The intensity and spatial distribution of functional activation in the left precentral and postcentral gyri during actual motor performance (MP) and mental representation [motor imagery (MI)] of self-paced finger-to-thumb opposition movements of the dominant hand were investigated in fourteen right-handed volunteers by functional magnetic resonance imaging (fMRI) techniques. Significant increases in mean normalized fMRI signal intensities over values obtained during the control (visual imagery) tasks were found in a region including the anterior bank and crown of the central sulcus, the presumed site of the primary motor cortex, during both MP (mean percentage increase, 2.1%) and MI (0.8%). In the anterior portion of the precentral gyrus and the postcentral gyrus, mean functional activity levels were also increased during both conditions (MP, 1.7 and 1.2%; MI, 0.6 and 0.4%, respectively). To locate activated foci during MI, MP, or both conditions, the time course of the signal intensities of pixels lying in the precentral or postcentral gyrus was plotted against single-step or double-step waveforms, where the steps of the waveform corresponded to different tasks. Pixels significantly (r > 0.7) activated during both MP and MI were identified in each region in the majority of subjects; percentage increases in signal intensity during MI were on average 30% as great as increases during MP. The pixels activated during both MP and MI appear to represent a large fraction of the whole population activated during MP. These results support the hypothesis that MI and MP involve overlapping neural networks in perirolandic cortical areas.

: MRI largely outperformed mammography, ultrasonography, and their combination for screening high-risk women below and over 50.

The accuracy of mammography, sonography and magnetic resonance imaging (MRI) in identifying residual disease after neoadjuvant chemotherapy is evaluated and imaging findings are correlated with pathologic findings. Fifteen patients enrolled in an experimental protocol of preoperative neoadjuvant chemotherapy underwent clinical examination, mammography, sonography and dynamic MRI, performed in this order, before and respectively after 2 and 4 cycles of neoadjuvant chemotherapy. Four radiologists, two for mammography, one for sonography and one for MR, examined the images, blinded to the results of the other examinations. All patients underwent radical or conservative surgery, and imaging findings were compared with pathologic findings. MRI identified 2/15 (13.3.%) clinically complete response (CR), 9/15 (60%) partial response (PR), 3/15 (20%) stable disease (SD) and 1/15 (6.7%) progressive disease. Mammography identified 1/15 (6.7%) clinically CR, 8/15 (53.3%) PR and 4/15 (27%) SD, and was not able to evaluate the disease in 2/15 (13%) cases. Sonography presented the same results as MRI. Therefore, MRI and sonography compared to mammography correctly identified residual disease in 100 vs. 86%. MRI resulted in two false-negative results because of the presence of microfoci of in situ ductal carcinoma (DCIS) and invasive lobular carcinoma (LCI). MRI was superior to mammography in cases of multifocal or multicentric disease (83 vs. 33%). Sonography performed after MRI improves the accuracy in evaluation of uncertain foci of multifocal disease seen on MR images with an increase of diagnostic accuracy from 73 to 84.5%. MRI assesses response to neoadjuvant chemotherapy better than traditional methods of physical examination and mammography.

Deep pelvic endometriosis is defined as subperitoneal infiltration of endometrial implants in the uterosacral ligaments, rectum, rectovaginal septum, vagina, or bladder. It is responsible for severe pelvic pain. Accurate preoperative assessment of disease extension is required for planning complete surgical excision, but such assessment is difficult with physical examination. Various sonographic approaches (transvaginal, transrectal, endoscopic transrectal) have been used for this purpose but do not allow panoramic evaluation. Furthermore, exploratory laparoscopy has limitations in demonstrating deep endometriotic lesions hidden by adhesions or located in the subperitoneal space. Despite some limitations, magnetic resonance (MR) imaging is able to directly demonstrate deep pelvic endometriosis. The MR imaging features depend on the type of lesions: infiltrating small implants, solid deep lesions mainly located in the posterior cul-de-sac and involving the uterosacral ligaments and torus uterinus, or visceral endometriosis involving the bladder and rectal wall. Solid deep lesions have low to intermediate signal intensity with punctate regions of high signal intensity on T1-weighted images, show uniform low signal intensity on T2-weighted images, and can demonstrate enhancement on contrast-enhanced images. MR imaging is a useful adjunct to physical examination and transvaginal or transrectal sonography in evaluation of patients with deep infiltrating endometriosis.

Post-cholecystectomy syndrome (PCS) is defined as a complex of heterogeneous symptoms, consisting of upper abdominal pain and dyspepsia, which recur and/or persist after cholecystectomy. Nevertheless, this term is inaccurate, as it encompasses biliary and non-biliary disorders, possibly unrelated to cholecystectomy. Biliary manifestations of PCS may occur early in the post-operative period, usually because of incomplete surgery (retained calculi in the cystic duct remnant or in the common bile duct) or operative complications, such as bile duct injury and/or bile leakage. A later onset is commonly caused by inflammatory scarring strictures involving the sphincter of Oddi or the common bile duct, recurrent calculi or biliary dyskinesia. The traditional imaging approach for PCS has involved ultrasound and/or CT followed by direct cholangiography, whereas manometry of the sphincter of Oddi and biliary scintigraphy have been reserved for cases of biliary dyskinesia. Because of its capability to provide non-invasive high-quality visualisation of the biliary tract, magnetic resonance cholangiopancreatography (MRCP) has been advocated as a reliable imaging tool for assessing patients with suspected PCS and for guiding management decisions. This paper illustrates the rationale for using MRCP, together with the main MRCP biliary findings and diagnostic pitfalls.

Diffusion-weighted MRI is an accurate tool in evaluating advanced liver fibrosis if an optimised single-shot spin-echo echo-planar sequence with maximum intermediate b value is used. The ADC threshold for liver fibrosis was 1.31.10(-3)mm(2)/s.

In women with ND, CEMRI should be recommended when conventional imaging is negative. Unexplained ND could be considered an indication for CEMRI.

Purpose:To investigate the relevance of increasing b-values in evaluating liver fibrosis through the agreement of two diffusion-weighted (DW) sequences. Materials and Methods:A total of 29 cirrhotic patients and 29 healthy volunteers were studied on a 1.5T system. Two single-shot spin-echo echo-planar sequences were acquired using sets of increasing b-values: 0, 150, 250, and 400 seconds/mm 2 (first sequence: DW1a) and 0, 150, 250, 400, 600, and 800 seconds/mm 2 (second sequence: DW2a). Apparent diffusion coefficients (ADCs) of the hepatic parenchyma were calculated on ADC maps. Noisescaled single-point ADCs were calculated for each sequence from b ϭ 400 seconds/mm 2 .Results: ADCs resulted significantly lower in cirrhotic patients compared to controls using both DW1a (mean 1.14 Ϯ 0.20 ϫ 10 2 /second vs. 1.04 Ϯ 0.18 ϫ 10 Ϫ3 mm 2 /second; P ϭ 0.0089). DW1 and DW2, respectively significantly differed in diagnostic performance at receiver operating characteristic (ROC) curve analysis (P ϭ 0.003), showing AUCs of 0.93 (sensitivity 89.7%, specificity 100%) and 0.73 (sensitivity 62.1%, specificity 79.3%), respectively. Noise-scaled single-point ADCs showed a progressive convergence to similar values in cirrhotic and healthy livers at b ϭ 800 seconds/mm 2 (1.12 Ϯ 0.27 ϫ 10 Ϫ3 mm 2 /second vs. 1.13 Ϯ 0.17 ϫ 10 Ϫ3 mm 2 /second). Conclusion:A DW sequence is accurate in assessing liver fibrosis using intermediate (400 seconds/mm 2 ) rather than high (800 seconds/mm 2 ) maximum b-values, but after proper recalculation of ADCs the effects of perfusion rather than diffusion should be considered responsible for the higher accuracy at lower b-values.