Digital photography in plastic surgery

Purpose

The first principle of photography as a medical record is to document the pre- and postoperative condition of the patient, serving as an accompaniment and function analogous to radiography ( Video Lecture 7.1 ). Preoperatively, the record is a guide in evaluating the patient's condition, highlighting relationships of the anatomy, and demonstrating aspects of physiologic function for tissues like the nose, eyes, mouth, and hand. Postoperatively, images record changes for patient teaching, self-evaluation for retrospective review, and assessment of results vis-à-vis planned outcome. Intra-operative imaging may feature key aspects of the surgical procedure for documentation and education.

Much of plastic surgery rests in an unusual setting in medicine. The core and history is reconstructive in nature, largely born from efforts to rebuild injuries sustained by First World War soldiers. Whether reconstructive or aesthetic, its essence is to restore form and function, and today, a great portion is neither urgent nor critical to immediate health. Instead, much is elective and focused on quality of life, especially in the aesthetic arena. Reviewing photographs with a patient may transform the preoperative planning from an interaction tilted one way from the doctor to the patient. Instead, the effort may be collaborative and consultative, an interaction between the doctor and the patient. Various scenarios can be examined and evaluated with digital imaging, modeling, and morphing. Care must be taken when showing potential postoperative results, to avoid the implication of an implied or guaranteed result. One popular software program (Mirror Image) contains an important default disclaimer, “Simulation only: Actual results may differ”.

The didactic nature of medical photography cannot be underestimated. Decades ago, sketches were used, followed by black and white photography, color transparencies and film, with the modern progression to digital images in the last 30 years. For all practical purposes, analog photography is a niche market, and digital imaging reigns supreme. Between the consultation and the operative procedure, planning requires good recall and representation of the anatomy. The images serve to refresh the memory of the surgeon. In addition, it is critical for patients to understand excesses or deficiencies of tissues, issues of symmetry. Features of their anatomy may facilitate or hinder surgical planning, influence choices in surgical approach, affect risks of complications, compromise or augment patient satisfaction. Patient teaching requires proper photographic representation of the preoperative condition and explanation of the changes achieved with surgical intervention. The evolution of a surgical practice can be tracked most easily over a period of years through systematic inspection of imaging of the patients’ condition through the course of their diseases or conditions. A particularly common phenomenon is for a patient to not recall how they looked before surgery when critically viewing the postoperative result. Occasionally in reconstructive procedures and more often in aesthetic ones, the patient's psychological “set point” is re-established at their current condition, and the desire for further enhancement leaves them with falsely elevated expectations. Photos are indispensable in this setting and may provide reassurance that goals have been reached.

Maintaining proper images and systematically evaluating them postoperatively can only improve awareness of surgical choices and outcomes. Properly preserved analog images may last decades with original fidelity and 100 years or more with mild degradation. Digital images may not last much longer. Challenges in the evolution of technology lead to viewing problems (incompatibilities in hardware), scrambling issues (changes in compression algorithms), inter-relation limitations (expired webpages or hyperlinks), custodial problems (where the data resides), and translation issues (how to read old storage with new technology) to name a few. If digital concerns are solved, images could last centuries or more. Building a digital database and engaging in periodic data-mining is a core component of self-improvement in clinical care. The advent of digital photography eliminates concerns about lack of space, difficulties in storage like degradation of image quality, the ability to compare past and present results over large series, and related issues. However, they are subject to their own vagaries. Old retrieval technologies (floppy disks, CDs, DVDs, etc.) are subject to catastrophic failure. For example, a scratch on a transparency may slightly degrade the quality of the image, while the same event in a digital image may make it unreadable. Digital images must be backed up, and the methodologies rapidly change necessitating continual hardware upgrades. The best storage methods have changed 5–10 times in the last 30 years from floppy disk to magneto-optical disks, magnetic tape back-up, compact discs (CDs), digital video discs (DVDs), USB flash drives, portable hard drives, network attached storage drives, and more recently, “in the cloud” at a remote data storage center on the internet. Much like the evolving standards in business and research regarding storage of e-mail and digital documents for potential legal cases, our de facto standards dictate that photographs must be preserved, organized, encrypted, properly referenced and identified, while easily retrievable.

Informed consent is a key part of medical record-keeping, and photography is essential to proper medical records. Almost every patient understands that photographs are part of the medical records. In fact, many insist on seeing “before and after” examples in their initial consultation, the best time to establish the necessity of accurate documentation. Some patients have a strong need for privacy; however, most surgeons will refuse to operate on a patient who refuses medical photography. Patients understand they have control and options on how their pictures will be used. Some practices allow only internal records in their private chart, others may permit sharing with other patients in consultation without identifying data, and some are comfortable with unrestricted use on the internet, in print, and television advertising. A thorough, detailed consent form specifically for the use of images is necessary for a proper medico-legal record. Consent forms from the American Society of Plastic Surgeons are available for member surgeons. Photography’s utility as a research and interpretative tool in our field is without question. Comparison of how our journals have progressed from the first decade of the twentieth to the twenty-first century shows that our publications have advanced from black and white to color photographs, to online digital images in low and high resolution, to online video and live streaming. Three-dimensional simulations that allow a “fly through” of the anatomy have been available for several years. Information density in images is an order of magnitude greater than the written word. With decreasing costs in the digital era, increasing use of imaging improves learning and documentation. In coming years, widespread use of artificial intelligence (AI) for image processing will likely allow for digital data-mining of the image content itself. This would be a major advancement beyond assigning database attributes to digital files like age, preoperative and postoperative photograph dates, type of procedure, etc. Instead, we may begin to see digital reference to quality of outcomes, conditions of anatomy on validated grading scales, etc. Even now, consumer digital cameras and photography software incorporate facial recognition algorithms, automated red-eye reduction, and similar computational photography tools. Professional systems have capabilities like automatic pore evaluation on the skin and cell counters for microscopic work. One could imagine many future potential applications like automatic color detection, evaluation of cutaneous vascularity, flap perfusion, and others.

Since the mass migration to the internet and social media by the general population, the public has turned online to research plastic surgery, compare results, investigate complications, nurture special interest groups and procedures, and engage in promotion and marketing. There are many egregious examples of excess, manipulation, and deception; however, there are even more beneficial opportunities for patient education, practice marketing, advocacy, and public health outreach. In addition, surgeons often disregard photographic documentation standards of care.

Standards in capturing images

Little has changed for the framing and composition of images since Morello et al . and Zarem, and many before them specified these aspects of photographic standards in plastic surgery. However, other factors have evolved in the transition to the digital world. Key principles must be followed. Consistency in results is affected by numerous factors. Facial photographs are taken at the 35 mm film camera 100 mm lens digital equivalent, while body images are taken at the 50 mm lens equivalent. Shadows should be avoided. Colors must be natural. Lighting should be unobtrusive and consistent. Standards must be obeyed.

Digital image characteristics

Many variables affect images, and many are in the control of the plastic surgeon. Parker et al . have documented four basic ways in which inconsistency is introduced into photography: (1) photographer-based; (2) publisher-based; (3) combined; and (4) patient-based. Category 1 in their scheme includes view (composition), background and zoom, which are generally consistent among journals. Publisher-based criteria: size and image labeling are less problematic. Combined criteria: color, brightness, contrast, and resolution vary in published journals. Category 4 criteria: clothing, accessory apparel, make-up, facial expression, and hairstyle, are designated as patient-based, but are substantially under the control of the photographer. A dark-colored “collar” drape can be used over the shoulders for facial photographs. Accessory apparel should be removed, as make-up, false eyelashes, and similar accoutrements of fashion may interfere. Hairstyle can be mitigated by using standardized hairbands or ties. Patients can be coached to maintain neutral facial expression.

Galdino categorizes factors into direct and indirect. Direct variables include lens, viewfinder, digital chip, resolution, compression and software algorithms of the camera. Indirect are listed as lighting, metering, depth of field, color temperature of lighting and output method. Both categories are easily controlled by retaining consistent techniques from visit to visit (see Key principles box ).

Focal length and distortion

The focal length of a lens is determined when the lens is focused at infinity, measured in millimeters between the point of convergence of the lens and the camera sensor. This characterizes the angle of view and the magnification of individual elements. The longer the focal length, the narrower the focal length and the higher the magnification. Lenses with long focal lengths tend to have a shallow depth of field and “compress” perspective into a flat image, giving the appearance of less space among elements through depth. A zoom lens covers a range of focal lengths that can be quickly adjusted (frequently attached to compact cameras), while prime lenses are fixed at specific focal lengths that may be interchanged.

A common misconception in photography has to do with the relationship of focal length and distortion, resulting from the conflation of optical distortion with perspective distortion. Most lenses suffer from some type of optical distortion, particularly wide-angle lenses, which can stretch the frame in a barrel fashion. Undesirable optical distortion can be easily corrected with software and rarely affects facial distortion at normal distances. However, the effect of perspective distortion is far more substantial when photographing the face (due to the close spatial relationship of anatomic features), a phenomenon that is determined exclusively by subject distance to the camera. Focal length affects the size of the subject relative to the frame, but it does absolutely nothing to affect perspective. Changing the focal length indirectly affects the perspective because subject distance must change to keep the compositional framing constant ( Fig. 7.1 ). This illustrates the critical importance of standardizing image capturing techniques including lens focal length, lens aperture, camera sensor, and distance to subject (see Key principles box ).

Composition and positioning

Full face

In the anterior–posterior (AP) view, the superior border of the head must be framed by a small amount of background, about 10% of the vertical height of the image or 2 cm above the vertex of the skull. The inferior border of the image should stop just below the suprasternal notch. The Frankfort horizontal plane connects the infra-orbital rim to the tragus and is kept parallel to the floor. For the frontal view, the ears can be used to ensure proper positioning. In the lateral view, the patient's body and head should be facing 90° from the focal plane of the camera. The eyebrows should be superimposed. While some cropping of the occipital region is acceptable, in general, lateral views should include the full view. Oblique views should be taken at 45° and, in this view, the tip of the nose should protrude slightly beyond or rest just at the contour of the distal malar eminence. Five standard views are taken: an AP, two oblique, and two lateral, right and left for each of the latter two ( Fig. 7.2 ). When indicated, the malar eminence may be imaged, generally the bird's-eye view is preferred over the worm's-eye view, unless a particular feature of anatomy is involved.

Musculature should be relaxed in all photographs unless otherwise specified.

Eyes

The same five image views (anterior, two laterals, and oblique views) are part of the basic set for the eyes. Close-up images of the eyes should include a small border of forehead skin above the eyebrows and extend inferiorly to the upper lip at the nasal spine. For the lateral and oblique views, positioning is similar to the views of the head honoring the superior and inferior borders herein. Additional views are essential and include the following at a minimum: (1) closed eye view to highlight the superior tarsal sulcus and fold, and (2) upward gaze to highlight inferior orbital fat pockets and the lower lid margin. A squinting view consists of open eyelids with contracting of the superior and inferior orbicularis oculi to feature the impact of muscle action on eyelid shape and function. Occasionally, a view with tightly closed eyelids to highlight the orbital orbicularis and zygomaticus muscles is required for certain surgical procedures ( Fig. 7.3 ).