Can non-calcified coronary artery plaques be detected on non-contrast CT calcium scoring studies?

RATIONALE AND OBJECTIVES: Coronary computed tomographic (CT) angiography has been shown to detect noncalcified coronary artery plaque. Depending on tissue composition, noncalcified plaque differs in CT attenuation from blood and epicardial fat. The aim of this study was to determine whether noncalcified plaque can be visually detected on non-contrast-enhanced CT calcium scoring studies. MATERIALS AND METHODS: A total of 106 patients (40 women; mean age, 59 years) who underwent coronary calcium scoring, coronary CT angiography, and quantitative catheter angiography were prospectively investigated. Two blinded observers independently reviewed calcium scoring studies for positive vascular remodeling and hypoattenuation within the vessel wall, suggestive of noncalcified plaque. Findings on calcium scoring studies were compared with those on coronary CT angiography and quantitative catheter angiography. RESULTS: The mean Agatston score was 515.8 ± 826.8. Overall interobserver agreement for the identification of noncalcified lesions was substantial (κ = 0.69). Observer 1 and observer 2 identified 21 and 17 patients, respectively, with 38 and 35 lesions suggestive of noncalcified plaque. Coronary CT angiography confirmed noncalcified plaque in 33 of 38 (86.8%; observer 1) and 31 of 35 (88.6%; observer 2) lesions. Thus, the overall positive predictive value for correct identification of noncalcified plaque on calcium scoring studies was 0.88, although overall sensitivity was low at 0.39. CONCLUSIONS: Noncalcified plaque can be visually detected on calcium scoring studies. Review of calcium scoring studies for features of noncalcified plaque may enhance the identification of patients with more active disease and higher cardiovascular risk.

Correlation of regional distribution and morphological pattern of calcification at CT coronary artery calcium scoring with non-calcified plaque formation and stenosis.

OBJECTIVE: To investigate whether regional calcification patterns at CT coronary artery calcium scoring (CCS) correlate with stenosis and non-calcified plaque formation. METHODS: We studied 106 patients with quantitative catheter angiography (QCA), CCS, and coronary CT angiography (cCTA). CCS was determined globally and for each artery separately. The morphological pattern of each calcification was classified as calcified nodule, shell-like, or diffuse. cCTA studies were evaluated for non-calcified plaque. The global and regional CCS and the calcification pattern were correlated with stenosis >or=50% and non-calcified plaque. RESULTS: A total of 48/106 patients had stenosis >or=50% on QCA. There was weak correlation (r = 0.36) of the global CCS with stenosis. Correlation was stronger per vessel (r = 0.55-r = 0.67). Shell-like and diffuse calcifications were significantly (p = 0.0001) more frequently associated with >or=50% stenosis and non-calcified plaque (p = 0.04) than calcified nodules. CONCLUSION: As shown before, the global CCS does not correlate well with stenosis. However, regional calcium distribution and specific patterns of calcification are correlated with stenosis and non-calcified plaque. Thus, the specificity of CT calcium scoring for identifying individuals with obstructive disease could be improved by vessel-based rather than global quantification of calcium and by differentiating specific morphological patterns of calcification.

Prostate cancer: MR imaging-guided galvanotherapy--technical development and first clinical results.

PURPOSE: To prospectively evaluate the safety and effectiveness of magnetic resonance (MR) imaging-guided galvanotherapy in prostate cancer. MATERIALS AND METHODS: This prospective study was approved and authorized by the institutional review board, and patients gave informed consent. Forty-four men (mean age, 63.1 years) with histologically proved prostate cancer were treated with galvanotherapy. After transgluteal puncture of the prostate with local anesthesia, two MR imaging-compatible electrodes were positioned under MR imaging guidance in the periphery of the right and left lobes of the prostate so that they had direct tumor contact. The patients were treated three times in 1-week intervals, and direct current was applied to the localized cancer in the prostate gland with a total charge of 350 coulombs. Follow-up with laboratory testing (prostate-specific antigen [PSA] levels) and endorectal MR imaging with tumor volume measurement was performed 3, 6, and 12 months after the procedure. The Friedman test was used to compare tumor volumes and PSA levels across the four time points. RESULTS: All patients tolerated MR imaging-guided galvanotherapy well without any major side effects or complications. Six patients had some reversible difficulty with urination, and five reported temporary unilateral leg paresthesia. Tumor volume as determined with MR imaging decreased from a pretherapeutic median of 1.90 to 1.12 cm(3), which corresponded to a significant (P < .01) reduction of 41%. One patient (2%) had complete remission and 18 (41%) had partial remission at follow-up 12 months after therapy. Twenty-three patients (52%) were classified as having stable disease. Two patients (5%) had progressive disease. Median PSA levels decreased in the 12-month control period from 7.05 to 2.4 ng/mL (66%, P < .01). CONCLUSION: MR imaging-guided galvanotherapy is a safe procedure and can result in local control of prostatic carcinoma, with a concomitant reduction in the PSA level. SUPPLEMENTAL MATERIAL: http://radiology.rsnajnls.org/cgi/content/full/245/2/895/DC1.

Extracardiac findings at cardiac CT: a practical approach.

Noncardiac findings occur in 10% to 60% of cases depending on the patient population studied. Although most of the abnormalities will turn out to be benign, important findings such as pulmonary embolism and lung cancer occur. Not all important abnormalities will occur within the coned down field-of-view for evaluating the coronary arteries, and the entire study should also be reviewed with an expanded field-of-view. In particular, the typical screen detected cancer occurs in the lung periphery. It is important to have a practical approach in detecting and evaluating incidental findings so as not to cause undue cost or patient anxiety, while ensuring timely management of critical diseases.