Role of 16-multidetector computed tomography in the assessment of coronary artery stenoses: A prospective study of consecutive patients.

BACKGROUND: Recent studies have demonstrated a high sensitivity (S) of 16-multidetector computed tomography (16-MDCT) for the detection of significant coronary artery stenoses. Whether these results are applicable to clinical practice is unclear. Therefore, the aim of the present study was to compare 16-MDCT angiography with conventional coronary angiography (CCA) for the detection of significant coronary artery stenoses in a consecutive series of patients. METHOD: A total of 93 consecutive patients (mean [+/- SD] age 59+/-9 years), in whom CCA was performed for stable angina pectoris, underwent 16-MDCT angiography (16x0.75 mm, table feed 6.5 mm/s, rotation time 0.42 s; Sensation 16, Siemens Medical Solutions, Germany) the day before performing CCA. Patients with diabetes mellitus, serum creatinine level higher than 132.6 mumol/L and/or acute coronary syndromes were excluded. Two observers blinded to CCA results evaluated MDCT angiograms according to standard criteria. Segment-based (13 segments per patient) and patient-based (at least one stenosis greater than 50% lumen diameter reduction) analyses were performed. RESULTS: A total of 1209 segments were analyzed. Of these segments, 173 (14%) were excluded due to poor image quality or massive calcification. In 86 segments, CCA revealed significant coronary artery stenosis (greater than 50% diameter reduction). However, 16-MDCT detected only 47 of these, resulting in a S of 55% and a specificity (SP) of 97% (positive predictive value 64%; negative predictive value 96%). On a patient-based analysis, the S increased to 89%, whereas the SP still remained high (87%). CONCLUSION: In this relatively large consecutive cohort, S for the detection of significant coronary artery stenoses was moderate on a segment-based analysis but increased on a patient-based analysis using 16-MDCT. In contrast, SP was high in both analyses, supporting the use of 16-MDCT for the exclusion of significant coronary artery stenoses. Further improvement of spatial and temporal resolution in MDCT technology may lead to a lower exclusion rate and higher S.

Diagnostic performance of MDCT for detecting aortic valve regurgitation.

OBJECTIVE: This study evaluates whether ECG-gated 16-MDCT coronary angiography provides a reliable imaging technique for detecting aortic regurgitation (AR). SUBJECTS AND METHODS: We examined 71 patients prospectively with 16-MDCT angiography using retrospective ECG gating during the mid-to-end diastolic phase. A visible central valvular leakage area was considered as a diagnostic criterion for AR. The central valvular leakage area was quantified in patients with positive transthoracic echocardiography (TTE). We compared 16-MDCT to Doppler TTE, the accepted diagnostic standard based on semiquantitative regurgitation jet analysis (grade 0-3+ for mild, moderate, and severe). RESULTS: The overall sensitivity of 16-MDCT for the identification of patients with AR was 81%. The specificity was 91%, the negative predictive value was 70%, and the positive predictive value was 95%. Of the 71 patients, 48 had AR determined by TTE, and 16-MDCT correctly detected AR in 39 of those 48 patients. The sensitivity of 16-MDCT for the detection of patients with moderate and severe AR (grade > or = 1.5+) was 95%, and the specificity was 96% (20 of 21 patients). The sensitivity of 16-MDCT for identification of patients with mild AR (grade < or = 1+) was 70%, and the specificity was 92% (19 of 27 patients). Quantification of the central valvular leakage area was not possible in 50% of cases with AR by TTE because of valve calcifications. CONCLUSION: Sixteen-MDCT coronary angiography provides an accurate, noninvasive imaging technique to detect moderate and severe aortic regurgitation (grade > or = 1.5+). However, severe valve calcifications and mild AR limit its results.

Reduction of soluble P-selectin by statins is inversely correlated with the progression of coronary artery disease.

BACKGROUND: Cell adhesion molecules (CAM) play an important role in the pathogenesis of atherosclerosis by mediating the binding of leukocytes to the endothelium. Soluble CAM isoforms are known to be elevated in the sera of patients suffering from coronary artery disease (CAD). METHODS: We measured the concentrations of soluble intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin, P-selectin, platelet endothelial cell adhesion molecule-1, and highly sensitive C-reactive protein (hs-CRP) in the blood of 47 CAD patients before and 6 months after starting statin therapy and in 16 untreated CAD patients. The progression of CAD was monitored by calculating the coronary calcium score using electron beam computed tomography. RESULTS: Soluble P-selectin (92+/-11 ng/ml vs. 59 +/- 4 ng/ml, p < 0.0001) and hs-CRP (0.92 +/- 0.14 mg/dl vs. 0.42 +/- 0.11 mg/dl, p < 0.001) decreased significantly in the statin-treated group compared to baseline levels. None of the other proteins studied showed significant changes. In contrast to hs-CRP, the reduction of soluble P-selectin concentrations correlated directly with the lowering of total cholesterol (r(2) = 0.236, p < 0.005) and inversely with the progression of CAD (r(2) = 0.393, p < 0.0001). CONCLUSIONS: Our results suggest P-selectin as an additional marker for the beneficial action of statins in patients with CAD.

[High frequency sonography in the detection of finger injuries in sport climbing]. / Hochauflösende Sonographie zur Erkennung von Fingerverletzungen beim Sportklettern.

Sport climbing shows an increasing popularity, including even school sport activity on high climbing levels. Climbing related injuries are predominantly located in fingers/ hands ("climber's finger"), and can present as annular pulley rupture or more common as overuse injury. Beside clinical examination imaging modalities such as MRI and high frequency sonography have shown to allow for detection of climbing related injuries. High frequency sonography enables for exact differential diagnosis of climbing related finger/hand injuries and therefore plays a central role in adequate therapeutic management.

Matching lung volume data sets--a novel approach.

There is a significant demand in matching CT datasets of the lung. The increasing number of CT slices per examination due to the higher resolution of modern CT scanners and the need for quantification of the progress of disease and healing processes in follow-up studies. A volunteer's lung was scanned by the means of multidetector CT in two different states of ventilation. The necessary lung structures for the matching procedure like lung surface and branching points were segmented. A thin-plate spline method was used to calculate the matched lung volume. The preliminary results show an average error of 2 voxel, i.e. 2mm. The calculation of the transformation matrix takes about one second on a conventional PC, which is considerably faster than other methods described in literature. The method described may be apt to be introduced in radiological practice when it comes to compare high resolution CT scans in follow-up studies quantitatively.

Value of magnetic resonance imaging in prostate cancer diagnosis.

MRI has shown its potential in prostate cancer (PCa) imaging. MRI is able to demonstrate zonal anatomy with excellent contrast resolution. Furthermore it can detect PCa dependent not only on tumor-size, histological grading, PSA levels, but also on technical equipment and reader's experience. Non-palpable PCas in the inner and outer gland can be detected by this technique. Another potential is that MRI is helpful for tumor staging and treatment planning as well as response evaluation. Besides the morphological information, MRI can give functional information based on metabolic evaluation with proton magnetic resonance spectroscopy and of tumor angiogenesis based on dynamic contrast-material enhanced MRI and diffusion-weighted imaging. In addition MRI can be used for targeted prostate biopsies; however, the clinical practicability is questionable. Furthermore many data about the value of MRI for PCa diagnosis are based on transrectal ultrasound (TRUS) biopsy findings. Since there is lack of accuracy in fusing MRI images with TRUS images these limit the results of MRI for cancer diagnosis. However, in the future MRI may play an additional role in planning and monitoring minimally invasive PCa therapies. Although, MRI of the prostate seems to be useful, nevertheless this method remains expensive and lacks availability regarding the oncoming requirements.

Appendicitis: should diagnostic imaging be performed if the clinical presentation is highly suggestive of the disease?

BACKGROUND & AIMS: Our aim was to investigate whether diagnostic imaging is required if the clinical presentation suggests acute appendicitis with high probability. METHODS: On the basis of clinical findings, 350 consecutive patients with clinical suspicion of acute appendicitis were prospectively divided into 3 groups as follows: low, intermediate, and high probability of having appendicitis. All patients then underwent diagnostic ultrasonography. The clinical likelihood of appendicitis and the ultrasonographic results were correlated with the definite diagnoses. RESULTS: In the patients with clinically low probability of having appendicitis, appendicitis was present in 10% (11 of 109 patients), and, in those with intermediate probability, appendicitis was present in 24% (23 of 97 patients). Patients with clinically high probability of having appendicitis had appendicitis in 65% (94 of 144 patients), an alternative diagnosis in 18% (26 of 144 patients), and no specific definitive diagnosis in 17% (24 of 144 patients). Ultrasonography diagnosed appendicitis and the differential diagnoses with a sensitivity of 98% and 97%, specificity of 98% and 100%, positive predictive value of 96% and 99%, negative predictive values of 99% and 99%, and accuracy of 98% and 99%, respectively. CONCLUSIONS: Even in patients with clinically high probability of acute appendicitis, diagnostic imaging should be performed because it accurately depicts a high percentage of normal appendices and differential diagnoses.