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Purpose: This study was done to evaluate by direct comparison the image quality of magnetic resonance urography (MRU) and computed tomography urography (CTU) and to assess the diagnostic confidence of the two techniques in detecting urothelial malignancy in patients with haematuria, Materials and Methods: Thirty-five patients with haematuria underwent both CTU and MRU. Two different investigators evaluated calyceal, renal pelvis, ureteral and bladder visibility. Their diagnostic confidence in detecting urothelial malignancy with the two procedures was assessed. A Wilcoxon matched-pairs test was performed to compare results. Inter-reader agreement was calculated by weighted kappa (WK) statistic. Patient history (further examinations, cystoscopy and histological specimens) was considered as reference standard to calculate receiver operating characteristic (ROC) curves of diagnostic confidence., Results: CTU provided better visibility of urothelial structures (p<0.01) and allowed for greater diagnostic confidence (ROC area 0.994 vs. 0.938) than MRU, with a good inter-reader agreement (WK=0.62). Nevertheless, in obstructive patients with impaired excretory function, MRU, thanks to the static-fluid technique, offered better visualisation than CTU., Conclusions: There is a potential role for MRU in urinary tract imaging, but as diagnostic confidence in detecting urothelial malignancy is poorer than in CTU, it might be stareserved for patients at low risk for malignancy and for evaluating obstructed patients.

Purpose: This study was undertaken to assess cortical activation during execution of a motor task in patients with multiple sclerosis (MS) and fatigue., Materials and Methods: We enrolled 24 right-handed patients affected by relapsing-remitting MS and mild disability (12 with and 12 without fatigue) and 15 healthy volunteers. Magnetic resonance imaging (MRI) examination (1.5 T) was performed with conventional sequences and an echoplanar imaging (EPI) sequence for functional MRI (fMRI). The motor task consisted of sequential finger tapping performed with the right hand. Statistical maps of motor activation were obtained. Comparison between the two subgroups of patients and between patients and controls was performed with analysis of variance (ANOVA) statistical analysis (p<0.05)., Results: Compared with controls, patients without fatigue showed greater activation of the primary sensorimotor cortex bilaterally, of the right supplementary motor cortex, of the left premotor cortex, of the left cerebellum and of the superior parietal lobule bilaterally. Compared with patients without fatigue, patients with fatigue demonstrated greater activation of the right premotor area, of the putamen and the dorsolateral prefrontal cortex., Conclusions: Patients with fatigue have greater activation of the motor-attentional network when performing a simple motor task.

Purpose: The aims of this study were to determine fractional anisotropy (FA) and the fibre density index (FDi) in the cervical spinal cord of patients with multiple sclerosis (MS) by using diffusion-tensor magnetic resonance imaging (DT-MRI) to identify possible differences between MS patients and controls., Materials and Methods: We studied 27 patients with MS - nine with primary progressive (PPMS), nine with secondary progressive (SPMS) and nine with relapsing-remitting (RRMS) disease - and 18 healthy individuals as controls. Conventional and DTI sequences with diffusion gradients applied in 32 directions were obtained. The results were compared between healthy controls and patients, between healthy controls and individual forms of MS and between the three forms of MS. Statistical analysis was performed by analysis of variance (ANOVA) and Student's t test., Results: The FDi in the three subgroups of patients and in controls showed a statistically significant difference. Using the t test, we found results from both PPMS and SPMS groups were different from controls. The correlation between FA and FDi was significant both in healthy controls and in MS patients evaluated as a single group. CONSLUCIONS: Despite the small group of patients, these findings suggest that FDi associated with FA is a sensitive parameter for assessing spinal cord damage in patients with MS.

Purpose: The objective of this study was to evaluate white matter tissue damage in patients with Alzheimer's disease (AD) and in patients with mild cognitive impairment (MCI) using diffusion tensor imaging (DTI)., Materials and Methods: Forty-seven subjects were evaluated: 14 patients with AD, 15 with MCI and 18 healthy volunteers. All subjects were studied using conventional magnetic resonance imaging (MRI) and DTI (32 directions) with a 1.5 T magnet. Fractional anisotropy (FA) was measured in the following regions: frontal, occipital, parietal and temporal white matter and in the genu and splenium of the corpus callosum. The results were compared between the different groups and correlated with the Mini-Mental State Evaluation (MMSE) scores., Results: A statistically significant difference was obtained between controls and MCI patients (p < 0.007) and between controls and AD patients (p < 0.05) with regard to FA of the white matter in the splenium. A statistically significant difference was obtained between controls and AD patients with regard to FA in the genu (p < 0.016). Moreover, there was a statistically significant difference between controls and AD patients considering the genu (p < 0.016) and the frontal white matter on the right side (p < 0.024). The MMSE scores correlated with the FA values measured in the genu, the splenium and frontal white matter on the right side. No significant differences were identified between patients with AD and those with MCI., Conclusions: DTI could be of value in the early detection of white-matter damage in patients with MCI and AD. The DTI values correlate with the neuropsychological tests.

Purpose: The purpose of this study was to evaluate cortical activation patterns in patients with Parkinson's disease during a relatively complex motor task., Materials and Methods: Seven patients (six men and one woman) with lateralised akinetic-rigid Parkinson's disease underwent functional magnetic resonance imaging (MRI) of the brain with a 1.5-T magnet. Finger tapping was chosen as a motor task. The control group included 11 volunteers (six men and five women) with no neurological disease., Results: Patients showed hyperactivity of the ipsilateral and contralateral motor cortex associated with bilateral over-activation of the parietal cortex during movement of the affected hand. In some cases, there was a lack of activation of the pre-motor and supplementary motor areas whereas, when present, activation in these areas was greater during movement of the healthy hand. Finally, activation of the occipital cortex was found in all patients as a result of their tendency to control movement visually., Conclusions: Results of this study confirm a re-organisation of cortical circuits due to subcortical damage in patient's with Parkinson's disease.

Purpose: To assess the anatomy of the mandibular lingual vascular canals with the use of computed tomography (CT)., Materials and Methods: Seventy consecutive patients underwent preimplantation CT of the mandible. CT images were obtained on axial plane by using a bone reconstruction algorithm and then processed with dedicated software (Dentascan). The number of lingual vascular canals, the diameter of their entrance foramina and the distance of the foramina from the symphysis menti and from the lower edge of the mandible were measured in each patient. The median superior canal (MSC), the median inferior canal (MIC), the lateral mesial canals (LMC) and the lateral distal canals (LDC) were evaluated separately., Results: 0 to 5 canals were found in each patient. The MSC was found to be present in 98.6% of cases; the mean diameter of the entrance foramen was 0.85+/-0.28 mm located adjacent the symphysis menti and 11.3+/-2.6 mm from the inferior margin of the mandible. The MIC was found to be present in 32.9% of cases; the mean diameter of the entrance foramen was 0.58+/-0.21 mm located adjacent the symphysis menti and 5.5+/-2.2 mm from the inferior margin of the mandible. LMCs were found to be present in 38.6% of cases; the mean diameter of their entrance foramina was 0.60+/-0.24 mm located 5.1+/-2.5 mm from the symphysis menti and 6.3+/-3.2 mm from the inferior margin of the mandible. LDCs were found to be present in 48.6% of the patients; the mean diameter of their entrance foramina was 0.58+/-0.19 mm located 19.3+/-7.3 mm from the symphysis menti and 6.6+/-5.4 mm from the inferior margin of mandible., Conclusions: Dental CT detects the lingual vascular canals of the mandible in a high percentage of subjects and allows a good demonstration of their number, location and entrance foramen diameter. The evaluation of these canals is important in the preoperative planning of dental implants or in the planning of dental surgery in general so as to avoid bleeding due to damage of the vessels present in these canals.

Purpose: To compare 2D single-shot Fast Spin-Echo (FSE) and two 3D FSE MR cholangiopancreatography (MRCP) sequences with different slice thickness in the evaluation of normal and abnormal biliary and pancreatic duct systems., Materials and Methods: Thirty-two consecutive patients, both with normal biliary and pancreatic ducts (n=14) and with different biliary and/or pancreatic duct disease (n=18) underwent MRCP with a 1.5 T superconductive magnet. One 2D single-shot FSE and two 3D FSE MRCP sequences with different slice thickness (1.6 mm and 3 mm) were performed in each patient. Images were analysed with regards to: artefacts (0=none, 1=minimal, 2=present but not affecting the diagnostic evaluation, 3=present and affecting the diagnostic evaluation), image quality (0=non-diagnostic, 1=poor, 2=fair, 3=good, 4=excellent), duct conspicuity (0=not-visible, 1=poor, 2=good, 3=excellent), diagnostic confidence (possible presence of dilatations, stones and stenoses)., Results: Artefacts were rarely present, without significant differences among the three sequences. The 2D single-shot FSE sequence provided a significantly better image quality and significantly better conspicuity of the intrahepatic and pancreatic ducts in comparison to both the 1.6-mm and 3-mm thickness 3D FSE sequences. The three sequences yielded identical results in the detection of 17 cases of dilatation and 10 cases of stenosis as well as in the evaluation of their degree. Stones in the biliary tree were detected in 6 cases with the 2D single-shot FSE sequence, in 5 cases in the MIP images of the 3D FSE sequence with slice thickness of 1.6 mm and in 4 cases in the MIP images of the 3D FSE sequence with slice thickness of 3 mm. The diagnostic confidence did not show statistically significant differences among the three sequences., Conclusions: The 2D single-shot FSE sequence proved to be superior to the 3D FSE sequences in the evaluation of normal and abnormal biliary and pancreatic duct systems.

Purpose: Virtual CT colonoscopy is a novel technique whose diagnostic accuracy and clinical yield are currently investigated. Several studies have shown its capabilities in detecting colon and rectal cancers. We report the results of a preliminary experience with the volume rendering technique and compare CT colonoscopy with endoscopy and surgery., Material and Methods: Our series consisted of 25 patients with colon cancer confirmed at endoscopy and/or surgery. All examinations were carried out with a spiral CT scanner Philips Tomoscan AVE1. Intestinal preparation was adequate in all patients, consisting in gas insufflated immediately before acquisition, after the injection of 100 mL iodinated contrast agent. All examination were performed in prone position using axial 5 mm slices with 5 mm table feed (pitch 1) and 2 mm reconstruction index; 120 kV and 200-250 mA were used. Images were transferred to a workstation (Easy Vision, Philips, release 4.2.1.1) for processing. We acquired multiplanar (MPR) and virtual endoscopic images with volume rendering; the selected threshold was -250 to -600 Hounsfield Units. Virtual endoscopic images could be obtained in 23 of 25 cases. The results of the radiological study were compared with endoscopic and surgical findings in 25 and 17 cases, respectively., Results: Endoscopy and surgery detected 46 lesions: 29 were malignant and 17 benign. Axial CT and MPR alone detected 35 lesions (76%), 29 of them malignant and 6 benign. The 11 benign lesions missed by axial CT ranged 6-8 mm in diameter. There were no false positives. CT colonoscopy alone detected 66 lesions, but 22 of them were false positive due to residual stool in the colon (21 cases) and to residual barium in the colon (1 case). Combining CT colonoscopy and axial and MPR images enabled to correct the false positive diagnoses made by CT colonoscopy alone and to decrease the false negative ratio of axial and MPR images. Forty-one of 44 lesions (93%) were detected. Thirty-seven lesions were found in the 17 surgical patients; 34 of them were correctly identified combining CT colonoscopy and axial and MPR findings, while endoscopy detected only 31 lesions. Thus, CT had 92% sensitivity, versus 83% of fiberoptic endoscopy., Conclusion: In this preliminary experience volume rendering CT colonoscopy exhibited high sensitivity in detecting colon cancers, but their correct evaluation and characterization can be obtained if axial and MPR studies are combined. Further investigation and technological developments are necessary to define the yield of this new technique.

Thirty-two patients affected with skeletal conditions were examined with MRI using Short TI Inversion Recovery sequence and Spectral Presaturation with Inversion Recovery (SPIR) sequence as well as Spin-Echo (SE) T1-weighted sequence and Fast Spin-Echo (FSE) T2-weighted sequence to compare their value in the assessment of skeletal lesions. SPIR sequence was performed after intravenous injection of Gd-DTPA. The lesions included primary bone tumors (10 cases: 1 osteosarcoma, 1 periosteal sarcoma, 1 Ewing's sarcoma, 1 chondrosarcoma, 2 non-ossifying fibromas, 1 chondroma, 1 chondromyxoid fibroma, 1 desmoplastic fibroma and 1 bone cyst), metastases (7 cases: 3 prostate, 3 breast, 1 lung-squamous cell carcinoma), infections (12 cases: 9 osteomyelitis, 3 spondylodiscitis), sacroiliitis (1 case) and posttraumatic bone bruise (2 cases of bone marrow edema). The four sequences were compared by using both qualitative and quantitative evaluation. Qualitative evaluation showed that STIR sequence was better than SPIR sequence (performed with Gd-DTPA) for lesion conspicuity (p < .016) and for signal intensity uniformity (p < .03). Compared with SE T1 and FSE T2 sequences, fat-suppressed sequences were superior for conspicuity, margins, and extension of the lesions (range of p < .001-.017). Only SPIR with Gd-DTPA sequence, compared with SE T1 sequence for lesion conspicuity was not statistically significantly different. Quantitative evaluation showed statistically significant higher values of percent contrast (%C) and contrast-to-noise ratio (C/N) for STIR sequence compared with SPIR sequence (%C p < .004; C/N p < .040). This study suggests that STIR sequence and SE T1-weighted sequence provide high sensitivity in lesion detection and good anatomical definition. The use of a fat-suppressed sequence with Gd-DTPA can be useful for lesion characterization.

To study the MR appearance of knee joint hyaline cartilage, 120 subjects were examined with MRI of the knee. Axial SE proton-density (PD) and T2, GE T1 and GE-MTC sequences were used, as well as coronal SE T1 and sagittal SE PD and T2 sequences. At the patellar and femorotibial cartilages the following variables were investigated: thickness, surface, signal intensity and visibility. Moreover, the three patellar sequences were compared qualitatively, by giving a 1-to-4 score to the images, depending on their yield in the four variables. As for articular cartilage thickness, a statistically significant difference was found between men and women in nearly all measurement sites, the mean values being always higher in men. A statistically significant inverse correlation between cartilage thickness and age was found, in men only, at the three load-bearing regions of the medial femoral condyle. Cartilage surface was irregular and/or its signal intensity altered in 28% of patients at the femoral condyles, while the cartilage of tibial plates exhibited normal surface and homogeneous signal intensity in most cases. The visibility rate of trilaminar cartilage was 82.5% for the medial femoral condyle, 87.5% for the lateral femoral condyle, 70% for the patella, 12.5% for the medial tibial plateau and 14.5% for the lateral tibial plateau. No statistically significant correlation was found between cartilage thickness, surface, signal intensity and visibility and age, sex, and body weight. The GE sequence was the best tool to study cartilage thickness and signal intensity, while the SE T2 sequence was the most accurate one to depict the articular surface and, together with the PD SE sequence, to visualize the trilaminar structure. Our study suggests that articular cartilage surface, thickness, and signal intensity can be studied accurately with SE PD and T2 sequences, combined with a GE T1 sequence.

In order to assess the accuracy of CT and MRI in evaluating the local extent of rectal carcinoma, 22 patients with a rectoscopic diagnosis of rectal cancer were examined before surgery with both techniques. Tumor extent into the perirectal fat, involvement of surrounding structures and local adenopathy were evaluated on both CT and MR images. These findings were compared with the micro- and macrohistologic findings obtained from the surgical specimens. As far as perirectal fat infiltration is concerned, the diagnostic accuracy of CT was 73% and that of MRI was 71%. Sensitivity was 100% for CT and 91% for MRI, while specificity was low for both techniques (45% for CT and 50% for MRI). In evaluating local adenopathy, CT accuracy was 82% and MR accuracy was 90%, with 89% sensitivity for both techniques and 77% specificity for CT and 92% for MRI. The overall accuracy was 59% for CT and 67% for MRI. In agreement with literature data, our study shows a similar accuracy for CT and MRI in evaluating the local extent of rectal carcinomas. Moreover, our results confirm the value of macrohistology in the local staging of rectal carcinoma and its prognostic value, as well as the low specificity of both CT and MRI in evaluating lesion spread into the perirectal fat.

In order to assess the value of the SPIR (Spectral Presaturation with Inversion Recovery) sequence (a fat-suppression technique) with Gd-DTPA in the investigation of skeletal diseases, 50 patients were examined with conventional SE T1- and T2-weighted sequences, as well as with SE T1 and SPIR sequences after the i.v. injection of Gd-DTPA. Twenty patients were affected with a skeletal infection (11 spondylodiscites and 9 osteomyelitis) and 5 with a primary tumor; 15 had metastases and 10 a hemolymphopoietic disorder (6 myelomas and 4 non-Hodgkin's lymphomas). In the four groups of patients, the mean visibility of skeletal lesions was higher on SPIR images with Gd-DTPA than on the other images, even though a statistically significant difference was observed only in the group of infections (p < 0.002) and in myelomas and lymphomas (p < 0.001). In 13 cases with extraosseous spread, visibility was higher on contrast-SPIR images than on the other sequences, even though high sensitivity was also exhibited by SE T2-weighted sequences. Even though the SPIR sequence still exhibits some technical limitations, our study assesses the value of this sequences with Gd-DTPA in the investigation of skeletal lesions. The major advantages of contrast-SPIR imaging follow: 1) it shows skeletal lesions, which are isointense on enhanced SE T1-weighted images, 2) it provides better visibility of the lesion than the other sequences, more accurately defining their borders, 3) it provides better anatomical detailing than SE T2-weighted images and 4) its sensitivity is higher.