AMERICAN JOURNALOFPHYSICALANTHROPOLOGY 55:101- 110(1981) Computed Tomography in Paleopathology: Technique and Case Study PATRICIA A . WONG Department of Anthropology, University of Utah, Salt Lake City, Utah 84112 Computed tomography, Scan, Density, KEY WORDS Desiccation, Contraction of lung tissue, Megacolon, Hirschsprung disease ABSTRACT With the development of computed tomography, soft tissues and foreign body collections are distinguished with remarkable resolution. This distinction is particularly useful when examining desiccated human remains, both in construction of research strategies and when invasive procedures (i.e., traditional autopsies, needle biopsies, etc.)are not possible. Though the organs differ markedly from living tissue, it is possible to distinguish major organs with some certainty. One case study exhibited three separate pathological conditions which were not demonstrated with traditional radiological procedures. The use of radiographic procedures in paleopathology has proven useful for many decades, but these have, for the most part, been helpful in distinguishing changes in bone materials rather than soft tissues. With the advent of other radiographic procedures such as Xeroradiography (see Heinemann, 1976) and computed tomography (Hounsfield, 1973; Harwood-Nash, 19791, we are now able to distinguish the more discrete tissues such as muscles, soft tissue organs, and foreign body collections such as cysts, abscesses, and tumors. This paper describes certain dessicated human remains which were examined by means of computed tomography. Cases 1 through 4 were unearthed during the early 1900's by Mormon settlers in southeastern Utah. The provenience of these remains, thus, is difficult to assess accurately. Cases 5 and 6 were uncovered during the excavation of Bernheimer Alcove (42SA7361, an archaeological site which has been cross-dated to the Basketmaker 11-111period (Bernheimer, n.d.). The usefulness of computed tomography is not only in visualizing the internal soft tissues but, perhaps more importantly, as a procedure that will enable the construction of research strategies prior to invasive procedures. MATERIALS AND METHODS Computed tomography utilizes an x-ray tube as a source of radiation just as does conventional radiography. It does not, however, record the image on a fluorescent screen or pho0002-9483/81/5501-0101%03.00 0 1981 ALAN R. LISS, INC. tographic film. Instead, the radiant energy traversing the part being examined is measured and from this value is calculated the attentuation (decrease) in energy of the x-ray beam by the tissue through which it has passed. As the x-ray attenuation of bone, fat, muscle, and other tissue are sufficiently different, these changes can be calculated and ultimately displayed on a viewing monitor (see Brooks and Di Chiro, 1975). Radiation detectors are located on the side opposite the x-ray beam. Both the beam and the detectors are maintained in a constant spatial relationship as they are mounted on a common frame. The Ohio Nuclear Delta 50 model was used in these procedures and is seen in Figure 1. Between the x-ray beam and the detectors is the area through which the subject is positioned while on a movable belt. By rotating the x-ray beam and the detectors, multiple transmission intensity measurements are made through the subject. Typically, thousands of measurements are made for each degree of the 180"of rotation used in the development of a single image. These measurements, after algorithm translation by the computer software, permit spatial displays in the form of anatomic cross sections on the monitor. From the monitor, Polaroids are taken and the images can be examined away from the console. Received November 7 , 1979; accepted October 2, 1980 102 P.A. WONG RESULTS Computed tomographic examinations were done on the remains of six individuals who were, in varying degrees in intactness, preserved solely by the very dry environment of southeastern Utah (Eubank, 1979). One of the best preserved individuals (Case 1) is a young female (UMNH 77.20) about 19 years of age, judging by the skeletal maturation (Lusted and Keats, 1972). She was unearthed during the early 1900's and, though no other evidence is known which would confirm the dating, she is in the characteristic flexed position (Fig. 1) of the Basketmaker I1 period (ca. A.D. 1-500) (Reed, 1964). The first scan (Fig. 2) is through the midregion of the skull. The tip of the pinna of the right ear is visualized (a). Dehydrated brain tissue (b)lying anterior to the internal occipital protruberance (c)is seen and the sagittal sulcus is present within this tissue. While this is not a pathologic condition, it does illustrate the detailed resolution possible using computed tomography. Figure 3 is a scan several centimeters lower than the previous level of Figure 2; it demonstrates the oral pharynx (a), the nasal cavity (b), and the maxillary sinuses (c) which are all filled with a dense, amorphous material. The density of this material is similar to the material found within the stomach (a) in Figure 5 . Further, though it appears that part of the esophagus has ruptured or decomposed to the point of being unrecognizable, this dense material can be found in segments of the remaining esophagus. This suggests the presence of a dense material which was ingested and rather violently aspirated. Figure 4 (a)demonstrates a contraction of the left lung, compared to the right (b). Dense material (c) along the left posterior pleural area is also seen. Conditions such as calcified empyema, which is secondary to inflammatory disease, such as pneumonia, could produce such an appearance. Figure 5 (a) indicates the midportion of the stomach. The lighter, more dense, area on the outer part of the stomach is, as has been mentioned, of a density similar to that of the mate- Fig. 1. ComputedTomography Scanner; (a) x-ray radiationdetectors mounted on common frame opposite (b) x-ray beam; Case 1 positioned on (c) movable belt. C.T. IN PALEOPATH TECHNIQUE AND CASE STUDY Fig. 2. (a)Ear pinna; (b)brain tissue with sagittal sulcus; (c) occipital protuberance; (d) falx; (el subdural space. 103 104 P.A. WONG Fig. 3. (a) Oral pharynx; (b) nasal cavity; (c) maxillary sinuses. C.T. IN PALEOPATH: TECHNIQUE AND CASE STUDY Fig. 4. (a) Contracted left lung tissue; (b) remnants of right lung tissue not contracted, (c)dense material along left posterior pleural area. 105 106 P.A. WONG Fig. 5. (a)Midportion of the stomach with ingested material; (b) distended segment of intestine. C.T. IN PALEOPATH: TECHNIQUE AND CASE STUDY Fig. 6. (a)Cross sections of the ascending and descending portions of the colon at the T12 level. 107 L Fig. 7. Case #2, distinct visualization of both cerebral hemispheres and cerebral sulcus. C.T. IN PALEOPATH: TECHNIQUE AND CASE STUDY rial found in the sinuses and cavities of the skull. A segment of the distended intestine (b) is seen lying laterally to the stomach. This particular segment of the intestine can be followed up to the level of the elevated diaphragm of the left lung. A t the T12 level (Fig. 6),we see the ascending and descending segments of the colon (a) which are filled with fecal material and are quite distended. Serial scans all the way to the pelvic floor demonstrate a continuously distended colon filled with material of density similar to that found in the upper intestine. The obvious question is how this specimen relates to other desiccated humans and whether these conditions which have been observed in one individual are pathological or are normal postmortem conditions. Computed tomographic scans were made on five other desiccated individuals. Figure 7 is a scan through the skull of a young male (BYU 6664.1), case 2, dated to the Pueblo 11 (ca. A.D. 1100-1300) period. The brain tissue of this individual is remarkably distinct, quite unlike the brain tissue of Case 1. Both cerebral hemispheres and sulci are well-visualized. Scans were made through the lower abdominal area and the results differed considerably from scans in Case 1in that there was no evidence of distension of the intestine. Records concerning the provenience of this individual are vague, though it appears that he, too, was originally uncovered in the early 1900's in southeastern Utah. The condition of the brain tissue, as it differs considerably from others scanned, raises the question of Pueblo provenience. The difference, of course, could be explained by differential conditions of preservation. Case 3 (BYU66-61.61)dated to Basketmaker I1 and was totally eviscerated, except for the brain tissue. This condition was unknown prior to examination by computed tomography. Case 4 (BYU 66-57.2) was a near or neonatal infant, of unknown provenience, whose internal organs were too small for adequate visualization, even using a special enlarging program of the Ohio Nuclear computer software. Case 5 (UMNH 24080 FS91-1) and Case 6 (UMNH 24080 FS90-1)were children (ca.4 and 6 years, respectively) dating to the Basketmaker 11-111period (ca. A.D. 1-750). The intestinal organs of both cases differ considerably from the distended intestines of Case 1and the intestinal contents are similar to those of Case 2, tending to support the conclusion that the distension noted in Case 1is probablypathological and not the result of postmortem changes. 109 DISCUSSION Hirschsprung disease, first reported in 1887 (Keeferand Mokrohisky, 1954)is apathological condition characterized by a dilated colon, retention of fecal material, abdominal distension, and a normal-appearing rectosigmoid region. The scans of Case 1are characterized by all of these conditions except that of the normal rectosigmoid region. Collapse of the sphincter muscles during the postmortem period may explain the distended rectal region in this young woman, though confirmation is not possible with this technique. This abnormality prevents adequate delivery of feces into the rectum. Classically, symptoms of congenital megacolon begin a t birth with constipation and progressive abdominal distension. In modern patients, intermittent relief may be obtained with conservative management and the degree of severity may be low enough so that longevity can be extended into adulthood (Keefer and Mokrohisky, 1954). A chest radiograph was taken of Case 1and compared with a chest radiograph of a living human with confirmed Hirschsprung disease. Both radiographs demonstrate a distinct flaring of the ribs which may well have been secondary to chronic abdominal distension. CONCLUSIONS Through the use of computed tomography, I have been able to distinguish three conditions which may be of pathological interest. One cadaver showed a dense material extending from the stomach to the oral and nasal cavities, possibly aspirated after ingestion and perhaps an agonal event. This technique also demonstrated a contracted lung and possibly calcified pleura which may have been secondary to inflammation. Finally, we saw the presence of a megacolon, the most common cause of which is Hirschsprung disease. It is, thus, possible to visualize soft tissue organs of desiccated human remains with computed tomography and, though the organs differ markedly from those of living tissue, it is possible to distinguish major organs with some certainty. Furthermore, it is possible to examine human remains when a n invasive procedure is not possible, an important point to consider due t o the sensitive nature of handling human remains (&sen, 1980). Computed tomography is suggested, therefore, as an excellent method to use either as an initial procedure in a comprehensive examination of desiccated human remains, allowing the construction of specific research strategies prior to 110 P.A. WONG an invasive procedure, or as an alternative approach when anatomic examination is not possible. ACKNOWLEDGMENTS I thank: PhilipR. Frederick, Gary W. Farnes, James Cuff, LDS Hospital, Salt Lake City; Jesse D. Jennings, Dennis Heskel, University of Utah, Department of Anthropology; Donald V. Hague, Ann Nelson, Utah Museum of Natural History, Salt Lake City; Dale Berge, Brigh a m Young University, Department of Anthropology, Provo, Utah. LITERATURE CITED Bernheimer, CL (n.d.1Field Notes, Bernheimer Expeditions of 1922,1923,1924,1926,1927,1929,1930,for the American Museum of Natural History. Manuscript, Utah State Historical Society. Salt Lake City, Utah. Brooks, RA, and DiChiro, G (1975) Theory of image reconstruction in computed tomography. 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