Thymus alterations and systemic sclerosis.

OBJECTIVES: The pathogenesis of systemic sclerosis (SSc) includes complex alterations to the immune system, possibly responsible for diffuse microvasculature and fibroblast dysfunction. Previous anecdotal observations suggest a possible role for thymus alterations in some autoimmune rheumatic diseases, including SSc. This study aimed to investigate the prevalence of radiological thymus alterations in SSc patients. METHODS: Thirthy-four unselected patients [28 female and 6 male, mean age (+/- S.D.) 49.7 +/- 9.5 yr, range 33-67 yr] and 34 age- and sex-matched controls were included in the study. The presence of major radiological thymus alterations, i.e. an abnormally enlarged or nodular thymus, were blindly investigated by means of unenhanced multidetector computed tomography. RESULTS: Abnormally enlarged or nodular thymuses were detected in a statistically significant percentage of SSc patients compared with controls (21 vs 0%, P = 0.011). More interestingly, radiological thymus alterations were invariably observed in patients with shorter disease duration (< or =5 yr, 41% vs >5 yr, 0%; P = 0.007), frequently associated with serum anti-Scl70 antibodies (P = 0.017). Among patients with thymus alterations one developed myasthenia gravis while two others showed thymus hyperplasia at histopathological evaluation after thymectomy. CONCLUSIONS: The present study suggests a possible role of thymic disorders, mainly thymus hyperplasia, in a significant number of SSc patients. Due to the limitations of radiological evaluation, the actual relevance of such an association might be underestimated. The relationship of thymus alterations with shorter disease duration, as well as with serum anti-Scl70, suggests that thymic dysfunction could play a pathogenetic role mostly in the early phases of the disease, and possibly in specific SSc patient subsets.

Relationship between extent of pulmonary emphysema by high-resolution computed tomography and lung elastic recoil in patients with chronic obstructive pulmonary disease.

We investigated the relationship between the extent of pulmonary emphysema, assessed by quantitative high-resolution computed tomography (HRCT), and lung mechanics in 24 patients with chronic obstructive pulmonary disease (COPD). The extent of emphysema was quantified as the relative lung area with CT numbers < -950 Hounsfield Units (HU). Patients with COPD had severe airflow obstruction (FEV(1) 35 +/- 15% pred) and severe reduction of CO diffusion constant (DCO/VA 37 +/- 19% pred). Maximal static elastic recoil pressure (Pst(max)) averaged 54 +/- 24% predicted, and the exponential constant K of pressure-volume curves was 258 +/- 116% predicted. Relative lung area with CT numbers < -950 HU averaged 21 +/- 11% (range 1 to 38%). It showed a highly significant negative correlation with DCO/VA (r = -0.84, p < 0.0001), a weak correlation with FEV(1)% predicted, and no correlation with either Pst(max) or constant K. A significant relationship was found between the natural logarithm of K and the full width at half maximum of the frequency distribution of CT numbers, taken as an index of the heterogeneity of lung density (r = 0.68, p < 0.0005). We conclude that currently used methods of assessing the extent of emphysema by HRCT closely reflect the reduction of CO diffusion constant, but cannot predict the elastic properties of the lung tissue.

Crohn disease of the small bowel: spiral CT evaluation after oral hyperhydration with isotonic solution.

PURPOSE: Our aim was to evaluate the accuracy of spiral CT study of small-bowel Crohn disease with use of oral hyperhydration with isoosmotic solution. METHOD: We prospectively analyzed 33 consecutive patients and 10 control subjects with spiral CT after oral administration of 2,000 ml of polyethylene glycol electrolyte-balanced solution. The CT diagnoses were compared with the results of conventional radiologic oral barium examination (33 cases), ileum colonoscopy (8 cases), and surgery (4 cases). RESULTS: The final diagnoses were Crohn disease (14 cases), no small-bowel disease (16 cases), cancer of ileocecal valve (1 case), carcinosis of mesenteric root (1 case), and intestinal lymphangiectasia (1 case). In the control group, no abnormalities of the small bowel were found. The sensitivity of spiral CT was 85.7%, specificity 100%, positive predictive value 100%, negative predictive value 90%, and diagnostic accuracy 93.9%. CONCLUSION: Our method allowed adequate distension of the small bowel for spiral CT studies, thus resulting in a safe and effective alternative to small-bowel spiral CT enema, which can be used in patients that refuse the nasojejunal balloon catheter.

MR virtual endoscopy of the upper urinary tract.

OBJECTIVE: We investigated the feasibility of applying surface-rendered virtual endoscopy to the visualization of the upper urinary tract by processing unenhanced MR urography data sets. SUBJECTS AND METHODS: Twenty-six patients, having neoplastic lesions (n = 9), calculi (n = 8), pelviureteric junction stenoses (n = 4), postoperative fibrotic strictures (n = 3), and extrinsic compressions of the ureter (n = 2), underwent unenhanced MR urography. Virtual endoscopy of the upper urinary tract was obtained using a thresholding technique and surface-rendering MR urography data sets. RESULTS: Virtual endoscopy of the renal pelvis and calices was feasible in all cases on the side of the urinary obstruction. Virtual endoscopy of the ureter was obtained for a diameter of at least larger than 5 mm. The nondilated side could be partially explored in 11 cases (43%). The mean virtual endoscopy threshold required for the visualization of the urinary tract was 157.36-159.94. The mean time for virtual endoscopy was 13.8 min. Endoluminal masses were found in three (12%) of 26 cases on the renal pelvis (corresponding to neoplastic lesions), and occlusions, in 23 (88%) of 26 on the pelviureteric junction and ureter (neoplastic lesions and other abnormalities). CONCLUSION: Virtual endoscopy of MR urography data sets is feasible in patients with urinary tract dilatation. Virtual endoscopy displays the renal pelvis, calices, and ureter and, moreover, can show endoluminal changes caused by abnormalities.

Virtual endoscopy of the middle and inner ear with spiral computed tomography.

OBJECTIVE: To evaluate the inner anatomy of the auditory apparatus by means of virtual endoscopy of spiral computed tomography (CT) data sets. BACKGROUND: Virtual endoscopy permits simulation of the fiberoptic endoscopy perspective by processing CT or magnetic resonance images. METHODS: Seven formalin-fixed specimens of human mastoid were scanned with spiral CT with the following protocol: beam collimation 1 mm, pitch ratio 1, reconstruction spacing 0.2 to 0.5 mm, field of view 90 mm. For the generation of endoscopic views of the auditory spaces, the axial images were processed with Navigator software 2.0 running on UltraSparc I workstation. RESULTS: Virtual endoscopy allowed the demonstration of the external auditory canal, the head and handle of the malleus, the stapes and incudostapedial articulation, the corpus, the long process of the incus with its lenticular process and the short limb, the malleoincudal articulation, the rounded promontory, the round and oval windows, and Prussak's space. From inside the basal turn of the cochlea, virtual endoscopy showed the orifices of the fenestrae cochlea and vestibuli, the origin of the lateral and the anterior semicircular canals, and the basal turn of cochlea. The optimal perspectives that allowed demonstration of the anatomical details of the middle and inner ear are described. CONCLUSION: Virtual endoscopy allows the generation of inner views of the auditory spaces. This new method of image processing can be proposed as an integrative tool of spiral CT imaging.

Giant pedunculated liposarcomas of the esophagus: literature review and case report.

Although liposarcoma is the second most common soft-tissue sarcoma in adults, its incidence within the gastrointestinal tract is distinctly low. Esophageal involvement is exceedingly rare and only four cases have been described so far. A fifth case is presented here along with a thorough review of the literature of polypoid lipomatous tumors of the esophagus. Diagnostic and therapeutical strategies of these tumors are discussed in detail.

Spontaneous epidural emphysema and pneumomediastinum during an asthmatic attack in a child.

CT revealed the presence of epidural emphysema as an incidental finding in a 13-year-old boy in whom mild infrequent coughing during an asthmatic attack resulted in a pneumomediastinum and subcutaneous emphysema. Epidural emphysema was not associated with neurological symptoms. The CT images demonstrated the pathway of air leakage from the posterior mediastinum through the intervertebral foramina into the epidural space. Repeat CT showed spontaneous resolution of the epidural emphysema.

[Comparison of computerized tomography and magnetic resonance in the assessment of benign and malignant pleural diseases]. / Confronto fra Tomografia Computerizzata e Risonanza Magnetica nella valutazione delle malattie pleuriche benigne e maligne.

To compare the diagnostic capabilities of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) in differentiating benign from malignant pleural disease, we examined with MRI at 0.5 T forty-five patients with pleural lesions identified on CT scans. For 34 patients, a final diagnosis of malignant (n = 18) or benign (n = 16) disease was made. T1, proton density/T2 and enhanced T1-weighted spin-echo images were acquired. CT and MR images were independently studied by two observers, who were unaware of the final diagnosis. Various morphological features suggesting benign or malignant pleural disease were evaluated. On the basis of the morphological CT features, a final diagnosis of benignity of malignancy was expressed in terms of two different levels of confidence-probable or definitive. The MR signal intensity of pleural lesions was compared with that of intercostal muscles (isohypointense or hyperintense). No significant differences were observed between CT and MR morphological findings. High signal intensity on proton density/T2-weighted images was observed in all malignant lesions and in 2 benign lesions (100% sensitivity, 87% specificity). In the absence of this sign (i.e., isointense or hypointense signal), the lesions were always benign (100% negative predictive value). All the definitive CT diagnoses were correct, while 6 of 17 probable CT diagnoses were incorrect. In the subgroup of lesions misinterpreted with CT, MR signal intensity on long-TR images always allowed the correct differentiation of benign from malignant conditions. To conclude, MR signal intensity is a valuable additional feature to differentiate benign from malignant pleural disease. We suggest the use of MRI in the pleural lesions where the level of confidence of CT diagnosis is low.

Usefulness of MR signal intensity in distinguishing benign from malignant pleural disease.

OBJECTIVE: The aim of this study was to analyze the potential usefulness of MR signal intensity in differentiating malignant from benign pleural disease. SUBJECTS AND METHODS: Forty-five patients with pleural lesions identified on CT scans were subsequently examined by MR imaging at 0.5 T. T1-weighted, proton density-weighted, T2-weighted, and enhanced T1-weighted spin-echo images were obtained. For 34 patients, a diagnosis of malignant (n = 18) or benign (n = 16) disease was established. The morphologic features of the pleural lesions and MR signal intensity on T1-weighted, proton density-weighted, T2-weighted, and enhanced T1-weighted images were evaluated, and the ratio of lesion to muscle signal intensity was computed. RESULTS: Assessment of morphologic features by MR imaging and CT was not significantly different. High signal intensity on proton density-weighted and T2-weighted images was observed in all malignant lesions and in two benign lesions (sensitivity, 100%; specificity, 87%; negative predictive value, 100%). The ratio of lesion to muscle signal intensity on T1-weighted, proton density-weighted, T2-weighted, and enhanced T1-weighted images discriminated between malignant and benign lesions (p < .0001). For the subgroup of lesions misinterpreted by CT (n = 6), the evaluation of MR signal intensity on long-TR images made it possible to differentiate malignant from benign conditions. CONCLUSION: MR signal intensity is a valuable additional feature for differentiating malignant from benign pleural disease. Signal hypointensity with long-TR sequences is a reliable predictive sign of benign pleural disease.

[The radiological assessment of the knee in the meniscectomy patient]. / La valutazione radiologica del ginocchio nel paziente meniscectomizzato.

The increasing number of radiologic examinations performed on patients previously submitted to arthroscopic meniscectomy led us to analyze the types of lesion most frequently found in these patients and the prognostic factors related to meniscectomy. Thus, the radiographs, CT and MR examinations were reviewed of 34 symptomatic patients submitted to arthroscopy at least 1 year earlier and in whom symptoms had appeared no more than 3 months earlier, thus ruling out the symptoms related to surgical complications. Lesions were found in the menisci, in the meniscal stumps and in the articular ends. The lesions involving the menisci not submitted to previous arthroscopy were not studied in detail. As to meniscal stumps, CT and MRI exhibited the same diagnostic accuracy, in detecting lesion recurrence, in 50% of cases. In the remaining cases their results were similar, with some false negatives (CT) and some false positives (MRI). As to osteoarthritis, MRI proved superior in detecting the microscopic evidence of cartilage-bone erosions even though 20% of patients exhibited findings of such entity as to be visible at CT. As regards the macroscopic evidence of articular ends deformity, CT and MRI yielded the same results. To define the prognostic factors of meniscectomy, all patient was asked to define their activity level after meniscectomy, that is before the onset or recurrence of symptoms. A detailed questionnaire was used to this purpose, using the Tapper-Hoover rating scale, expressly developed to derive a functional knee score after meniscectomy. The results indicate that the functional knee score (related to prognosis) was lower in patients older than 40, in meniscectomy performed in older age, in long intervals between trauma and meniscectomy, after complex and horizontal-cleavage lesions and, finally, in sedentary activity.

[Diagnostic imaging of intestinal invaginations in the adult. Report of 9 cases]. / Diagnostica per immagini delle invaginazioni intestinali dell'adulto. Descrizione di 9 casi.

Adult intestinal intussusception affects the distal portions of the small bowel and the colon in 90% of cases. As a rule, its nature is neoplastic, its clinical presentation aspecific and its diagnosis is frequently an occasional finding during routine imaging examinations. We report on 9 adult patients with intestinal intussusception. All patients were examined with more than one of the following imaging modalities: radiologic study of the small bowel, barium enema, ultrasonography (US), and Computed Tomography (CT). The first diagnostic suspicion of intussusception was correctly made at US in 5 patients and at CT in 4 patients. At surgery, intussusception sites were the following: jejunum in one case, ileum in two cases, ileocolon in two cases and colon in four cases. CT correctly detected lesion site in all the patients who underwent it as the first diagnostic step, while US missed lesion site in one case. Pathology diagnosed a hamartomatous jejunal polyp, a lymphomatous ileal polyp, a lymphomatous polyp of the ileocecal valve, four cecocolonic adenocarcinomas and a left colic lipoma. Lesion nature was suspected at US in one case of ileal lymphoma, while CT suggested the presence of lipoma in one case of ileoileal intussusception. Our experience shows that intussusception can be diagnosed not only with conventional radiologic modalities, but also with US and CT, which are useful to depict both the lesion and its site and extent.

[Quantification of pulmonary emphysema with computerized tomography. Comparison with various methods]. / Quantificazione dell'enfisema polmonare mediante Tomografia Computerizzata. Confronto tra diversi metodi.

Computed Tomography (CT) has been proved to be the most accurate imaging modality to diagnose emphysema in vivo. Our study was aimed at comparing different CT methods for pulmonary emphysema quantification in patients with severe chronic obstructive pulmonary disease (COPD). Forty-six consecutive inpatients affected with COPD underwent high resolution CT (HRCT). Three scans were acquired at 3 preselected anatomic levels at both full inspiration and expiration. Three different observers were asked to subjectively evaluate, under blind conditions, the extent alone and both the severity and the extent of emphysema on the 6 scans. HRCT findings were also analyzed quantitatively by measuring the mean CT number in Hounsfield Units (HU) and the % of lung area with CT numbers < -900 HU (pixel index). Quantitative CT data were compared with reference values obtained in 7 normal nonsmokers. The CT visual score of emphysema exhibited medium-high interobserver reproducibility with correlation coefficients ranging from 0.80 to 0.96 and a good correlation with pulmonary function tests, particularly relative to the assessment of the extent of emphysema alone as expressed by one observer. CT quantification demonstrated an excellent correlation with functional indices of expiratory airflow, lung volumes and diffusion coefficients (p < 0.001). The expiratory measurements were better than the inspiratory ones while the analysis of both CT number and pixel index gave comparable results. Only the CT expiratory quantitative data allowed to differentiate the patients affected with COPD from the controls. In conclusion, the severity of emphysema as expressed by CT correctly reflects the functional impairment of patients with severe COPD.(ABSTRACT TRUNCATED AT 250 WORDS)

Portal vein thrombosis after percutaneous ethanol injection for hepatocellular carcinoma: value of color Doppler sonography in distinguishing chemical and tumor thrombi.

OBJECTIVE: The distinction between benign (chemical) and tumor thromboses of the portal vein after treat,ent with percutaneous injection of ethanol for hepatocellular carcinoma is crucial for the proper management of the patient. The purpose of this study was to determine whether color Doppler sonography can be used to differentiate between the two types of thrombi. SUBJECTS AND METHODS: Between October 1991 and April 1994, portal vein thrombosis was detected by color Doppler sonography in 19 patients (13 men and six women 59-77 years old; mean age, 67 years) who had hepatocellular carcinomas and who had received percutaneous ethanol injection (n = 11) or percutaneous ethanol injection after transcatheter arterial embolization (n = 8). The criterion for diagnosing tumor thrombosis by color Doppler sonography was the detection of pulsatile arterial flow in the thrombus. The benign or malignant nature of the thrombosis was subsequently established by percutaneous fine-needle biopsy of the thrombus; malignant thrombosis was seen in 13 patients, and chemical thrombosis was seen in six patients. RESULTS: Pulsatile arterial flow in the thrombus was observed by color Doppler sonography in 12 of the 13 malignant thrombi and in none of the bland thrombi. The flow was hepatopetal in seven cases and hepatofugal in five cases. The peak systolic frequency shift ranged from 0.59 to 2.65 kHz (mean, 1.35 kHz), and the resistive index ranged from 0.37 to 0.69 (mean, 0.55). The sensitivity and the specificity of color Doppler sonography for the detection of tumor thrombosis were 92% and 100%, respectively. CONCLUSION: Our study shows that color Doppler sonography is a reliable way to differentiate between chemical and tumor thromboses of the portal vein in patients with hepatocellular carcinomas treated by ethanol injection. When the sonogram shows pulsatile arterial flow within the thrombus, percutaneous biopsy of the thrombus is unnecessary. The finding is always indicative of malignant thrombosis.

Chest radiography and high resolution computed tomography in the evaluation of workers exposed to silica dust: relation with functional findings.

OBJECTIVES: To compare the usefulness of high resolution computed tomography (HRCT) with chest radiography (CR) in the diagnosis and assessment of severity of silicosis. METHODS: 27 workers exposed to silica underwent CR, HRCT, and pulmonary function tests. Two experienced readers independently evaluated CR by International Labour Office classification, and grouped the results into four categories. HRCT categories of nodule profusion and the extent of emphysema were graded on a four point scale; in 20 subjects the percentage distribution of lung densities were measured by HRCT. RESULTS: Concordance between readers was higher for HRCT than for CR (K statistic = 0.49 and 0.29 respectively). There was poor concordance between CR and HRCT in the early stage of silicosis. No significant difference in pulmonary function tests was found among different CR categories, but forced expiratory volume in one second (FEV1), maximal expiratory flow at 50% and 75% of FVC (MEF50, MEF75), and diffusion capacity significantly decreased with increasing HRCT categories. Subjects with simple silicosis detected by HRCT had a lower FEV1 than subjects without silicosis, whereas subjects with conglomerated silicosis showed higher residual volume and functional residual capacity than subjects with simple silicosis. These relations were not affected by smoking or symptoms of chronic bronchitis. Different grades of emphysema detected by HRCT were significantly different in diffusion capacity. Only the HRCTs of the lowest and the highest categories of profusion of parenchymal opacities were significantly different in their distribution of density classes. CONCLUSION: HRCT is more reproducible and accurate than CR, as suggested by the higher agreement between readers and the better correlation with pulmonary function tests, irrespective of smoking and chronic bronchitis; however, these data do not support the hypothesis that HRCT is more sensitive than CR in the early detection of silicosis.

[High-resolution computed tomography compared with the thoracic radiogram and respiratory function tests in assessing workers exposed to silica]. / Tomografia computerizzata ad alta risoluzione a confronto con il radiogramma del torace e con le prove di funzionalità respiratoria nella valutazione dei lavoratori esposti a silice.

To compare the usefulness of high-resolution computed tomography (HRCT) and chest radiography in the functional evaluation of silica-exposed workers, 27 workers were submitted to posteroanterior and lateral chest radiographs, apex to base HRCT scans and pulmonary function tests. Two experienced readers studied plain films independently to assess small opacities profusion (ILO-UC, Geneva 1980): from 0/- to 3/+. HRCT grading and extent of silicotic nodules and associated emphysema were scored on a four-point scale. Inter-reader analysis showed better agreement for HRCT (K = 0.49) than chest radiography (K = 0.29). Poor agreement was observed between chest radiography and HRCT classes, particularly in the early stages of silicosis. No correlation was observed between chest radiography score and pulmonary function tests, while a significant correlation was observed between HRCT classes (grade and extent of the nodules) and FEV1, MEF50, MEF75, RV and FRC. In conclusion, HRCT exhibited better reproducibility and higher accuracy than chest radiography in identifying the absence of silicotic nodules and in depicting functionally important lesions. To this purpose, HRCT can be considered a useful support to conventional chest radiography.

[Gadolinium-DTPA combined with a fat suppression technique in studies with magnetic resonance at 0.5 T in soft-tissue neoplasms]. / Associazione di gadolinio-DTPA con tecnica di soppressione del grasso nello studio con risonanza magnetica a 0.5 T nelle neoplasie dei tessuti molli.

Combination of fat suppression techniques with intravenous paramagnetic contrast administration is usually performed using high-field MR systems. We combined a modified three-point Dixon technique for fat suppression with gadolinium-DTPA administration in the investigation of soft tissue neoplasms at 0.5 T. Nineteen patients with 21 neoplasms (14 primary malignant, 2 metastatic, 5 benign tumors) were examined. Examination protocol included unenhanced SE T1, PD and T2-weighted images. After the intravenous administration of gadolinium-DTPA (0.1 mmol/kg), a modified three-point Dixon technique provided three image sets, i.e., conventional T1-weighted SE images, fat-suppressed T1-weighted images and water-suppressed T1-weighted images. Two observers evaluated the lesions for conspicuity and size in three image groups: unenhanced T1-, PD and T2-weighted images, enhanced conventional T1-weighted images, enhanced T1-weighted images with fat suppression. Ten lesions showed greater conspicuity on enhanced fat-suppressed images than on unenhanced T1-, PD and T2- and enhanced conventional T1-weighted images. In 16 cases lesions were more conspicuous on enhanced water images than on conventional enhanced T1 images. Ten tumors exhibited a larger size (difference exceeding 20%) on enhanced fat-suppressed images. The combination of gadolinium with the modified Dixon technique improves the demonstration of soft tissue neoplasms at 0.5 T and allows lesion size to be measured more accurately.

[Reconstruction of the anterior cruciate ligament with patellar tendon. Comparison between magnetic resonance and computerized tomography]. / Ricostruzione del legamento crociato anteriore con tendine rotuleo. Confronto tra Risonanza Magnetica e Tomografia Computerizzata.

CT and MR potentials were compared in 30 patients submitted to anterior cruciate ligament reconstruction using the patellar tendon. In each patient the clinical data were correlated with the following radiologic parameters: the course of the tibial and femoral tunnels, their intraarticular outlet sites and their shape, the shape of the intercondylar notch and of the medial wall of the lateral femoral condyle and, finally, the shape of the graft and of the synovia. The intraarticular outlet site of the tibial tunnel was studied on the sagittal or transverse planes. In the former case the distance from the anterior tibial edge was considered, together with its relationship to sagittal tibial depth. The intraarticular outlet site of the femoral tunnel which was studied on sagittal and coronal MR planes was determined at CT by calculating its distance, i.e., the number of scans, from the intercondylar notch and from the posterior edge of the femoral condyle. MRI yielded better results thanks to its multiplanarity, but CT proved superior in defining size and shape of the bone outlets, the presence of bone chips (sometimes responsible for synovial reaction), the shape of the intercondylar notch and of the medial wall of the lateral condyle. As regards graft visualization, both CT and MRI yielded satisfying results in most cases. Nevertheless, MR potentials appeared superior thanks to its capabilities in demonstrating the graft in its full length and in differentiating it from surrounding synovial reaction.

[Magnetic resonance angiography at 0.5 Tesla of the renal arteries. Capabilities and limitations of the 2-dimensional phase contrast technique]. / Angiografia a risonanza magnetica da 0.5 Tesla delle arterie renali. Possibilità e limiti della tecnica contrasto di fase bidimensionale.

To investigate the potentials and limitations of Magnetic Resonance Angiography (MRA) of the renal arteries at mid-field strength, 16 patients with arterial hypertension of suspected renovascular origin were submitted to MRA at 0.5 T with the two-dimensional (2D) phase-contrast technique and to arteriography. MRA yielded diagnostic images in 15 (94%) patients in whom MRA and arteriography identified 38 and 39 renal arteries, respectively. MRA sensitivity and specificity to steno-occlusive alterations of the renal arteries demonstrated by arteriography were 83% and 96%, respectively. These results, although obtained in a small group of patients, indicate that MRA of the renal arteries with a mid-field MR system and the 2D phase-contrast technique can allow the diagnosis of steno-occlusive alterations of the renal arteries. Main MRA limitations were its long acquisition time and some variability in the quality of the MRA images. Nevertheless, the ongoing rapid technical developments in the hardware of MR systems leave room for improving the accuracy of mid-field MRA of the renal arteries and justifies optimism as to its role in the screening of renovascular hypertension.