The Lateral Chest Radiograph: Is It Doomed to Extinction? I

Arvin 1=. Robinson, MD

I have always had a special place in my heart for the lat- eral chest radiograph. It seems to be the Rodney Dan- gerfield of diagnostic radiologic examinations, never re- ceiving the respect it deserves. It is not usually missing from an image folder. Whenever the posteroanterior view has a chance to wander--for example, during ward

rounds, for use with correlative radiologic studies or in

teaching files, for photography--the lateral view is often left behind. It is most refreshing to see an article that

speaks of its virtues. Such is the case with "Identifying Left Lower Lobe Pneumonia at Chest Radiography: Per-

formance of Family Practice Residents before and after a

Didactic Session," which appears in this issue (1). In all of our radiographic examinations, we want to

obtain the most information possible at a single sitting. Consequently, right angle or other complementary views are usually obtained to accommodate three-dimensional evaluation of a two-dimensional image. In the chest, this

is particularly important for the heart, mediastinum, and posterior portion of the thorax. In addition, it provides a

second chance to separate pathologic areas from overlap- ping structures and to determine variation attributed to positioning or incomplete inspiration.

The arguments given for single view chest examina-

tions are usually cost containment and radiation risk. The issue of cost is more philosophical than real and follows the premise that medical care costs would decrease if we limited imaging services. Relative value units (RVUs) used for reimbursement are currently 0.72 for postero- anterior and lateral views and 0.92 for posteroanterior views only. Perhaps professional charges should be the

same, since it is more difficult to interpret the frontal chest radiograph without the lateral view. Although cost

Acad Radiol 1998; 5:322-323

1 From the Department of Radiology, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY 14642, Received February 3, 1998; accepted February 4. Address reprint requests to the author,

©AUR, 1998

differences are minimal, there may well be pressure to bear for lower technical costs and less professional reim- bursement by limiting the scope of the examination.

In the past, acquisition of the lateral chest radiograph required twice as much radiation as acquisition of the frontal view. However, this is not necessarily the case

with more modern technology. A well-collimated lateral examination does not add substantial risk to any critical organ and the radiation exposure is minuscule (2).

Much of the disrespect for the lateral view comes from our own specialty. The prevalence of bedside examina-

tions have provided increased familiarity with single

frontal examinations. Some of my younger and more modern colleagues believe that the chest radiograph ob- tained with any technique is merely a scout image for more detailed evaluation with computed tomography or

magnetic resonance imaging. Consequently, the single plane digital scout radiograph is becoming more familiar

to them than the frontal and lateral chest radiographs. As we rapidly approach filmless radiography, we run

into the added problem of fitting frontal and lateral views

and their comparison images onto a two-screen worksta- tion. This will continue to be a difficulty for us until we can train ourselves to scroll serial studies rather than rely

on lateral gaze. Those who claim that there is less information avail-

able on the lateral view have not taken the time and en- ergy to review the radiographic anatomy and pathologic abnormalities that the lateral view offers. This was well illustrated by Proto and Speckman in the Kodak series of

Medical Radiography and Photography published in 1979 and 1980 (3,4). Numerous follow-up reports have been added in textbooks, scientific exhibits, and refresher

courses. The large amount of information available on the lateral view warrants special efforts in education.

Therefore, there is more information available on pos-

teroanterior and lateral radiographs of the chest than on a frontal radiograph alone (5). Such is true for evaluation of heart size, mediastinal mass effect, or pulmonary vascular engorgement. The lateral view is also helpful in separat-

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ing the appearance of vessels on end from granulomas or other perihilar nodules.

The locations of other mediastinal abnormalities are

also more clearly defined on the lateral view. In the pedi- atric chest, a thymus gland may become prominent from a rebound effect and simulate cardiomegaly unless one

has a lateral view for correlation. Pneumomediastinum and other mediastinal details are also better defined on the lateral view. As the article by Thompson et al in this

issue indicates, there is a considerable amount of lung tis- sue to be evaluated in the lateral projection that may be

obscured on the frontal view by the more anteriorly lo- cated heart and domes of the diaphragm.

In many instances, there is legitimate argument for not obtaining a chest radiograph at all. It is not an effective

screening modality for occult disease and has been elimi-

nated from many preoperative protocols. However, when radiographic evaluation of the chest is necessary, we

should insist on providing ourselves with the information

that we need. It is essential that we not let the lateral view become a dinosaur of the past.

EFERENCE:

1, Thompson BH, Berbaum KS, George M J, Ely JW, Identifying left lower lobe pneumonia at chest radiography: performance of fam- ily practice residents before and after a didactic session. Acad Radio11998; 5:324-328.

2. Gray JE. Safety (risk) of diagnostic radiology exposures, In: Radia- tion risk: a primer, Reston, Va: American College of Radiology, 1996; 15-17,

3, Proto AV, Speckman JM. The left lateral radiograph of the chest, I. Med Radiogr Photogr 1979; 55:30-74.

4. Proto AV, Speckman JM, The left lateral radiograph of the chest. II. Med Radiogr Photogr 1980; 56:38-63.

5. Sagel SS, Evens RG, Forrest JV, Bramser RT, Efficacy of routine screening and lateral chest radiographs in hospital-based popula- tion, N Engl J Med 1974; 291:1001-1004.

~nnouncemenl

The University of Chicago will host the First Internat ional Workshop on Computer-Aided Diagnosis (CAD) on Sep-

tember 20-23, 1998, at the University of Chicago Downtown Center, Chicago, Illinois. The meeting will provide a fo- rum for the leading researchers and practitioners in CAD and will encompass automated image analysis, quantitation of image information, two-dimensional and three-dimensional multimodality image integration, advanced image process-

ing, and artificial neural network applications. Sessions will include new developments in chest, breast, vascular, and three-dimensional/CT/multimodality imaging. Related developments in digital image acquisition and picture archiving and communication systems, or PACS, will also be addressed. The sponsoring chairman is Martin J. Lipton, MD, and the organizing committee consists of Kunio Doi, PhD, Heber MacMahon, MD, Maryellen L. Giger, PhD, and Kenneth R. Hoffmann, PhD. Attendance will be limited to 150 attendees on a first-come basis. The registration fee is $300 if re-

ceived before May 1 or $400 if received after May 1. For more information, contact the International Workshop on Computer-Aided Diagnosis, The University of

Chicago, Department of Radiology MC2026, 5841 S Maryland Ave, Chicago, IL 60637; e-mail: cad@uchicago.edu; fax: 773-702-0371.

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