CONTEXT There is extensive overlap among the imaging characteristics of pseudocyst, mucinous cystic neoplasm (MCN) and side branch intraductal papillary mucinous neoplasm (IPMN) on CT images. OBJECTIVE The purpose of this study was to evaluate the usefulness of attenuation measurement in differentiating pseudocysts from MCN and IPMN of pancreas on CT images. PATIENTS Seventy-five pathologic...

1. We have examined the relationship between the attenuation of broadband ultrasound in the os calcis in vitro and its bone mineral density measured by quantitative computed tomography and by physical density. 2. Broadband ultrasound attenuation was found to correlate closely with physical density (r = 0.85, P less than 0.0001), but the correlation was less than that observed between quantitati...

Purpose: To investigate important factors affecting the frequency of air trapping through observation of normal lung attenuation, and propose a cause of heterogeneous attenuation. Materials and Methods: In this ethical committee-approved study, a total of 109 patients (30 males, 79 females; mean age, 58.2 years; range, 27 81 years) were included. All patients had undergone inspiratory and expir...

PURPOSE Presence of photon attenuation severely challenges quantitative accuracy in single-photon emission computed tomography (SPECT) imaging. Subsequently, various attenuation correction methods have been developed to compensate for this degradation. The present study aims to implement an attenuation correction method and then to evaluate quantification accuracy of attenuation correction in s...

A light attenuation sensor system (LASS) for measurements in waters is described in this paper. The LASS records irradiance at multiple levels in the water column to provide a measure of the diffuse light attenuation coefficient which is strongly affected by suspended sediment. Dimensional analysis and geometric optical theory are used to relate the irradiance attenuation to sediment properties...

Despite advancements in technologies, non-uniform soft tissue attenuation still affects the diagnostic accuracy of single photon emission computed tomography (SPECT) myocardial perfusion imaging. A variety of indirect measures have been used to reduce the impact of attenuation, most notably electrocardiography-gated SPECT imaging. However, all available techniques have limitations, making inter...

Attenuation-difference, borehole-radar tomography was used to monitor a series of sodium chloride tracer injection tests conducted within the FSE wellfield at the U.S. Geological Survey Fractured-Rock Hydrology Research Site in Grafton County, New Hampshire, USA. Borehole-radar tomography surveys were conducted by using the sequential-scanning and injection method in three boreholes that form a...

Hearing protection devices (HPDs) play a significant role in protecting workers from occupational noise-induced hearing loss. Individual HPD fit-testing estimates the amount of protection, or attenuation, that an individual achieves from a given HPD as it is worn. Results from a single fit-test may not be representative of real-world HPD performance over time, however, due to inconsistency in h...

German Cancer Research Center (DKFZ), Heidelberg, Germany Accurate quantification of the activity distribution in positron emission tomography (PET) mandates attenuation correction (AC). Unlike in PET/CT, AC in PET/MR is, however, challenging, since information about the attenuation properties of the patient tissue distribution is not available directly. Standard MR-based AC (MRAC) does not acc...

Quantitative ultrasound features such as the attenuation slope, sound speed and scatterer size, have been utilized to evaluate pathological variations in soft tissues such as the liver and breast. However, the impact of variations in the sound speed and backscatter due to underlying fat content or fibrotic changes, on the attenuation slope has not been addressed. Both numerical and acoustically...