The feasibility of contrast-enhanced spectral mammography immediately after contrast-enhanced CT.

Contrast-enhanced spectral mammography (CESM) is a digital mammography method that requires an intravenous injection of iodinated contrast material to detect hypervascular lesions. In patients undergoing evaluation for metastases before breast tumor surgery, a contrast material must be injected for computed tomography (CT) and CESM studies. The purpose of our study was to investigate the feasibility of performing CESM immediately after contrast-enhanced CT, without injecting additional contrast material. We enrolled 77 women with 88 breast carcinomas. Immediately after contrast-enhanced CT, we performed CESM without injecting additional contrast material. The patients were divided into two groups based on the length of the interval between contrast material injection and the start of mammography. In group A (n = 51), it was less, and in group B (n = 26) it was more than 7 min. We measured the tumor gland contrast of each tumor on the CESM images and recorded the tumor opacification on a 4-point visual scale. The mean interval between the start of contrast material injection for CT and the acquisition of mammograms in groups A and B was 5.41 and 10.40 min, respectively. All lesions were detectable on the CESM images. There was no significant difference in the visual evaluation between the two groups (p = 0.21). CESM immediately after contrast-enhanced CT without the injection of additional contrast material is feasible and cost-effective.

[Detection of cerebral hypoperfusion using single photon emission computed tomography image analysis and statistical parametric mapping in patients with Parkinson's disease or progressive supranuclear palsy].

PURPOSE: We carried out differential diagnosis of brain blood flow images using single-photon emission computed tomography (SPECT) for patients with Parkinson's disease (PD) or progressive supranuclear paralysis (PSP) using statistical parametric mapping (SPM) and to whom we had applied anatomical standardization. MATERIALS AND METHODS: We studied two groups and compared brain blood flow images using SPECT (N-isopropyl-4-iodoamphetamine [(123)I] hydrochloride injection, 222 MGq dosage i.v.). A total of 27 patients were studied using SPM: 18 with PD and 9 with PSP; humming bird sign on MRI was from moderate to medium. RESULTS: The decline of brain bloodstream in the PSP group was more notable in the midbrain, near the domain where the humming bird sign was observable, than in the PD group. CONCLUSIONS: The observable differences in brain bloodstream decline in the midbrain of PSP and PD patients suggest the potential usefulness of this technique's clinical application to distinction diagnosis.

Development of a noise reduction filter algorithm for pediatric body images in multidetector CT.

Recently, several types of post-processing image filter which was designed to reduce noise allowing a corresponding dose reduction in CT images have been proposed and these were reported to be useful for noise reduction of CT images of adult patients. However, these have not been reported on adaptation for pediatric patients. Because they are not very effective with small (<20 cm) display fields of view, they could not be used for pediatric (e.g., premature babies and infants) body CT images. In order to solve this restriction, we have developed a new noise reduction filter algorithm which can be applicable for pediatric body CT images. This algorithm is based on a three-dimensional post processing, in which output pixel values are calculated by multi-directional, one-dimensional median filters on original volumetric datasets. The processed directions were selected except in in-plane (axial plane) direction, and consequently the in-plane spatial resolution was not affected by the filter. Also, in other directions, the spatial resolutions including slice thickness were almost maintained due to a characteristic of non-linear filtering of the median filter. From the results of phantom studies, the proposed algorithm could reduce standard deviation values as a noise index by up to 30% without affecting the spatial resolution of all directions, and therefore, contrast-to-noise ratio was improved by up to 30%. This newly developed filter algorithm will be useful for the diagnosis and radiation dose reduction of pediatric body CT images.