The role of diffusion-weighted magnetic resonance imaging (DWI) to differentiate breast lesions in vivo was evaluated. Sixty women (mean age, 53 years) with 81 breast lesions were enrolled. A coronal echo planar imaging (EPI) sequence sensitised to diffusion (b value=1,000 s/mm(2)) was added to standard MR. The mean diffusivity (MD) was calculated. Differences in MD among cysts, benign lesions and malignant lesions were evaluated, and the sensitivity and specificity of DWI to diagnose malignant and benign lesions were calculated. The diagnosis was 18 cysts, 21 benign and 42 malignant nodules. MD values (mean +/- SD x 10(-3) mm(2)/s) were (1.48 +/- 0.37) for benign lesions, (0.95 +/- 0.18) for malignant lesions and (2.25 +/- 0.26) for cysts. Different MD values characterized different malignant breast lesion types. A MD threshold value of 1.1 x 10(-3) mm(2)/s discriminated malignant breast lesions from benign lesions with a specificity of 81% and sensitivity of 80%. Choosing a cut-off of 1.31 x 10(-3) mm(2)/s (MD of malignant lesions -2 SD), the specificity would be 67% with a sensitivity of 100%. Thus, MD values, related to tumor cellularity, provide reliable information to differentiate malignant breast lesions from benign ones. Quantitative DWI is not time-consuming and can be easily inserted into standard clinical breast MR imaging protocols.

This paper investigates the joint pilot-assisted estimation of the residual carrier frequency offset (RCFO) and sampling frequency offset (SFO) in an orthogonal frequency division multiplexing (OFDM) system. As it is known, the exact maximum-likelihood (ML) solution to this problem involves a bidimensional grid-search that cannot be pursued in practice. After introducing an enlarged set of auxiliary unknown parameters, however, the RCFO and SFO recovery tasks can be decoupled and the bidimensional search is thus replaced with a simpler mono-dimensional search. This results into an estimation algorithm of reasonable complexity which is suitable for practical implementation. To further reduce the processing load, we also present an alternative scheme yielding frequency estimates in closed-form. Numerical simulations indicate that the proposed methods outperform existing estimators available in the literature in terms of both estimation accuracy and error-rate performance

Orbital angular momentum (OAM) has aroused a widespread interest in many fields, especially in telecommunications due to its potential for unleashing new capacity in the severely congested spectrum of commercial communication systems. Beams carrying OAM have a helical phase front and a field strength with a singularity along the axial center, which can be used for information transmission, imaging and particle manipulation. The number of orthogonal OAM modes in a single beam is theoretically infinite and each mode is an element of a complete orthogonal basis that can be employed for multiplexing different signals, thus greatly improving the spectrum efficiency. In this paper, we comprehensively summarize and compare the methods for generation and detection of optical OAM, radio OAM and acoustic OAM. Then, we represent the applications and technical challenges of OAM in communications, including free-space optical communications, optical fiber communications, radio communications and acoustic communications. To complete our survey, we also discuss the state of art of particle manipulation and target imaging with OAM beams.

The objective of our work was to evaluate the long-term results of percutaneous ethanol injection (PEI) for the treatment of hepatocellular carcinoma (HCC) in patients with liver cirrhosis. A total of 184 cirrhotic patients with HCC underwent PEI as the only anticancer treatment over an 8-year period. Patients were followed after therapy by means of clinical examinations, laboratory tests, and US and CT studies performed at regular time intervals. Survival rates were determined according to the Kaplan-Meier method. The overall survival was 67% at 3 years, 41% at 5 years, and 19% at 7 years. The 3-, 5-, and 7-year survival rates of patients with single HCC < or = 3 cm (78, 54, and 28%, respectively) were significantly higher (p < 0.01) than those of patients with single HCC of 3.1-5 cm (61, 32, and 16, respectively) or multiple HCCs (51, 21, and 0%, respectively). Survival of Child-Pugh A patients (79% at 3 years, 53% at 5 years, and 32% at 7 years) was significantly longer (p < 0.01) than that of Child-Pugh B patients (50% at 3 years, 28% at 5 years, and 8% at 7 years). A selected group of 70 patients with Child-Pugh A cirrhosis and single HCC < or = 3 cm had a 7-year survival of 42%. Long-term survival of cirrhotic patients with HCC treated with PEI is comparable to that reported in published series of matched patients submitted to surgical resection.

The aim of this study was to evaluate feasibility, safety, and effectiveness of radio-frequency (RF) thermal ablation, performed by using a cooled-tip electrode needle, in the treatment of liver metastases. Twenty-nine patients (20 males and 9 females; age range 43-77 years) with one to four hepatic metastases 1.1-4.8 cm in diameter (mean 2.9 +/- 0.8 cm) from previously resected intra-abdominal primary malignancies were treated. All patients were excluded from surgery and had partial or no response to chemotherapy. Radio-frequency ablation was performed by using a 100-W generator and 17-gauge, dual-lumen, cooled-tip electrode needles with a 2- to 3-cm exposed tip. Exposure time was 12 min for each needle insertion. Findings at spiral CT were used to assess the therapeutic response. A total of 127 insertions were performed (mean 2.4 +/- 1.7 insertions/lesion) during 84 treatment sessions (mean 1.6 +/- 0.7 sessions/lesion) in absence of major complications. Complete tumor response (i. e., unenhancing area of thermal necrosis larger than the treated tumor) was seen in 41 (77 %) of 53 lesions, including 33 (87 %) of 38 lesions 3 cm or less in diameter. After a mean follow-up period of 6.5 +/- 2.1 months (range 3-9 months), recurrence of the treated lesion was seen in 5 (12 %) of the 41 cases. New metastatic lesions appeared in 7 patients. Two patients died after 6 and 8 months, respectively. Of the 27 patients still in follow-up, 14 are currently free of disease. Radio-frequency thermal ablation with a cooled-tip electrode needle is a safe and effective local treatment for hepatic metastases 3 cm or less in greatest dimension.