Perfusion-CT monitoring of cryo-ablated renal cells tumors

<p>Abstract</p> <p>Background</p> <p>No single and thoroughly validated imaging method in monitoring of cryoablated renal cell carcinoma (RCC) is available. The purpose of our study was to determine the feasibility of dynamic contrast-enhanced perfusion CT (pCT) in evaluating the hemodynamic response of RCC.</p> <p>Methods</p> <p>15 patients (14 male, 1 female; age range, 43-81 years; mean age, 62 years) with cryoablated RCC via a transperitoneal approach, underwent to pCT 6-8 months after cryo-therapy. pCT was performed for 65 seconds after intravenous injection of contrast medium (80 mL, 370 mg iodine per millilitre, 4 mL/sec). Perfusion parameters (Time/Density curve; Blood flow, BF; Blood Volume, BV; Mean Transit Time, MTT; Permeability-Surface Area Product, PS) were sampled in the cryoablated tumor area and in ipsilateral renal cortex using deconvolution-based method. A tumor was considered to be not responsive to treatment by CT evidence of pathological contrast enhancement in the cryoablated area or renal mass persistence compared with the preoperative CT control. Written informed consent was obtained from all participants before the study.</p> <p>Results</p> <p>After cryotherapy, successfully ablated tumor (n = 13) showed decrease in BV (5,39 +/- 1,28 mL/100 g), BF (69,92 +/- 20,12 mL/100 g/min) and PS (16,66 +/- 5,67 mL/100 g/min) value and increased value of MTT (25,35 +/- 4,3 sec) compared with those of normal renal cortex (BV: 117,86 +/- 31,87 mL/100 g/min; BF: 392,39 +/- 117,32 mL/100 g/min; MTT: 18,02 +/- 3,6 sec; PS: 81,68 +/- 22,75 mL/100 g/min). In one patient, assessment of perfusion parameters was not feasible for breathing artifacts. One tumor showed poor response to treatment by the evidence of nodular contrast enhancement in the region encompassing the original lesion. Two typical enhancement patterns were obtained comparing the Time-Density curves of responsive and not responsive ablated tumors.</p> <p>Conclusion</p> <p>Perfusion CT seems to be a feasible and promising technique in monitoring the effects of cryoablation therapy.</p

The HotSpot Code as a Tool to Improve Risk Analysis During Emergencies: Predicting I-131 and CS-137 Dispersion in the Fukushima Nuclear Accident

Conventional and non-conventional emergencies are among the most important safety and security concerns of the new millennium. Nuclear power and research plants, high-energy particle accelerators, radioactive substances for industrial and medical uses are all considered credible sources of threats both in warfare and in terror scenarios. Estimates of potential radiation releases of radioactive contamination related to these threats are therefore essential in order to prepare and respond to such scenarios. The goal of this paper is to demonstrate that computational modeling codes to simulate transport of radioactivity are extremely valuable to assess expected radiation levels and to improve risk analysis during emergencies helping the emergency planner and the first responders in the first hours of an occurring emergency

Percutaneous kyphoplasty: New treatment for painful vertebral body fractures

Aims and Background: The purpose of this study was to assess the effectiveness and safety of Percutaneous Kyphoplasty as a new method of treatment for pain deriving from vertebral compression firactures (VCF). Patients and Methods: We treated sixteen patients with unremitting pain over spine, which increased particularly when pressure was applied over the spinous process, in absence of neurological signs and refractory to conventional medical therapy. Results: The method demonstrated swift pain relief associated with an evident augmentation in the resistance and restoration of the vertebral body's physiological shape. Polymethylmethacrylate (PMMA) leakages were not observed in the epidural space or foraminal area. The presence of complications such as pulmonary embolism involving the venous plexus, toxicity due to PMMA and infection due the procedure did not occur. Conclusion: Kyphoplasty is an effective, alternative, simple and safe treatment of vertebral collapse consequent to osteoporosis, aggressive haemangiomas, myelomas and metastases

Disorder of sex development: a rare case of a boy with an XY karyotype and Magnetic Resonance Imaging findings of hermaphroditism

Disorders of sexual differentiation are rare congenital conditions in which the chromosomal, anatomic or gonadal sex development is atypical. In some of these patients, chromosomal sex is inconsistent with phenotypic sex; in other cases, the phenotype is not classifiable as either male or female, resulting in a condition known as ambiguous genitalia. These are very complex cases in which diagnostic certainty is not always possible. A multidisciplinary team including geneticists, pediatricians, radiologists is certainly needed to approach these patients. We present the case of an 18-year-old boy with an XY karyotype, ambiguous genitalia, uterus and blind-ending vaginal pouch. The patient had not been previously diagnosed with a disorder of sex development. The patient underwent a panel of genetic analyses and diagnostic imaging investigations. Magnetic resonance imaging was decisive for the identification of the internal genital organs, especially the uterus. At the end of investigations, the patient was diagnosed with 46,XY disorder of sex development. Our purpose is to underline the role of imaging in the diagnosis and management of congenital disorders of sex differentiation

Acquisition Parameters Influence Diffusion Metrics Effectiveness in Probing Prostate Tumor and Age-Related Microstructure

: This study aimed to investigate the Diffusion-Tensor-Imaging (DTI) potential in the detection of microstructural changes in prostate cancer (PCa) in relation to the diffusion weight (b-value) and the associated diffusion length lD. Thirty-two patients (age range = 50-87 years) with biopsy-proven PCa underwent Diffusion-Weighted-Imaging (DWI) at 3T, using single non-zero b-value or groups of b-values up to b = 2500 s/mm2. The DTI maps (mean-diffusivity, MD; fractional-anisotropy, FA; axial and radial diffusivity, D// and D┴), visual quality, and the association between DTI-metrics and Gleason Score (GS) and DTI-metrics and age were discussed in relation to diffusion compartments probed by water molecules at different b-values. DTI-metrics differentiated benign from PCa tissue (p ≤ 0.0005), with the best discriminative power versus GS at b-values ≥ 1500 s/mm2, and for b-values range 0-2000 s/mm2, when the lD is comparable to the size of the epithelial compartment. The strongest linear correlations between MD, D//, D┴, and GS were found at b = 2000 s/mm2 and for the range 0-2000 s/mm2. A positive correlation between DTI parameters and age was found in benign tissue. In conclusion, the use of the b-value range 0-2000 s/mm2 and b-value = 2000 s/mm2 improves the contrast and discriminative power of DTI with respect to PCa. The sensitivity of DTI parameters to age-related microstructural changes is worth consideration

Sievert or Gray: Dose Quantities and Protection Levels in Emergency Exposure

Mitigation or even elimination of adverse effects caused by ionizing radiation is the main scope of the radiation protection discipline. The interaction of radiation with living matter is quantified and correlated with biological effects by dose. The Sievert is the most well-known quantity, and it is used with the equivalent and effective dose to minimize stochastic effects. However, Grey is the reference quantity for sizing tissue reactions that could occur under high-exposure conditions such as in a radiation emergency. The topics addressed in this review are the choice to move from Sievert to Grey, how the operational quantities for environmental and individual monitoring of the detectors should consider such a change of units, and why reference levels substitute dose levels in emergency exposure