British Journal of Plastic Surgery (197~), 27, 352-356

NASAL XERORADIOGRAPHY

By PETER MCKINNEY, M.D.,l and WILLIAM MILLER” Department of Surgery, Division of Plastic and Reconstructive Surgery,

Northwestern University, McGaw Medical Center, Chicago, Illinois

CONVENTIONAL radiographs are of little worth in the evaluation of nasal injuries (McArthur, 1971). Although they can reveal an osseous fracture, soft tissue and especially cartilaginous injury can go unrecognised and result in permanent deformity (Tipton, 1971; Bruck, 1973).

Soft tissue xeroradiography with low voltage X-ray (24-30 kV) has been successfully employed in the clinical investigation of breast tumours (Wolfe et al., 1971). Recently xeroradiography of skull, neck and larynx at higher voltage (120-125 kV) has been reported (Hollinger et al., 1972).

Xeroradiography for nasal injury was investigated in the hope of achieving clearer definition of nasal osseous-cartilaginous structures. Xeroradiographs are made on electrically charged selenium-coated aluminium plates enclosed in a cassette. Exposure to an X-ray beam produces positive and negative charges in a pattern which differen- tiates the varying densities of anatomical structures being examined, according to the amount of absorbed radiation. When a cloud of negatively charged fine blue plastic powder is blown over the plate, an image is formed producing a vertical electrical field component with enhanced edges that can be transferred to paper electrostatically.

MATERIALS AND METHODS

A technical expert from the Xerox Corporation assisted in the initial cadaver studies in which a standard G.E. portable X-ray unit (ranges 25-200 mA, o-100 kV, 1/60-10 sec.) was used. Xeroradiographs were first taken of an undissected cadaver (Fig. I) at both 50 and 25 mA with variation of the duration of exposure from I/IS to I second. Voltage was varied from 78 kV to IOO kV. The distance from source to plate ranged from 26 to 40 inches (o.65-Im) and both positive and negative modes were tried in straight lateral, three-quarter oblique, three-quarter superior-lateral and inferior views. The nasal skin and subcutaneous tissue were then dissected from alar bases to glabella without disturbing the nasal cartilages. A triangular wedge of upper lateral cartilage was removed and an incomplete rim strip was performed on the alar cartilages (Fig. 2). The skin was replaced in its natural position and a complete series of exposures were taken with a wide range of settings and modes (Fig. 3). The previously removed cartilages were then replaced and the series repeated (Fig. 4). In the hope of increasing resolution, the skin flaps were removed from the cartilages and a separate series taken. The best results were obtained at 25 mA, g6 kV and 0.5 second at 40 inches (Im) in the straight lateral and three-quarter lateral views on six separate cadavers. The three- quarter superior-lateral and inferior views were uninformative and therefore discarded.

Clinically we found that the optimum setting for cadaver studies gave inadequate resolution. A new series of xeroradiographs was run at 50 mA, 80 kV to 120 kV, and time settings ranging from 0.6 to I/IS second in the positive and negative modes on a different machine. Greatest resolution was found at 120 kV, 50 mA, 1/5 second at

1 Assistant Professor of Surgery. 2 Senior Medical Student.

352

NASAL XERORADIOGRAPHY 3.53

FIG. I. Xerograph of undissected cadaver: 25 mA, g6 kV at 015 seconds, 40 inches (rm) from source. Printed in negative mode.

Cartilage definition outlined by air column.

FIG. 2. Dissected cadaver to show the amount removed from the alar cartilage aild the wedge-shaped piece removed from the upper

lateral septal junction

354 BRITISH JOURNAL OF PLASTIC SURGERY

36 inches. With this setting, pre-operative xerographs were obtained on three rhino- plasty patients in both positive and negative modes and are shown with their pre- operative photographs for comparison. Submucous resection, rhinoplasty with complete strip of the alar cartilages and insertion of columnar nasal spine grafts, and augmenta- tion mentoplasty were performed on this group of patients, and 2 months later, post- operative xerographs and photographs were obtained for comparison. The case shown in Figures 5 and 6 is typical of the three.

FIG. 3 FIG. 4

FIG. 3. A negative mode xeroradiograph demonstrates the cartilage removed from the upper lateral and the lower lateral. The positive mode picture was similar.

FIG. 4. A positive mode xeroradiograph defines the “suture line” in the cartilages with the strips replaced.

DISCUSSION

In all the cadavers, xeroradiographs at the same settings could demonstrate the triangular wedge of cartilage removed from the upper lateral cartilage, as well as the upper border of the alar rim strip. However, little difference in the xerographs could be determined between those taken with the cartilage removed and those with the cartilage replaced. Lifting the skin off the nose did not enhance resolution, nor could any significant difference be found between the positive and negative modes.

Clinical xeroradiographs, despite an increase in voltage, gave insufficient definition of the nasal cartilages to be clinically useful although cartilages inserted for augmentation mentoplasty and columellar augmentation could be seen as well as the laryngeal cartilages. The latter had previously been demonstrated by Hollinger et al.

NASAL XERORADIOGRAPHY 355

FIG. 5. A, Pre-rhinoplasty appearance and, B, xeroradiograph.

FIG. 6. A, Post-operative appearance and, B, xeroradiograph, although excellent definition was obtained of other structures, the shape of the nasal cartilages was ill defined. The columellar and mental implants

are defined.

356 BRITISH JOURNAL OF PLASTIC SURGERY

These results suggest that the thickness and bulk of the cartilage are decisive to their visualisation by xeroradiography. Technical refinement of xeroradiography might therefore bring the necessary sensitivity to identify the delicate nasal cartilages. How- ever, xeroradiography is not yet a useful adjunct to the treatment of nasal injury, nor can it supplant the clinical acumen of the reconstructive surgeon in planning corrective rhinoplasty.

We are grateful to William Bondareff, M.D., Chairman, Department of Anatomy; Harvey White, M.D., Professor and Chairman, Department of Radiology, and Mr John Fromke, Repre- sentative of the Xerox Corporation, for their assistance in this project.

REFERENCES

BRUCK, H. G. (1973). Corrective rhinoplasty. Archives of Otolaryngology, 97, 441-446. HOLLINGER, P. H., LUTTERBECK, E. F. and BULGER, R. (1972). Xeroradiography of the

larynx. Annals of Otology, Rhinology and Laryngology, 81, 806-808. MCARTHUR, P. (1971). The value of radiographs in the management of injuries to the nasal

skeleton. British Journal of Plastic Surgery, 24, 97-98. TIPTON, J. B. (1971). Dislocation of the upper lateral cartilages as a cause for nasal deformity.

plastic and Reconstructive SUrgery, 47, 459-462. WOLFE, J. N., DOOLEY, R. P. and HARKINS, L. E. (1971). Xeroradiography of the breast-

a comparative study with conventional film mammography. Cancer, 28, 1569-1574.