31 research outputs found
Cystic appearance of low-grade endometrial stromal sarcoma in the right atrium: case report
A 71-year-old woman presented with a right adnexal solid mass invading the right gonadal vein and inferior vena cava up to the hepatic veins revealed by CT and confirmed by MRI. A thin-walled cyst and a solid mass were unexpectedly found in the right atrium by transesophageal echocardiography (TEE) in the operating room. Using color Doppler and air bubbles as contrast material a circumscribed cyst was confirmed and localized close to the IVC. The cyst was connected to the mass in the inferior vena cava. The tumor, including the cyst, was removed without using cardiopulmonary bypass and described as a low-grade endometrial stromal sarcoma, a rare slowly growing tumor. This is the first TEE description of endometrial stromal sarcoma manifesting as a right atrial cyst
Image Texture Characterization Using the Discrete Orthonormal S-Transform
We present a new efficient approach for characterizing image texture based on a recently published discrete, orthonormal space-frequency transform known as the DOST. We develop a frequency-domain implementation of the DOST in two dimensions for the case of dyadic frequency sampling. Then, we describe a rapid and efficient approach to obtain local spatial frequency information for an image and show that this information can be used to characterize the horizontal and vertical frequency patterns in synthetic images. Finally, we demonstrate that DOST components can be combined to obtain a rotationally invariant set of texture features that can accurately classify a series of texture patterns. The DOST provides the computational efficiency and multi-scale information of wavelet transforms, while providing texture features in terms of Fourier frequencies. It outperforms leading wavelet-based texture analysis methods
Respiratory maneuvers in echocardiography: a review of clinical applications
During echocardiographic examination, respiration induces cyclic physiological changes of intracardiac haemodynamics, causing normal variations of the right and left ventricle Doppler inflows and outflows and physiological variation of extracardiac flows. The respiration related hemodynamic variation in intra and extracardiac flows may be utilized in the echocardiography laboratory to aid diagnosis in different pathological states. Nevertheless, physiologic respiratory phases can cause excessive translational motion of cardiac structures, lowering 2D image quality and interfering with optimal Doppler interrogation of flows or tissue motion
Decrease in shunt volume in patients with cryptogenic stroke and patent foramen ovale
<p>Abstract</p> <p>Background</p> <p>In patients with patent foramen ovale (PFO) there is evidence supporting the hypothesis of a change in right-to-left shunt (RLS) over time. Proven, this could have implications for the care of patients with PFO and a history of stroke. The following study addressed this hypothesis in a cohort of patients with stroke and PFO.</p> <p>Methods</p> <p>The RLS volume assessed during hospitalisation for stroke (index event/T0) was compared with the RLS volume on follow-up (T1) (median time between T0 and T1 was 10 months). In 102 patients with a history of stroke and PFO the RLS volume was re-assessed on follow-up using contrast-enhanced transcranial Doppler/duplex (ce-TCD) ultrasound. A change in RLS volume was defined as a difference of ≥20 microembolic signals (MES) or no evidence of RLS during ce-TCD ultrasound on follow-up.</p> <p>Results</p> <p>There was evidence of a marked reduction in RLS volume in 31/102 patients; in 14/31 patients a PFO was no longer detectable. An index event classified as cryptogenic stroke (P < 0.001; OD = 39.2, 95% confidence interval 6.0 to 258.2) and the time interval to the follow-up visit (P = 0.03) were independently associated with a change in RLS volume over time.</p> <p>Conclusions</p> <p>RLS volume across a PFO decreases over time, especially in patients with cryptogenic stroke. These may determine the development of new strategies for the management in the secondary stroke prevention.</p