The effect of a pre-reconstruction process in a filtered back projection reconstruction on an image quality of a low tube voltage computed tomography.

This study aims to evaluate the effect of pre-reconstruction process for low tube voltage computed tomography (CT) on image quality of filtered back projection (FBP) reconstruction. Small and large quality assurance water phantoms (19 and 33 cm diameter) were scanned on a third-generation dual-source CT with 70 kVp and 120 kVp at various dose levels. Image quality was assessed in terms of the noise power spectrum (NPS) and task-based transfer function (TTF).

Patient dose reduction for a localizer radiograph with an additional tin filter in chest-abdomen-pelvis, spine, and head computed tomography examinations.

This study aimed to evaluate the dose reduction potential of adding a tin filter to localizer radiographs (LR) on computed tomography (CT) examinations in both phantom and clinical studies. LRs were performed using combinations of 120 kVp and 20 mA (120/20), 100 kVp with a tin filter, and 50 mA or 20 mA (Sn100/50, Sn100/20). For the phantom experiment, entrance surface doses (ESD) of the LRs were evaluated for each protocol using an anthropomorphic phantom.

Biological fingerprint for patient verification using trunk scout views at various scan ranges in computed tomography.

Immediate verification of whether a patient being examined is correct is desirable, even if the scan ranges change during different examinations for the same patient. This study proposes an advanced biological fingerprint technique for the rapid and reliable verification of various scan ranges in computed tomography (CT) scans of the torso of the same patient. The method comprises the following steps: geometric correction of different scans, local feature extraction, mismatch elimination, and similarity evaluation.

Hounsfield Unit Value of Interpeduncular Cistern Hematomas Can Predict Symptomatic Vasospasm.

Background and Purpose- Symptomatic vasospasm is an important factor that affects the outcomes of aneurysmal subarachnoid hemorrhage. Subarachnoid blood volume can predict symptomatic vasospasm, and we postulated that the blood clot density would also be an important factor involved in such events. The present study aimed to determine the relationship between the incidence of symptomatic vasospasm and the Hounsfield unit (HU) value of the interpeduncular cistern that reflects the density of hematomas.

Usefulness of biological fingerprint in magnetic resonance imaging for patient verification.

The purpose of our study is to investigate the feasibility of automated patient verification using multi-planar reconstruction (MPR) images generated from three-dimensional magnetic resonance (MR) imaging of the brain. Several anatomy-related MPR images generated from three-dimensional fast scout scan of each MR examination were used as biological fingerprint images in this study. The database of this study consisted of 730 temporal pairs of MR examination of the brain.

Automatic ROI construction for analyzing time-signal intensity curve in dynamic contrast-enhanced MR imaging of the breast.

Our purpose in this study was to construct a 3-dimensional (3D) region of interest (ROI) for analyzing the time-signal intensity curve (TIC) semi-automatically in dynamic contrast-enhanced magnetic resonance (DCE-MR) imaging of the breast. DCE-MR breast imaging datasets were acquired by a 3.0-Tesla MR system with the use of a 3D fast gradient echo sequence.

Added value of lung perfused blood volume images using dual-energy CT for assessment of acute pulmonary embolism.

Purpose: To investigate the added value of lung perfused blood volume (LPBV) using dual-energy CT for the evaluation of intrapulmonary clot (IPC) in patients suspected of having acute pulmonary embolism (PE).

Materials And Methods: Institutional review board approval was obtained for this retrospective study. Eighty-three patients suspected of having PE who underwent CT pulmonary angiography (CTPA) using a dual-energy technique were enrolled in this study.

The effect of the section thickness used for 2- and 3-dimensional quantification of dual-energy perfusion computed tomography.

Purpose: To retrospectively investigate the effect of the section thickness used for quantifying dual-energy perfusion computed tomography (DEpCT) during 2- and 3-dimensional evaluation.

Methods: Sixty-six patients (22 males and 44 females; mean age, 59.3 years) suspected of having an acute pulmonary embolism underwent DEpCT, and 15patients were diagnosed to have intrapulmonary clots (IPCs).

Comparison of lumbar drainage and external ventricular drainage for clearance of subarachnoid clots after Guglielmi detachable coil embolization for aneurysmal subarachnoid hemorrhage.

Objective: Subarachnoid clots play an important role in development of delayed vasospasm after subarachnoid hemorrhage (SAH). The purpose of this study was to compare clearance of subarachnoid clots using external ventricular drainage (EVD) or lumbar drainage (LD) after Guglielmi detachable coil (GDC) embolization for aneurysmal SAH.

Methods: The subjects were 51 treated with GDC coil embolization for aneurysmal Fisher group 3 SAH within 72 h of ictus.

Dual-energy perfusion CT of non-diseased lung segments using dual-source CT: correlation with perfusion SPECT.

Purpose: To determine the utility of dual-energy perfusion CT (DEpCT) of non-diseased lung segments, using dual-source CT, in comparison with perfusion single-photon emission computed tomography (SPECT).

Materials And Methods: 28 patients (18 male and 10 female; mean age 63 years; age range 18-86 years) underwent DEpCT and SPECT within a 3-day interval. The presence and location of perfusion defects in each segment of the lungs were evaluated.

The low attenuation area on dual-energy perfusion CT: correlation with the pulmonary function tests and quantitative CT measurements.

Purpose: To retrospectively investigate the distribution of the low attenuation area (LAA) on dual energy perfusion CT (DEpCT) in comparison with the results of pulmonary function tests (PFTs) and quantitative CT measurements.

Materials And Methods: Twenty-eight patients (15 male and 13 female; mean age: 62.21 years) underwent DEpCT and PFTs within a 1-month interval.

Correction of liver displacement due to irregular respiration for SPECT images obtained using a multiple short-time acquisition with breath-holding technique.

Recently, a new method for acquiring single photon emission computed tomography (SPECT) data during breath-holding with a high-speed rotation (HSR-SPECT) technique was applied to hepatic-function scintigraphy. This technique can suppress motion artifact caused by respiration. However, it is challenging to apply this technique to patients with respiratory problems.

[Evaluation of image quality of multiplanar reconstruction images: Effect of Z-increment of original axial images].

Purpose: The aim of our study was to evaluate the image quality of multiplanar reconstruction images (MPRs) focusing on the effect of z-increment of original axial images using signal to noise ratio (SNR) measurement in in- plane and longitudinal directions.

Methods And Materials: SNRs of MPRs were calculated using modulation transfer function (MTF) and noise power spectrum (NPS). We scanned a bead phantom with a diameter of 0.

[Measurement of residual effect in the amorphous selenium flat panel detector system].

The purpose of this study was to evaluate the residual effect generated by the amorphous selenium flat panel detector system (a-Se FPD). A residual effect occurs as a result of the addition of delayed electrons by previous X-ray irradiation joining the signal and change in detector sensitivity caused by hole-electron recombination or trapped electrons in a-Se. To evaluate the effect of previous radiation exposure, we irradiated a-Se FPD that were half-shielded by a 3 mm thick lead plate.

Evaluation of the spatial resolution of multiplanar reconstruction images.

We present a simple method for evaluating the spatial resolution of multi-slice computed tomography (MSCT) multiplanar reconstruction images (MPRs). We scanned a bead phantom to obtain the three-dimensional point spread function (PSF), and bead-centric MPRs were generated. The modulation transfer function (MTF) was calculated from the MPRs via a two-dimensional Fourier transform (2DFFT) of the PSF.