Abstract
Virtual autopsy or post-mortem imaging is a rapidly developing field in medical imaging that deals with the visualization and study of the human body after death. This review provides an overview of different imaging modalities used in post-mortem imaging, including computed tomography (CT), magnetic resonance imaging (MRI), ultrasound (US), and radiography. It also discusses the importance of virtual autopsy in forensic medicine, pathology, and research, and highlights the applications and benefits of this technique in each field. The review further examines the strengths and limitations of each imaging modality and provides examples of their use in specific cases. Overall, this overview serves as a comprehensive guide to post-mortem imaging and provides readers with a deeper understanding of this important and growing area of forensic imaging.
Introduction
Virtual autopsy has emerged as a valuable tool in forensic science for the examination of human remains. These techniques allow forensic pathologists and other medical professionals to see inside the body and identify injuries, diseases, and other conditions that may have contributed to a person’s death or injury. In Forensic medicine, these techniques allow to identify fractures and other injuries, which can be crucial in determining the cause of death or injury in a forensic investigation. Detecting foreign objects, such as bullets and knives, is also possible using radio imaging techniques, and this information can help law enforcement and forensic investigators in reconstructing the events. Radio imaging techniques can also be used to diagnose medical conditions that may have contributed to a person’s death or injury. For instance, a magnetic resonance imaging (MRI) scan can reveal a brain tumor that may have caused a person to experience seizures or other symptoms.
Unlike traditional autopsies, virtual autopsies rely on non-invasive imaging techniques, such as computed tomography (CT) scans, to visualize the internal structures and anatomy of the body. This technology allows forensic pathologists to obtain a detailed, three-dimensional (3D) view of the body’s anatomy, which can help to identify the cause of death, identify evidence of disease or injury, and provide crucial information for investigations. The use of imaging techniques has numerous advantages over traditional autopsies, including faster and more accurate results, greater preservation of the body, and reduced risk of contamination. Post-mortem imaging is not a new concept. Radiographic examination of deceased individuals has a long history, dating back to the early 20th century, and CT and MRI are in use for post-mortem imaging since the 1990s. However, it was not until the development of modern imaging techniques that post-mortem imaging became a more widely used tool in forensic investigations.
History
Radio imaging techniques have been used in forensic investigations for several decades. Forensic radiology is a branch of radiology that uses medical imaging techniques, such as X-rays, CT, MRI, and ultrasound (US), to help solve legal cases. These techniques use radio waves to create images of objects, substances, and tissues in the human body and in other materials. They provide a non-invasive way to visualize what lies beneath the surface, making them valuable tools for forensic investigations. 1 One of the earliest radio imaging techniques used in forensics was X-ray imaging. X-rays were first used to scan bones and other things for signs of damage or concealed objects in the early 20th century after their discovery in 1895. 2 These are still widely used today in forensics, particularly in the examination of gunshot wounds, fractures, and other injuries. However, X-rays have limitations in their ability to distinguish between different types of tissues, and they provide only two-dimensional images. In some cases, a CT scan or MRI may be necessary to provide more detailed images of the body. 3
In 1973, the development of CT scanning technology revolutionized medical imaging. The development of CT scanning is credited to the British engineer Sir Godfrey Hounsfield and the South African physicist Allan Cormack. Hounsfield developed the idea of using X-rays to create images of the human body from different angles. However, the mathematical computations needed to transform the X-ray data into an image were beyond the capabilities of the time. Cormack developed the mathematics needed to convert the X-ray data into a visual image, a technique called “reconstruction.” This breakthrough enabled Hounsfield to build the first CT scanner, which he called the EMI (Electric and Musical Industries) scanner. One of the earliest and most notable applications of CT scanning in forensic investigations was in the case of the unidentified victims of the serial killer John Wayne Gacy, who was executed in 1994 for the murder of 33 boys and young men in the Chicago area. 4 The Cook County Medical Examiner’s Office in Chicago used CT scans to help identify the remains of eight victims who had been buried in Gacy’s crawl space. The scans were used to create 3D reconstructions of the skulls of the victims, which were then compared to antemortem (AM) dental records and other identifying information. Currently, CT scans have become an important tool in forensic investigations, particularly in the examination of blunt force trauma and skull fractures.
MRI is another radio imaging technique that has been used in forensics since the 1980s. 5 MRI uses a strong magnetic field and computer-generated radio waves to produce 3D detailed anatomical images. It is particularly useful for examining soft tissues, such as the brain, and has been used in forensic investigations to examine head injuries and other types of traumas. In 1990, a study describes the use of MRI in the pre-autopsy examination of human bodies. The authors conducted a study to determine the feasibility and effectiveness of pre-autopsy MRI in the evaluation of pathology in a variety of organs, including the brain, liver, kidneys, and prostate. The authors found that pre-autopsy MRI was useful in identifying pathology in the examined organs, and that the findings were consistent with those obtained during conventional autopsy. They also found that MRI could identify small lesions that may have been missed during conventional autopsy. 6
In 2006, the Institute of Forensic Medicine in Bern initiated a project with the University of Bern’s institutes of Diagnostic Radiology and Neuroradiology. 7 The project was named Virtopsy® and the aim was to use advanced imaging technologies, such as CT scans, MRI scans, and other imaging modalities to perform non-invasive autopsies on deceased individuals. The goal is to obtain detailed information about the cause of death and underlying health conditions without the need for a traditional invasive autopsy.8–12 Virtopsy® involved the use of various imaging techniques to create 3D images of the internal organs and tissues of the deceased person. To ascertain the cause of death, forensic pathology and radiology experts examined these photos. The project also involved the collection of clinical and demographic data and other specimens to validate the results of the autopsy. This project has been recognized as a pioneer in the field of virtual autopsies and has been widely cited in the scientific literature. To further spread their experiences, the project’s founders, Professors Michael Thali, Richard Dirnhofer, and Peter Vock, published a textbook on forensic imaging. 13 The results of the project have shown that virtual autopsies can provide reliable and valuable information about the cause of death in a non-invasive and cost-effective manner. The Virtopsy® project has also demonstrated the potential for virtual autopsies to play a valuable role in the investigation of sudden and unexpected deaths, as well as in the study of disease pathology and epidemiology. 14
Later in 2007, a study introduces post-mortem CT (PMCT) as a new method for disaster victim identification (DVI), which has the advantage of being non-invasive and providing high-resolution images of internal structures. 15 The author discusses different applications of PMCT in DVI, including estimating the cause of death, establishing a victim’s biological profile, and identifying unique features which can be used for the purpose of identification.
During the COVID-19 pandemic, virtual autopsies have gained increased attention and utilization, as traditional autopsies may pose a risk of infection to medical examiners and other staff. In addition, virtual autopsies can be conducted more quickly than traditional autopsies, allowing for faster identification and analysis of cases. Several countries have implemented virtual autopsy programs and provided autopsy guidelines during the pandemic, including Italy, where a program was launched in early 2020 to help manage the large number of COVID-19 deaths.16,44
Application of Virtual Autopsy in Different Cases of Forensic Legal Medicine
Drowning
Drowning is a leading cause of death among young American males, and virtual autopsies offer valuable insights into the circumstances of death while identifying key findings associated with drowning. Virtual autopsies in drowning cases typically can gather crucial evidence without the need for traditional invasive autopsies, which can be particularly beneficial in cases where the deceased’s body condition or circumstances may make a physical autopsy challenging or impractical. These imaging methods can provide detailed images of the body’s internal structures and help pathologists to identify fluid in the lungs, heart, or other organs that may indicate drowning. The CT scan data on the size, weight, volume, and quantity of liquid found in the lungs of drowned victims can provide valuable insights into the cause and circumstances of death. 17 Studies have shown that virtual autopsies provide comparable results to traditional autopsies in diagnosing drowning. For example, in 2007, Levy et al. published a study which aimed to compare the results of virtual autopsies with traditional autopsies in drowning cases. 18 The study involved 28 individuals who had drowned and underwent both a virtual autopsy and a traditional autopsy. The virtual autopsies were performed using the PMCT, which provided 2D and 3D images of the body’s internal structures. The results of the study showed that virtual autopsies provided valuable information on the drowning cases. The virtual autopsies were also found to be highly reliable at determining cause of death, with only minor discrepancies observed between the virtual and traditional autopsy results. In 2012, Kawasumi et al. published a study aimed to investigate how drowning and fluid buildup in the paranasal sinuses on PMCT scans are related. 17 The study involved 33 individuals who had drowned and underwent PMCT scans. The scans were analyzed to assess the presence and quantity of fluid accumulation in the paranasal sinuses, and the results were compared with the findings from traditional autopsies. The study suggested that fluid accumulation in the paranasal sinuses is a reliable indicator of drowning on PMCT scans. The presence and quantity of fluid in the paranasal sinuses were found to be positively correlated with the duration of submersion, indicating that longer submersion times are associated with greater fluid accumulation in the sinuses. Overall, this study provides important information on the association between drowning and fluid accumulation in the paranasal sinuses on PMCT scans, which can be useful in the evaluation of drowning cases. In China, Jian et al. (2019), investigated the changes in lung CT images in a drowning rabbit model and to evaluate the usefulness of virtual autopsy in drowning cases. 19 The study involved using rabbits as a model for drowning and performing PMCT scans of their lungs. The CT scans were analyzed to assess changes in lung CT image parameters, such as lung density and air space size, and compared to the results from traditional autopsies. The study showed that PMCT scans were able to detect characteristic changes in the lung CT image parameters in the drowning rabbit model, such as increased lung density and decreased air space size. The virtual autopsy was also able to accurately measure these changes, providing insights into the events leading up to the incident.
Heat Injury
Virtual autopsy of charred bodies is a non-invasive method of examining the internal anatomy of a deceased person who has suffered significant burning or charring. The main advantage of virtual autopsy in charred bodies is that it allows for the examination of the internal anatomy without the need for a traditional post-mortem examination, which can be challenging due to the extensive external and internal damage caused by the burning. It can provide valuable information on the cause of death, including the presence of bone fractures, organ damage, and internal bleeding. Additionally, virtual autopsy can also help in determining the extent and pattern of burning, which is crucial for criminal investigations and for understanding the circumstances surrounding the individual’s death. Thali et al. (2002), conducted a study wherein multi-slice CT scans and MRI were employed to execute virtual autopsies on incinerated remains, specifically in instances where fatalities occurred due to fire resulting from a collision between a motor vehicle and a stationary object. 20 The findings indicated that virtual autopsy techniques were capable of yielding significant insights into the internal anatomy of charred remains, encompassing the identification of skeletal fractures or the presence of air embolism. 20
Charred Bodies
In forensic cases involving charred bodies, the use of advanced imaging techniques like multidetector computed tomography (MDCT) offers significant advantages for documenting injuries and determining cause and manner of death. Cittadini et al. (2011) demonstrated the value of MDCT in three cases of charred bodies, where traditional autopsy methods were complicated by extensive burns. 21 The study found that MDCT could effectively visualize heat-induced injuries, such as pulmonary edema, fractures, and changes to the brain parenchyma, providing important insights into the victim’s condition before and after the fire. Notably, the technique also allowed for the detection of vital reactions, such as mucosal congestion and peribronchovascular edema, which suggested that the victim was alive and breathing during the fire. Additionally, MDCT provided a clear, 3D representation of the body, which was essential for analyzing the anatomical details that were obscured by the burns. Despite some limitations, such as the inability to detect soot in the airways of all cases, the study concluded that postmortem imaging techniques like MDCT can complement traditional autopsy methods, offering a non-invasive approach to examine complex cases. 21 The integration of radiological imaging with forensic pathology, can improve the accuracy and documentation of findings, which is particularly useful in determining the cause and manner of death in charred bodies.
Firearm Injury
In the context of firearm injury cases, virtual autopsies can provide valuable information about the type and severity of internal injuries brought on by a gunshot wound. The trajectory of the bullet, the quantity of bullets, and the position of any pieces can all be determined using a virtual autopsy. This information can serve as a critical factor in elucidating the determinants of death, regardless of whether it stems from an accident, self-harm, or external interference. Virtual autopsies may additionally yield insights regarding the existence of supplementary injuries or underlying medical conditions that could have contributed to the individual’s passing. An important merit of virtual autopsies in scenarios involving firearm-related injuries is their capacity to be executed rapidly and without necessitating invasive methods. This capability can aid in diminishing the interval between the time of death and the release of the decedent’s remains to their family, while also alleviating the necessity for conventional autopsies, which may be emotionally distressing for the relatives. Virtual autopsies are not a replacement for traditional autopsies, and in some cases, a traditional autopsy may still be necessary to fully investigate the cause of death. However, virtual autopsies can provide important supplementary information in firearm injury cases and can offer crucial supplemental information in cases involving violent crimes. The advantages and limitations of employing virtual autopsy techniques in forensic ballistics have been discussed in several studies. Oehmichen et al. (2004) emphasized the utility of CT and MRI in reconstructing gunshot injuries to the brain, enabling detailed visualization of entrance and exit wounds, missile tracks, and secondary changes. 22 Andenmatten et al. (2008) demonstrated the reliability of post-mortem multislice computed tomography (MSCT) in identifying bullet trajectories, fragment locations, and inflicted injuries in 22 cases of gunshot fatalities. 23 Thali et al. (2003) further highlighted the integration of MSCT and MRI, which allowed accurate correlations between radiological findings and autopsy results in cases of ballistic trauma. 24 Lastly, Poulsen and Simonsen (2007) documented the routine use of CT scanning prior to medico-legal autopsies, showcasing its value in detecting bone fractures, hemorrhages, and bullet fragments, thus supplementing traditional methods with improved precision and efficiency. 25 These studies suggest that virtual autopsy has significant importance for forensic medicine and the criminal justice system, as accurate and reliable investigations of violent deaths are crucial for determining the cause of death and identifying those responsible.
Forensic Odontology
In forensic odontology, virtual autopsy can be particularly useful when a traditional autopsy may not be feasible or desirable. One of the key benefits of virtual autopsy is that it can provide detailed images of the deceased person’s body, including the teeth and jaw, without the need for invasive procedures. 26 This information can be extremely valuable for forensic dentists, who use the structure and arrangement of a person’s teeth to identify them and to determine the cause of death. Virtual autopsy can also be helpful in investigating cases of bite mark analysis, as it can provide detailed images of the bite marks and the surrounding tissue. 27 Another advantage of virtual autopsy is that it is less intrusive and less time-consuming than a traditional autopsy. 28 This means that it can be performed more quickly and efficiently, which can be important in cases where the remains need to be released to the next of kin or where the cause of death needs to be determined quickly. The utility of virtual autopsy in odontology has been discussed by several authors.29, 30 Virtual autopsies have been performed using dental data by experts in the field of human identification 30 and DVI, 31 virtual autopsies have been performed using dental data by experts. Virtual autopsy can also be used to examine the mouth and jaw for any signs of injury or trauma that may be relevant to the cause of death. For example, if a person died from a blow to the head, the virtual autopsy images can help the forensic dentist determine the location and severity of the injury. Additionally, virtual autopsy can provide information about the presence of any dental work, such as fillings, crowns, or bridges, which can further aid in the identification process. 32 The images can also reveal any pathological conditions, such as tumors or abscess, that may have affected the person’s oral health. Furthermore, some authors have explored Automatic dental segmentation and matching systems, which use computer algorithms and software tools to analyze and compare dental images and data to identify individuals. This technology is becoming increasingly important in forensic dentistry as it helps to simplify and streamline the process of dental identification. The process of dental segmentation involves separating dental images into distinct regions of interest, such as individual teeth or specific features such as fillings or crowns. 33 This allows for a more precise and accurate analysis of the images, making it easier to identify individual characteristics. The matching process involves comparing these segmented images with other dental images in a database to find a match. The software uses various algorithms to compare features such as the shape, size, and position of teeth, as well as the location and type of dental restorations.34, 35 Overall, automatic dental segmentation and matching systems offer a more efficient and reliable method of dental identification compared to traditional manual methods.34–36 This technology can be particularly useful in forensic cases, such as mass disasters, where large numbers of individuals need to be identified quickly and accurately.
Recent Advances and Emerging Trends in Virtual Autopsy
Recent technological advancements and emerging trends are redefining the scope and application of virtual autopsy in forensic science. 3D reconstruction technologies have further revolutionized virtual autopsies. By rendering detailed, lifelike models of internal and external injuries, 3D reconstructions enable forensic experts to analyze complex trauma patterns and reconstruct events leading to death. Traditional PC-assisted craniofacial superimposition, which involves layering a facial image with a skull image, has long been a staple in forensic practice, yet it often demands the physical presence of a skull and precise alignment parameters. Recent advancements, however, have overcome these limitations through the application of CT-based 3D reconstruction, which generates detailed digital models of the skull without necessitating physical handling or the removal of soft tissues. Ishii et al. (2011) demonstrated the utility of CT in forensic identification by reconstructing 3D skull images for superimposition with AM facial images. 37 Using a single-slice CT scanner with a 2 mm slice thickness, the study produced detailed reconstructions that showed high morphological consistency with real skulls, effectively matching facial images. 37 While challenges such as the partial volume effect and dental metal artifacts were noted, the research highlighted 3D CT as a promising tool for identifying skeletonized remains. Similarly, Iino et al. (2015) showcased the potential of CT superimposition in identifying a mutilated jawless skull from a murder investigation. By comparing AM and PM CT data through multi-planar reconstruction (MPR) and 3D volume rendering (VR), they successfully matched anatomical features like frontal sinuses, confirming the identity of the remains. With its ease of application and ability to analyze partial remains, CT superimposition represents a significant advancement in modern forensic practices. 38
The integration of artificial intelligence (AI) and machine learning into virtual autopsy processes has streamlined image analysis and interpretation. AI algorithms can automatically detect fractures, hemorrhages, and other anomalies, significantly reducing the time required for manual analysis. Deep learning models are being developed to identify specific forensic markers, such as drowning-related pulmonary changes or firearm injuries, with remarkable accuracy. These advancements not only enhance efficiency but also minimize human error, leading to more standardized and reliable results. The application of machine learning in virtual autopsies is further enhanced by the development of virtual biobanks, which combine non-invasive imaging data such as CT, MRI, and US with digital pathology images of corresponding biological samples. These biobanks allow for the systematic analysis of diseases by integrating macroscopic, microscopic, medical imaging, and molecular phenotype data. Algorithms can be designed to self-learn from these datasets, making data-driven predictions or decisions based on limited sample sizes—a critical feature given the relatively small number of virtopsy cases available compared to traditional machine learning requirements. Interactive machine learning approaches are particularly promising. These algorithms incorporate expert knowledge directly into their design, enabling accurate predictions even with fewer cases. Unlike conventional black-box methods that require vast amounts of data, interactive algorithms streamline the process by embedding domain expertise into the analytic loop, significantly reducing the data and time required for training.
Innovative techniques such as nuclear magnetic resonance (NMR) spectroscopy are being integrated into virtopsy to analyze metabolomic profiles. NMR provides detailed information about tissue chemical composition and allows for comparisons between MRI data, histological findings, and molecular characteristics. This comprehensive approach addresses a significant gap in forensic pathology by differentiating disease-related changes from post-mortem effects, such as autolysis. Digital pathology also plays a critical role in the virtopsy framework. High-resolution images of tissue samples obtained via traditional autopsy can now be compared with medical imaging data, enhancing the correlation between microscopic and macroscopic findings. By systematically comparing these data types, machine learning models are being trained to distinguish between disease-related alterations and post-mortem changes. Such efforts promise to generate robust databases that support further algorithm development and refine forensic investigations.
The development of portable imaging devices, such as mobile CT scanners and handheld US systems, is extending the applicability of virtual autopsies to remote areas and mass casualty incidents. These devices facilitate on-site examinations, reducing the need to transport bodies to forensic facilities and expediting investigations in scenarios such as natural disasters, terrorist attacks, or battlefield casualties. Votino et al. (2014) conducted a prospective validation study to assess the feasibility, sensitivity, and specificity of PM-US in detecting major congenital abnormalities in fetuses, comparing the results with conventional autopsy. The study demonstrated that PM-US could successfully visualize fetal anatomy as early as 11 weeks’ gestation, with a high success rate (95.5%) in performing complete virtual autopsies. 39 By utilizing high-frequency linear and transvaginal probes, the researchers were able to capture detailed 2D and 3D images of the brain, thorax, and abdomen, crucial for identifying structural abnormalities. The study found that PM-US exhibited strong sensitivity and specificity, particularly for detecting brain abnormalities, thoracic issues like heart and lung defects, and abdominal malformations. 39 Notably, PM-US proved especially beneficial in cases where conventional autopsy was compromised, such as when severe maceration or fetal fragility hindered traditional dissection. These findings highlight the potential of PM-US not only as a reliable diagnostic tool but also as a valuable adjunct to traditional autopsy, offering advantages in terms of accessibility, cost-effectiveness, and the ability to maintain anatomical integrity. The study’s results support the expanding role of US in virtual autopsy, enhancing both prenatal diagnostic capabilities and postmortem investigation in cases of fetal death. 39
Non-invasive techniques, including magnetic resonance spectroscopy (MRS) and advanced imaging biomarkers, are being explored for forensic toxicology applications. These methods enable the detection of toxic substances, such as drugs or poisons, within tissues and organs without the need for invasive sampling. This is particularly useful in cases involving suspected poisoning or substance abuse, where rapid toxicological analysis is crucial. One persistent challenge in the field is the limited number of virtopsy datasets available for algorithm training. Addressing this issue involves leveraging existing data from previous studies and incorporating innovative methods, such as rapid autopsy protocols performed within three hours of death. This minimizes the impact of autolysis and ensures high-quality material for molecular analyses. Virtual autopsy represents a paradigm shift in forensic investigations, driven by advancements in imaging technologies, AI, and non-invasive techniques. By offering accurate, efficient, and ethical solutions, it is redefining how post-mortem examinations are conducted. The ongoing development of portable devices, machine learning algorithms, and specialized applications ensures that virtual autopsies will remain at the forefront of forensic innovation, addressing both current challenges and future demands.
Advantages and Disadvantages of Virtual Autopsy
Advantage of Using Virtual Autopsy
Virtual autopsies are non-invasive and do not require incisions or opening of the body. This minimizes potential damage to the body and reduces the risk of contamination. 40
Virtual autopsies can be completed much more quickly than traditional autopsies, as imaging technology and computer algorithms can process and analyze large amounts of data in a matter of minutes. 41
The use of high-resolution imaging and advanced computer algorithms can lead to improved accuracy in identifying and diagnosing the cause of death. 42
Virtual autopsies minimize the risk of exposure to hazardous materials, such as infectious diseases, that can pose a risk to medical examiners and other staff. 43
Virtual autopsies are typically less expensive than traditional autopsies, as they do not require specialized equipment or facilities and can be performed more quickly. 40
Virtual autopsies can be performed remotely, making it easier for medical examiners in remote or underserved areas to access the technology and expertise needed to perform autopsies.
The non-invasive nature of virtual autopsies helps to preserve evidence, making it possible to perform multiple examinations on the same body if necessary.
Disadvantages
Virtual autopsies do not allow for a hands-on examination of the body, which can provide important information about the cause of death. 40
The accuracy of virtual autopsies depends on the quality of the imaging technology used and the expertise of the individuals interpreting the images.
Virtual autopsies may not be widely available in all locations, particularly in low-resource settings, where access to advanced imaging technology and specialized personnel may be limited.
Although virtual autopsies are typically less expensive than traditional autopsies, the cost of the necessary imaging technology and specialized personnel can still be prohibitive in some settings.
In some jurisdictions, virtual autopsies may not be legally recognized as a substitute for a traditional autopsy.
The use of high-resolution imaging and computer algorithms in virtual autopsies raises potential privacy concerns, as the images and data generated during the autopsy can potentially be used for purposes beyond the original intention.
Some causes of death, such as certain types of poisoning or suffocation may be difficult to identify using virtual autopsy methods alone.
Conclusion
Virtual autopsy has been applied in various fields within forensic science, including the examination of mass disasters, the evaluation of cases of sudden unexpected death, and the investigation of cases of suspicious or violent death. In each of these areas, virtual autopsy provides valuable information that can assist in the determination of cause and manner of death and can provide crucial evidence for investigations. Application of virtual autopsy in forensic science is also a rapidly evolving field, and new developments in technology are constantly increasing the accuracy and utility of this tool. Despite its advantages, virtual autopsy must be used in conjunction with other forms of evidence and must be interpreted with caution to ensure accurate results. In conclusion, virtual autopsy is a valuable tool in the field of forensic science and has numerous applications in the investigation of death. By providing non-invasive imaging techniques, virtual autopsy offers faster and more accurate results, greater preservation of the body, and reduced risk of contamination, making it an important tool for forensic pathologists and investigators.
Footnotes
Declaration of Conflicting Interest
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Ethical Approval and Informed Consent
Ethical permission was not applicable for this article, as this is a review article drafted from various research articles and not from patients directly.
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
