Introduction to coronary imaging with 64-slice computed tomography

The aim of this article is to illustrate the main technical improvements in the last generation of 64-row CT scanners and the possible applications in coronary angiography. In particular, we describe the new physical components (X-ray tube-detectors system) and the general scan and reconstruction parameters. We then define the scan protocols for coronary angiography with the new generation of 64-row CT scanners to enable radiologists to perform a CT study on the basis of the diagnostic possibilities.     

Contrast-enhanced MR angiography and digital subtraction angiography in living renal donors: diagnostic agreement, impact on decision making, and costs

OBJECTIVE: The objective of our study was to evaluate the diagnostic agreement, the impact on decision making, and the costs of contrast-enhanced MR angiography and digital subtraction angiography in the workup of living renal donors. CONCLUSION: Contrast-enhanced MR angiography for the preoperative evaluation of renal donors is superior to digital subtraction angiography in revealing vascular anomalies and depicting parenchymal abnormalities and is less costly; furthermore, it does not lead to preoperative decisions that differ from those based on digital subtraction angiography. If contrast-enhanced MR angiography does not provide sufficient information to make a confident decision, an additional digital subtraction angiography examination should be performed.     

Non-invasive 16-row multislice CT coronary angiography: usefulness of saline chaser

The aim of this study was to investigate the usefulness of saline chaser in 16-row multislice CT (16-MSCT) coronary angiography. Forty-two patients were divided into two groups for contrast material (CM) administration: group 1 (140 ml at 4 ml/s) and group 2 (100 ml at 4 ml/s followed by 40 ml of saline chaser at 4 ml/s). All patients underwent retrospectively ECG-gated 16-MSCT coronary angiography. The attenuation at the origin coronary vessels was assessed. Three regions of interest (ROIs) were drawn throughout the data set: (a) ascending aorta (ROI 1); (b) descending aorta (ROI 2); and (c) pulmonary artery (ROI 3). The attenuation in the superior vena cava was recorded (ROI 4). The average attenuation and the slope were calculated in each ROI and differences were assessed with a Students t test. The average attenuation in the coronary vessels was not significantly different in the two groups. The average attenuations in ROI 1 were 325 and 327 HU, in ROI 2 were 328 and 329 HU and in ROI 3 were 357 and 320 HU, for groups 1 and 2, respectively (p>0.05). The slopes in ROI 1 were –0.2 and 1.1, in ROI 2 were 2.8 and 2.1 (p>0.05) and in ROI3 were 3.9 and –9.0 (p<0.05), for groups 1 and 2, respectively. The average attenuations in ROI 4 were 927 and 643 HU (p<0.05), for groups 1 and 2, respectively. One hundred milliliters of CM with 40 ml of saline chaser provides the same attenuation as 140 ml of CM (35% less) with decreased hyper-attenuation in the superior vena cava.     

Parameters affecting bolus geometry in CTA: a review

CT angiography (CTA) is based on acquisition of data during the arterial phase of contrast material passage. CTA needs timing of the contrast bolus, which should be based on accurate knowledge of bolus geometry. Experimental and human studies on bolus geometry and bolus timing in CTA were reviewed. Important parameters of bolus geometry and methods of bolus timing (test bolus and bolus tracking) are described. Recommendations are given for an optimal CTA protocol.     

Evaluation of the chronic toxicity and oncogenicity of N,N-diethyl-m- toluamide (DEET)

Chronic toxicity and/or oncogenicity studies were conducted in rats, mice, and dogs with the insect repellent DEET. DEET was mixed in the diet and administered to CD rats for two years at concentrations that corresponded to dosage levels of 10, 30 or 100 mg/kg/day for males and 30, 100, or 400 mg/kg/day for females; to CD-1 mice for 18 months at dosage levels of 250, 500, or 1000 mg/kg/day; and to dogs for one year, via gelatin capsules, at dosage levels of 30, 100, or 400 mg/kg/day. In the rodent studies, each group consisted of 60 animals of each sex, and two concurrent independent control groups, each containing 60 animals/sex were included in each study. Each group in the dog study consisted of four male and four female dogs and one control group was included in the study. Treatment-related effects were observed at the highest dose level in all three studies. For rats, the effects included decreases in body weight and food consumption and an increase in serum cholesterol in females only. In mice, the effects observed were decreases in body weight and food consumption in both sexes. The effects observed in dogs included increased incidences of emesis and ptyalism, and levels of transient reduction in hemoglobin and hematocrit, increased alkaline phosphatase (males only), decreased cholesterol, and increased potassium. One male dog in the high-dose group also exhibited ataxia, tremors, abnormal head movements, and/or convulsions on several occasions during the study. The highest no- observed-effect levels (NO-ELs) for rats, mice and dogs were determined to be 100, 500, and 100 mg/kg/day, respectively. No specific target organ toxicity or oncogenicity was observed in any of the studies.      

Endoluminal brachytherapy for recurrent laryngeal carcinoma

Early-stage squamous cell carcinoma of the larynx is usually treated with local field radiotherapy. Surgery is used for salvage following recurrence. Further recurrences present a more difficult therapeutic problem which requires individualized management. The aims of local control, survival, maintenance of function and minimizing side effects all need to be balanced according to the site and extent of disease. The present case study looks at the management of a 54-year-old man with multiple recurrences from a squamous cell carcinoma of the larynx. It describes a technique of endoluminal brachytherapy using an iridium-192 wire spiralled around the outer part of a tracheostomy tube that achieves good local control while enabling self-insertion and self-cleaning during the procedure. The dose given was 2500 cGy at 5 mm over 25.2 h and was achieved with minimal early or delayed side effects. The patient had no further symptoms relating to the stomal recurrence until his death from metastatic disease 6 months later.     

A qualitative study of women's views about how health professionals communicate about infant feeding

Objective

To look at how communication by health professionals about infant feeding is perceived by first time mothers.

Design

Qualitative semi‐structured interviews early in pregnancy and 6–10 weeks after birth.

Subjects and setting

Twenty‐one white, low income women expecting their first baby were interviewed mostly at home, often with their partner or a relative.

Results

The personal and practical aspects of infant feeding which were important to women were seldom discussed in detail in ante‐natal interviews. In post‐natal interviews women described how words alone encouraging them to breastfeed were insufficient. Apprenticeship style learning of practical skills was valued, particularly time patiently spent watching them feed their baby. Women preferred to be shown skills rather than be told how to do them. Some felt pressure to breastfeed and bottle feeding mothers on post‐natal wards felt neglected in comparison. Women preferred their own decision‐making to be facilitated rather than being advised what to do. Some women experienced distress exposing their breasts and being touched by health professionals. Continuity of care and forming a personal relationship with a health professional who could reassure them were key factors associated with satisfaction with infant feeding communication.

Conclusions

The infant feeding goal for many women is a contented, thriving baby. In contrast, women perceive that the goal for health professionals is the continuation of breastfeeding. These differing goals can give rise to dissatisfaction with communication which is often seen as ‘breastfeeding centred’ rather than ‘woman centred.’ Words alone offering support for breastfeeding were often inadequate and women valued practical demonstrations and being shown how to feed their baby. Spending time with a caring midwife with whom the woman had developed a personal, continuing relationship was highly valued. Women were keen to maintain ownership, control and responsibility for their own decision‐making about infant feeding.

     

The use of carbon dioxide in magnetic resonance angiography: a new type of black blood imaging

The injection of boluses of carbon dioxide (CO(2)) during T1-weighted magnetic resonance angiography (MRA) resulted in sharp depiction of the vascular lumen during the performance of in vitro and in vivo animal experiments. We propose the use of the low-cost, relatively safe CO(2) as a negative contrast agent for MRA and speculate on its use in future interventional MRA.     

含巨菊形团的玻璃样变梭形细胞肿瘤--附3例报告及电镜分析

含巨菊形团的玻璃样变梭形细胞肿瘤 (ＨＳＣＴＧＲ)是近年来才被命名的间叶性肿瘤 ,光镜下类似低度恶性纤维粘液肉瘤。作者观察了 3例ＨＳＣＴＧＲ的光镜、电镜及免疫组化表现。3例中男性 2例 ,分别为 41和 5 4岁 ,女性 1例 ,6 2岁。肿瘤位于深部软组织 ,2例在下肢 ,1例在上臂。大体上 ,最大径 3～ 13 3ｃｍ不等 ,境界清楚 ,呈棕红色或黄白色 ,质实 ,可伴囊性变 ,其中发生于小腿的 1例合并有股骨骨肉瘤 ,小腿部肿块仅做了活检。光镜下 3例图像相似 ,均有纤维粘液样区 ,2例伴有玻璃样变 ,1例有灶性骨化。肿瘤细胞为温和的卵圆形至梭形细胞 ,…     

Superparamagnetic iron oxide contrast agents: physicochemical characteristics and applications in MR imaging

Superparamagnetic iron oxide MR imaging contrast agents have been the subjects of extensive research over the past decade. The iron oxide particle size of these contrast agents varies widely, and influences their physicochemical and pharmacokinetic properties, and thus clinical application. Superparamagnetic agents enhance both T1 and T2/T2* relaxation. In most situations it is their significant capacity to reduce the T2/T2* relaxation time to be utilized. The T1 relaxivity can be improved (and the T2/T2* effect can be reduced) using small particles and T1-weighted imaging sequences. Large iron oxide particles are used for bowel contrast [AMI-121 (i.e. Lumirem and Gastromark) and OMP (i.e. Abdoscan), mean diameter no less than 300 nm] and liver/spleen imaging [AMI-25 (i.e. Endorem and Feridex IV, diameter 80-150 nm); SHU 555A (i.e. Resovist, mean diameter 60 nm)]. Smaller iron oxide particles are selected for lymph node imaging [AMI-227 (i.e. Sinerem and Combidex, diameter 20-40 nm)], bone marrow imaging (AMI-227), perfusion imaging [NC100150 (i.e. Clariscan, mean diameter 20 nm)] and MR angiography (NC100150). Even smaller monocrystalline iron oxide nanoparticles are under research for receptor-directed MR imaging and magnetically labeled cell probe MR imaging. Iron oxide particles for bowel contrast are coated with insoluble material, and all iron oxide particles for intravenous injection are biodegradable. Superparamagnetic agents open up an important field for research in MR imaging.