Split-bolus single-phase cardiac multidetector computed tomography for reliable detection of left atrial thrombus: comparison to transesophageal echocardiography

PURPOSE

Evaluation of a new cardiac MDCT protocol using a split-bolus contrast injection protocol and single MDCT scan for reliable diagnosis of LA/LAA thrombi in comparison to TEE, optimizing radiation exposure and use of contrast agent.

MATERIALS AND METHODS

A total of 182 consecutive patients with drug refractory AF scheduled for PVI (62.6 % male, mean age: 64.1 ± 10.2 years) underwent routine diagnostic work including TEE and cardiac MDCT for the evaluation of LA/LAA anatomy and thrombus formation between November 2010 and March 2012. Contrast media injection was split into a pre-bolus of 30 ml and main bolus of 70 ml iodinated contrast agent separated by a short time delay.

RESULTS

In this study, split-bolus cardiac MDCT identified 14 of 182 patients with filling defects of the LA/LAA. In all of these 14 patients, abnormalities were found in TEE. All 5 of the 14 patients with thrombus formation in cardiac MDCT were confirmed by TEE.

CONCLUSION

MDCT was 100 % accurate for thrombus, with strong but not perfect overall results for SEC equivalent on MDCT.

KEY POINTS

• Patients with no filling defect or thrombus in MDCT in the LA/LAA region are unlikely to have thrombus and may undergo PVI without TEE.• Here, the role of an additional TEE in pre-procedural management prior to PVI in patients with AF has to be redefined.• Using a split-bolus injection protocol increases the diagnostic accuracy of thrombus in the LA/LAA region.

Miniaturized high-precision piezo driven two axes stepper goniometer

A miniaturized inertial stepper goniometer with two orthogonal axes (θ and φ axes) has been realized using four shear piezo based actuators arranged in a tetrahedral configuration tangent with a polished sapphire spherical rotor. The measured sensitivity is about 11.5 microdegree (μ°) per Volt. The smallest angular step size, achieved with a minimal peak-to-peak voltage Upp of 200 V is about 0.6 millidegree (m°). The crosstalk between both axes is below 10%. Our specific design is used to accurately position a glass fiber, but the concept can be utilized for many different applications as well.

Current role of cardiac and extra-cardiac pathologies in clinically indicated cardiac computed tomography with emphasis on status before pulmonary vein isolation

PURPOSE

The aim of this study was to assess the incidence of cardiac and significant extra-cardiac findings in clinical computed tomography of the heart in patients with atrial fibrillation before pulmonary vein isolation (PVI).

MATERIALS AND METHODS

224 patients (64 ± 10 years; male 63 %) with atrial fibrillation were examined by cardiac 64-slice multidetector CT before PVI. Extra-cardiac findings were classified as "significant" if they were recommended to additional diagnostics or therapy, and otherwise as "non-significant". Additionally, cardiac findings were documented in detail.

RESULTS

A total of 724 cardiac findings were identified in 203 patients (91 % of patients). Additionally, a total of 619 extra-cardiac findings were identified in 179 patients (80 % of patients). Among these extra-cardiac findings 196 (32 %) were "significant", and 423 (68 %) were "non-significant". In 2 patients (1 %) a previously unknown malignancy was detected (esophageal cancer and lung cancer, local stage, no metastasis). 203 additional imaging diagnostics followed to clarify the "significant" findings (124 additional CT, costs 38 314.69 US dollars). Overall, there were 3.2 cardiac and 2.8 extra-cardiac findings per patient. Extra-cardiac findings appear significantly more frequently in patients over 60 years old, in smokers and in patients with a history of cardiac findings (p <0.05).

CONCLUSION

Cardiac CT scans before PVI should be screened for extracardiac incidental findings that could have important clinical implications for each patient.

Features of aphasic gesturing--an exploratory study of features in gestures produced by persons with and without aphasia

The purpose of this study was to see how features of gestures produced by persons with aphasia (PWA) are affected and to relate the findings to possible underlying factors. Spontaneous gestures were studied in two contexts: (i) associated with the production of nouns and verbs and (ii) in relation to word finding or production difficulties. The method involved assembling two datasets of co-speech gestures, produced by PWA and by persons without aphasia and to code the gestures for a number of features of expression and content. Features that were affected in the Aphasia dataset were gaze, head movements, hand use and semantic features. The results point to possibly converging explanations, such as generally lower semantic complexity as a direct effect of the aphasia, more cognitive effort and/or a greater dependence on one-hand gestures leading more indirectly to increased gaze aversion, more head shakes and lower complexity in gestures in PWA.

[Acute tubulointerstitial nephritis as hyperergic reaction of the kidneys]

Acute tubulointerstitial nephritis was formerly only observed during the early phase of infections. With the emergence of antibiotics this disease became a rarity. In contrast the importance of drug-associated acute tubulointerstitial nephritis grew in importance and is now the most common form and expression of a hyperergic reaction of the kidneys. Acute tubulointerstitial nephritis occurs as a third form in cases of systemic autoimmune diseases, e.g., in idiopathic tubulointerstitial nephritis or within the scope of Sjögrens syndrome with distal tubular acidosis. The common symptoms of the drug-induced form are fever, side pain, microhematuria or macrohematuria and a mostly sharp increase in creatinine levels but to a greatly differing extent. Histologically, there is interstitial edema and interstitial lymphocyte-rich infiltration with tubulitis. The symptoms can be subclinical or even non-existent. In most case remission occurs, sometimes only partial remission or transformation to chronic interstitial nephritis. Risk factors are for example delayed diagnosis, recurrent episodes and the accompanying use of analgesics. The more acute and intense the clinical symptoms are, the earlier the diagnosis and therefore the better the prognosis. A temporary steroid treatment can promote regression.

Renal comorbidity after solid organ and stem cell transplantation

After transplantation of solid organs or hematopoietic stem cells, a significant acute decrease in renal function occurs in the majority of patients. Depending on the degree of kidney injury, a large number of patients develop chronic kidney disease (CKD) and some develop end-stage renal disease requiring renal replacement therapy. The incidence varies depending on the transplanted organ, but important risk factors for the development of CKD are preexisting renal disease, hepatitis C, diabetes, hypertension, age, sex, posttransplant acute kidney injury and thrombotic microangiopathy. This review article focuses on the risk factors of posttransplant chronic kidney disease after organ transplantation, considering the current literature and integrates the incidence and the associated mortality rates of acute and chronic kidney disease. Furthermore, we introduce the RECAST (REnal Comorbidity After Solid organ and hematopoietic stem cell Transplantation) registry.

Do insulin-like growth factor associated proteins qualify as a tumor marker? Results of a prospective study in 163 cancer patients

OBJECTIVE

Insulin-like growth factor (IGF)-1, -2 and Insulin like growth factor binding proteins (IGFBP) are involved in the proliferation and differentiation of cells. It has never been evaluated, if the IGF-system can serve as a tumor marker in neoplasms.

METHODS

In our prospective study 163 patients with colorectal cancer (22), prostate cancer (21), head and neck tumors (17), lymphomas (20), lung cancer (34) and other entities (49) were analysed for their IGF and IGFBP serum levels at the beginning and the end of radiotherapy and compared to 13 healthy people. Subgroups of patients with local tumor disease versus metastatic disease, primary and recurrent therapy and curative versus palliative therapy were compared.

RESULTS

The serum levels of IGF-2 were significantly elevated in patients with prostate and colorectal cancer. However, sensitivity and specificity were only 70%. IGFBP-2 serum levels were elevated in patients with head and neck tumors. Again sensitivity and specificity were only 73%. A difference between local disease and metastatic disease could not be found. A difference between IGF serum levels before and after radiotherapy could not be detected.

CONCLUSION

The IGF-system cannot serve as a new tumor marker. The detected differences are very small, sensitivity and specificity are too low. IGF measurement is not useful for the evaluation of the success of radiotherapy in malignancies.

Quantitative measurement of the magnetic exchange interaction across a vacuum gap

We demonstrate that magnetic exchange force spectroscopy allows for a quantitative determination of the distance-dependent magnetic exchange interaction across a vacuum gap. Experiments were performed on the antiferromagnetic Fe monolayer on W(001) with magnetically sensitive tips and compared to first-principles calculations performed for different cluster tip models. For stable tips, which can be distinguished from unstable tips by analyzing the dissipation signal, very good agreement with theory is observed.