Ex vivo expanded umbilical cord blood T cells maintain naive phenotype and TCR diversity.

BACKGROUND: Umbilical cord blood (CB) is a promising source of hematopoietic stem cells for allogeneic transplantation. However, delayed engraftment and impaired immune reconstitution remain major limitations. Enrichment of donor grafts with CB T cells expanded ex vivo might facilitate improved T-cell immune reconstitution post-transplant. We hypothesized that CB T cells could be expanded using paramagnetic microbeads covalently linked to anti-CD3 and anti-CD28 Ab. METHODS: CB units were divided into three fractions: (1) cells cultured without beads, (2) cells cultured with beads and (3) cells cultured with beads following CD3+ magnetic enrichment. All fractions were cultured for 14 days in the presence of IL-2 (200 IU/mL). RESULTS: A mean 100-fold expansion (range 49-154) of total nucleated cells was observed in the CD3+ magnetically enriched fraction. Following expansion, CB T cells retained a naive and/or central memory phenotype and contained a polyclonal TCR diversity demonstrated by spectratyping. DISCUSSION: Our data provide evidence that naive and diverse CB T cells may be expanded ex vivo and warrant additional studies in the setting of human CB transplantation.

[The "EVA" Trial: Evaluation of the Efficacy of Diagnostic Methods (Mammography, Ultrasound, MRI) in the secondary and tertiary prevention of familial breast cancer. Preliminary results after the first half of the study period]. / Die "EVA"-Studie: Evaluierung der Leistungsfähigkeit diagnostischer Verfahren (Mammographie, Sonographie, MRT) zur sekundären und tertiären Prävention des familiären Mammakarzinoms -- Zwischenergebnisse nach der ersten Hälfte der Förderungsperiode.

PURPOSE: To investigate the respective diagnostic accuracies of the different breast imaging modalities, i. e., mammography (Mx), high-frequency breast ultrasound (US), and dynamic contrast-enhanced breast (MRI) regarding the early diagnosis of familial (hereditary) breast cancer. MATERIALS AND METHODS: A prospective, non-randomized controlled clinical multi-center trial is performed at 4 academic tertiary care centers in Germany (Ulm, Munchen/Grosshadern, Munster and Bonn) for a total period of 4 years, sponsored by the German Cancer Aid. The protocol consists of semiannual clinical visits and breast ultrasound, and annual bilateral two-view Mx, US and MRI. Imaging studies were first analyzed independently, then Mx was read in conjunction with US, followed by Mx combined with MRI, and finally, all three imaging modalities were read in synopsis. We present the concept and first results of this trial. RESULTS: So far, 748 screening rounds are available for analysis in 613 women. A total of 12 breast cancers have been identified, with 11/12 cases in the pTis or pT1/N0 stage. The mean size of detected invasive cancers was 7 mm. A total of 19 benign lesions were biopsied due to false-positive imaging diagnoses. The breast cancer detection rates were: Mx: 5/12 (42 %), US 3/12 (25 %), MRI 10/12 (83 %), and the positive predictive values: Mx 5/17 (29 %), US 3/15 (30 %), and MRI 10/23 (43 %). CONCLUSION: The preliminary data suggest that early diagnosis of familial breast cancer is feasible by intensified surveillance, in particular with the addition of MRI.

[Quantifying the inflammatory activity in Crohn's disease using CE dynamic MRI]. / Kontrastmittel-gestützte dynamische MRT des Dünndarms zur Beurteilung der lokalen Entzündungsaktivität bei Morbus Crohn.

PURPOSE: Evaluation of dynamic contrast enhanced MRI in patients with Crohn's disease to assess local inflammatory activity. MATERIAL AND METHODS: Prospective study of 13 patients with histologically proven Crohn's disease. Axial and coronal slices were acquired by a 1.5 T MR (Magnetom Vision, Siemens, Germany): T1 flash 2 D (TR 72.5 ms, TE 4.1 ms), T2 (TR 2730 ms, TE 138 ms), turbo-flash sequences T1 (TR 94.2 ms, TE 4.1 ms) post contrast media fat saturated (Magnevist, 0.2 ml/kg, flow 4 ml/s). In area of maximal thickening of terminal ileal wall, axial dynamic T1 sequences (TR 11 ms, TE 4.2 ms) were acquired every 1.5 s post contrast media application for a total duration of 1 min. Contrast uptake was subjectively measured by semiquantitative score and computed assisted ROI evaluation. MR parameters were correlated with CDAI (Crohn's disease activity index) and SAI (severe activity index). RESULTS: Contrast uptake in the intestinal wall occurred after 18.5 s (range: 3.0 - 28.0), contrast upslope until plateau phase lasted for 16.1 s (range: 8.0 - 50.0). Maximum contrast enhancement into the bowel wall was 266 % (105 - 450 %) of baseline. After maximum contrast uptake, we observed a plateau phase in all cases for the total duration of measurement. A significant correlation existed for maximum contrast uptake to CDAI (r = 0.591; p = 0.033), for beginning of contrast upslope to the time until plateau phase (r = 0.822; p = 0.001), and for the time until plateau phase to CDAI (r = 0.562; p = 0.046). CDAI was on average 108, median 106; SAI was on average 114, median 115. SAI correlated significantly to CDAI (r = 0.874). Maximum contrast uptake, beginning of contrast upslope, and time until plateau phase were independent to creeping fat, local lymphadenitis, laboratory parameters, temperature, body mass index, heart frequency and systolic blood pressure. CONCLUSION: Dynamic MRI enables to quantify local inflammatory activity of bowel wall in patients with Crohn's disease. Larger studies are necessary to establish this method in clinical routine.

[Comparison of conventional enteroclysis, intestinal ultrasound and MRI-enteroclysis for determining changes in the small intestine and complications in patients with Crohn's disease]. / Vergleich von Darmwandsonographie, Enteroklysma und Magnetresonanztomographie in der Erkennung von Darmwandveränderungen und Komplikationen im Dünndarm bei Patienten mit M. Crohn.

BACKGROUND: Enteroclysis, intestinal wall ultrasound (IWU) and abdominal magnetic resonance imaging (MRI) are three established methods in the diagnosis of Crohn's disease (CD). To date, however, the three methods have not been compared in one patient collective. AIMS: The present prospective study compared the relative performance of IWU, MRI and enteroclysis in determining the extent of disease involvement and intestinal complications in patients with CD both at initial diagnosis and during follow-up. PATIENTS AND METHODS: Included in the present study were 48 patients with confirmed CD (age: 19-66 years) examined with all three methods between August 1999 and December 2000. IWU was performed in B-mode with a 4-7 MHz convex transducer head and a 5-12 MHz linear transducer head by an experienced examiner. At MRI, T1 and T2 weighted sequenced (Flash 2D before and after intravenous application of gadolinium DTPA or TSE) were acquired in coronal and transverse planes. Enteroclysis was performed using conventional biphasic technique. Interpretation was conducted on the basis of a standardized catalogue of findings. RESULTS: Changes in bowel segments consistent with inflammation were identified in 41 of 48 patients. All three methods returned equivalent findings with regard to the length of inflamed bowel segments (IWU, range: 3-25 cm, mean: 12 cm; MRI, range: 3-25 cm, mean: 10 cm; enteroclysis, range: 3-30 cm, mean: 11 cm) and wall thickness (IWU, range: 4-10 mm, mean: 7 mm; MRI, range: 5-10 mm, mean: 7 mm; of nine patients with stenotic change, five were correctly diagnosed with IWU (sensitivity, 55.6%; specificity, 97.4%), four with MRI (sensitivity, 44.4%; specificity, 100%) and six with enteroclysis (sensitivity, 66.7%; specificity, 100%). Fistulae were correctly identified in five patients with IWU (sensitivity, 55.6%; specificity, 97.4%), in four with MRI (sensitivity, 44.4%; specificity, 100%) and in six with enteroclysis (sensitivity, 66.7%; specificity, 100 %) of a total of nine patients with confirmed fistula formation. Abscesses were correctly identified in five patients with IWU (specificity, 66.7%; specificity, 100%), in five with MRI (sensitivity, 83.3%; specificity, 100%) and in no patients with enteroclysis (sensitivity, 0%; specificity, 100%) in six patients with abscesses. CONCLUSION: Both IWU and MRI identify extent, severity and intestinal complications with adequate diagnostic accuracy in patients with CD. Both techniques possess the potential for replacing enteroclysis in the work-up of CD. Enteroclysis should be reserved for the work-up of complex fistula systems.

Pre-operative staging of invasive breast cancer with MR mammography and/or PET: boon or bunk?

This study compared pre-operative staging with MR mammography (MRM) and positron emission tomography (PET) in patients with clinically suspected breast cancer according to the Breast Imaging Reporting and Data System, category 5. A total of 43 patients with breast cancer were examined. MRM included both T(2) weighted turbo spin echo sequences and T(1) weighted gradient echo sequences (three-dimensional fast low angle shot) before and after application of gadolinium-DPTA. All patients then underwent examination with a modern full-ring PET scanner following injection of fluorodeoxyglucose. We evaluated the efficacy of these methods in the diagnosis of primary tumour, contralateral carcinomas, bifocal, trifocal or multifocal disease, as well as non-invasive cancer portions and tumour size. Determination of patients' N-status was only attempted using PET. All findings were validated by histological examination. MRM was slightly superior to PET in several areas, such as in the respective methods' sensitivity and specificity. Sensitivities for MRM and PET were: 100% vs 93.0% in diagnosis of the primary tumour; 100% vs 100% in diagnosis of contralateral carcinomas; and 95.2% vs 92.5% in diagnosis of bifocal, trifocal or multifocal disease. Specificities for MRM and PET were: 100% vs 97.5% in diagnosis of contralateral carcinomas; and 96.8% vs 90.3% in diagnosis of bifocal, trifocal or multifocal disease. Non-invasive cancer portions and tumour sizes were equally well determined with both methods. The sensitivity of PET for detection of lymph node involvement was 80% and specificity 95%. MRM and PET were superior to conventional methods in nearly all areas studied; the findings of one or both of the methods impacted positively on patients' surgical treatment in 12.5-15% of cases. Pre-operative MRM and/or PET can have a positive influence on surgical treatment planning. Therefore, it appears useful to perform pre-operative staging with MRM or PET in these patients.

High prevalence of osteoporotic vertebral fractures in patients with Crohn's disease.

BACKGROUND AND AIMS: Osteopenia and osteoporosis are frequent in Crohn's disease. However, there are few data on related vertebral fractures. Therefore, we evaluated prospectively the prevalence of osteoporotic vertebral fractures in these patients. METHODS: A total of 293 patients were screened with dual energy x ray absorptiometry of the lumbar spine (L1-L4) and proximal right femur. In 156 patients with lumbar osteopenia or osteoporosis (T score <-1), x ray examinations of the thoracic and lumbar spine were performed. Assessment of fractures included visual reading of x rays and quantitative morphometry of the vertebral bodies (T4-L4), analogous to the criteria of the European Vertebral Osteoporosis Study. RESULTS: In 34 (21.8%; 18 female) of 156 Crohn's disease patients with reduced bone mineral density, 63 osteoporotic vertebral fractures (50 fx. (osteoporotic fracture with visible fracture line running into the vertebral body and/or change of outer shape) and 13 fxd. (osteoporotic fracture with change of outer shape but without visible fracture line)) were found, 50 fx. in 25 (16%, 15 female) patients and 13 fxd. in nine (5.8%, three female) patients. In four patients the fractures were clinically evident and associated with severe back pain. Approximately one third of patients with fractures were younger than 30 years. Lumbar bone mineral density was significantly reduced in patients with fractures compared with those without (T score -2.50 (0.88) v -2.07 (0.66); p<0.025) but not at the hip (-2.0 (1.1) v -1.81 (0.87); p=0.38). In subgroups analyses, no significant differences were observed. CONCLUSIONS: In patients with Crohn's disease and reduced bone mineral density, the prevalence of vertebral fractures-that is, manifest osteoporosis-was strikingly high at 22%, even in those aged less than 30 years, a problem deserving further clinical attention.

Breast MRI for monitoring response of primary breast cancer to neo-adjuvant chemotherapy.

The objective of the present study was to monitor response to preoperative chemotherapy with breast MRI in patients with large breast cancer. Fifty-eight women in whom core biopsy had confirmed the presence of breast carcinoma underwent breast MRI prior to beginning chemotherapy and before surgical excision. In 24 cases patients underwent one or two additional examinations during chemotherapy to monitor their progress. Breast MRI included both T2-weighted spin-echo sequences and T1-weighted gradient-echo sequences before and 1, 2, 3, and 8 min after bolus injection of gadolinium-DTPA. Tumor size and the dynamic contrast medium uptake patterns of the respective carcinomas were evaluated and compared with the final histology findings. Based on their MR tomographic findings (change in tumor size and intensity of contrast media uptake), patients were assigned to groups with non-response (NR), partial response (PR), and complete response (CR). Based on MR tomographic findings, there were 12 patients in the NR group, 34 in the PR group, and 12 in the CR group. In NR group contrast medium uptake tended to increase or show no more than minimal decrease. Diagnostic accuracy for assigning patients to the NR group was 83.3% and to the PR group 82.4%. In patients whose tumors showed only slight response to chemotherapy, breast MRI proved very reliable in determining the size of the lesions. In patients whose tumors displayed significant response and in the CR group, the size of the residual tumor was underestimated in 8 of 12 cases. In 66.7% of patients in the CR group histology revealed residual tumor masses in areas up to 5 cm in diameter. During chemotherapy, intensity of contrast medium uptake decreased in 88.2% of patients with PR and in all patients with CR. Reliable determination of response was possible within 6 weeks following the initiation of chemotherapy. Breast MRI is suitable as a monitoring method. The determination of residual tumor size is unreliable in carcinomas exhibiting significant response to chemotherapy which may lead to false-negative results. The method may be employed for monitoring response to chemotherapy after 6 weeks.

Ultrasound and magnetic resonance imaging in Crohn's disease: a comparison.

The objective of this retrospective study was to compare MRI of the abdomen with ultrasound of the abdomen and gastrointestinal tract in patients with Crohn's disease. Forty-six patients were included in the study. We analyzed the localization of Crohn's lesions, the number of affected bowel segments, the number of stenoses, and the presence of abscesses, fistulae, and any additional findings. Findings were verified by means of one or more of the following: enteroclysis; surgical findings; and colonoscopy. The results show that MRI is superior to ultrasound in the localization of affected bowel segments (sensitivity: MRI 97.5%; US 76%) and in recognizing fistulae (sensitivity: MRI 87%; US 31%), stenoses (sensitivity: MRI 100%; US 58%) and abscesses (sensitivity: MRI 100%; US 89%). Magnetic resonance imaging of the abdomen should be obtained to clarify discrepant clinical and sonographic findings. In addition, despite its higher cost, MRI of the abdomen is justified in patients in whom Crohn's lesions are known or suspected in anatomic areas proximal to the terminal or neoterminal ileum and in cases with suspicion of fistulae and abscesses.

MRI of the abdomen with positive oral contrast agents for the diagnosis of inflammatory small bowel disease.

Magnetic resonance imaging (MRI) is being used more often in the evaluation of inflammatory bowel diseases. A prerequisite for adequate image quality is the oral application of contrast medium, which can be administered with different modalities. Positive and negative oral contrast media can be used; in terms of diagnostic efficacy, there appears to be no relevant differences between them. Sequences usually are acquired using breath-hold or respiration-triggered protocols. The underlying principle is visualization of circumscribed thickening of the intestinal wall, which shows a pathologic pattern of contrast medium uptake. The available data suggest that MRI is equally as effective as enteroclysis in the primary diagnosis of Crohn's disease and actually more sensitive in the detection of extraintestinal manifestations such as fistulae or abscesses. Supporters of the method predict that MRI will replace enteroclysis in the long term.

[Radiologic diagnosis of fistulas and abscesses in Crohn's disease: cost-effectiveness analysis of 2 different imaging strategies]. / Radiologische Diagnostik von Fisteln und Abszeessen bei Morbus Crohn: Kosten-Effektivitäts-Analyse zweier bildgebender Verfahren.

PURPOSE: To analyze cost-effectiveness of magnetic resonance imaging and conventional enteroclysis in the assessment of fistulas and abscesses in patients with Crohn's disease (CD). METHODS: A decision analytic model was used to compare enteroclysis with MRI, performing a cost-effectiveness analysis of both diagnostic strategies. Data from 84 patients undergoing a clinical trial were used. Primary outcome was defined as one correctly diagnosed patient regarding Crohn's disease, fistulas, and abscesses, including true-positive and true-negative cases. Costs of the two procedures were estimated in German Marks (DM) using fee schedules. The influence of different definitions of effects was calculated. For all variables single and multiple sensitivity analyses were performed. RESULTS: Incremental cost effectiveness of MRI vs. enteroclysis was 3,119.33 DM per one additional correctly diagnosed patient. The results of sensitivity analyses suggest that MRI use in certain patient subgroups (patients at higher prevalence of CD, fistulas, and abscesses) even becomes more cost-effective. In this case one additional effect could be gained below 1,650 DM. CONCLUSIONS: From an economic perspective, decision makers should consider the use of MRI in the work-up of patients with Crohn's disease as an efficient procedure under certain conditions. To support treatment policies for physicians or insurance coverage of certain diagnostic strategies the costs possibly saved with MRI should also be considered.

Metallic stents in benign biliary strictures: long-term effectiveness and interventional management of stent occlusion.

OBJECTIVE: The objective of our study was to evaluate the long-term effectiveness of metallic stent placement in the treatment of benign biliary strictures and to report our experience with interventional procedures for the management of stent occlusion to achieve secondary patency. CONCLUSION: The clinical course of these patients is compromised by repeated stent occlusions, caused by stone or mucosal hyperplasia. The results of primary stent patency are disappointing with the primary patency rate decreasing from 75% after 12 months to 25% after 36 months. The different interventional procedures used to restore bile flow make an important contribution to the secondary stent patency and provide a satisfactory clinical result in a patient subpopulation in whom stent placement is considered the last resort.

Alveolar liver echinococcosis: a comparative study of three imaging techniques.

BACKGROUND: We compared the imaging findings in patients with alveolar liver echinococcosis using ultrasound (US), computerized tomography (CT) and magnetic resonance imaging (MRI) in a prospective study. PATIENTS AND METHODS: 30 patients with alveolar echinococcosis (AE) were examined with the above imaging techniques. RESULTS: 30 lesions were detected with all three methods and most lesions (n = 55) were detected with CT. Calcifications were seen in 15 lesions with US, in 21 with CT and in 16 with MRI. MRI best detected necrotic areas and multivesicuLar structures. CONCLUSION: US is the screening method of choice and should primarily be complemented by CT due to its ability to detect the greatest number of lesions and clear demarcation of the characteristic calcifications. MRI may facilitate the diagnosis in uncertain cases with noncalcified or partially calcified lesions by showing the characteristic multivesicular structure, necrotic areas and proximity to vascular structures.

Preoperative diagnosis of ovarian tumors with MR imaging: comparison with transvaginal sonography, positron emission tomography, and histologic findings.

OBJECTIVE: Our study evaluated the diagnostic performance of MR imaging compared with that of transvaginal sonography and positron emission tomography (PET) in patients with clinically asymptomatic adnexal findings. An additional goal was to determine whether the combination of the three methods enhanced their diagnostic accuracy. SUBJECTS AND METHODS: Included in the study were 103 women with suspicious adnexal findings on sonography. Patients underwent transvaginal sonography, MR imaging, and PET within 3 weeks of the initial sonography. For MR imaging, axial and sagittal T1-weighted gradient-echo sequences (unenhanced and enhanced) and T2-weighted turbo-spin-echo sequences were acquired. Transvaginal sonography was performed with a 7.5-MHz transducer head. For PET, a modern full-ring scanner was used. The results of diagnostic imaging techniques were first evaluated separately, and reviewers were blinded to the results of other methods. Finally, a second session resulted in a consensus diagnosis based on the findings of all three methods. Results of histology were considered the gold standard. RESULTS: Histology revealed 12 malignant and 91 benign ovarian tumors. The following data were calculated for MR imaging, transvaginal sonography, PET, and consensus diagnosis: sensitivities, 83%, 92%, 58%, 92%; specificities, 84%, 59%, 78%, 84%; diagnostic accuracies, 83%, 63%, 76%, 85%, respectively. MR imaging, particularly with contrast-enhanced fat-saturated T1-weighted sequences, was found to correctly reveal dermoid and endometrial cysts. All three methods had false-negative findings with borderline tumors. CONCLUSION: Transvaginal sonography is the diagnostic method of choice as a screening technique for ovarian processes. Suspicious findings on transvaginal sonography should be confirmed on MR imaging. If MR imaging confirms a dermoid or endometrial cyst, further diagnostic procedures may be unnecessary. In all other cases, a surgical evaluation must be considered.

Fluorine-18 2-deoxy-2-fluoro-D-glucose PET in the preoperative staging of breast cancer: comparison with the standard staging procedures.

The present study compared the diagnostic accuracy of fluorine-18 2-deoxy-2-fluoro-D-glucose positron emission tomography (FDG-PET) with conventional staging techniques. The differentiation between malignant and benign lesions and the detection of multifocal disease, axillary and internal lymph node involvement, and distant metastases were evaluated. One hundred and seventeen female patients were prospectively examined using FDG-PET and conventional staging methods such as chest X-ray, ultrasonography of the breast and liver, mammography and bone scintigraphy. All patients were examined on a modern full-ring PET scanner. Histopathological analysis of resected specimens was employed as the reference method. The readers of FDG-PET were blinded to the results of the other imaging methods and to the site of the breast tumour. The sensitivity and specificity of FDG-PET in detecting malignant breast lesions were 93% and 75% respectively. FDG-PET was twofold more sensitive (sensitivity 63%, specificity 95%) in detecting multifocal lesions than the combination of mammography and ultrasonography (sensitivity 32%, specificity 93%). Sensitivity and specificity of FDG-PET in detecting axillary lymph node metastases were 79% and 92% (41% and 96% for clinical evaluation). FDG-PET correctly indicated distant metastases in seven patients. False-positive or false-negative findings were not encountered with FDG-PET. Chest X-ray was false-negative in three of five patients with lung metastases. Bone scintigraphy was false-positive in four patients. Three patients were upstaged since FDG-PET detected distant metastases missed with the standard staging procedure. It is concluded that, compared with the imaging methods currently employed for initial staging, FDG-PET is as accurate in interpreting the primary tumour and more accurate in screening for lymph node metastases and distant metastases. Due to a false-negative rate of 20% in detecting axillary lymph node metastases, FDG-PET cannot replace histological evaluation of axillary status.

Diagnosis of papillomas of the breast: value of magnetic resonance mammography in comparison with galactography.

The aim of this study was evaluation of MRI alone and in combination with mammography and galactography in the diagnosis of intraductal papillomas. From 1994 to 1998, a total of 48 women presenting with pathologic mammary secretion underwent galactography and magnetic resonance mammography (MRM). Thirty-five patients aged 16-71 years (average age 46 years) subsequently underwent surgery or diagnostic puncture and the histologic findings were compared with the results of the radiologic examination. Histology revealed papillomas in 16 cases. In 6 of these patients, there was associated malignant degeneration. Malignancy without associated papilloma was observed in 3 cases. Galactography displayed a sensitivity of 94% and a specificity of 79% with five false-positive findings and one false-negative finding in the recognition of intraductal papillomas. Malignant processes were detected by mammography/galactography in only one instance. Magnetic resonance mammography visualized pathologic contrast medium uptake in 8 of 9 cases of malignant disease (sensitivity 89%). One patient with in situ ductal carcinoma escaped detection with MRM. Papillomas showed no or below-the-threshold-lying contrast uptakes with no specific sign suggestive of papilloma. Galactography in combination with mammography remains the primary diagnostic procedure in cases of pathologic mammary secretion or suspected papilloma. The addition of MRI permits exclusion of malignant disease with a high degree of certainty; thus, expectant management in individual cases with negative findings appears justified.

MRI in the diagnosis of small bowel disease: use of positive and negative oral contrast media in combination with enteroclysis.

The aim of the study was to evaluate the additional findings of MRI following small bowel enteroclysis and to compare the efficacy of negative and positive intraluminal contrast agents. Fifty patients with inflammatory or tumorous small bowel disease were investigated by small bowel enteroclysis and consecutive MRI using breathhold protocol (T1-weighted fast low-angle shot, T2-weighted turbo spin echo). Patients were randomly assigned to either receiving a positive oral (Magnevist, Schering, Berlin, Germany) or a negative oral MR contrast media (Abdoscan, Nycomed, Oslo, Norway). The pattern of contrast distribution, the contrast effect, presence of artifacts, as well as bowel wall and extraluminal changes, were determined and compared between the contrast type using Fischer's exact test. Sensitivity, specificity, and diagnostic accuracy for MRI and enteroclysis were calculated. Twenty-seven patients had clinically proven Crohn's disease and two patients surgically proven small bowel tumours. Magnetic resonance imaging had important additional findings as abscesses and fistulae in 20 patients. Surgically compared sensitivities were 100 and 0% for MRI and enteroclysis, for the detection of abscesses, and 83.3 and 17 % for the diagnosis of fistulae, respectively. Bowel wall thickening was more reliably detected with use of positive oral contrast media without intravenous enhancement (p < 0.001), whereas postcontrast negative oral contrast media allow for a superior detection (p < 0.001). T2-weighted sequences were necessary with use of negative oral contrast media, because loop abscesses may be masked. Magnetic resonance imaging should be performed in all patients with suspicion of extraintestinal complications, because the complications are more reliably detected by MRI. Negative oral contrast media show advantages with the use of intravenous contrast but can mask loop abscesses using only T1-weighted imaging.

Diagnostic imaging in Crohn's disease: comparison of magnetic resonance imaging and conventional imaging methods.

Conventional enteroclysis remains the method of choice in the diagnosis of inflammatory small bowel disease. The reported sensitivity rates, however, for the diagnosis of extraintestinal processes, such as fistulae and abscesses, are moderate. Computed tomography (CT) is the method of choice for the diagnosis of extraintestinal complications. The anatomical designation of the affected bowel segment may, however, prove difficult due to axial slices, and the applied radiation dose is high. The use of magnetic resonance imaging (MRI) in the diagnosis of inflammatory small bowel disease is a relatively new indication for the method; prerequisites were the development of breathhold sequences and phased array coils. Optimized magnetic resonance tomographic imaging requires a combined method of enteroclysis and MRI, which guarantees an optimal filling and distension of the small bowel. The high filling volume leads to a secondary paralysis of the small bowel and avoids motion artifacts. In a trial of 84 patients with histological and endoscopic correlation the sensitivity in diagnosing inflammatory bowel disease was 85.4% for enteroclysis and 95.2% for MRI, and the specificity was 76.9% for enteroclysis and 92.6% for MRI. As none of the abscesses was diagnosed with enteroclysis, the sensitivity was 0% for enteroclysis, but 77.8% for MRI. The sensitivity in diagnosing fistulae was 17.7% for enteroclysis and 70.6% for MRI. In summary, MRI can detect the most relevant findings in patients with inflammatory small bowel disease with an accuracy superior to that of enteroclysis.

Classification of asymptomatic adnexal masses by ultrasound, magnetic resonance imaging, and positron emission tomography.

OBJECTIVE: The purpose of this study was to determine the diagnostic accuracy of sonography versus magnetic resonance imaging (MRI) and positron emission tomography (PET) in the characterization of adnexal masses. METHODS: One hundred and one patients with asymptomatic adnexal masses, which were scheduled for laparoscopy, underwent preoperative transvaginal ultrasound, MRI, and 2-[(18)F]fluoro-2-deoxy-d-glucose PET. Two different sonomorphological scoring systems were used to distinguish malignant from benign lesions. In addition, transvaginal Doppler flow velocimetry was performed and the resistance index (RI) of ovarian blood vessels was calculated. RI values below 0.45 were considered to indicate malignancy. MRI was evaluated on the basis of signal intensity and morphologic features such as wall thickness, septations, fluid or solid components, and vascularity. PET imaging was used to determine 2-[(18)F]fluoro-2-deoxy-D-glucose uptake. Malignancy was suspected if radiotracer uptake equaled or exceeded that of the liver. Based on histologic findings, sensitivity, specificity, positive and negative predictive values, and accuracy were first calculated independently for each imaging technique. Finally, a second session resulted in a consensus diagnosis being made based on the findings of all three modalities. RESULTS: Sonographic evaluation of adnexal masses resulted in correct classification of 11 of 12 ovarian malignancies (sensitivity 92%) but with a specificity of only 60%. With MRI and PET, specificities improved to 84 and 80% respectively, but sensitivities decreased. When all imaging modalities were combined, sensitivity and specificity were 92 and 85%, respectively, and accuracy was 86%. CONCLUSION: Combination of ultrasound with MRI and PET may improve accuracy in differentiation of benign from malignant ovarian lesions. However, negative MRI or PET results do not rule out early-stage ovarian cancer or borderline malignancies.