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

Assessment of congenital coronary artery fistulas by transesophageal color Doppler echocardiography

PURPOSE: Coronary angiography is the gold standard for imaging the coronary tree, but the relation of coronary artery fistulas to other structures, and their origin and course, may not be apparent. We evaluated the ability of multiplane color Doppler transesophageal echocardiography to identify coronary fistulas. PATIENTS AND METHODS: Twenty-one patients with angiographically confirmed coronary artery fistulas were investigated by transesophageal echocardiography in four Italian hospitals between January 1997 and May 2001. RESULTS: Transesophageal echocardiography correctly diagnosed fistulous connection in all 21 patients. This included 6 patients with connections from the left circumflex artery (into the right chambers of the heart in 5 patients, and into the left ventricle in 1 patient), 10 patients with a fistula arising from the left anterior descending artery or left main coronary artery (with drainage into the right ventricle or main pulmonary artery), and 5 patients with a fistula from the right coronary artery (with drainage sites in the lateral aspect of the right ventricle, the low posterior right atrium, or the superior vena cava). In 4 of the 21 patients, angiography did not identify the precise site of a fistula into the coronary sinus or right ventricle. CONCLUSION: Color Doppler transesophageal echocardiography is useful in the diagnosis and in the precise localization of coronary artery fistulas

A comparison between two different concentration of contrast media with multidetector CT for the study of abdominal vascular system

To evaluate two different concentrations of contrast medium (CM) and two different acquisition techniques to obtain vascular images with multislice spiral CT (msCT)

Cineradiographic study of spine during cycling: Effects of changing the pedal unit position on the dorso-lumbar spine angle [Studio cineradiografico della colonna nell'attività ciclistica: Variazioni angolari del tratto di rachide dorso-lombare nelle modificazioni della posizione della pedaliera]

Purpose. Low back pain is a frequent pathology among bicyclists, probably due to unappropriate saddle position. This radiographic study was conducted to evaluate dorso-lumbar angular values in two different pedal unit positions; the first one in a bicycle frame type with pedals in front of the saddle axis and the second one with the pedals behind the saddle axis, in order to define the most physiological sitting position. Materials and methods. Ten voluntary healthy adults, ranging in age between 21 to 45 years, were randomly choosen among a group of cyclist not involved in competition and underwent serial fluoroscopic studies while cyclists sit on two different saddles of a prototype cyclette; dorso-lumbar angles at both different sitting positions were measured on film according to modified Lippmann-Cobb method using as reference the upper somatic limitant of the eleventh or twelth dorsal vertebra and the lower somatic limitant of the third lumbar vertebra. Results. Statistical analysis of the measured angles demonstrates that the differences between the dorso-lumbar spine angle in the different saddle positions are statistically significative with a coefficient correlation equals to 0.64015 and p>0.01; angular values are more physiological in the second position with pedal unit behind the saddle axis. Conclusions. The incidence and importance of low back pain in cyclists can be reduced with appropriate pedal unit position; the position with pedals behind the saddle axis permits more physiological spine angles in comparison with the classic one having the pedals in front of the saddle axis; this fact is due to a different pelvic position which coincides with lumbar angles

Diffusion-weighted MR imaging in the evaluation of renal tumours

The aim of this study was to evaluate the capability and the reliability of diffusion-weighted MR imaging to differentiate benign from malignant renal lesions. Twenty healthy volunteers and 48 patients with known renal lesions underwent MR of the kidneys by using a 1.5 T superconductive magnet. Diffusion-weighted images (DWI) were obtained on the axial plane during breathhold (17 s) with a SE EPI single shot sequence using a b value of 500 s/mm2. One region of interest (ROI) (lesions than 3 cm) were placed within the lesion for the measurement of apparent diffusion coefficient (ADC). ADC map was obtained at each slice position. Mean ADC value in normal renal parenchyma was 2.2 +/- 0.20 x 10(-3) mm2/s, while ADC values in simple cysts (n = 20) were higher (mean ADC values 3.65 +/- 0.09 x 10(-3) mm2/s). Solid benign and malignant renal tumors (n = 19) showed a mean ADC value of 1.7 +/- 0.48 x 10(-3) mm2/sec. The comparison between ADC values in normal parenchyma group and tumour group were found to be statistically significant (p < 0.0001). ADC values of cystic renal cell carcinomas were higher than those of clear cell carcinomas (p < 0.001). In conclusion, DW MRI of the kidney seems to be a reliable means for differentiating normal renal parenchyma from different renal tumors