T2-weighted,apparent diffusion coefficient and 18F-FDG PET histogram analysis of rectal cancer after preoperative chemoradiotherapy

Techniques in Coloproctology - The aim of our study was to investigate the correlation among T2-weighted (T2w) images, apparent diffusion coefficient (ADC) maps, 18F-fluorodeoxyglucose (18F-FDG)...     

Color Doppler appearance of penile cavernosal-spongiosal communications in patients with normal and impaired erection

Our objective was to investigate prevalence and Doppler characteristics of penile cavernosal-spongiosal communications (CSC). These vessels are either anastomoses connecting the cavernosal arteries with the urethral arterial network or afferent vessels to the corpus spongiosum. Sixty-one consecutive patients underwent penile color Doppler US. Waveform changes in CSC were evaluated in comparison with changes in the cavernosal artery. Eighteen of 61 patients had normal erection, 17 of 61 had arterial insufficiency, and 26 of 61 had veno-occlusive dysfunction. Resistance index (RI) in CSC was significantly lower than in cavernosal arteries in all patients and increased during phases 1-2 (positive diastolic flow). Peak systolic velocity (PSV) in CSC was significantly higher in the patients with veno-occlusive dysfunction. During cavernosal phase 4 (diastolic flow reversal) CSC of patients with normal erection or with arterial insufficiency disappeared, underwent markedly reduced diastolic flow, or had systolic flow inversion. Conversely, low resistance flow was appreciable in CSC of patients with veno-occlusive dysfunction who reached phase 4. During phase 5 (systolic peak reduction) all CSC disappeared. Color Doppler US allows evaluation of CSC both in patients with normal and impaired erection.     

Color Doppler appearance of penile cavernosal-spongiosal communications in patients with severe Peyronie's disease

Our objective was to investigate the prevalence and Doppler characteristics of penile cavernosal-spongiosal communications (CSC) in patients with severe Peyronie's disease. These vessels are either anastomoses connecting the cavernosal arteries with the urethral arterial network or afferent vessels to the corpus spongiosum. Twenty patients with severe Peyronie's disease underwent penile color Doppler US after intracavernous injection of prostaglandin E(1). Study inclusion criteria were penile curvature or shortening which made intercourse difficult or impossible. The quality of erectile response was subjectively scored. The spectral characteristics of CSC were evaluated in comparison with waveform changes in cavernosal artery. There were 4 patients with normal erectile response, 10 with discrepancy in rigidity of the penile base and tip, 4 with veno-occlusive dysfunction and 2 with arteriogenic dysfunction. The CSC just proximal to the plaques had peak systolic velocity (PSV) significantly higher and resistance index (RI) significantly lower than the other CSC. The PSV in CSC near the plaques of patients with base-tip discrepancy and with veno-occlusive dysfunction were significantly higher than in the other patients. In patients with severe Peyronie's disease CSC near the plaques remain patent with low-resistance flow supporting the hypothesis that blood leakage can occur through these vessels.     

Benign focal liver lesions: spectrum of findings on SonoVue-enhanced pulse-inversion ultrasonography

The prevalence of benign focal liver lesions (BFLL) is high both in the general population and in patients with known malignancies. The gray-scale ultrasound (US) technique is usually the first-line imaging modality used in the radiological workup of such lesions, but unfortunately it lacks specificity. Furthermore, Doppler examination may often be unsatisfactory owing to motion artefacts, or when small or deeply located lesions are evaluated. Recently, microbubble-based contrast agents used in combination with gray-scale US techniques, which are very sensitive to nonlinear behavior of microbubbles, have led to a better depiction of both microvasculature and macrovasculature of focal hepatic masses, thus improving the reliability of using US in the assessment of liver tumors. This review illustrates the spectrum of enhancement patterns of BFLL on contrast-enhanced ultrasonography with SonoVue, a second-generation microbubble-based contrast agent.This paper is based on a work accepted for presentation as a scientific paper at the Scientific Assembly and Annual Meeting of the ECR 2004.     

The application of ultrasound contrast agents in the characterization of renal tumors

The aim of this article is to describe the current ultrasound (US) contrast agents employed in the characterization of renal tumors and to report our experience in the use of a contrast-specific ultrasound technique pulse inversion harmonic imaging (PIHI).A total of 23 renal masses were prospectively evaluated by conventional US, CDUS, PIHI and finally by helical-CT (HCT). The study was performed using a wideband convex array 2–5 MHz transducer and a US digital apparatus . PIHI scanning of each renal mass was performed before and after the injection of Levovist. To reach a definitive diagnosis HCT and/or histological findings were considered as the reference procedures. Eleven solid renal cell carcinomas (RCCs), one embryonal metanephric adenoma (EMA), seven angiomyolipomas (AMLs), and four cystic RCCs were analyzed. Solid RCCs revealed a higher contrast enhancement than AMLs with a typical pattern on conventional US. The EMA and AML with an atypical pattern revealed intense contrast enhancement during the arterial phase, progressively decreasing during the delayed phase. Cystic RCCs showed intense contrast enhancement on the peripheral thick wall during the arterial phase decreasing during the delayed phase. PIHI with Levovist may differentiate solid RCCs from AMLs with no hypervascular pattern while solid RCCs show a higher intensity of contrast enhancement than hypervascular AML.     

Flavone acetic acid distribution in human malignant tumors

The pharmacokinetics of flavone acetic acid (FAA) after a dose of 4.8 mg/m2 given i.v. over 1 h was investigated in 13 patients with different solid tumors. The mean volume of distribution and clearance were 52 +/- 4 l/m2 and 2.6 +/- 0.2 l/h x m2, respectively. A tumor or metastasis biopsy was obtained from six patients 2 h after the end of infusion. Tumor FAA levels ranged from 39.6 to 148.8 micrograms/g and were similar to those obtained after a therapeutic i.v. dose of 200 mg/kg FAA in animals bearing Pan/03 tumor, which is very sensitive to the drug. Although FAA tumor concentration could be detected only during one interval and we therefore cannot draw a definitive conclusion, differences in the agent's antitumor activity in mice and patients (i.e. very active in the former and inactive in the latter) are apparently not due to discrepancies in drug distribution and pharmacokinetics.     

Color Doppler sonographic appearance of renal perforating vessels in subjects with normal and impaired renal function

PURPOSE: The purpose of this study was to assess the prevalence and color Doppler sonographic characteristics of perforating vessels-small arteries and veins connecting the intrarenal vasculature with the capsular plexus-in healthy subjects, in hypertensive patients, and in patients with renal failure due to hypertensive nephroangiosclerosis or ischemic nephropathy. METHODS: Fifteen healthy subjects 24-34 years old, 15 healthy subjects 68-80 years old, 25 hypertensive patients, 25 patients with hypertension and chronic renal failure (15 mild, 10 severe), and 12 patients with hypertension and chronic renal failure and acute renal insufficiency due to ischemic nephropathy underwent color Doppler sonography of both kidneys. RESULTS: The few perforating arteries in healthy and hypertensive patients had various resistance indices and flow toward the capsule. Perforating veins in these patients were much more common than perforating arteries. Perforating arteries with a lower mean resistance index than the mean interlobar resistance index and flow toward the capsule were detected in 76% of kidneys in the patients with mild chronic renal failure and in 20% of those in patients with severe chronic renal failure. Only a few perforating veins were seen in patients with chronic renal failure. In 64% of the kidneys with renal artery stenosis detected in the patients with chronic renal failure complicated by acute renal insufficiency, there were perforating arteries with flow toward the kidney and a mean resistance index higher than the mean interlobar resistance index. CONCLUSIONS: Perforating vessels are recognizable using color Doppler sonography both in healthy subjects and in patients with renal failure. The prevalence and flow characteristics of perforating vessels differ between healthy subjects, patients with mild and with severe chronic renal failure, and patients with chronic renal failure complicated by acute renal insufficiency caused by renal artery stenosis.