Acute coronary syndrome: evaluation of detection capability using non-electrocardiogram-gated parenchymal phase CT imaging

Purpose

To evaluate the capability to detect acute coronary syndrome (ACS) by using non-electrocardiogram-gated parenchymal phase CT imaging.

Materials and methods

Of 962 consecutive patients who underwent emergent coronary angiography for suspected ACS, 32 with ACS who underwent CT ≤24 h before angiography and 15 without ACS who underwent CT ≤24 h before or after angiography were included. Parenchymal phase was acquired at 100-s scan delay. The presence of a myocardial perfusion defect (MPD) on the left ventricle (a decrease of >20 HU) and its capability to detect ACS were evaluated. Results were compared with laboratory findings.

Results

MPD was detected in 29 of 32 ACSs. The sensitivity, specificity, and positive and negative predictive values were 91 % (29/32), 93 % (14/15), 97 % (29/30), and 82 % (14/17), respectively. The sensitivities of ST- and non-ST-elevation ACSs were 89 % (16/18) and 93 % (13/14), respectively, without significant difference (P > 0.99). Of the CT-detectable ACS, non-ST-elevation on the electrocardiogram and a normal creatine kinase-myocardial band were observed in 41 % (12/29) and 24 % (7/29), respectively.

Conclusion

ACS is highly detectable even using conventional parenchymal phase CT imaging. Therefore, even when CT is non-gating, radiologists should carefully evaluate the heart to avoid overlooking ACS.

     

Acute massive gastrointestinal bleeding: detection and localization with arterial phase multi-detector row helical CT

PURPOSE: To prospectively evaluate accuracy of arterial phase multi-detector row helical computed tomography (CT) for detection and localization of acute massive gastrointestinal (GI) bleeding, with angiography as reference standard. MATERIALS AND METHODS: Institutional review board approved this study; written informed consent was obtained from each patient or patient's family after procedures, including radiation dose, were explained. Twenty-six consecutive patients (17 men, nine women; age range, 18-89 years) had acute massive GI bleeding (defined as requirement of transfusion of at least 4 units of blood during 24 hours in the hospital or as hypotension with systolic blood pressure <90 mm Hg) and underwent arterial phase multi-detector row CT before angiography. Scans were obtained during arterial phase to identify extravasation of contrast material with attenuation greater than 90 HU within bowel lumen; this finding was considered diagnostic for active GI bleeding. Presence of contrast medium extravasation in each anatomic location was recorded. Sensitivity, specificity, positive and negative predictive values, and accuracy of multi-detector row CT for detection of acute GI bleeding were assessed. Accuracy for localization of acute GI bleeding was assessed by comparing locations of active bleeding at both multi-detector row CT and angiography in each patient who had active bleeding. RESULTS: Arterial phase multi-detector row CT depicted extravasation of contrast material in 21 of 26 patients. Overall location-based sensitivity, specificity, accuracy, and positive and negative predictive values of multi-detector row CT for detection of GI bleeding were 90.9% (20 of 22), 99% (107 of 108), 97.6% (127 of 130), 95% (20 of 21), and 98% (107 of 109), respectively. Overall patient-based accuracy of multi-detector row CT for detection of acute GI bleeding was 88.5% (23 of 26). The location of contrast material extravasation on multi-detector row CT scans corresponded exactly to that of active bleeding on angiograms in all patients with contrast medium extravasation at both multi-detector row CT and angiography. CONCLUSION: Arterial phase multi-detector row CT is accurate for detection and localization of bleeding sites in patients with acute massive GI bleeding.     

Comparative studies on the value of acute phase proteins and CA-125 for monitoring patients with ovarian cancer

In a study of 71 patients with malignant ovarian tumors serum levels of CA-125, C-reactive protein (CRP), alpha-1-antitrypsin and coeruloplasmin were analysed. In contrast to the tumor-free group significantly higher values of CA-125, CRP and alpha-1-antitrypsin were found in the group with recurrent disease. However, the serum-concentrations of coeruloplasmin remained unchanged in both groups. In the group with progressive disease the median values of CA-125 were greater than 65 U/ml and of CRP greater than 12 micron/ml, respectively. The median serum concentrations of alpha-1-antitrypsin (2 to 4 mg/ml) and coeruloplasmin (150 to 600 ng/ml) did not reach their cut-off levels. Beside CA-125 the analysis of CRP and alpha-1-antitrypsin is an additional helpful procedure for the monitoring of patients with malignant ovarian tumors.     

Acute and long‐term effects of blood flow restricted training on heat shock proteins and endogenous antioxidant systems

Blood flow restricted exercise (BFRE) with low loads has been demonstrated to induce considerable stress to exercising muscles. Muscle cells have developed a series of defensive systems against exercise‐induced stress. However, little is known about acute and long‐term effects of BFRE training on these systems. Nine previously untrained females trained low‐load BFRE and heavy load strength training (HLS) on separate legs and on separate days to investigate acute and long‐term effects on heat shock proteins (HSP) and endogenous antioxidant systems in skeletal muscles. BFRE and HLS increased muscle strength similarly by 12 ± 7% and 12 ± 6%, respectively, after 12 weeks of training. Acutely after the first BFRE and HLS exercise session, αB‐crystallin and HSP27 content increased in cytoskeletal structures, accompanied by increased expression of several HSP genes. After 12 weeks of training, this acute HSP response was absent. Basal levels of αB‐crystallin, HSP27, HSP70, mnSOD, or GPx1 remained unchanged after 12 weeks of training, but HSP27 levels increased in the cytoskeleton. Marked translocation of HSP to cytoskeletal structures at the commencement of training indicates that these structures are highly stressed from BFRE and HLS. However, as the muscle gets used to this type of exercise, this response is abolished.     

Multistep phase difference phase contrast imaging

A new technique for multistep phase-contrast image processing is presented. The N-step method consists of simply forming the linear average of the N — 1 adjacent phase-difference signals. It has similar noise reduction properties as other multistep techniques, but the simplicity of the noise variance of the N-step technique allows intuitive insight into phase-difference phase-contrast processing and noise reduction, which can aid in the design of efficient and improved phase-contrast imaging sequences. As well, the computational simplicity of the N-step phase-difference technique compared with any other known multistep technique is advantageous. Like other multistep techniques, it has far more efficient noise reduction properties than simple two-step, multiple average phase-contrast imaging, even when normalized for total scan time. A three-step phase-difference velocity image has 50% less variance than an image acquired with two steps and two scans averaged but is obtained in 25% less scan time. Given its advantages, it should now be the chosen technique for increasing velocity-to-noise and contrast-to-noise ratios in all phase-difference phase-contrast clinical applications.     

Acute pulmonary schistosomiasis

Acute pulmonary schistosomiasis occurs in non-immune hosts, particularly visitors to regions where Schistosoma species are endemic. While radiological findings of acute pulmonary schistosomiasis might resemble neoplastic or granulomatous disease, an appropriate travel history might suggest the diagnosis. With rising popularity of travel to Africa and South-East Asia, the incidence of acute pulmonary schistosomiasis can be expected to increase. We describe a case of acute pulmonary schistosomiasis occurring in an Australian returning from Lake Malawi, Sub-Saharan Africa.