Target Identification for Biopsy and Retrieval

In many cases, radiography reveals an area of interest that warrants closer study. Typically, this is a particular pathological anomaly or an artifact either within the mummy or among the mummy wrappings. If it is within the research protocols and the target is to be biopsied or removed, conventional radiography can be employed to pinpoint the spatial relationship

Figure 2.80 A PA projection on a Guanajuato mummy, MH2.
Figure 2.81 a chest radiograph of a chinese mummy recovered from northern Nevada. Note the old fracture of the humerus (arrow).

of that target. Clearly, the imaging modality of choice for this task is computed tomography, CT. However, in the field conventional radiography can be successfully employed to pinpoint lesions and artifacts. The object may be located by using two long needles, such as spinal needles, inserted at right angles into the approximate target location. Taking into account inherent characteristics such as magnification and distortion, the depth and direction of needle insertion are determined from the original radiographs. Radiographs taken at right angles to the needles while in place will provide an assessment of the target's spatial relationship relative to the needles. The target, once located, can then be biopsied or extracted under endoscopic guidance.

Figure 2.82 A lateral skull of a mummy known as the cook of Ra that was radiographed at Yale university's Peabody Museum. note the fracture (arrow) of the occipital bone.

Figure 2.83 A compression fracture of a thoracic vertebrae (arrow) demonstrated on the lateral chest radiograph of a Chachapoya mummy.

Two examples using conventional radiography with needle localization are provided. In the first case, a radiopaque mass, thought to be a kidney stone, was demonstrated on the abdominal radiograph of a mummy located in a crypt under a church in Popoli, Italy (Tales of an Italian Crypt 2001). In order to remove the mass endoscopically,

Figure 2.84A An AP pelvis image of a mummy (U6) from Urbania, Italy, with an apparent extremely large bladder stone.
Figure 2.84B A small bladder stone noted within the pelvis of another mummy (u18) from urbania, Italy.

spinal needles were inserted at right angles in the suspected region to serve as a guide (Figure 2.87A). Periodically, while the endoscope was advanced, radiographs were taken to document the precise location of the device until the mass was removed (Figure 2.87B). Subsequent analysis of the mass verified it was a kidney stone (Fornaciari et al. 2002). This field application for spatial location reduces the need to move the study subject to an imaging facility, thereby reducing the risk any dislocation of the target within the internal context.

Figure 2.85 another mummy (u5) from urbania, Italy, with an apparent congenital dislocation of the right hip. The poor condition of the mummy was readily identified by the loose ribs in the pelvis.
Figure 2.86 Bilateral calcified arteries (arrows) were noted within the pelvis of a mummy from urbania, Italy.

The second case involved a sideshow mummy known as Hazel Farris. Polaroid radiographs demonstrated a radiopaque mass in the chest (Figure 2.88A). A CT examination confirmed the presence of the mass but clearly indicated that it was located within the major vessels of the heart (Figure 2.88B). Because the "owner" of the mummy had scheduled the mummy to be cremated following the examination, an autopsy was permitted. At autopsy, the heart and lungs were removed. In an attempt to correlate the location of the mass seen on the conventional radiography and the CT image, pins were placed at right angles to each other and the specimen was radiographed (Figure 2.88C) (Cartmell et al. 2002). The resulting image confirmed the location of the mass previously noted and after removal it was determined to be a hardened blood clot. Similar radiopaque masses had been noted within the vessels associated with the heart of other sideshow mummies that had been embalmed with arsenic. It was concluded that the dense clots were associated with the embalming procedure.

In a recent study (Beckett et al. 2008), we evaluated another possible field technique for specific target needle biopsy using standard radiography, endoscopic guidance, and tissue target triangulation using a radiopaque "locator grid" technique.

Figure 2.87A a Polaroid radiograph of the left medabdominal region of the mummy from Popoli, Italy, with the two spinal needles (arrows) placed at right angles in order to locate the kidney stone.

Context in bioanthropology refers to the place where mummified remains are found as well as the surrounding environment, associated grave goods, and the relationships among these many variables. Typically, context refers to the external environment and the relationship of the mummified remains to those surroundings. Internal context refers to

Figure 2.87B the renal stone after it was extracted from the mummy.

Figure 2.88A A Polaroid AP radiograph of the chest of Hazel Farris, demonstrating a radiopaque mass (arrow) located to the left of the midline.

those anatomical structures or artifacts within the mummy itself. Contextual information is critical when attempting to interpret anthropological, archaeological, and paleopatho-logical data (Buikstra and Beck 2006). The more information and data recorded in situ, the better able those data may inform researchers about the person and how his or her biology interacted with the environment. If the internal context is disturbed, relationships between morphological features may be disrupted, which in turn may lead to misinterpretations regarding the mummified remains. In an attempt to preserve both the external

Figure 2.88B An axial CT image demonstrating the radiopaque mass (arrow) in the heart.

Figure 2.88C A radiograph of the heart and lungs after they were removed from the body. Pins were place vertically and horizontally (arrows) in order to localize the radiopaque mass.

and internal context associated with mummified remains, scientific study, including tissue biopsy, should be conducted in situ.

The goal of this study was to explore a possible field technique for needle biopsy in an attempt to preserve context. The study was conducted under endoscopic guidance to ensure tissue target location and penetration of the biopsy needle.

The subject of this study was a late 19th to early 20th century mummified male. The subject was a sideshow mummy known as George/Fred, curated by Ripley's Believe it or Not, which was subsequently donated to the Bioanthropology Research Institute for research and educational purposes (Figure 2.89). The mummy is that of a male whose external and internal preservation are very good, making the subject an excellent choice for organ tissue biopsy.

The state of preservation of the subject's internal organs was excellent, with cardiac, pulmonary, and hepatic organs intact. For this study, the liver was targeted for biopsy as its radiographic density indicated that the hepatic tissue was easily recognizable and accessible for biopsy.

Figure 2.89 A photograph of the mummy George/Fred.
Figure 2.90 Locator grids positioned on George/Fred.

In field settings, using CT instrumentation to allow for guided biopsy is not practical due to size and availability. Using conventional radiography, AP and lateral radiographs were taken of the area of interest to estimate the organ target location, in this case, the liver. Two "locator grids" were constructed using standard garden fencing with 0.5 x 0.5 in. (1.25 x 1.25 cm) "windows," which were attached to frames large enough to hold a standard 14 x 17 in. (35.5 x 43 cm) x-ray cassette. The two locator grids were constructed to produce a right angle to one another directly over and next to the subject, ensuring that the image produced would encompass the target organ region as determined by the initial set of x-rays (Figure 2.90). The grid was constructed so that the horizontal level could be adjusted. A small metallic marker was placed on each grid at the approximate location of the target organ and in the same axial plane. X-ray cassettes were placed for the AP and lateral views in a manner such that the grid and metallic markers would appear on the developed films. Using the locator grid markers as a guide, the depth and the lateral location of the target organ were determined by counting the locator grid squares in relationship to the locator grid markers (Figure 2.91). A bone marrow biopsy aspiration needle was used to create the percutaneous route to the target organ identified by the grid markers. Once the route was

Figure 2.91 Radiograph showing locator grid markers used to locate target organ.
Figure 2.92 coaxial needle in place using locator grid as a guide.

established, a coaxial percutaneous biopsy needle was placed at the depth and lateral position established using the grid markers (Figure 2.92). Radiographs were repeated to ensure biopsy needle location in relation to the target organ.

The AP and lateral radiographs (Figures 2.93 and 2.94) demonstrate that the location of the target organ using marked locator grids for triangulation was readily accomplished. The drawing in Figure 2.95 demonstrates the triangulation and target location method in the axial plane.

The use of the locator grid system with standard radiography appears to hold promise in the target organ identification and subsequent biopsy in field settings. Key features of the locator grid include making sure the system is adjustable to accommodate varied morphologic configurations and stabilization of the system to ensure that right angles are easily produced and maintained.

The triangulation method using the locator grid with standard radiography may prove to be a useful field approach to precise tissue- or organ-targeted biopsies. The ability to conduct such biopsies in the field helps preserve the context and eliminates the risks associated with transporting those remains to an advanced imaging facility. Continued research needs to be conducted using smaller targets to assess the precision of this field technique.

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