Needs, Seeds, and Solutions Around Medical Imaging: History and Perspectives
Needs in Medical Education and Clinical Practice
From the Viewpoint of Medical Education
Faculty of Medical Sciences, University of Fukui, Eiheiji-cho, Fukui, 910-1193, Japan
Medical education needs to be highly structured to impart the enormous amount of information necessary just to go on to further clinical training. The basic framework is similar all over the world. It consists of basic sciences (e.g., anatomy, physiology, and biochemistry) and clinical training (e.g., internal medicine, surgery) where skills are mastered. Anatomy is considered to be basic science but is strongly related to and interwoven with clinical medicine [14,15]. In fact, clinical instructors often interact with students taking anatomy. The educational method called “image anatomy” emphasizes the inclusion of medical imaging . Image anatomy is a method for studying anatomy, in which the nondestructively visualized human body structures are used.
We describe the practice of human anatomy using cadaver imaging, which was inspired by autopsy imaging (Ai), in our facility, and then review history of anatomy education. Finally, we describe the present problems of teaching human anatomy and the future of the relationship between anatomy education and computational anatomy.
In Japan, the application of cadaver computed tomography (CT) imaging to educational anatomy training is becoming a big current, and its trials are carried out at several medical schools, where CT scanners only for the dead body are introduced.
CT images of cadavers have been used for anatomy practice by the Faculty of Medicine at Fukui University since 2010 [17-20]. Imaging data are acquired over 128 cm and reconstructed at 5-mm section thickness. The medical students can refer to the CT images as well as MRI images of cadavers under dissection in the anatomy department (Fig. 1.1). iPads connected with wireless LAN and desktop PCs connected with school LAN are used to refer to the images (Fig. 1.2).
In Japan, this is carried out at several medical schools including Fukui, Chiba, and Gunma Universities and is becoming more widespread with the growing installation of computed tomography (CT) scanners in pathology departments for postmortem examinations. An Ai conference, in which radiologists, pathologists, and forensic specialists participate, is held so that the anatomy teaching staff can understand the interpretation of the images. Then, the anatomy teaching staff pass on the CT images to the students.
Human anatomy was first described by the ancient Egyptians approximately 3500 years BCE. Minute descriptions of the cranial sutures and the brain surface are found in the Edwin Smith Papyrus, an ancient Egyptian medical text
Fig. 1.1 CT image (left) and MR image (right) of a cadaver chest for anatomical study
Fig. 1.2 Students can refer to CT images on the monitor, which is put adjacent to the cadaver
from approximately 1700 BCE . Hippocrates, an ancient Greek physician, investigated the goat brain. Various findings about anatomy are described in the Corpus Hippocraticum, which the pupils of Hippocrates edited. Though it is told that Herophilos (335-280 BCE) and Erasistratus (304-250 BCE) dissected the human body in ancient Alexandria, their writings have vanished. After that, Alexandria prohibited human dissection for religious reasons, and new knowledge about anatomy did not arise for 1000 years or more. During this period, Galen (129216 CE) dissected animals energetically . He left inclusive and detailed anatomy books, mostly based on dissections of apes.
There was a revival of interest in anatomy during the Renaissance. Leonard da Vinci created human anatomical drawings, although his notebook was not published during his lifetime . In the early 1500s, the study of anatomy commenced at the University of Bologna, and Andreas Vesalius (1514-1564) of the University of Padua published De humani corporis fabrica (Structure of the Human Body) based on dissections performed in 1543. This became the basis of modern anatomy.
After this, research in human anatomy advanced, and cadaver dissection became part of medical education. At the present time, physical dissection is partly replaced with image-based dissection, that is, image anatomy, such as Ai. The history of Ai is described in the other section (Chapter 4.4.1) of this book. Especially “Virtopsy” in Switzerland is actively used in the forensic field . The purpose of Virtopsy is not the education of anatomy to medical students but the investigation of the cause of death. That is, there is little collaboration between experts in the Ai and educational anatomy fields in countries other than Japan. Ai and its related research areas including Virtopsy are also called “postmortem imaging (PMI).” Medical educational reform is leading to more concentration on clinical studies and less on basic science. In some areas, obtaining cadavers for dissection is difficult . Human anatomy is considered a fundamental subject in medical education . Adding imaging techniques, such as X-rays, CT, MRI, and new technologies (e.g., web-based learning), is becoming more common.
The “Visible Human Project,” which provides cross-sectional human body imaging data including high-resolution optical, CT, and MR images [27-29], has become a resource in the study of anatomy that integrates traditional instruction with modern CT and MRI technologies realizing a three-dimensional image (http:// www.nlm.nih.gov/research/visible/visible_human.html).
Moreover, there are reports on clinical anatomy training for nerve block anesthesia using a 3D anatomy system that can display the cadaver from one’s preferred direction and in one’s chosen depth in three dimensions [30, 31]. The advent of the 3D printer means that in addition to volume-rendered images, physical anatomical models may now be produced. Surgeons are beginning to use these to examine surgical procedures during preoperative planning.
In computational anatomy research, the comparison and registration of 3D images constructed from huge and elaborate CT/MRI image datasets (internal organs) with 3D data obtained by 3D surface scanners may be needed. A physician speculates an internal state from the body surface and performs diagnosis and treatment. A nurse also guesses the patient’s condition from the body surface. Therefore, there are many points that are important to diagnose on the body surface. Some of them are called tender points, and such pain is regarded as radiating pain (referred pain). McBurney’s point and Lanz point are famous in the case of appendicitis. So, if we could see through to an internal organ and an organic state from the body surface, it would be useful for medical education. Although there is a report in which transparency of the ranine (frog’s) skin was achieved , it will likely be difficult in humans. If we could project the 3D information of the internal organs on the surface of the body by projection mapping, this would be useful for medical education. In addition, approaches using computational anatomy for not only normal cadavers but also cadavers with diseases such as malformations, tumors, and inflammation will be requested.