Diagnostic challenges in pyogenic spinal infection: an expanded role for FDG-PET/CT.

In a preliminary investigation of FDG-PET/CT for assessment of therapy response of pyogenic spine infection, it was concluded that activity confined to the margins of a destroyed or degenerated joint with bone-on-bone contact represents nonseptic inflammation, regardless of the intensity of uptake. Only activity in bone, soft tissue, or within the epidural space represents active infection. The purpose of this investigation was to assess the performance of these pattern-based interpretation criteria in a series of problem cases of proven or suspected spine infection. Eighty-two FDG-PET/CTs were done for initial diagnosis because other imaging failed to provide a definitive diagnosis and 147 FDG-PET/CTs were done to assess treatment responses. Pattern-based interpretations were compared with the clinical diagnosis based on bacterial cultures and outcomes after cessation or withholding of antibiotic therapy. Pattern-based interpretation criteria achieved a sensitivity and specificity of 98 and 100%, respectively, for initial diagnosis and a specificity of 100% for assessment of treatment response. The same data was analyzed using intensity of activity as the primary factor. Sensitivity and specificity using the intensity-based criteria were 93 and 68%, respectively, for initial diagnosis, and the specificity of a negative interpretation for therapy response was 55%. Differences from pattern-based criteria are highly significant. Pattern-based criteria perform well in problem cases with equivocal MR and for treatment response because they correctly eliminate activity from nonspecific inflammation associated with destroyed joints with bone-on-bone contact. Response occurs within a timeframe that is useful for managing antibiotic therapy.

Prevalence and spectrum of conditions associated with severe tricuspid regurgitation.

BACKGROUND: Data regarding the prevalence and spectrum of conditions associated with severe tricuspid regurgitation (TR) are limited to small cohorts. METHODS: We retrospectively identified all patients with severe native tricuspid valve regurgitation in a large echocardiogram database between January 2004 and December 2010. Patients were classified into 1 of 3 groups based on the echocardiogram results: (1) organic TR; (2) functional TR; and (3) idiopathic TR. RESULTS: Severe TR was identified in 768 (1.2%, 72 ± 16 years, 64.3% females) of 63, 472 consecutive patients referred for transthoracic echocardiography. The conditions associated with severe TR could be established in 91% of patients. The remaining 9% were classified as idiopathic severe TR with these patients being older (78 ± 10 years) and having a higher frequency of atrial fibrillation (63.8%) compared to patients with organic (65 ± 22 years; 31%) or functional severe TR (73 ± 16 years; 47.8%). Overall, organic severe TR was identified in 11.3% of all cases. Functional severe TR occurred in 79.7% of the overall cohort and was related to pulmonary hypertension and/or left-sided heart disease. CONCLUSION: Severe TR occurred with a prevalence of 1.2% in our patients referred for echocardiography and was more common in females. Functional severe TR was the most common etiology with only a minority of cases secondary to organic severe TR. Idiopathic severe TR was found in a small proportion of patients who were older and more likely to have atrial fibrillation.