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Objective: To compare whole-body MRI (WB-MRI) and axial skeleton MRI (AS-MRI) in detecting and measuring bone metastases in patients with prostate cancer (PCa)., Methods: WB-MRI and AS-MRI examinations were performed in 60 patients with PCa at high risk of metastases. Two radiologists separately categorised the AS-MRI and WB-MRI as negative or positive for metastases, and measured focal metastases using the "Response evaluation criteria in solid tumours" (RECIST) criteria transposed to bone. One radiologist reviewed all examinations 2 months later. Inter- and intraobserver agreements in establishing the presence/absence of metastases were calculated. Bland-Altman plots were used to assess measurement agreement between AS-MRI and WB-MRI., Results: Strong to perfect inter- and intraobserver agreements were found between AS-MRI and WB-MRI in defining the presence/absence of bone metastases. There were no patients with isolated "peripheral" metastases at WB-MRI, missed at AS-MRI. There was no difference in lesion count between the two radiologists. AS-MRI and WB-MRI provided statistically equivalent RECIST values for one radiologist and slightly lower values at AS-MRI for the other., Conclusions: In our series of PCa patients, AS-MRI and WB-MRI were equivalent in determining the presence/absence of bone metastases and provided similar evaluation of the metastatic burden.

Purpose: To prospectively compare the sensitivity and specificity of magnetic resonance (MR) elastography with those of the routinely available aspartate aminotransferase-to-platelet ratio index (APRI) test for staging hepatic fibrosis in patients who have undergone liver biopsy for suspicion of chronic liver disease, with histopathologic examination as the reference standard., Materials and Methods: The study was approved by the ethics committee. All patients gave written informed consent. Eighty-eight patients (37 men, 51 women; mean age, 54.0 years +/- 13.1 [standard deviation]) who underwent liver biopsy for suspicion of chronic liver disease underwent MR elastography and APRI testing within 2 days after liver biopsy. At histopathologic examination, the fibrosis stage was assessed according to METAVIR scores (fibrosis scores F0 [no fibrosis] to F4 [cirrhosis]). MR elastography was performed by transmitting mechanical waves within the liver and measuring the small cyclic displacement of the liver spins with a phase-contrast spin-echo sequence. The performances of MR elastography and APRI testing were assessed, and the optimal cutoff values for fibrosis stage were determined with receiver operating characteristic (ROC) curve analysis., Results: At MR elastography, areas under the ROC curves (A(z)) for elasticity and viscosity, respectively, were 0.999 and 0.863 at fibrosis scores greater than or equal to F2, 0.997 and 0.962 at scores greater than or equal to F3, and 1.000 and 0.986 at score F4. A(z) values for elasticity at MR were significantly larger than those for the APRI (0.854 at scores > or = F2, P < .001; 0.886 at scores > or = F3, P = .003; and 0.851 at score F4, P = .004). Optimal cutoff values of elasticity were 2.5 kPa for fibrosis scores greater than or equal to F2, 3.1 kPa for scores greater than or equal to F3, and 4.3 kPa for score F4., Conclusion: Large A(z) values for elasticity (>0.990 for scores > or = F2, > or = F3, and F4) show that MR elastography was accurate in liver fibrosis staging and superior to biochemical testing with APRIs.

Purpose: To evaluate the diagnostic performance, costs, and impact on therapy of one-step magnetic resonance imaging (MRI) of the axial skeleton (MRIas) for detecting bone metastases in patients with high-risk prostate cancer (PCa)., Patients and Methods: Sixty-six consecutive patients with high-risk PCa prospectively underwent MRIas in addition to the standard sequential work-up (SW) of bone metastases (technetium-99m bone scintigraphy [BS] completed with targeted x-rays [TXR] in patients with equivocal BS findings and with MRI obtained on request [MRIor] in patients with inconclusive BS/TXR findings). Panel review of initial and 6-month follow-up MRI findings, BS/TXR, and all available baseline and follow-up clinical and biologic data were used as the best valuable comparator to define metastatic status. Diagnostic effectiveness of MRIas alone was compared with each step of the SW. Impact of MRIas screening on patient management and costs was evaluated., Results: On the basis of the best valuable comparator, 41 patients (62%) had bone metastases. Sensitivities were 46% for BS alone, 63% for BS/TXR, 83% for BS/TXR/MRIor, and 100% for MRIas; the corresponding specificities were 32%, 64%, 100%, and 88%, respectively. MRIas was significantly more sensitive than any other approach (P < .05, McNemar). MRIas identified metastases in seven (30%) of 23 patients considered negative and eight (47%) of 17 patients considered equivocal by other strategies, which altered the initially planned therapy. Economic impact was variable among countries, depending on reimbursement rates., Conclusion: MRIas is more sensitive than the current SW of radiographically identified bone metastases in high-risk PCa patients, which impacts the clinical management of a significant proportion of patients.

Purpose: To determine the correlations between hemodynamic parameters of hepatic flow measured with magnetic resonance (MR) imaging and Doppler ultrasonography (US) and the severity of cirrhosis and portal hypertension., Materials and Methods: Forty-six patients referred for measurements of portal venous pressure (three with normal liver, 12 with chronic hepatitis, and 31 with cirrhosis [10 with Child-Pugh class A cirrhosis; 13 with class B cirrhosis; and eight with class C cirrhosis]) were included in the study. Apparent liver perfusion, apparent arterial and portal perfusion, portal fraction, distribution volume, and mean transit time were measured with dynamic contrast material-enhanced MR imaging. Portal velocity, portal flow, congestion index, right hepatic artery resistance index, and modified hepatic index were measured with Doppler US. Results in patients with cirrhosis and those without cirrhosis were compared with the Wilcoxon rank sum test. Correlations were assessed with Spearman rank correlation coefficients., Results: With MR imaging, all flow parameters except distribution volume were significantly different between patients with and those without cirrhosis (P <.05). There was a significant correlation between all flow parameters measured with MR imaging and portal pressure (P <.02). Apparent arterial (P =.024) and portal (P <.001) perfusion, portal fraction (P <.001), and mean transit time (P =.004) were correlated with Child-Pugh class. Flow parameters measured with Doppler US did not differ significantly between patients with and those without cirrhosis. Only right hepatic arterial resistance (P <.007) and portal flow (P <.043) were weakly (r < 0.7) correlated with portal pressure. No Doppler US parameter was correlated with Child-Pugh class., Conclusion: Hepatic flow parameters measured with MR imaging correlate with the severity of cirrhosis and portal hypertension. Doppler US parameters are only weakly correlated with portal pressure., (Copyright RSNA, 2003)

Purpose: To assess dual-detector spiral CT arthrography in the evaluation of the entire knee cartilage obtained from cadavers., Materials and Methods: Two independent observers characterized articular cartilage in 12 cadaver knees in which MR imaging and dual-detector spiral CT arthrography were performed and compared their findings to those found during macroscopic assessment. The sensitivity and specificity of MR imaging and spiral CT arthrography for detecting grade 2A or higher and grade 2B or higher cartilage lesions, the Spearman correlation coefficient between arthrographic and macroscopic grading, and kappa statistics for assessing interobserver reproducibility were determined., Results: At spiral CT arthrography, sensitivities and specificities ranged between 80% and 88% for the detection of grade 2A or higher cartilage lesions and ranged between 85% and 94% for the detection of grade 2B or higher cartilage lesions. At MR imaging, sensitivities and specificities ranged between 78% and 86% and between 76% and 91% for the detection of grade 2A or higher and grade 2B or higher cartilage lesions, respectively. Spearman correlation coefficients between spiral CT arthrography or MR imaging and macroscopic grading of articular surfaces were 0.797 and 0.702, respectively., Conclusion: Dual-detector spiral CT arthrography of the knee is a valuable method for the assessment of open cartilage lesions of the entire knee.

The purpose of this study was to compare in the same patients tailored and fixed scanning delays during gadolinium-enhanced arterial-phase magnetic resonance imaging of hypervascular liver tumors. Tailored scanning delays were obtained with automated region of interest threshold triggering. A delay of 23 seconds between the start of contrast material injection and imaging was used for fixed delay examinations. Quantitative and qualitative evaluation was performed in 21 patients with normal cardiac function referred for MR assessment of hypervascular liver tumors. In the tailored examinations, the median time delay between the start of contrast material injection and the start of magnetic resonance imaging was 21 seconds (range, 18-34 seconds). The median tumor-to-liver contrast during tailored examinations was 19.1 versus 14.7 during fixed delay examinations. This difference, however, was not significant. Similarly, the enhancement in the aorta, the portal vein, the liver, and the tumor did not differ significantly between examinations performed with tailored and fixed delays. It is concluded that in our group of patients with hypervascular liver tumors and normal cardiac function, no significant improvement in tumor-to-liver contrast and enhancement during the arterial phase was found when gadolinium-enhanced magnetic resonance imaging was performed with a tailored scanning delay rather than with a fixed delay.

Purpose: The purpose of this work was to assess the natural course of biopsy-proven focal nodular hyperplasia (FNH)., Method: Eighteen biopsy-proven FNHs in 14 patients (12 women and 2 men) who were followed for at least 6 months with CT and/or MRI were included in the study. The volume of the lesions was calculated twice by two observers using the summation of areas method. Intra- and interobserver variability was assessed by intraclass correlation coefficients. Longitudinal data analysis was performed with generalized estimating equations., Results: The volume of FNH was stable in 6 cases, decreased in 10 cases, and increased in 2 cases. Intra- and interobserver variability in size measurements was 5-10%. Intraclass correlation coefficients were >0.992. Longitudinal data analysis showed that there was a general trend of lesion regression., Conclusion: Long-term follow-up and objective measurements performed in patients with biopsy-proven lesions show that the natural course of FNH is variable. In particular, lesion regression is not rare.

Background and Study Aims: The aim of this study was to compare prospectively the diagnostic efficacy of magnetic resonance (MR) imaging and endoscopic ultrasonography (EUS) in extrahepatic biliary obstruction., Patients and Methods: A total of 50 patients with suspected benign or malignant extrahepatic biliary obstruction underwent MR imaging, including MR cholangiopancreatography, and EUS, within a median time delay of 1 day. The final diagnosis was established by endoscopic retrograde cholangiopancreatography in 37 cases, intraoperative cholangiography in nine cases, and clinical and biochemical follow-up in four cases., Results: In total, 33 patients had extrahepatic biliary obstruction, of benign origin in 21 cases and of malignant origin in 12 cases, whereas 17 had no evidence of obstruction. The sensitivity and specificity of MR imaging were 91% and 94 %, respectively. There were one false-positive and three false-negative results, all related to choledochal sludge. The corresponding values for EUS were 97% and 88%. There were two false-positive results and one false-negative result. False-positive diagnoses were related to the presumed presence of biliary sludge and choledocholithiasis, whereas the false-negative diagnosis occurred in one patient with a final diagnosis of sludge. No significant difference in sensitivity and specificity was observed between the two imaging methods (P>0.05)., Conclusion: In our study MR imaging was as accurate as EUS in the diagnosis of extrahepatic biliary obstruction.

Purpose: To determine the frequency of several subchondral magnetic resonance (MR) imaging features observed in bone marrow edema lesions of the femoral head and to determine their value for differentiation of irreversible from transient lesions., Materials and Methods: The authors reviewed MR images of 72 femoral head lesions in 42 men and 25 women (median age, 48 years) with equivocal radiographic findings and bone marrow edema seen at MR imaging (T1- and T2-weighted images in all patients and contrast material-enhanced T1-weighted images in 39 patients). Follow-up MR images showed 57 lesions to be transient and 15 to be irreversible. The presence and size of subtle subchondral features observed on initial MR images were compared for both types of lesion., Results: Lack of any additional subchondral change on T2-weighted or contrast-enhanced T1-weighted images had 100% positive predictive value for transient lesions. For irreversible lesions, presence of a subchondral area of low signal intensity at least 4 mm thick or 12.5 mm long had positive predictive values of 85% and 73%, respectively, on T2-weighted images and 87% and 86%, respectively, on contrast-enhanced T1-weighted images., Conclusion: Careful assessment of subchondral changes enables confident differentiation between early irreversible lesions and transient bone marrow edema lesions.

The purpose of our study was to assess the effects of intravenous administration of ferumoxides on normal and abnormal vertebral bone marrow T1 and T2 relaxation times. Changes in bulk T1 and T2 relaxation times induced by intravenous administration of ferumoxides were determined in the normal vertebral marrow of two healthy subjects and four patients. In the four patients, changes in bulk T1 and T2 values induced by furomoxides injection were also determined in 12 vertebral metastases. Relative to precontrast relaxation time values, bulk T1 and T2 values of normal bone marrow had declined by a mean of 24% and 19%, respectively, in the two subjects and the four patients 45 minutes after ferumoxides administration. Relative to precontrast values, bulk T1 and T2 values of abnormal bone marrow had decreased by a mean of 16% and 2%, respectively. Decreases in bulk T1 and T2 values in normal bone marrow and in bulk T1 values in metastases were statistically significant (P<0.001). Changes in bulk T2 values observed in metastases were not statistically significant. Quantitative MRI demonstrates that ferumoxides infusion induces a decrease in bulk T1 and T2 relaxation times of normal bone marrow. It also suggests a lack of T2 shortening in bone metastases.

Purpose: To determine the clinical and prognostic value of spinal bone marrow magnetic resonance (MR) imaging in stage III multiple myeloma., Materials and Methods: In 80 patients with untreated, newly diagnosed stage III multiple myeloma, initial MR imaging patterns of spinal bone marrow involvement were correlated with hematologic parameters and response to induction chemotherapy. The influence of these patterns on survival was studied in 57 patients who did not undergo cytotoxic therapy with stem cell transplantation., Results: MR imaging patterns of marrow involvement were normal in 19 (24%) patients, focal in 35 (44%), and diffuse in 26 (32%). Patients with the diffuse pattern had higher marrow plasmacytosis (P < or = .003) and cellularity (P < or = .001), higher serum calcium (P < or = .005) and beta 2-microglobulin (P < or = .008) levels, and lower hemoglobin values (P < or = .001) than did those with the normal or focal patterns. Patients with the normal pattern responded better to therapy (P = .007) and survived longer than patients with an abnormal pattern (P = .026). MR imaging findings and C-reactive protein level were the best independent prognostic indicators of survival., Conclusion: MR imaging patterns of spinal bone marrow involvement are correlated with several clinical parameters of disease severity and have prognostic value in stage III multiple myeloma.

The purposes of this study were (a) to determine the prevalence of bone marrow abnormalities in patients with chronic lymphocytic leukemia (CLL) using quantitative MR assessment of axial marrow composition and peripheral marrow distribution; (b) to assess the agreement between both quantitative MR methods and compare their sensitivities to detect marrow alterations; and (c) to correlate MR findings with clinical and laboratory parameters. Twenty-nine consecutive patients with biopsy-proven CLL were investigated on a .5-T MR imager to determine bulk T1 relaxation times of the vertebral bone marrow and proportion of proximal femur surface area occupied by nonfatty marrow on coronal T1-weighted MR images of one hip. Of the 29 patients, 12 (41%) had abnormal increase in lumbar marrow T1 values (>600 msec) and 16 (55%) had increased proportion of surface area occupied by nonfatty marrow in the proximal femur (>+1 SD compared to normal values determined in sex- and age-matched healthy subjects). The results of both quantitative MR methods were normal in 12 patients and abnormal in 11 patients (agreement, 79%). Patients with alterations in peripheral marrow distribution had significantly higher T1 relaxation times (P = .001) than those with normal peripheral marrow. Patients with abnormal marrow composition or distribution at MRI had significantly higher blood and marrow lymphocytosis than patients without these features. In conclusion, the agreement between both quantitative MR methods suggests a parallelism between changes in axial marrow composition and in peripheral marrow distribution in patients with CLL. The limits of quantitative MRI in CLL must be kept in mind, because quantitative MR methods failed to detect leukemic marrow infiltration in 41% of patients.

Purpose: We assessed the relationship between the presence and size of focal marrow abnormalities detected with MRI in vertebral bodies and the subsequent occurrence of vertebral fractures at follow-up in patients with multiple myeloma (MM)., Method: We reviewed 179 follow-up MR examinations of the thoracic and lumbar spine prospectively obtained in 37 patients with Stage 3 MM. For each of 131 vertebral bodies that fractured during follow-up, the status of the vertebral bone marrow was assessed on the last MR study obtained at a mean time interval of 4 months prior to fracture occurrence. When focal lesions were observed before fracture in vertebral bodies that later collapsed, their size was compared with that of the contemporary lesions observed in vertebrae that did not collapse., Results: Of 131 fractures, 82 (63%) appeared in vertebrae previously free of focal bone marrow abnormality at MRI and 49 (37%) appeared in vertebrae in which focal lesions were present on the previous MR study. The size of the lesions that preceded fractures (median 15 mm; range 6-50 mm) was not statistically different from the size of the contemporary lesions (median 15 mm; range 5-60 mm) that did not lead to fracture (p > 0.30)., Conclusion: This study in patients with MM suggests a lack of correlation between the preexistence of focal vertebral marrow lesions detected with MRI and the subsequent development of vertebral fractures.

Objective: The purpose of this study was to determine the MR imaging features that enable differentiation between early irreversible osteonecrosis and transient lesions in nontraumatic lesions of the femoral condyle having the "bone marrow edema" pattern on MR imaging., Materials and Methods: We reviewed 23 nontraumatic painful lesions of the femoral condyle in 23 patients (12 men and 11 women; mean age, 62 years). All patients had undergone radiography of the knee with findings that were normal or inconclusive. Also, all patients underwent MR imaging that revealed the bone marrow edema pattern in a condyle. Lesions observed after trauma, surgery, or glucocorticoid medication, or with epiphyseal collapse or degenerative joint disease on initial plain radiographs, were excluded from this study. Of the 23 lesions, 14 showed complete resolution (and were designated as transient epiphyseal lesions). The remaining nine lesions were irreversible and, on follow-up radiographic and MR imaging studies, evolved to collapsed osteonecrosis (and were designated as early osteonecrosis). The presence and size of the subchondral features observed by two radiologists on initial MR studies were compared for both irreversible and transient epiphyseal lesions., Results: Initial MR imaging characteristics indicative of an early irreversible osteonecrosis included a subchondral area of low signal intensity on T2-weighted images with a thickness of more than 4 mm (sensitivity, 100% and 100%; specificity, 82% and 74% for the two observers) or a length of more than 14 mm (sensitivity, 89% and 88%; specificity, 93% and 87% for the two observers), focal epiphyseal contour depressions, and lines of low signal intensity located deep in the affected condyle. The extent of edema was similar for both transient epiphyseal lesions and early osteonecrosis., Conclusion: Careful assessment of MR imaging changes occurring in the subchondral area can enable confident differentiation between transient epiphyseal lesions and early irreversible osteonecrosis of the femoral condyle.

Purpose: To determine the frequency of abnormal findings from quantitative bone marrow magnetic resonance (MR) imaging in patients with early-stage chronic lymphocytic leukemia, to correlate these findings with clinical parameters, and to compare spontaneous outcome in patients with normal or abnormal MR imaging findings., Materials and Methods: In 21 patients with Binet stage A (Rai stage 0-I) disease, bulk T1 values of the vertebral bone marrow were determined and correlated with initial clinical, laboratory, histopathologic, and cytogenetic findings and with treatment-free survival., Results: Bulk T1 values were normal (< 600 msec) in 14 patients and prolonged in seven. Patients with increased T1 had significantly higher blood (P = .017) and bone marrow (P = .015) lymphocytosis. None of the 14 patients with normal T1 values required specific therapy after a median follow-up of 13 months. Of the seven patients with abnormal T1 values, five required treatment after progression to Binet stage B or C disease at a median of 10 months., Conclusion: In patients with abnormal quantitative MR imaging findings, treatment-free survival appears to be significantly shorter (P < .001) than in patients with normal MR imaging findings.

Purpose: To determine the utility of bone marrow magnetic resonance (MR) imaging in the assessment of risk of vertebral compression fractures in patients with multiple myeloma., Materials and Methods: In 50 patients with stage III multiple myeloma, 280 MR examinations of the thoracolumbar spine obtained at diagnosis and during treatment (mean follow-up, 28 months) were analyzed to determine MR patterns of bone marrow involvement before treatment and the occurrence of vertebral compression fracture at follow-up. Four MR patterns of marrow involvement were determined: A, normal marrow appearance; B, fewer than 10 focal lesions; C, more than 10 focal lesions; and D, diffuse infiltration. Fracture-free survival was compared according to these patterns., Results: During follow-up, 131 vertebral compression fractures appeared in 37 patients. Patients with pattern A (n = 10) or B (n = 16) had significantly longer fracture-free survival before occurrence of the first, second, and third fractures than those with pattern C or D (P < 10(-5)). Relative risks of first, second, and third fracture occurrence for patients with pattern C or D compared with those with pattern A or B were 6.2, 9.1, and 11.0, respectively., Conclusion: Determination of MR patterns of spinal bone marrow involvement is a potential relevant factor to predict the risk of vertebral fractures in patients with stage III multiple myeloma.

Objective: The aim of our prospective study was to compare the values of ferumoxides-enhanced gradient-echo and T2-weighted spin-echo MR imaging for the detection and segmental location of malignant hepatic tumors., Subjects and Methods: Eighteen patients underwent ferumoxides-enhanced T2 weighted spin-echo and steady-state gradient-echo imaging before surgery. Intraoperative sonography was used as the reference examination and showed 28 malignant tumors involving 39 of the 144 hepatic segments. The MR images were reviewed independently by two observers who recorded the number of tumors and their segmental location. The results of the segmental location were subjected to receiver-operating-characteristic analysis. Tumor-liver, vessel-liver, and tumor-vessel contrast-to-noise ratios were calculated., Results: Detection on the gradient-echo images did not differ significantly from that on the T2-weighted spin-echo MR images (observers A and B detected 23 and 24 tumors, respectively, on the gradient-echo images; the two observers each detected 22 tumors on the T2-weighted spin-echo images). Segmental localization was significantly better on the gradient-echo images than on the T2-weighted spin-echo images (mean area under the receiver-operating-characteristic curve: 0.974 versus 0.895 for observer A and 0.962 versus 0.906 for observer B, p = .024). The highest contrast-to-noise ratios for vessel to liver and tumor to vessel were obtained on the gradient-echo images and the highest tumor-liver contrast-to-noise ratio was obtained on the T2-weighted spin-echo images., Conclusion: In our study, ferumoxides-enhanced gradient-echo imaging was as accurate as T2-weighted spin-echo imaging for revealing malignant hepatic tumors and was superior for showing their segmental location.

The tumor-to-liver uptake of two reticuloendothelial agents, namely ferumoxides and technetium-99m (Tc-99m) sulfur colloid, was compared in focal nodular hyperplasia (FNH). Twelve patients with FNH who had undergone ferumoxides-enhanced MR imaging and planar Tc-99m sulfur colloid scintigraphy within 1 year were included from the study. Fourteen patients with FNH with a diameter larger than 3 cm were selected for the comparison. The tumor-to-liver ferumoxides uptake was calculated and the Tc-99m sulfur colloid uptake was assessed visually. Fermuoxides uptake was observed in all but one patient with FNH (mean tumor-to-liver ratio = .36). The six tumors showing normal (n = 5) or increased (n = 1) radiocolloid uptake when compared to the liver accumulated more ferumoxides than the eight tumors showing decreased radiocolloid uptake (P < .01). However, in some tumors, no direct relation was observed between ferumoxides and Tc-99m sulfur colloid uptake. Our observations suggest that ferumoxides uptake might not exactly mimic Tc-99m sulfur colloid uptake in FNH.

Rationale and Objectives: The authors assessed whether the small-molecular-weight magnetic resonance (MR) imaging contrast agents dysprosium diethylenetriamepentaacetic acid bismethylamide (sprodiamide injection), which enhances T2*, and gadolinium diethylenetriamepentaacetic acid bismethylamide (gadodiamide injection), which enhances T1, could improve the detection of reperfused ischemia of the rat intestine., Methods: Eighteen rats were subjected to vascular occlusion of the distal ileum for 30 minutes, followed by reperfusion. Ten minutes after reperfusion, T1- and T2-weighted spin-echo (SE) images were obtained before and after administration of sprodiamide, gadodiamide, or both. The same imaging protocol was applied in another group of 18 rats subjected to 10 minutes of occlusion and reperfusion. Histologic examination of the intestine was performed after MR imaging., Results: Villous injury (ie, denudation) was observed in most cases after 30 minutes of occlusion, but not after 10 minutes of occlusion. After 30 minutes of occlusion, the superficial part of the ischemic intestine was hyperintense to the normal intestine on unenhanced T2-weighted images. Administration of sprodiamide improved the contrast between the normal and ischemic intestine on T2-weighted images, and administration of both gadodiamide and sprodiamide improved the contrast on T1- and T2-weighted images. After 10 minutes of occlusion, no contrast was discernible before or after contrast material administration., Conclusion: These results suggest that the detection of reperfused intestinal ischemia of sufficient duration to cause villous injury can be improved by using sprodiamide injection alone or in combination with gadodiamide.

Purpose: To determine the frequency of abnormal bone marrow magnetic resonance (MR) images in patients with nonmyelomatous monoclonal gammopathy and to compare the outcomes in patients with normal and in those with abnormal MR studies., Materials and Methods: In 37 patients with monoclonal gammopathy of undetermined or borderline significance (19 men, 18 women; aged 28-85 years), MR imaging findings of the vertebral, pelvic, and femoral bone marrow were analyzed and correlated with initial laboratory findings and outcome after a follow-up of 15-60 months (median, 31 months) with no treatment., Results: Thirty patients had normal MR studies; none required specific therapy after a median follow-up of 30 months. Seven had either diffuse (n = 4) or focal (n = 3) bone marrow abnormalities. Four required treatment after 15, 20, 50, or 58 months; three did not require treatment after 18, 26, or 40 months. Treatment-free survival curves in patients with normal and in those with abnormal MR studies were statistically significantly different (P = .005)., Conclusion: Bone marrow abnormalities were detected with MR imaging in seven patients (19%) with monoclonal gammopathy of undetermined or borderline significance. All patients with a normal MR investigation still had not required treatment after a median follow-up of 30 months.

Objective: The purpose of this study was to describe the MR appearance of the acetabular labrum in asymptomatic subjects and correlate the MR appearance with age and sex., Materials and Methods: We evaluated high-resolution T1-weighted spin-echo coronal MR images of one hip in each of 200 asymptomatic individuals (84 men, 116 women; mean age, 44 years old; range, 15-82 years old). The labral shapes (triangular, round, flat, or absent), the intralabral signal intensity changes, and the possible extension of the intralabral signal intensity changes to the labral surface were assessed on two sections for each subject and correlated with age and sex., Results: Triangle was the dominant shape seen on MR imaging (66%). However, its frequency decreased significantly with age. Absence of labrum was the second most frequent pattern (14%) and increased significantly with age. Round and flat labra were found in 11% and 9% of subjects, respectively, with no significant age correlation. The frequency of homogeneous labra with low signal intensity decreased with age. Intralabral areas of high signal intensity communicating with the free surface increased with age., Conclusion: The large variability of the MR appearance of the labrum in asymptomatic hips must be considered when interpreting MR examinations of patients in whom labral lesions are suspected.

The purpose of this study was to correlate the MRI features of the anal canal with histologic findings. T1- and T2-weighted MR images of nine anal canals were obtained after fixation in 10% formalin. In three specimens, imaging was repeated after removal of histologic layers with a dissecting microscope. Corresponding histologic slices were stained with hematoxylin-eosin, Masson trichrome, and periodic acid-Schiff. Four layers were visualized on T2-weighted images. An inner layer of high signal intensity and a second layer of low signal intensity corresponded to the mucosa as well as mucous secretions and to the submucosa. The high signal intensity layer vanished at the distal part of the anal canal in accordance with the lack of mucus-secreting epithelium below the level of the dentate line. A third layer of intermediate signal intensity corresponded to the internal sphincter. A fourth layer of low signal intensity corresponded to the longitudinal muscle and external sphincter. T2-weighted MRI is capable of showing the internal architecture of the wall of the anal canal. In particular, the internal sphincter can be differentiated from the external sphincter and longitudinal muscle.

To detect reperfused ischemia of the rat intestine, T2-weighted spin-echo images were acquired, followed by T1-weighted images before and after administration of polylysine-Gd-DTPA or Gd-DTPA. Before administration of the contrast agent, the reperfused intestine was hyperintense on T2-weighted images, and to a lesser extent on T1-weighted images. After administration of polylysine-Gd-DTPA, the reperfused intestine enhanced more than the normal one, giving a significantly better contrast-to-noise (CNR) ratio than on unenhanced images. Gd-DTPA induced the same enhancement of the reperfused and the normal intestine and the CNR was lower than on unenhanced T2-weighted images. Reperfused intestinal ischemia could thus be better detected on polylysine-Gd-DTPA-enhanced MR images than on unenhanced images or on Gd-DTPA-enhanced images.

Purpose: To assess the use of magnetic resonance (MR) imaging in monitoring treatment response in patients with acute myeloid leukemia (AML)., Materials and Methods: Bulk T1 and T2 were determined with at least four MR imaging examinations (strictly timed) during the first 6 weeks of treatment in 29 patients with AML (age range, 16-75 years; 15 female, and 14 male). Bulk T1 and T2 in responder (n = 22) and nonresponder (n = 7) patients were compared., Results: Relative to pretreatment bulk T1 values, bulk T1 had increased a mean of 11% at week 1 and had decreased a mean of 7% and 39% at weeks 2 and 6, respectively. Values in nonresponder patients were not statistically significantly different (+11%, -14%, -38%)., Conclusion: MR imaging of lumbar bone marrow in patients with AML demonstrated statistically significant changes in bulk T1 during treatment that correlated with changes in cellularity. However, neither the early increase in bulk T1 nor the rate or magnitude of the subsequent decrease in bulk T1 were indicative of a positive response to treatment.

Computed tomography (CT) was compared with magnetic resonance (MR) imaging in depicting the capsule and the mosaic pattern of hepatocellular carcinoma in 34 patients. The kappa statistic was used to compare results from both modalities. For the detection of the capsule, there was a substantial agreement beyond chance between late enhanced CT (more than 5 min after dynamic CT) and MR imaging (kappa = 0.76). Late enhanced CT and MR imaging had almost perfect agreement for the demonstration of the mosaic pattern (kappa = 0.85). These agreements were better than the agreements between unenhanced CT and MR imaging or between early enhanced CT and MR imaging. These results suggest that late enhanced CT compares favorably with MR imaging in depicting the capsule and the mosaic pattern of hepatocellular carcinoma.

To determine the value of oral magnetic particles (OMP) as a superparamagnetic MR contrast agent for the gastrointestinal tract in lower abdominal and pelvic lesions, 30 patients underwent spin-echo imaging before and after ingestion of OMP at a dose of approximately 80 mg of iron in 800 ml water. The preparation was divided into four portions and taken by the patient over a 2-h period. Two readers independently reviewed the MR images. The contrast material was well tolerated and the distribution of the contrast material was good to excellent in the proximal and pelvic small bowel, but was not sufficient in the colon with the dose and timing used in the study. Postcontrast images showed a significantly better delineation of the lesions, the small bowel, and the paraaortic region, but no significant improvement in the delineation of the colon, the iliac vessels area, the bladder or genital tract. Compared with precontrast images, confidence in defining or excluding disease on postcontrast images was better, equal or worse in 40, 60 and 0% of cases, respectively (P less than 0.001) with a substantial agreement between readers (kappa = 0.71). OMP produced susceptibility artefacts of significant intensity in only one case. These results indicate that OMP may be useful in the delineation of lower abdominal and pelvic lesions at MR imaging. Marking of the colon by a contrast agent might improve the results.

To evaluate the accuracy of surface coil gradient-echo (GRE) imaging in the detection of regenerative nodules of hepatic cirrhosis, 53 patients with diffuse liver disease, among whom 31 had cirrhosis, were prospectively investigated. Three GRE sequences acquired with a surface coil were used in the study: a T2*-weighted, a T1-weighted, and a gadopentetate-enhanced sequence. ROC analysis showed that two surface coil GRE sequences were superior to conventional T2-weighted spin-echo imaging acquired with a body coil for the detection of regenerative nodules. The detection of regenerative nodules was also more accurate for the diagnosis of cirrhosis than the measurement of the caudate-to-right lobe ratio. These results suggest that there could be a potential for surface coil GRE imaging in the assessment of the characteristic macroscopic alterations of cirrhosis.

Thirty patients with hemangiomas (n = 6), benign liver cell tumors (n = 7), and primary or metastatic malignant tumors of the liver (n = 17) underwent dynamic MR imaging with Gd-DTPA to determine the value of the procedure in the differentiation of hepatic tumors. The diagnoses were proved by histology or follow-up. Hemangiomas had a significantly greater mean T2 value (192.1 +/- 34.8 msec) than did both benign liver cell tumors (71.9 +/- 16.9 msec; p less than .01) and primary or metastatic malignant tumors (79.7 +/- 21.2 msec; p less than .01), but the T2 values of benign liver cell tumors and malignant tumors were not significantly different. Both hemangiomas and benign liver cell tumors had a significantly greater mean signal-intensity ratio (1.86 +/- 0.60 and 1.77 +/- 0.26, respectively) than did malignant tumors (1.04 +/- 0.34; p less than .01) in the early phase after Gd-DTPA administration, and hemangiomas had a significantly greater signal-intensity ratio (1.59 +/- 0.21) than did both benign liver cell tumors (1.21 +/- 0.08; p less than .01) and malignant tumors (1.06 +/- 0.26; p less than .01) in the delayed phase. These results suggest that dynamic MR images obtained after administration of Gd-DTPA are useful in differentiating hepatic hemangiomas, benign liver cell tumors, and malignant liver lesions.

Aim - Left atrial size is correlated with left ventricle diastolic dysfunction grade and chronicity. We used echocardiography Doppler parameters to assess the relation between the type of left atrium dilatation (symmetrical or asymmetrical) and left ventricular diastolic dysfunction in patients with nonvalvular atrial fibrillation. Methods - We enrolled prospectively 70 patients in stable sinus rhythm and 100 patients with nonvalvular AF and left atrium area more than 20 cm2. Asymmetrical remodelling defined as basal dimension measured at the left atrium posterior wall greater than the mitral annular dimension was correlated with the parameters of the left ventricular diastolic dysfunction and left atrium function. Results - Asymmetrical remodelling was detected in 64% of patients: 46% in AF and 54% in stable SR (p=0.04); it was associated with LA dilatation degree and atrial fibrillation presence. Asymmetrical remodelling in atrial fibrillation patients was significantly correlated with: peak E' wave (r=0.72); L wave (r=0.87); peak systolic (r=0.75) and diastolic pulmonary vein waves (r=0.81). Conclusions - Echocardiography Doppler parameters of left ventricular diastolic dysfunction are correlated with left atrium asymmetric structural remodeling. Left atrial dilatation in atrial fibrillation is frequently associated with asymmetric structural remodelling which is related to LA dilation degree. [ABSTRACT FROM AUTHOR]