Artificial Intelligence in Image-Based Screening, Diagnostics, and Clinical Care of Cardiopulmonary Diseases

Cardiothoracic and pulmonary diseases are a significant cause of mortality and morbidity worldwide. The COVID-19 pandemic has highlighted the lack of access to clinical care, the overburdened medical system, and the potential of artificial intelligence (AI) in improving medicine. There are a variety of diseases affecting the cardiopulmonary system including lung cancers, heart disease, tuberculosis (TB), etc., in addition to COVID-19-related diseases. Screening, diagnosis, and management of cardiopulmonary diseases has become difficult owing to the limited availability of diagnostic tools and experts, particularly in resource-limited regions. Early screening, accurate diagnosis and staging of these diseases could play a crucial role in treatment and care, and potentially aid in reducing mortality. Radiographic imaging methods such as computed tomography (CT), chest X-rays (CXRs), and echo ultrasound (US) are widely used in screening and diagnosis. Research on using image-based AI and machine learning (ML) methods can help in rapid assessment, serve as surrogates for expert assessment, and reduce variability in human performance. In this Special Issue, “Artificial Intelligence in Image-Based Screening, Diagnostics, and Clinical Care of Cardiopulmonary Diseases”, we have highlighted exemplary primary research studies and literature reviews focusing on novel AI/ML methods and their application in image-based screening, diagnosis, and clinical management of cardiopulmonary diseases. We hope that these articles will help establish the advancements in AI

Special Topics in Cardiac Surgery

This book considers mainly the current perioperative care, as well as progresses in new cardiac surgery technologies. Perioperative strategies and new technologies in the field of cardiac surgery will continue to contribute to improvements in postoperative outcomes and enable the cardiac surgical society to optimize surgical procedures. This book should prove to be a useful reference for trainees, senior surgeons and nurses in cardiac surgery, as well as anesthesiologists, perfusionists, and all the related health care workers who are involved in taking care of patients with heart disease which require surgical therapy. I hope these internationally cumulative and diligent efforts will provide patients undergoing cardiac surgery with meticulous perioperative care methods

Case series of breast fillers and how things may go wrong: radiology point of view

INTRODUCTION: Breast augmentation is a procedure opted by women to overcome sagging breast due to breastfeeding or aging as well as small breast size. Recent years have shown the emergence of a variety of injectable materials on market as breast fillers. These injectable breast fillers have swiftly gained popularity among women, considering the minimal invasiveness of the procedure, nullifying the need for terrifying surgery. Little do they know that the procedure may pose detrimental complications, while visualization of breast parenchyma infiltrated by these fillers is also deemed substandard; posing diagnostic challenges. We present a case series of three patients with prior history of hyaluronic acid and collagen breast injections. REPORT: The first patient is a 37-year-old lady who presented to casualty with worsening shortness of breath, non-productive cough, central chest pain; associated with fever and chills for 2-weeks duration. The second patient is a 34-year-old lady who complained of cough, fever and haemoptysis; associated with shortness of breath for 1-week duration. CT in these cases revealed non thrombotic wedge-shaped peripheral air-space densities. The third patient is a 37‐year‐old female with right breast pain, swelling and redness for 2- weeks duration. Previous collagen breast injection performed 1 year ago had impeded sonographic visualization of the breast parenchyma. MRI breasts showed multiple non- enhancing round and oval shaped lesions exhibiting fat intensity. CONCLUSION: Radiologists should be familiar with the potential risks and hazards as well as limitations of imaging posed by breast fillers such that MRI is required as problem-solving tool

Characterization of alar ligament on 3.0T MRI: a cross-sectional study in IIUM Medical Centre, Kuantan

INTRODUCTION: The main purpose of the study is to compare the normal anatomy of alar ligament on MRI between male and female. The specific objectives are to assess the prevalence of alar ligament visualized on MRI, to describe its characteristics in term of its course, shape and signal homogeneity and to find differences in alar ligament signal intensity between male and female. This study also aims to determine the association between the heights of respondents with alar ligament signal intensity and dimensions. MATERIALS & METHODS: 50 healthy volunteers were studied on 3.0T MR scanner Siemens Magnetom Spectra using 2-mm proton density, T2 and fat-suppression sequences. Alar ligament is depicted in 3 planes and the visualization and variability of the ligament courses, shapes and signal intensity characteristics were determined. The alar ligament dimensions were also measured. RESULTS: Alar ligament was best depicted in coronal plane, followed by sagittal and axial planes. The orientations were laterally ascending in most of the subjects (60%), predominantly oval in shaped (54%) and 67% showed inhomogenous signal. No significant difference of alar ligament signal intensity between male and female respondents. No significant association was found between the heights of the respondents with alar ligament signal intensity and dimensions. CONCLUSION: Employing a 3.0T MR scanner, the alar ligament is best portrayed on coronal plane, followed by sagittal and axial planes. However, tremendous variability of alar ligament as depicted in our data shows that caution needs to be exercised when evaluating alar ligament, especially during circumstances of injury

Optimising Radiation Dose of CT Pulmonary Angiogram for Imaging Pulmonary Embolism and Alternative Acute Respiratory Diseases

Abstract CT pulmonary angiogram (CTPA) is utilised to diagnose pulmonary embolus in various clinical settings. CT imaging has considerable advantages over other imaging modalities. Whilst considering its widespread application and advantages, it tends to have high radiation exposure. Additionally, there are high rates of suboptimal and non-diagnostic examinations that result in unnecessary radiation dose. Therefore appropriate radiation dose reduction techniques are required without compromising imaging quality; unfortunately, efforts to reduce radiation dose can also diminish image quality and lead to missed pulmonary emboli and other lung pathologies. Several studies have investigated 80kV CTPA protocols and found a considerable upsurge in image noise and reduced imaging quality. The purpose of this research project was to develop an 80kV CTPA protocol with reduced imaging noise, decreased radiation dose and simultaneously reducing suboptimal examinations in patients with suspected pulmonary embolism. Both qualitative and quantitative approaches were conducted to achieve this purpose. This study has demonstrated that the new 80kV CTPA protocol can significantly (t (60) = -17.8, p < 0.05) reduce patient mean effective radiation dose by 66% with a mean radiation dose 1.005mSv compared to 3.03mSv with current 100kV protocols. The study has also demonstrated a reduced rate of suboptimal examinations and a significant increase (t (75) =9.1, p<0.05) in contrast enhancement of the pulmonary arterial tree at the 80kV exposures. It has also been found that a gentle breath-hold open mouth technique with an 80kV scanning protocol also improves imaging quality. In terms of imaging quality assessment, the improved 80kV CTPA yielded acceptable image quality comparable to the standard protocol as per the radiologist assessment. This study's original contribution to knowledge is introducing a new, improved 80kV CTPA that allows the imaging departments to achieve an excellent contrast enhancement and lower suboptimal examinations. This study's overall significance is a demonstrable reduction in radiation dose without affecting the CTPA image quality in the majority of the patients

Blood Vessel Segmentation and shape analysis for quantification of Coronary Artery Stenosis in CT Angiography

This thesis presents an automated framework for quantitative vascular shape analysis of the coronary arteries, which constitutes an important and fundamental component of an automated image-based diagnostic system. Firstly, an automated vessel segmentation algorithm is developed to extract the coronary arteries based on the framework of active contours. Both global and local intensity statistics are utilised in the energy functional calculation, which allows for dealing with non-uniform brightness conditions, while evolving the contour towards to the desired boundaries without being trapped in local minima. To suppress kissing vessel artifacts, a slice-by-slice correction scheme, based on multiple regions competition, is proposed to identify and track the kissing vessels throughout the transaxial images of the CTA data. Based on the resulting segmentation, we then present a dedicated algorithm to estimate the geometric parameters of the extracted arteries, with focus on vessel bifurcations. In particular, the centreline and associated reference surface of the coronary arteries, in the vicinity of arterial bifurcations, are determined by registering an elliptical cross sectional tube to the desired constituent branch. The registration problem is solved by a hybrid optimisation method, combining local greedy search and dynamic programming, which ensures the global optimality of the solution and permits the incorporation of any hard constraints posed to the tube model within a natural and direct framework. In contrast with conventional volume domain methods, this technique works directly on the mesh domain, thus alleviating the need for image upsampling. The performance of the proposed framework, in terms of efficiency and accuracy, is demonstrated on both synthetic and clinical image data. Experimental results have shown that our techniques are capable of extracting the major branches of the coronary arteries and estimating the related geometric parameters (i.e., the centreline and the reference surface) with a high degree of agreement to those obtained through manual delineation. Particularly, all of the major branches of coronary arteries are successfully detected by the proposed technique, with a voxel-wise error at 0.73 voxels to the manually delineated ground truth data. Through the application of the slice-by-slice correction scheme, the false positive metric, for those coronary segments affected by kissing vessel artifacts, reduces from 294% to 22.5%. In terms of the capability of the presented framework in defining the location of centrelines across vessel bifurcations, the mean square errors (MSE) of the resulting centreline, with respect to the ground truth data, is reduced by an average of 62.3%, when compared with initial estimation obtained using a topological thinning based algorithm

Establishment of mouse lung tumor models and development of new therapeutic approaches

Two mouse models of lung cancer were used to investigate cancer progression, cancer treatment, and cancer imaging. One model was established by subcutaneous injection of human adenocarcinoma A549 cells and lewis lung carcinoma (LLC1) cells, the other by intratracheal instillation of LLC1 cells. In the first study, the role of HIF-1 in tumor progression was investigated. Overexpression of HIF-1alpha by genetic alteration of adenocarcinoma cells decreased tumor size, due to decreased proliferation and increased apoptosis, despite an augmented vascularization observed in these tumors. In a further study, tumor regression by immunological approaches was attempted. Hybrids were generated by fusing dendritic cells and syngeneic poorly immunogenic LLC1 cells of C57/BL6 origin. Hybrid immunization induced the expression of a variety of cytokines and the partial host protective immunity against LLC1 tumor challenge. Moreover, hybrid vaccination and adoptive immunotherapy resulted in notable tumor regression. For establishing small animal tumor imaging in our study, three different imaging modalities, micro computed tomography (müCT), multi slice computed tomography (MSCT), and flat panel volumetric computed tomography (fpvCT) were investigated. The müCT images of intrapulmonary tumors suggested that µCT is a reliable and non-destructive method for quantifying the volume of intrapulmonary tumors in the mouse model. In addition, müCT can be used to evaluate tumor angiogenesis. We exploited MSCT and fpvCT for the in vivo imaging and detection of lung nodules in a mouse LLC1 lung tumor model. FpvCT allowed easy monitoring of a lung tumor model with high resolution, facilitating follow-up investigations in cancer research. In addition, the superiority of fpvCT over MSCT was clearly demonstrated. Furthermore, both imaging modalities (müCT and fpvCT), along with fluorescent microspheres, were applied to delineate the relative contribution of blood supply via the pulmonary and the systemic arteries to LLC1 lung tumors. All three methods revealed the pulmonary artery to be the primary functional source for feeding vessels to the lung tumors. Moreover, both modalities demonstrated the microanatomy of the vessels and blood-supplying tissue. The development of experimental mouse lung tumor models is essential to the understanding of tumor pathophysiology and vascular microanatomy. Our findings can be used to identify novel targets for anticancer treatment and for site specific drug targeting. Additionally, the successful employment of various computed tomography systems for lung cancer imaging in rodents offers in vivo evaluation of such strategies.Zur Untersuchung von Tumorwachstum, Tumortherapie und Tumordarstellung wurden zwei verschiedene Lungentumor-Mausmodelle etabliert. Das eine Modell wurde durch die subkutane Injektion von menschlichen Adenokarzinom A549 Zellen oder Lewis-lung-karzinom zellen (LLC1), das andere durch die intratracheale Verabreichung von LLC1 Zellen ausgelöst. In der ersten Studie wurde die Rolle von HIF-1 auf das Tumorwachstum analysiert. Die genetisch verursachte Überexpression von HIF-1alpha in Adenokarzinom-Zellen führte, trotz erhöhter Gefäßbildung in den untersuchten Tumoren, über eine verminderte Proliferation und gesteigerte Apoptose zu einer Verminderung des Tumorwachstums. Eine weitere Untersuchung beschäftigte sich mit einem immunologischen Ansatz der Tumortherapie. Es wurden dendritische Zellen und syngene, schwach immunogene LLC1 Zellen, abgeleitet von C57/BL6 Mäusen, fusioniert. Immunisierung mit diesen Zellhybriden induzierte die Expression verschiedener Zytokine. Desweiteren wurde eine effektive Immunantwort gegen schwach immunogene Tumorzellen und eine gesteigerte T-lymphozytär vermittelte Zerstörung der Tumorzellen beobachtet. Dieser Effekt ließ sich sowohl durch Zellhybrid-Vakzinierung als auch durch die Übertragung von zuvor Zell hybrid-aktivierten T-Lymphozyten herbeiführen. Zur Darstellung der induzierten Maus-Tumore wurden die Methoden der Mikro-Computertomographie (müCT), der Mehrschicht- Computertomographie (MSCT) und der Flachwandvolumen- Computertomographie (fpvCT) angewendet. Die mü;CT Darstellung von intrapulmonalen Tumoren erwies sich als eine geeignete, nicht-destruktive Methode für die Quantifizierung des Tumorvolumens. Außerdem war es mit müCT möglich, die Gefäßversorgung der Tumore darzustellen. Weiterhin haben wir die in vivo Darstellung und Detektion von Lungentumorknoten im LLC1-Lungen Modell mittels MSCT und fpvCT, untersucht. Aufgrund der präzisen Bestimmung der Tumorgröße ermöglicht die fpvCT die Analyse der Tumorprogression in zeitlicher Abfolge. Zusätzlich konnte eine Überlegenheit der fpvCT gegenüber der MSCT nachgewiesen werden. In Ergänzung wurden die Methoden der müCT und fpvCT zur Detektion von Fluoreszenzmikropartikeln für die Differenzierung von pulmonalarteriellen und systemarteriellen Blutflusses hinsichtlich der Versorgung des Tumorgewebes eingesetzt. Der strenge Hinweis, dass die Pulmonalarterien als funktionelle Quelle der Lungentumorgefäßversorgung dienten, konnte von allen drei eingesetzten Methoden erbracht werden. Darüber hinaus war es möglich, die Mikroanatomie der Gefäße sowie blutversorgende Gewebsbrücken darzustellen