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Low Kilovoltage, Nonscreen Mummy Radiography.

Egyptian mummies have long been a source of fascination. By the 19th century, a lucrative trade in these and other artifacts from Egypt developed. Robert James Hubbard had this in mind in January 1894 when be began an extended journey abroad to procure artifacts for the Cazenovia Library in Cazenovia, NY. He had donated a building to the Cazenovia Library Society in 1890 with the intention that it be used as a library and museum. Upon his return in November 1894, he had cases built on the second floor of the building to house the artifacts he collected, including a sarcophagus or coffin containing a human mummy. (See Fig. 1.)

[Figure 1 ILLUSTRATION OMITTED]

Because the acquisition of these artifacts was not controlled, no record regarding where the mummy was recovered accompanied the purchase. Between 1944 and 1945, patrons of the Cazenovia Library sent photographs of the sarcophagus and mummy to the Metropolitan Museum of Art in New York City to determine the meaning of the inscriptions on the coffin lid. The hieroglyphics were translated by the museum's curator as a common prayer that accompanied food offerings for the dead. Because of the diamond-patterned wrapping visible in the photograph of the mummy, the curator determined that the mummy was from the late Greco-Roman period (332 to 395 AD).[1]

In 1984, the mummified remains were removed from the library, transported to a local hospital and radiographed using cassettes both in the Bucky and on the tabletop. Radiography of mummies is not a new procedure; Flinders Petrie published a radiograph of the leg bones of a wrapped mummy in 1898.[2] Transporting remains to imaging equipment also had historical precedent. In 1904, Elliot Smith and Howard Carter transported the rigid mummy of Tuthmosis IV in a taxi to the only x-ray facility in Cairo, Egypt.[3]

Although references to the radiographic exposure factors were not noted in these early studies, in 1967 Gray[4] provided the technical data from his extensive examination of mummies in museums in Great Britain and other European countries. He used medium-speed screens and kilovoltage settings based on the presence or absence of a cartonnage. A cartonnage is an outer covering over the head made of layers of linen or papyrus stiffened with glue or plaster (see Fig. 1 A). It is narrower in the back and wider and longer in the front, extending over the chest.[5] On the surface, brightly colored figures or hieroglyphics were painted and frequently set off with gold. When the cartonnage was present, the kilovoltage (kVp) ranged from 76 for the skull, thorax and abdomen to 68 for the entire lower extremity. Without the covering, the settings were decreased to 65 and 60 kVp, respectively.

Fodor et al[6] also provided technical factors in a 1983 study of 2 mummies from the Cincinnati Art Museum. They used 65 and 60 kVp with a 200-speed film-screen combination with the cassettes in the Bucky.

As more sophisticated imaging techniques such as computed tomography (CT) and magnetic resonance (MR) were developed, they were employed in the examination of mummies. However, because mummies are composed of dried tissue that lacks mobile hydrogen, attempts at MR were unsuccessful.[7] CT, however, has proved more promising. The first CT scan performed on a brain removed from a mummy revealed the internal structure of the brain including the cerebral ventricles.[8] More recently, 3-D CT was used to reconstruct the face of a woman who died around 950 BC.[9] However, these studies are more expensive than conventional radiography. For example, a 1995 CT study of a mummy from Suffolk County Vanderbilt Museum in New York required a donation of $5000.[10]

Advanced imaging techniques such as CT may not be necessary to provide insights into the mummification process, social status, age at time of death, sex and pathologic condition of the mummy because embalming techniques were quite specific for each period during the 30 centuries the custom prevailed in Egypt. For example, the relative position of the incision used to remove the abdominal viscera is significant.

According to Brier,[11] a vertical incision was used to remove the abdominal contents before the Eighteenth Dynasty (1567-1320 BC). The organs were divided into 4 groups (liver, stomach, lungs and intestines) and placed into separate specialized containers known as "canopic" jars and the body cavity was packed with material such as sawdust.[12] During the Eighteenth Dynasty, the incision became slanted from the hip to pubic area. The practice of wrapping and returning the 4 visceral packets to the abdominal cavity began in the Twenty-first Dynasty (1085 to 945 BC). The heart was always left in situ.[11] Conventional radiography can differentiate the type of material located within the abdomen, reveal the location of the incision used to remove abdominal contents and therefore aid in estimating the date when a mummy was prepared.

Conventional radiographs also can demonstrate the approach used to prepare the head, which also varied over time. The method of removing the brain by fracturing the cribriform plate and extracting the organ through the nostrils was probably not employed before the Eighteenth Dynasty.[11] Bourriau and Bashford[13] radiographed a Roman Era mummy (30 BC to 323 AD) in which a missing posterior arch on the right side of the atlas suggested that the brain had been removed through the foramen magnum. Brier noted that during the Ptolemaic period (332 to 30 BC), molten resin was poured through the nostrils into the empty calvaria. He also stated that artificial or stone eyes have been noted in mummies from the Twenty-first Dynasty (1085 to 945 BC), but the practice apparently stopped by the Twenty-sixth Dynasty (664 to 525 BC).[11] The presence of the highly radiopaque resin or artificial stone eyes can be seen easily on a radiograph. In addition, a tangential projection will demonstrate a fluid line, indicating the relative position of the skull when the resin solidified.

Body positioning for mummification can indicate social status. During the Middle Kingdom period (2040 to 1640 BC), the hands were stretched out alongside or covering the pubic area. During the Eighteenth Dynasty, hands were positioned alongside the body unless the individual was of royalty, in which case the hands were crossed over the breast. Brier (written communication, August 1996) stated that by the Greco-Roman period, the arms crossed over the chest was no longer an indication of royal lineage. Standard anterior-posterior (AP) chest and abdomen radiographs not only demonstrate the position of the upper extremities but also provide an opportunity to evaluate epiphysial closure for estimating age at the time of death. These radiographs also reveal configuration of the pelvis, allowing for determination of the individual's sex.[11]

Many mummies, such as the one in the Cazenovia Library, have been stored in rooms without humidity or temperature controls, thus increasing their fragility. Moving them for examination could easily result in structural damage, whereas on-site examination with a mobile x-ray unit could help preserve the integrity of the mummy.

As part of a fund-raising drive in Spring 1994, the Cazenovia Library-Museum began preparations to celebrate the 100th anniversary of the arrival of the mummy. The museum curator wanted an assessment of the condition of the mummy since the last examination 10 years previously. However, the curator believed the mummy could not be transported to an imaging facility. This article describes a low-cost, mobile radiographic procedure that used low kilovoltage and nonscreen film holders to produce low-contrast, high-resolution images. The images are compared with those obtained in the 1984 study when the same mummy was transported to a local hospital and radiographs were produced using higher kilovoltage with cassettes (with intensifying screens) both in the Bucky and on the table top.

Methods and Materials

The mummy was located on the second floor of the museum, an 1830 Greek Revival house. A Picker Field Army mobile unit, circa 1944, which was intended to be parachuted into battlefield situations, was disassembled into the transformer, control unit, tower, tube and cables and transported in sections up a narrow staircase to the display room.

Two types of film holders were used with Private Practice Brand film provided by Konica. Konica also donated a 400-speed screen system that was used to establish technical factors. A nonscreen film holder was constructed using 1/16-inch foam core cut to 14.25 x 17.25 inches to provide a stiff backing for the film. Two sheets of film were placed on top of the foam core. Double loading the film holder eliminated the need to duplicate a particular image. The foam core and film were covered with 4 layers of 4 mm-thick black plastic sheeting (Frost King - Thermwell). Through experimentation, 4 layers of sheeting were determined to be sufficiently opaque to prevent light fogging of the film.

The mummy and the shelf on which it was displayed were removed from the cabinet and placed on 1 x 3 x 48 inch boards. The boards formed a "cassette tunnel" that could be moved under the shelf. (See Fig. 2.)

[Figure 2 ILLUSTRATION OMITTED]

A source-to-image receptor distance (SID) of 50 inches was used for all projections. All exposures were made at 50 kVp and 13 mA; only the exposure time varied. (See Table 1.) The low kilovoltage setting enabled visualization of desiccated soft tissue and wrappings. Foregoing the use of intensifying screens permitted direct exposure of the film and produced images with less contrast, wider latitude and more visible detail. Because there was no darkroom on the premises, a series of exposures was made and the films were transported several miles to a veterinary clinic for processing.

Table 1
Exposure Factors for Radiographs of the Mummy(*)

Region                Image       Exposure Time          Total mAs
                      Receptor    (seconds)

AP ches               Screen            1                      13
                      Nonscreen       195                    2535

AP and lateral        Screen            1                      13
chest                 Nonscreen       208                    2704

Extremities           Nonscreen       195                    2535


(*) Exposures were made at a 50-inch SID at 50kVp and 13 mA.

Image Findings

Two radiographs, a lateral projection of the skull (Fig. 3) and an AP projection of the lower chest and upper abdomen (Fig. 4) from the 1984 study are presented for comparison and discussion. The lateral projection of the skull from the present study (Fig. 5), indicates an absence of any brain remnants or other radiopaque material such as resin and clearly demonstrates a lambdoidal suture and flattened dorsum sella. All the teeth seem to be present and do not appear to have been subjected to excessive wear. The lack of tooth wear suggests the individual ate bread made from the finest flour instead of flour that contained sand.[14] The mandible is below the level of the chin of the cartonnage. Body wrappings are evident posterior to the spinous processes of the cervical spine. The vertex of the cartonnage is indented, corresponding to the external damage on the mask. Cracking of the entire internal surface of the cartonnage is apparent, with the most extensive area of damage underlying the face. Some of the material appears to have crumbled onto the surface of the head wrappings. The inferior margin of the cartonnage is visible, curving over the body of the mandible and across the spinous process of the second cervical vertebra.

[Figures 3, 4 and 5 ILLUSTRATION OMITTED]

On the frontal or modified AP projections of the skull and upper thorax (Figs. 6A, 6B), which are slightly rotated to the right, the crista galli appears to be displaced to the right. The suggested displacement of the crista galli and apparent intact dens and atlanto-occipital articulation are consistent with the type of trauma resulting from a device such as a rod or brain hook pushed through the cribriform plate to remove the brain.

[Figure 6 ILLUSTRATION OMITTED]

Large prominent frontal sinuses and both lambdoidal and sagittal sutures are noted. Other skeletal components -- the first 5 thoracic vertebrae, ribs, clavicles, portions of the scapulae and proximal humeri -- are intact with clearly visualized cortices, suggesting the individual lacked skeletal pathology such as osteoporosis. No epiphyses are seen on the proximal humeri, indicating the individual was older than 25 years of age at the time of death. Cracking of the cartonnage, also evident on the lateral projection (Fig. 5), is noted along the inferior margins of the mask. The parts of the cartonnage that extend over the anterior and posterior portions of the chest are clearly demonstrated on the right side. The margin of the more narrow posterior portion of the cartonnage also is evident over the left side of the chest.

The AP projections of the lower chest and upper abdomen (Figs. 7A, 7B) reveal skeletal structures and articulations without gross pathology. The arms are crossed over the chest. The hands are extended in slightly different positions; the fingers of the left hand are seen over the proximal right humerus while the right hand appears to be in ulnar deviation.

[Figure 7 ILLUSTRATION OMITTED]

In Figure 7B a soft tissue defect is demonstrated on the left side of the abdomen (A). Two oval radiopaque structures of similar size are found in the abdomen. The structure on the left (B) is oriented diagonally and partially obscures the upper half of the soft tissue defect; the mass on the right (C) is located midway between the vertebrae and the lateral margin of the body. A third radiopaque structure (D) is noted on the right side over the psoas muscle. What may be a fourth oval radiopaque structure (E) is seen on the right side superior and medial to the previously described oval mass.

The margins of the posterior portion of the cartonnage are visible under both hands and across the body of the eighth thoracic vertebra. On the left side, at the level of the 11th thoracic vertebra, the inferior margin of the anterior portion of the cartonnage (F) appears to terminate. Another structure, similar in appearance to the cartonnage, is noted over a portion of the abdomen. The "cracking" pattern, revealed on the images of the head, also is seen through the soft tissue defect on the left side of the abdomen. The margin of this structure appears to overlap on the right side under the shadows of the ribs and forearm. A distinct lateral margin on the lower cartonnage-like structure (G) is demonstrated on the right side of the body and clearly visible over the wing of the ilium.

On the AP projection of the lower abdomen and pelvis (Fig. 8), soft tissue is evident around the pelvis and proximal femur. Wrappings also are clearly visible. Folded material is apparent in the area of the groin, and the crisscross pattern of the wrappings is seen between the femurs. Fogging (A), caused by a pinhole light leak through the plastic cover, is noted over the left sacrum.

[Figure 8 ILLUSTRATION OMITTED]

Anterior-posterior projections of the femurs (Fig. 9) and tibias and fibulas (Fig. 10) demonstrate soft tissue, wrappings and skeletal components free of gross pathology. Growth arrest, or Harris lines, are noted on the proximal fibulas (Fig. 10 A) and distal tibias (Fig. 10 B). Harris lines, also known as transverse lines of Park, develop during periods of biological stress such as injury, starvation and infection.[15] Sandison and Tapp reported this occurrence in 30% of mummy tibias, suggesting a poor state of health during childhood and adolescence in ancient Egypt.[16] This view also reveals a semicircular defect (Fig. 9 A) in the shelf on which the mummy rests, visible at the level of the proximal third of the left femur.

[Figure 9-10 ILLUSTRATION OMITTED]

Discussion

The 1984 radiographic study led to the following conclusions: the individual was a woman between 30 and 50 years old at her death with a "good" spine and "good" teeth but some evidence of arthritis. Because those images (Figs. 3, 4) were obtained using higher kVp settings and intensifying screens, the resulting higher-contrast radiographs obscured some skeletal detail and prevented visualization of low-density structures such as the cartonnage. Such structures and details were readily demonstrated on the corresponding radiographs of the current study (Figs. 5, 7B). In fact, there was no evidence of arthritis or any other degenerative processes found in the present study.

The nonscreen, lower kilovoltage images not only demonstrated damage to the internal surface of the cartonnage but also the relative position of the underlying skull. Because of this, the mandible was noted at a level considerably lower than that of the cartonnage mask, suggesting the mummy was placed in a vertical position at some period. An abdominal incision also was readily identifiable that had not been detected on the 1984 radiograph. Although radiopaque visceral packages were seen on the abdominal radiographs in both studies, they were more clearly defined on the nonscreen image. In addition, what appeared to be a fourth visceral package was noted only on the nonscreen radiograph.

As with any imaging study, a radiographer must be knowledgeable of the composition of the object to be examined and select the most appropriate type of film holder, exposure factors and radiographic unit. The function of an intensifying screen is to reduce the exposure and increase image contrast where subject contrast is low. Because mummies are composed of bone, desiccated tissue and wrappings, the film-screen technique employed in the 1984 study was less appropriate. Additionally, exposure time is not a factor in any type of specimen radiography. Therefore the nonscreen, non-Bucky imaging method provided more skeletal detail due to lower contrast, and the lower kilovoltage demonstrated extremely low-density structures such as the wrappings and cartonnage.

A number of mummies, from Egypt and other cultures that practiced preservation of the dead, have been stored in non-climatically controlled environments. They are fragile objects that may not be safely transported for examination. Low contrast, nonscreen skeletal assessment of the Cazenovia Library mummy demonstrated not only the extent of the damage to the exterior surface of the cartonnage but also flaking on the interior surface. Because of this damage, moving the mummy from the library could have produced much more extensive deterioration of the internal surface of the mask. When it is important to investigate the spatial relationship of internal structures, computed tomography can be justified if the specimen can be safely transported. Otherwise, portable radiography using low kilovoltage and nonscreen film holders has been shown to provide valuable information at a low cost and with the least risk to the specimen.

References

[1.] Michael B, Marshall A. Cazenovia's Mummy. Regional Conference of Historical Agencies: 1984;14(10):1-2.

[2.] Spencer AJ. Death in Ancient Egypt. New York, NY: Penguin Books; 1982:135.

[3.] Dunand F, Lichtenberg R. Mummies: A Voyage Through Eternity. New York, NY: Harry N. Abrams, Inc; 1994:80.

[4.] Gray PHK. Radiography of ancient Egyptian mummies. Med Radiog Photog. 1967;43:34-44.

[5.] David R, ed. Mysteries of the Mummies. New York, NY: Charles Scribner's Sons; 1978:63.

[6.] Fodor J, Mallott J, King A. The radiographic investigation of two Egyptian mummies. Radiol Technol. 1983;54:443-448.

[7.] Hatfield S. MRI useless for unraveling mummy mystery. Advance for Radiologic Science Professionals. April 1992:46.

[8.] Vahey T, Brown D. Comely Wenuhotep: computed tomography of an Egyptian mummy. J Comput Assist Tomogr. 1984;8(5):992-997.

[9.] Marx M, D'Auria SH. Three dimensional CT reconstruction of an ancient human Egyptian mummy. AJR. 1988;150:147-149.

[10.] Stout D. CAT Scan for 3,000-year-old mummy. New York Times. Nov. 1, 1995:B6.

[11.] Brier B. Egyptian Mummies. New York, NY: William Morrow and Company, Inc. 1994:89-94.

[12.] Peck WH. Mummies of ancient Egypt. In: Cockburn A, Cockburn E, Reyman TA, eds. Mummies, Disease and Ancient Cultures. 2nd ed. Cambridge, UK. Cambridge University Press; 1998:15-37.

[13.] Bourriau J, Bashford J. Radiological examination of two mummies of the Roman Era. M.A.S.C.A. Journal. 1988;1 (6):168-171.

[14.] Brahin JL, Fleming SJ. Children's health problems: some guidelines for their occurrence in ancient Egypt. M.A.S. C.A. Journal. 1988;2(1):75-81.

[15.] Ogden J. Skeletal Injury in Children. Philadelphia, Pa: WEB Saunders Co; 1990:80.

[16.] Sandison AT, Tapp E. Diseases in ancient Egypt. In: Cockburn A, Cockburn E, Reyman TA, eds. Mummies, Disease and Ancient Cultures. 2nd ed. Cambridge, UK. Cambridge University Press; 1998:38-58.

Gerald Collogue, M.H.S., R.T.(R)(CT)(MR), is director of the Diagnostic Imaging Program at Quinnipiac College in Hamden, Conn. The author acknowledges Betsy Kennedy of the Cazenovia Public Library, T. Chris Tormey and Byron Conlogue for their assistance and Gregory Hackett, DVM, for the donation of the mobile radiographic unit.

Reprint requests may be sent to the American Society of Radiologic Technologists, Communications Department, 15000 Central Ave. SE, Albuquerque, NM 87123-3917.

[C] 1999 by the American Society of Radiologic Technologists.3
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Author:CONLOGUE, GERALD
Publication:Radiologic Technology
Geographic Code:1USA
Date:Nov 1, 1999
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