), pandemic (March 2020–March 2022), and post-pandemic (April 2022–March 2023) periods. Total emergency admissions were similar in the pre-pandemic and post-pandemic periods (pre-pandemic period: 21,984 ± 2087; post-pandemic period: 22,732 ± 1701). Compared to the pre-pandemic period, the CCT rate increased (pre-pandemic period: 4.9 ± 0.9, post-pandemic period: 7.46 ± 1.2), and the CXR rate decreased (pre-pandemic period: 16.6 ± 1.7%, post-pandemic period: 13.3 ± 1.9%) in the post-pandemic period (p < 0.001). The mean age of patients who underwent chest imaging (CXR; Pre-pandemic period: 56.6 ± 1.1 years; post-pandemic period: 53.3 ± 5.6 years. CCT; Pre-pandemic period: 68.5 ± 1.7 years; post-pandemic period: 61 ± 4.0 years) in the post-pandemic period was lower than in the pre-pandemic period (p < 0.001). Chest imaging preferences in the emergency department have changed during the post-pandemic period. In the post-pandemic period, while younger patients underwent chest imaging in the emergency department, CCT was preferred, and the rate of CXR decreased. It is alarming for public health that patients are exposed to higher doses of radiation at a younger age. Full article
(This article belongs to the Section Artificial Intelligence in Medical Imaging)
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12 pages, 680 KiB  
Article
How Does Diagnostic Accuracy Evolve with Increased Breast MRI Experience?
by Tong Wu, Afsaneh Alikhassi and Belinda Curpen
Tomography 2023, 9(6), 2067-2078; https://doi.org/10.3390/tomography9060162 - 6 Nov 2023
Viewed by 1750
Abstract
Introduction: Our institution is part of a provincial program providing annual breast MRI screenings to high-risk women. We assessed how MRI experience, background parenchymal enhancement (BPE), and the amount of fibroglandular tissue (FGT) affect the biopsy-proven predictive value (PPV3) and accuracy for detecting [...] Read more.
Introduction: Our institution is part of a provincial program providing annual breast MRI screenings to high-risk women. We assessed how MRI experience, background parenchymal enhancement (BPE), and the amount of fibroglandular tissue (FGT) affect the biopsy-proven predictive value (PPV3) and accuracy for detecting suspicious MRI findings. Methods: From all high-risk screening breast MRIs conducted between 1 July 2011 and 30 June 2020, we reviewed all BI-RADS 4/5 observations with pathological tissue diagnoses. Overall and annual PPV3s were computed. Radiologists with fewer than ten observations were excluded from performance analyses. PPV3s were computed for each radiologist. We assessed how MRI experience, BPE, and FGT impacted diagnostic accuracy using logistic regression analyses, defining positive cases as malignancies alone (definition A) or malignant or high-risk lesions (definition B). Findings: There were 536 BI-RADS 4/5 observations with tissue diagnoses, including 77 malignant and 51 high-risk lesions. A total of 516 observations were included in the radiologist performance analyses. The average radiologist’s PPV3 was 16 ± 6% (definition A) and 25 ± 8% (definition B). MRI experience in years correlated significantly with positive cases (definition B, OR = 1.05, p = 0.03), independent of BPE or FGT. Diagnostic accuracy improved exponentially with increased MRI experience (definition B, OR of 1.27 and 1.61 for 5 and 10 years, respectively, p = 0.03 for both). Lower levels of BPE significantly correlated with increased odds of findings being malignant, independent of FGT and MRI experience. Summary: More extensive MRI reading experience improves radiologists’ diagnostic accuracy for high-risk or malignant lesions, even in MRI studies with increased BPE. Full article
(This article belongs to the Section Cancer Imaging)
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15 pages, 2266 KiB  
Article
A Quantitative Multiparametric MRI Analysis Platform for Estimation of Robust Imaging Biomarkers in Clinical Oncology
by Eve LoCastro, Ramesh Paudyal, Amaresha Shridhar Konar, Peter S. LaViolette, Oguz Akin, Vaios Hatzoglou, Alvin C. Goh, Bernard H. Bochner, Jonathan Rosenberg, Richard J. Wong, Nancy Y. Lee, Lawrence H. Schwartz and Amita Shukla-Dave
Tomography 2023, 9(6), 2052-2066; https://doi.org/10.3390/tomography9060161 - 3 Nov 2023
Viewed by 2948
Abstract
There is a need to develop user-friendly imaging tools estimating robust quantitative biomarkers (QIBs) from multiparametric (mp)MRI for clinical applications in oncology. Quantitative metrics derived from (mp)MRI can monitor and predict early responses to treatment, often prior to anatomical changes. We have developed [...] Read more.
There is a need to develop user-friendly imaging tools estimating robust quantitative biomarkers (QIBs) from multiparametric (mp)MRI for clinical applications in oncology. Quantitative metrics derived from (mp)MRI can monitor and predict early responses to treatment, often prior to anatomical changes. We have developed a vendor-agnostic, flexible, and user-friendly MATLAB-based toolkit, MRI-Quantitative Analysis and Multiparametric Evaluation Routines (“MRI-QAMPER”, current release v3.0), for the estimation of quantitative metrics from dynamic contrast-enhanced (DCE) and multi-b value diffusion-weighted (DW) MR and MR relaxometry. MRI-QAMPER’s functionality includes generating numerical parametric maps from these methods reflecting tumor permeability, cellularity, and tissue morphology. MRI-QAMPER routines were validated using digital reference objects (DROs) for DCE and DW MRI, serving as initial approval stages in the National Cancer Institute Quantitative Imaging Network (NCI/QIN) software benchmark. MRI-QAMPER has participated in DCE and DW MRI Collaborative Challenge Projects (CCPs), which are key technical stages in the NCI/QIN benchmark. In a DCE CCP, QAMPER presented the best repeatability coefficient (RC = 0.56) across test–retest brain metastasis data, out of ten participating DCE software packages. In a DW CCP, QAMPER ranked among the top five (out of fourteen) tools with the highest area under the curve (AUC) for prostate cancer detection. This platform can seamlessly process mpMRI data from brain, head and neck, thyroid, prostate, pancreas, and bladder cancer. MRI-QAMPER prospectively analyzes dose de-escalation trial data for oropharyngeal cancer, which has earned it advanced NCI/QIN approval for expanded usage and applications in wider clinical trials. Full article
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13 pages, 4548 KiB  
Article
Dedicated Cone-Beam Breast CT: Reproducibility of Volumetric Glandular Fraction with Advanced Image Reconstruction Methods
by Srinivasan Vedantham, Hsin Wu Tseng, Zhiyang Fu and Hsiao-Hui Sherry Chow
Tomography 2023, 9(6), 2039-2051; https://doi.org/10.3390/tomography9060160 - 2 Nov 2023
Viewed by 2787
Abstract
Dedicated cone-beam breast computed tomography (CBBCT) is an emerging modality and provides fully three-dimensional (3D) images of the uncompressed breast at an isotropic voxel resolution. In an effort to translate this modality to breast cancer screening, advanced image reconstruction methods are being pursued. [...] Read more.
Dedicated cone-beam breast computed tomography (CBBCT) is an emerging modality and provides fully three-dimensional (3D) images of the uncompressed breast at an isotropic voxel resolution. In an effort to translate this modality to breast cancer screening, advanced image reconstruction methods are being pursued. Since radiographic breast density is an established risk factor for breast cancer and CBBCT provides volumetric data, this study investigates the reproducibility of the volumetric glandular fraction (VGF), defined as the proportion of fibroglandular tissue volume relative to the total breast volume excluding the skin. Four image reconstruction methods were investigated: the analytical Feldkamp–Davis–Kress (FDK), a compressed sensing-based fast, regularized, iterative statistical technique (FRIST), a fully supervised deep learning approach using a multi-scale residual dense network (MS-RDN), and a self-supervised approach based on Noise-to-Noise (N2N) learning. Projection datasets from 106 women who participated in a prior clinical trial were reconstructed using each of these algorithms at a fixed isotropic voxel size of (0.273 mm3). Each reconstructed breast volume was segmented into skin, adipose, and fibroglandular tissues, and the VGF was computed. The VGF did not differ among the four reconstruction methods (p = 0.167), and none of the three advanced image reconstruction algorithms differed from the standard FDK reconstruction (p > 0.862). Advanced reconstruction algorithms developed for low-dose CBBCT reproduce the VGF to provide quantitative breast density, which can be used for risk estimation. Full article
(This article belongs to the Special Issue Artificial Intelligence in Breast Cancer Screening)
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10 pages, 1557 KiB  
Article
Reporting Diagnostic Reference Levels for Paediatric Patients Undergoing Brain Computed Tomography
by Ali Alhailiy, Essam Alkhybari, Sultan Alghamdi, Nada Fisal, Sultan Aldosari and Salman Albeshan
Tomography 2023, 9(6), 2029-2038; https://doi.org/10.3390/tomography9060159 - 1 Nov 2023
Viewed by 1048
Abstract
Brain computed tomography (CT) is a diagnostic imaging tool routinely used to assess all paediatric neurologic disorders and other head injuries. Despite the continuous development of paediatric CT imaging, radiation exposure remains a concern. Using diagnostic reference levels (DRLs) helps to manage the [...] Read more.
Brain computed tomography (CT) is a diagnostic imaging tool routinely used to assess all paediatric neurologic disorders and other head injuries. Despite the continuous development of paediatric CT imaging, radiation exposure remains a concern. Using diagnostic reference levels (DRLs) helps to manage the radiation dose delivered to patients, allowing one to identify an unusually high dose. In this paper, we propose DRLs for paediatric brain CT examinations in Saudi clinical practices and compare the findings with those of other reported DRL studies. Data including patient and scanning protocols were collected retrospectively from three medical cities for a total of 225 paediatric patients. DRLs were derived for four different age groupings. The resulting DRL values for the dose–length product (DLP) for the age groups of newborns (0–1 year), 1-y-old (1–5 years), 5-y-old (5–10 years) and 10-y-old (10–15 years) were 404 mGy cm, 560 mGy cm, 548 mGy cm, and 742 mGy cm, respectively. The DRLs for paediatric brain CT imaging are comparable to or slightly lower than other DRLs due to the current use of dose optimisation strategies. This study emphasises the need for an international standardisation for the use of weight group categories in DRL establishment for paediatric care in order to provide a more comparable measurement of dose quantities across different hospitals globally. Full article
(This article belongs to the Section Brain Imaging)
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13 pages, 5402 KiB  
Review
Assessment of Computed Tomography Perfusion Research Landscape: A Topic Modeling Study
by Burak B. Ozkara, Mert Karabacak, Konstantinos Margetis, Vivek S. Yedavalli, Max Wintermark and Sotirios Bisdas
Tomography 2023, 9(6), 2016-2028; https://doi.org/10.3390/tomography9060158 - 1 Nov 2023
Viewed by 3019
Abstract
The number of scholarly articles continues to rise. The continuous increase in scientific output poses a challenge for researchers, who must devote considerable time to collecting and analyzing these results. The topic modeling approach emerges as a novel response to this need. Considering [...] Read more.
The number of scholarly articles continues to rise. The continuous increase in scientific output poses a challenge for researchers, who must devote considerable time to collecting and analyzing these results. The topic modeling approach emerges as a novel response to this need. Considering the swift advancements in computed tomography perfusion (CTP), we deem it essential to launch an initiative focused on topic modeling. We conducted a comprehensive search of the Scopus database from 1 January 2000 to 16 August 2023, to identify relevant articles about CTP. Using the BERTopic model, we derived a group of topics along with their respective representative articles. For the 2020s, linear regression models were used to identify and interpret trending topics. From the most to the least prevalent, the topics that were identified include “Tumor Vascularity”, “Stroke Assessment”, “Myocardial Perfusion”, “Intracerebral Hemorrhage”, “Imaging Optimization”, “Reperfusion Therapy”, “Postprocessing”, “Carotid Artery Disease”, “Seizures”, “Hemorrhagic Transformation”, “Artificial Intelligence”, and “Moyamoya Disease”. The model provided insights into the trends of the current decade, highlighting “Postprocessing” and “Artificial Intelligence” as the most trending topics. Full article
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10 pages, 646 KiB  
Article
Idiopathic Normal Pressure Hydrocephalus: The Real Social and Economic Burden of a Possibly Enormous Underdiagnosis Problem
by Gianpaolo Petrella, Silvia Ciarlo, Stefania Elia, Rita Dal Piaz, Paolo Nucera, Angelo Pompucci, Mauro Palmieri and Alessandro Pesce
Tomography 2023, 9(6), 2006-2015; https://doi.org/10.3390/tomography9060157 - 30 Oct 2023
Viewed by 953
Abstract
Normal Pressure Hydrocephalus (iNPH) typically affects the elderly and can cause cognitive decline, resulting in its differential diagnosis with other neurodegenerative conditions. Moreover, it is probably underdiagnosed; such under- and misdiagnosis prevents the patient from receiving the right treatment and significantly affects the [...] Read more.
Normal Pressure Hydrocephalus (iNPH) typically affects the elderly and can cause cognitive decline, resulting in its differential diagnosis with other neurodegenerative conditions. Moreover, it is probably underdiagnosed; such under- and misdiagnosis prevents the patient from receiving the right treatment and significantly affects the quality of life and life expectancy. This investigation is an in-depth analysis of the actual incidence of iNPH in the population of the province served by our hospital (circa 580,000 individuals). The first phase of this study was conducted by visualizing a total of 1232 brain CT scans performed in the Emergency Departments of the four hospitals of our network on patients who were admitted for different complaints yet screened as suspicious for iNPH. Subsequently, corresponding Emergency Department medical records were investigated to understand the medical history of each patient in search of elements attributable to an alteration of CSF dynamics. The cohort of positive CT scans, according to the radiological and clinical inclusion criteria, included 192 patients. Among the reasons to require acute medical care, “Fall” was the most common. The cumulative incidence of CT scans suggestive of iNPH among the patients undergoing CT scans was as high as 15.58%, and the period prevalence calculated for the total amount of patients accessing the Emergency Departments was 1.084%. The real incidence of iNPH in the population may be underestimated, and the social burden linked to the assistance of patients suffering from such untreated conditions could be significantly relieved. Full article
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7 pages, 780 KiB  
Case Report
High-Riding Conus Medullaris Syndrome: A Case Report and Literature Review—Its Comparison with Cauda Equina Syndrome
by Ya-Lin Huang and Shin-Tsu Chang
Tomography 2023, 9(6), 1999-2005; https://doi.org/10.3390/tomography9060156 - 27 Oct 2023
Viewed by 2235
Abstract
Introduction: Conus medullaris syndrome (CMS) is a distinctive spinal cord injury (SCI), which presents with varying degrees of upper motor neuron signs (UMNS) and lower motor neuron signs (LMNS). Herein, we present a case with a burst fracture injury at the proximal Conus [...] Read more.
Introduction: Conus medullaris syndrome (CMS) is a distinctive spinal cord injury (SCI), which presents with varying degrees of upper motor neuron signs (UMNS) and lower motor neuron signs (LMNS). Herein, we present a case with a burst fracture injury at the proximal Conus Medullaris (CM). Case Presentation: A 48-year-old Taiwanese male presenting with lower back pain and paraparesis was having difficulty standing independently after a traumatic fall. An Imaging survey showed an incomplete D burst fracture of the T12 vertebra. Posterior decompression surgery was subsequently performed. However, spasticity and back pain persisted for four months after surgical intervention. Follow-up imaging with single photon emission computed tomography (SPECT) and a whole body bone scan both showed an increased uptake in the T12 vertebra. Conclusion: The high-riding injury site for CMS is related to a more exclusive clinical representation of UMNS. Our case’s persistent UMNS and scintigraphy findings during follow-up showcase the prolonged recovery period of a UMN injury. In conclusion, our study provides a different perspective on approaching follow-up for CM injuries, namely using scientigraphy techniques to confirm localization of persistent injury during the course of post-operative rehabilitation. Furthermore, we also offered a new technique for analyzing the location of lumbosacral injuries, and that is to measure the location of the injury relative to the tip of the CM. This, along with clinical neurological examination, assesses the extent to which the UMN is involved in patients with CMS, and is possibly a notable predictive tool for clinicians for the regeneration time frame and functional outcome of patients with lumbosacral injuries in the future. Full article
(This article belongs to the Section Neuroimaging)
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12 pages, 4561 KiB  
Article
The Tomosynthesis Broken Halo Sign: Diagnostic Utility for the Classification of Newly Diagnosed Breast Tumors
by Johannes Deeg, Michael Swoboda, Daniel Egle, Verena Wieser, Afschin Soleiman, Valentin Ladenhauf, Malik Galijasevic, Birgit Amort, Silke Haushammer, Martin Daniaux and Leonhard Gruber
Tomography 2023, 9(6), 1987-1998; https://doi.org/10.3390/tomography9060155 - 24 Oct 2023
Viewed by 1391
Abstract
Background: Compared to conventional 2D mammography, digital breast tomosynthesis (DBT) offers greater breast lesion detection rates. Ring-like hypodense artifacts surrounding dense lesions are a common byproduct of DBT. This study’s purpose was to assess whether minuscule changes spanning this halo—termed the “broken halo [...] Read more.
Background: Compared to conventional 2D mammography, digital breast tomosynthesis (DBT) offers greater breast lesion detection rates. Ring-like hypodense artifacts surrounding dense lesions are a common byproduct of DBT. This study’s purpose was to assess whether minuscule changes spanning this halo—termed the “broken halo sign”—could improve lesion classification. Methods: This retrospective study was approved by the local ethics review board. After screening 288 consecutive patients, DBT studies of 191 female participants referred for routine mammography with a subsequent histologically verified finding of the breast were assessed. Examined variables included patient age, histological diagnosis, architectural distortion, maximum size, maximum halo depth, conspicuous margins, irregular shape and broken halo sign. Results: While a higher halo strength was indicative of malignancy in general (p = 0.031), the broken halo sign was strongly associated with malignancy (p < 0.0001, odds ratio (OR) 6.33), alongside architectural distortion (p = 0.012, OR 3.49) and a diffuse margin (p = 0.006, OR 5.49). This was especially true for denser breasts (ACR C/D), where the broken halo sign was the only factor predicting malignancy (p = 0.03, 5.22 OR). Conclusion: DBT-associated halo artifacts warrant thorough investigation in newly found breast lesions as they are associated with malignant tumors. The “broken halo sign”—the presence of small lines of variable diameter spanning the peritumoral areas of hypodensity—is a strong indicator of malignancy, especially in dense breasts, where architectural distortion may be obfuscated due to the surrounding tissue. Full article
(This article belongs to the Section Cancer Imaging)
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