Evaluation of a training program for detection of carotid artery calcifications on panoramic radiographs.

OBJECTIVE: To evaluate the effectiveness of the American Academy of Oral and Maxillofacial Radiology-sponsored training packet for identification of carotid artery calcifications on panoramic radiographs. STUDY DESIGN: Two examiners, who completed the training (trainees), examined 778 panoramic radiographs. The sample included 298 men, with a mean age of 66, and 480 women, with a mean age of 68. Findings were compared with those obtained by an oral and maxillofacial radiologist. A kappa statistic was used to determine agreement between the 2 trainees. The positive predictive value (PPV) of the program was estimated by comparing the trainees rating of disease status with an expert in case identification. RESULTS: Examiners 1 and 2 identified 99 and 78 positive cases, respectively. A kappa statistic of 0.87 (95% CI, 0.81-0.92) was obtained, indicating good interexaminer agreement. The expert identified 27 positive cases, resulting in a PPV of 34.6% (95% CI, 24.4-46.3). CONCLUSION: Although the training packet offers valuable training, it does not provide a high PPV, suggesting the need to modify it or to seek an expert opinion before classification of a patient as having calcification on a panoramic radiograph.

Carotid calcifications on panoramic radiography identify an asymptomatic male patient at risk for stroke. A case report.

Although stroke may be preventable, a major challenge is to find effective methods of detection of stroke-prone patients. Most noncardiogenic strokes occur as a result of atherosclerosis involving the proximal internal carotid artery, calcifications of which can be detected on dental panoramic radiography. This report describes the case of an asymptomatic patient whose dental radiographic findings led to carotid endarterectomy. Calcifications were viewed bilaterally in the soft tissues of the neck in the area of the carotid bifurcation on a screening panoramic radiograph of an asymptomatic 75-year-old man. Subsequent duplex Doppler ultrasound revealed extensive atherosclerotic changes bilaterally with critical stenosis (90%+) in the right internal carotid artery. Carotid digital subtraction angiography revealed a 95%+ stenosis at the origin of the right internal carotid artery. The patient underwent right carotid endarterectomy involving the internal, external, and common carotid arteries. Twelve months later the patient was alive and well. Dental panoramic radiography represents a useful imaging modality for detection of some asymptomatic stroke-prone patients. Identification of calcifications in the area of a patient's carotid vasculature should prompt expeditious referral to a physician for a cerebrovascular and cardiovascular work-up as part of an active stroke prevention strategy.

Infection due to Clostridium difficile among elderly residents of a long-term-care facility.

In a study of the epidemiology of infection due to Clostridium difficile at long-term-care facilities, we conducted point-prevalence surveys and obtained stool samples from residents receiving antibiotics and from those developing diarrhea during 1 year at a 350-bed nursing home and an adjoining 280-bed chronic-care hospital. C. difficile and/or its cytotoxin was detected in 236 specimens from 94 residents. Only 16 (17%) of these 94 individuals had diarrhea at the time C. difficile was detected. The prevalence of C. difficile infection ranged from 2.1% to 8.1% in the nursing home and from 7.1% to 14.7% in the hospital. The organism was recovered from six (8.8%) of 68 residents receiving antibiotics, and four of the six developed antibiotic-associated diarrhea. The receipt of antibiotic treatment within the previous 8 weeks (odds ratio [OR], 7.9), the presence of a nasogastric or gastrostomy feeding tube (OR, 6.5), urinary and fecal incontinence (OR, 2.5), and the presence of more than three underlying diseases (OR, 2.0) were statistically significant independent variables associated with C. difficile infection. Typing of isolates by restriction-endonuclease analysis indicated that most C. difficile infections at this long-term-care facility were associated with endogenous enteric carriage of the organism, with little evidence of cross-infection.