Correspondence
CT Scans and the Common Cold?
N Engl J Med 1994; 330:1826-1827June 23, 1994
- Article
To the Editor:
Gwaltney and his colleagues obtained 45 computed tomographic (CT) scans in 31 volunteers (Jan. 6 issue)1 and conclude that “the common cold is actually a viral rhinosinusitis.” Well done, guys!
To justify their study and its results, Gwaltney et al. suggest that the data help us understand “the pathogenesis of . . . the common cold.” I do not think so. Only 27 percent of their subjects had rhinovirus infection, the presence of which did not correlate with sinus abnormalities or infundibular occlusions.
I find it hard to justify the use of CT scans that include irradiation of the orbits to tell us that a cold is a viral illness associated with mucosal swelling and temporary abnormalities of the contents of the sinuses.
1 ReferencesJonathan Hourihane, M.R.C.P.I.
Southampton General Hospital, Southampton SO9 4XY, United Kingdom1
Gwaltney JM Jr ,Phillips CD ,Miller RD ,Riker DK . Computed tomographic study of the common cold. N Engl J Med 1994;330:25-30
Full Text | Web of Science | Medline
To the Editor:
In this era of shrinking health care and resources, we cannot believe that the Journal would publish a study on the incidence of sinus disease and the common cold. Surely every grandmother knows that sinus involvement is frequent with the common cold, without the need for CT scans. We would have thought that the Journal would devote its limited pages to more important research issues.
Malcolm S. Trimble, M.D.
John A. Axelson, M.D.
1100 E. Michigan Ave., Jackson, MI 49201To the Editor:
There have been many reports in the otolaryngologic and imaging literature on CT and magnetic resonance imaging (MRI) findings in the nasal passages and sinuses, not only in patients with upper respiratory infections but in asymptomatic patients as well1.
It is well known by radiologists that inflammatory changes in the nasal passages and paranasal air sinuses are frequently seen in patients undergoing CT and MRI examinations of the brain, head, and neck for other reasons. Incidental sinus mucosal thickening is seen in 39 to 43 percent of asymptomatic patients,2,3 particularly in the ethmoid and maxillary sinuses. Sinus abnormalities are seen on 54.3 percent of CT scans in asymptomatic patients with seasonal allergies2. MRI may be even more sensitive to these changes than CT, with mucosal thickening, mucous retention cysts, and polyps detected in 13 to 63 percent of asymptomatic patients4-7. Normal nasal mucosal cycling may cause apparent mucosal thickening, but even when this is compensated for, 35 percent of asymptomatic patients have definite mucosal thickening7. Air-fluid levels or complete sinus opacification can be seen in 3 to 5 percent of such patients5-7. MRI shows sinus abnormalities in 65 percent of symptomatic patients with viral infections of the upper respiratory tract5.
Inflammatory disease of the paranasal sinuses has thus been well documented in both asymptomatic and symptomatic patients with upper respiratory viral infection, so this finding should not have been surprising to the authors. The fact that they found little correlation between the clinical course and follow-up CT findings in their patients is also not surprising. They included no control group in their small series.
It is surprising that a journal of your reputation would publish a report on a small, uncontrolled study in which an expensive test, delivering a substantial dose of radiation to the eyes, demonstrates a well-known anatomical finding, with no appreciable benefit resulting from the exercise.
7 ReferencesDavid M. Pelz, M.D.
University Hospital, London, ON N6A 5A5, Canada1
Yousem DM . Imaging of sinonasal inflammatory disease. Radiology 1993;188:303-314
Web of Science | Medline2
Havas TE ,Motbey JA ,Gullane PJ . Prevalence of incidental abnormalities on computed tomographic scans of the paranasal sinuses. Arch Otolaryngol Head Neck Surg 1988;114:856-859
Web of Science | Medline3
Lloyd GA . CT of the paranasal sinuses: study of a control series in relation to endoscopic sinus surgery. J Laryngol Otol 1990;104:477-481
CrossRef | Web of Science | Medline4
Conner BL ,Roach ES ,Laster W ,Georgitis JW . Magnetic resonance imaging of the paranasal sinuses: frequency and type of abnormalities. Ann Allergy 1989;62:457-460
Medline5
Cooke LD ,Hadley DM . MRI of the paranasal sinuses: incidental abnormalities and their relationship to symptoms. J Laryngol Otol 1991;105:278-281
CrossRef | Web of Science | Medline6
Moser FG ,Panush D ,Rubin JS ,Honigsberg RM ,Sprayregen S ,Eisig SB . Incidental paranasal sinus abnormalities on MRI of the brain. Clin Radiol 1991;43:252-254
CrossRef | Web of Science | Medline7
Rak KM ,Newell JD II ,Yakes WF ,Damiano MA ,Luethke JM . Paranasal sinuses on MR images of the brain: significance of mucosal thickening. AJR Am J Roentgenol 1991;156:381-384
Web of Science | Medline
Author/Editor Response
The authors reply:
To the Editor: Two issues are raised by Drs. Hourihane, Trimble and Axelson, and Pelz: the originality of our findings and the safety of the procedure we used. Textbooks of medicine, infectious diseases, and otolaryngology do not mention the sinus abnormalities we observed in adults with the early stages of a cold. We have not been able to locate the work of Dr. Trimble's grandmother; perhaps she did not publish her findings. It has been said that the last stage of discovery and final proof of acceptance is the assertion that everybody knew it all along. Sinusitis in the later stages of or following a cold is indeed an old story, but an 87 percent incidence of sinus disease in the early stages of a cold really does qualify as news.
Cataracts can develop as a direct effect of radiation in a dose-, time-, and age-dependent fashion. The minimal dose that causes cataracts in humans is approximately 2 Gy (200 rad) given as a single dose1. Our exposure range was 4 to 6 rad. We used a dose-limiting technique and followed the institutional standards of radiation safety approved by the human investigation and radiation safety committees. MRI, although very useful in evaluating soft-tissue abnormalities, has critical susceptibility artifacts in the areas between air and bone and between air and soft tissue, which are the most important areas in imaging the lateral nasal wall and the ostiomeatal complex. This is why we did not use MRI as we had in an earlier study of colds and sinus disease2.
To set the record straight, we reviewed the papers cited by Dr. Pelz. Rak et al. found 1 to 2 mm of mucosal thickening, particularly in the ethmoid sinuses, in asymptomatic patients, but over 4 mm of thickening was more common in patients with sinus symptoms3. No asymptomatic patients had air-fluid levels or sinus opacification, as Dr. Pelz seems to imply. Moser et al. used only the referral history on the MRI request form, and no clinical review was done4. These studies lacked careful epidemiologic surveillance and made no attempt to determine the exact time of onset of the colds. Also, scans were obtained only once, so it was not possible to distinguish among short-, medium-, and long-term changes. Cooke and Hadley pointed out that it was not possible to interpret their findings without such information5.
The common cold costs an estimated $11 billion annually and is the leading cause of acute morbidity and time lost from work and school. Large amounts of antibiotics are used, often inappropriately, to treat colds. Truly effective treatment for colds might prevent some cases of sinusitis, otitis media, meningitis, and brain abscess. From our findings, it appears that effective cold treatments must reverse the ostiomeatal and sinus abnormalities very early in the course of the cold. The next step is to determine how much of the disease is due to mucosal swelling and how much to thickened, retained secretions. Treatment would differ depending on the answer.
5 ReferencesJack M. Gwaltney, Jr., M.D.
C. Douglas Phillips, M.D.
University of Virginia Health Sciences Center, Charlottesville, VA 22908Donald K. Riker, Ph.D.
Procter & Gamble, Cincinnati, OH 452411
Direct effects of radiation. In: Mettler FA Jr, Moseley RD Jr. Medical effects of ionizing radiation. Orlando, Fla.: Grune & Stratton, 1985:136-8.
2
Turner BW ,Cail WS ,Hendley JO , et al. Physiologic abnormalities in the paranasal sinuses during experimental rhinovirus colds. J Allergy Clin Immunol 1992;90:474-478
CrossRef | Web of Science | Medline3
Rak KM ,Newell JD II ,Yakes WF ,Damiano MA ,Luethke JM . Paranasal sinuses on MR images of the brain: significance of mucosal thickening. AJR Am J Roentgenol 1991;156:381-384
Web of Science | Medline4
Moser FG ,Panush D ,Rubin JS ,Honigsberg RM ,Sprayregen S ,Eisig SB . Incidental paranasal sinus abnormalities on MRI of the brain. Clin Radiol 1991;43:252-254
CrossRef | Web of Science | Medline5
Cooke LD ,Hadley DM . MRI of the paranasal sinuses: incidental abnormalities and their relationship to symptoms. J Laryngol Otol 1991;105:278-281
CrossRef | Web of Science | Medline
Author/Editor Response
Editor's reply:
We were satisfied that the study by Gwaltney et al. was not unethical. We also believe that the common cold is a subject worthy of research, for the reasons pointed out by the authors. However, our decision to publish the study should in no way be taken as an endorsement of the routine performance of CT scanning in patients with head colds.
Edward W. Campion, M.D.
