MR imaging of Schmorl's nodes: Imaging characteristics and epidemio-clinical relationships.

PURPOSE: The purpose of our prospective study was to assess the presentation of Schmorl's nodes (SN) on magnetic resonance imaging (MRI) and investigate their possible association with demographic and clinical findings. MATERIALS AND METHODS: Three hundred and thirty-three patients were prospectively included. Thirteen (3.9%) patients were excluded because of contraindication to MRI and/or Scheuermann's disease. The final study population included 320 patients. T1-weighted and short TI inversion recovery sequences were performed to assess SN prevalence, the vertebral level and their anatomical distribution in vertebra. Medical history was recorded focusing on previous diseases including degenerative, rheumatoid and neoplastic disease, and any existing spinal traumatism. Epidemiological information was also obtained, including age, gender, ethnicity, professional and sporting activity. RESULTS: The final study population included 320 patients (172 men, 148 women) with a mean age of 54 years±17.5 (SD) (range: 19-87 years). A total of 421 SN were found in 158/320 patients (49.4%). SN were localized in thoracic spine for 48%, in lumbar spine for 46% and cervical spine for 6%. The middle part of the thoracic vertebra was the most affected area (80%), mostly in the middle superior endplate (41%). SN were more frequently observed in manual workers who worked more than 10 years (P<0.0001) and less frequently in patients of the 30-39-year-old age group (P=0.0048). No significant associations were found with gender (P=0.17) and remarkable medical history (P=0.21). SN were less frequently observed in patients with sport activities of 1-5hours/week (P=0.04) and those with an African origin (P<0.0001). CONCLUSION: Our study suggests a potential role for ethnical and physical factors in the pathogenesis of SN. Furthers studies are mandatory to evaluate their clinical relevance, especially in patients such as Caucasian manual workers in whom SN have a high prevalence.

Evaluation of visual recognition memory for the early diagnosis of Alzheimer's disease in patients over 75 years.

INTRODUCTION: Current diagnostic criteria of Alzheimer Disease (AD) are mainly based on clinical definition. In France, the Delayed Matching Sample (DMS48) test, a recently introduced test that explores visual object recognition, is recommended for the early diagnosis of AD. However, little is known on the DMS48 performances of older subjects over 75 years. Therefore, our aim was to assess its specific clinical value for early detection of AD in older patients. METHOD: We studied 93 consecutive patients over 75 years from an expert memory clinic in a geriatric hospital. This population included 31 patients with single domain amnestic Mild Cognitive Impairment (aMCI), 31 AD patients and 31 controls subjects. RESULTS AND DISCUSSION: The aMCI and AD performances on the DMS48 were significantly lower than those of the control subjects (set 1 and set 2, P<10(-7)). The DMS48 performances in the healthy group appeared closely related to the previously published normative data. However, the DMS48 performances appeared unexpectedly high in these older patients, especially in the AD subgroup (set 1, 82.2±12.1 and set 2, 75.2±16.2). Moreover, there was an unexpected frequent discordance between the results on the DMS48 and the Free and Cued Selective Reminding tests (FCSR). The DMS test appears useful for highlighting the heterogeneity of the syndromes of aMCI and AD in old-old people aged 75+: our results also underline the need for further characterization of cognitive impairment in this fastest growing subgroup of patients.

Leukoaraiosis and pulse-wave encephalopathy: observations with phase-contrast MRI in mild cognitive impairment.

PURPOSE: To test the pathogenic hypothesis of a breakdown in the vital buffering of the arterial pulsations behind leukoaraiosis (LA) in mild cognitive impairment (MCI). METHODS: Seventy-one elderly patients with MCI underwent a combined structural and dynamic MR examination (3D T1-weighted and fast-FLAIR T2-weighted sequences, phase contrast sequences). Arterial indices of pulsatility (IP) and composite indicators of the amplitude transfer function between cerebrospinal fluid and cerebral venous flow (Icsf/veins) were used to assess the large artery stiffness and the intracranial compliance respectively. Cerebral total arterial blood flow (tCBF), superficial and deep venous flow rates were also measured. Intracranial dynamic parameters and potential confounders including age, gender and vascular risk factors were compared between two groups respectively with and without significant LA. RESULTS: The only dynamic changes on multivariate analyse were an IP increase, a lowering of deep venous outflow and Icsf/veins in patients with LA. There was a significant interaction between IP and Icsf/veins in the logistic regression: as compared with patients with low IP (suggestive of high large artery compliance) and high Icsf/veins (suggestive of high intracranial compliance), the adjusted odds ratios for the presence of LA were 9 (95% CI 1-64, P=0.02) in cases of both high IP and Icsf/veins, 10 (95% CI 1-64, P=0.02) in cases of both high IP and low Icsf/veins and 19 (95% CI 3-127, P=0.002) in cases of both low IP and Icsf/veins. CONCLUSION: LA may reflect an arteriosclerotic and/or resistive pulse wave encephalopathy in MCI.

Alzheimer's disease in late-life dementia: a minor toxic consequence of devastating cerebrovascular dysfunction.

Alzheimer's disease (AD) is thought to be the most common cause of late-life dementia. But pure AD is infrequent whereas AD pathology is often insufficient to explain dementia in the elderly. Conversely, cerebrovascular disease is omnipresent and the crucial role of microvascular alterations increasingly recognized in late dementia or "Alzheimer syndrome". Pathomechanisms of vascular cognitive impairment are still debated but recent data indicate that the initial concept of chronic low grade cerebral hypoxia should not have been abandoned. Thus, it is proposed that windkessel dysfunction is the missing link between vascular and craniospinal senescence on the one hand, and chronic low grade cerebral hypoxia, "senile brain degeneration" and "Alzheimer syndrome" on the other hand. An age-related decrease in the buffering capacity of both the vessels and the craniospinal cavity favours cerebral hypoxia; due to increased capillary pulsatility with disturbances in capillary exchanges or due to a marked reduction in craniospinal compliance with a mechanical reduction in cerebral arterial inflow. "Invisible" windkessel dysfunction, most often related to "hardening of the arteries" may be the most frequent pathomechanism of late-onset dementia whereas associated mild or moderate AD may be merely a toxic manifestation of a primarily hypoxic disease. Structural patterns of arteriosclerotic dementia fit well with an underlying arterial windkessel dysfunction: with secondary mechanical damage to the cerebral small vessels and the brain and predominantly deep hypoxia. The clinical significance of leukoaraïosis, small foci of necrosis, ventricular dilatation, hippocampal and cortical atrophy is in good agreement with their value as indirect markers of windkessel dysfunction. An age-related "invisible" reduction in craniospinal compliance may also contribute to the associations between heart failure, arterial hypotension and cognitive impairment in the elderly and to the high percentage of dementia of unknown origin in the very old. Both neuropathological and clinical overlap between AD and windkessel dysfunction can explain that cerebrovascular dysfunction remains misdiagnosed for AD in the elderly. Evidence of the key role of cerebrovascular dysfunction should markedly facilitate and widen therapeutic research in late-life dementia. Routine MRI including direct assessment of intracranial dynamics should be increasingly used to define etiological subtypes of the "Alzheimer syndrome" and develop a well-targeted therapeutic strategy.

MRI of the 'Alzheimer syndrome'.

Interest in the identification of cognitive decline in its earliest manifestations and the heterogeneity of clinically diagnosed Alzheimer's disease (AD) explain the growing number of neuroimaging studies of AD. Alzheimer-type lesions are associated with loss of neurons, and magnetic resonance imaging (MRI) can detect predominantly left atrophic changes in the entorhinal cortex, amygdala and anterior hippocampus several years before the onset of clinical symptoms. Cerebrovascular disease can mimic AD in the elderly whereas MR markers of subcortical vascular disease-leukoaraiosis, lacunar infarcts, microbleeds, ventricular enlargement, cortical and hippocampal atrophy-appear to be structural changes associated with vascular-related cognitive impairment. Furthermore, analysis of prodromal forms of late-onset dementia of Alzheimer's type (DAT) differentiates amnesic single-domain mild cognitive impairment, which shows MR patterns similar to those observed in early-onset DAT, from other predementia patterns without atrophy at the earliest sites of AD pathology. Mesiotemporal atrophy on MRI predicts late-onset DAT, but the current rating scales or measurements of mesiotemporal atrophy do not differentiate anteromesial temporal atrophy that is highly suggestive of AD from predominantly hippocampal atrophy, suggestive of non-AD damage and, usually, vascular disease. The other, most common MRI predictors of late-onset DAT may be considered indirect markers of arterial senescence whereas brain atrophy is diffusely milder and MR markers of small-vessel disease more frequent in late-onset, compared with early-onset, DAT. Thus, MRI suggests an overestimation of AD pathology while underestimating 'arteriosclerotic brain degeneration' in the clinical picture of 'Alzheimer syndrome'.

[Multiple aortic aneurysms in chronic atrophic polychondritis]. / Anévrysmes aortiques multiples au cours d'une polychondrite atrophiante.

BACKGROUND: Although rare, cardiovascular involvement is the second most frequent cause of mortality in chronic relapsing polychondritis behind tracheobronchial tree chondritis. The most frequent cardiovascular complications are valvulopathy and aortic aneurysm. CASE REPORT: We report a case of chronic relapsing polychondritis with multiple aortic aneurysms that were clinically silent but continued to progress despite systemic corticosteroids and immunosuppressive therapy. DISCUSSION: Progression of aortic aneurysms and extravascular disease do not appear to be correlated. Although the disease may appear to be in remission, vascular lesions can continue to progress independently. This case shows that medical treatment has little effect on the progression of these aneurysms. Consequently, it is necessary to opt for surgical therapy at the opportune moment.

[Panniculitis induced by interferon beta-1a vascular toxicity]. / Panniculites secondaires à la toxicité vasculaire de l'interféron béta-1a.

BACKGROUND: Interferon-beta-1b is a valuable first-line therapy for patients with relapsing-remitting multiple sclerosis. Many non-severe cutaneous reactions to recombinant interferon beta are described at injection sites. Panniculitis after subcutaneous injection of beta interferon is a rare adverse event; we describe two such cases at beta interferon injection sites. CASE-REPORTS: Two women aged 22 years and 45 years with severe multiple sclerosis receiving immunotherapy with beta interferon were admitted to an emergency department following the appearance of extremely painful induration at injection sites rendering walking impossible after several months of interferon injections. One of the patients had fever. Histology tests showed vasculitis and capillary thrombosis in one-woman and dermal oedema in the other. MRI scanners showed extensive avascular necrosis of soft tissue without fasciitis in both patients. Interferon withdrawal and surgical debridement was carried out in one case and beta interferon was successfully reintroduced in both cases. DISCUSSION: Only two cases have been reported of panniculitis induced by subcutaneous beta interferon injection. Clinically, such cases may mimic infectious processes. The present cases show that MRI may be useful in diagnosis and that the vascular toxicity of interferon beta probably plays a role in panniculitis. Temporary withdrawal of treatment, rotation of several injection sites and alternative routes of administration may all be proposed.

Changes in effective connectivity during incidental and intentional perception of fearful faces.

The present fMRI study examined effective connectivity within an emotional network composed of three brain areas: Amygdala (AMY), Anterior Cingulate Cortex (AAC) and Orbito-Frontal (OFC) in processing fearful faces. Two tasks: an incidental perception (gender identification) and an intentional detection (effortful discrimination) task were performed by 14 and 10 young healthy volunteers, respectively. Participants were scanned while viewing fearful, neutral and ambiguous facial expressions. Effective connectivity was assessed using Structural Equation Modeling (SEM). Results show that the hypothetical network fits the experimental data for both tasks and in both hemispheres. The comparison between Tasks 1 and 2 reveals significant differences in strength and direction of the connectivity patterns for the left and to a less stringent threshold for the right hemisphere. The path coefficients analysis suggests that the fearful information generated in AMY, reaches the OFC through the ACC in incidental perception, while in intentional perception, the route followed is in a reverse direction from OFC to ACC. Our findings confirm a differential brain connectivity between incidental and intentional processing of fearful faces.

[Imaging of dementia with magnetic resonance]. / Imagerie des démences par résonance magnétique.

The diagnostic approach of dementia has clearly improved with the progress in medical imaging, notably magnetic resonance imaging. The conventional T1 and T2 sequences or morphological imaging have demonstrated their interest in the positive and differential diagnosis of dementia, together with the more precise description of normal ageing of the brain. The ANAES (French medicines agency) proposes systematic brain imaging, notably by magnetic resonance imaging (MRI) in their practical guidelines for the diagnosis of Alzheimer's disease (http://www.anaes.fr). THE INTEREST OF CERTAIN IMAGING TECHNIQUES: The therapeutic progress in treatment of dementia implies that the different affections be recognised as early as possible. With this in mind, the functional MRI is capable of describing the damage in cases when morphological imaging is not sufficiently specific. Recent studies have reported the interest of diffusion and perfusion imaging, activation MRI and proton spectroscopy. FROM A THERAPEUTIC POINT OF VIEW: The combination of morphological and functional approaches will provide a better definition of the groups at risk in order to target current treatments and those to come.

[Dementia: role of imaging]. / Démences: place de l'imagerie.

This article summarizes the role of imaging in the evaluation of cognitive disorders of the elderly. The primary goal of imaging is to exclude potentially reversible dementia due to intracranial lesions such as tumor, subdural hematoma or normal pressure hydrocephalus. The value of neuroimaging in the diagnosis of degenerative disorders is then discussed: Alzheimer's disease, frontotemporal dementias, dementia with Lewy bodies, dementia associated with parkinsonian syndromes, vascular dementias and mild cognitive impairment.

Imaging appearances of metastases from neuroendocrine tumours of the pancreas.

Endocrine tumours of the pancreas (ETPs) are rare neoplasms that are frequently malignant. Despite their usual slow growth, metastases do occur and have a major impact on prognosis. Metastases may be the first manifestation of disease, and recognition of particular radiological features of these hypervascular metastases should suggest their possible neuroendocrine origin. Although somatostatin receptor scintigraphy has changed the imaging strategy for these tumours and has become their principal imaging modality, radiological techniques are still required for precise localization of scintigraphic hot spots and monitoring of response to therapy. This pictorial review shows the typical radiological features of ETP metastases and emphasizes the role of different imaging modalities.

Cerebrospinal fluid dynamics and relation with blood flow: a magnetic resonance study with semiautomated cerebrospinal fluid segmentation.

RATIONALE AND OBJECTIVES: To investigate and measure temporal and amplitude aspects of blood and cerebrospinal fluid (CSF) flow waveform relations. METHODS: A cine phase-contrast magnetic resonance imaging pulse sequence was used to measure blood and CSF flow in 16 healthy subjects aged 27 +/- 4 years. A semiautomated segmentation algorithm was developed to study CSF flow. RESULTS: Standard deviations of the aqueductal and cervical flow measurements carried out by five observers were 1% and 4%, respectively. The peak systolic arterial flow was 1087 +/- 169 mL/min, and the peak cervical CSF flush (173 +/- 59 mL/min) occurred at 5% +/- 3% of the cardiac cycle after the internal carotid systolic peak flow. Peak aqueductal flush flow (13 +/- 5 mL/min) occurred at 21% +/- 7% of the cardiac cycle after the internal carotid systolic peak flow. CONCLUSIONS: The CSF segmentation algorithm is reproducible. Brain expansion was quickly regulated by a major extracerebral CSF flush flow, whereas ventricular CSF made only a very small contribution.

Cerebrospinal fluid flow waveforms: MR analysis in chronic adult hydrocephalus.

UNLABELLED: Henry-Feugeas MC, Idy-Peretti I, Baledent O, et al. Cerebrospinal fluid flow waveforms: MR analysis in chronic adult hydrocephalus. Invest Radiol 2001;36:146-154. RATIONALE AND OBJECTIVES: To analyze changes in cerebrospinal fluid (CSF) hydrodynamics in chronic adult hydrocephalus. METHODS: Phase-contrast cine-MR acquisitions were used to explore the ventricular system and the upper ventral cervical spaces of 16 patients. The aqueductal jet was explored in 32 control subjects. RESULTS: The duration of pulsatile caudal CSF flow (ie, CSF systole) was abnormally short in patients with active idiopathic and obstructive hydrocephalus. The duration of CSF cervical systole was normal in patients with stable hydrocephalus. The aqueductal stroke volume could be increased in stable communicating hydrocephalus. Patients who responded to shunting had shortened CSF systoles and hyperpulsatile ventricular patterns. Successful CSF diversion resulted in longer CSF systoles and CSF ventricular patterns that were no longer hyperpulsatile. CONCLUSIONS: Magnetic resonance analysis of CSF flow can show craniospinal dissociation and limitation of CSF outflow from the ventricles in both obstructive and communicating hydrocephalus; it should help determine the response to shunting in communicating hydrocephalus.

MRI analysis of brain atrophy after severe closed-head injury: relation to clinical status.

The purpose of this study was to determine the clinical correlates of supratentorial ventricular dilations and of corpus callosal atrophy at the subacute stage after a severe closed-head injury (CHI). Thirty-three CHI patients underwent MRI 2 months or more after injury. Morphometric measures were compared to clinical data (coma score, coma duration and Glasgow Outcome Scale). There were numerous significant correlations between clinical data and mid-third ventricle and frontal horns measurements. Fewer significant correlations were found with the lateral ventricle bodies and the corpus callosal body. There was no significant correlation with the posterior part of the corpus callosum and of the ventricles. Corpus callosum atrophy correlated significantly with anterior and deep ventricular dilatation. In conclusion, the best indicator of clinical status was ventriculomegaly, and particularly third ventricle enlargement, which probably reflects the extent of both anterior and deep white matter lesions.

Origin of subarachnoid cerebrospinal fluid pulsations: a phase-contrast MR analysis.

Cerebrospinal fluid (CSF) pulsations result from change of blood volume in the closed craniospinal cavity. We used cine phase contrast MR analysis to determine whether spinal CSF pulsations result from spinal vascular pulsations or intracranial subarachnoid pulsations, whether intracranial CSF pulsations result from intracranial large arteries pulsations or cerebrovascular bed changes. We performed a quantified physiological mapping of CSF velocity waveforms along the craniospinal axis. Thirty-six volunteers participated in the study. MR acquisitions were obtained at the intracranial level, the upper, midcervical, cervicothoracic, mid thoracic, and/or the thoracolumbar levels. The temporal velocity information were plotted as wave form and key temporal parameters were determined and analyzed; intervals from the R wave to the onset of CSF systole, to CSF systolic peak, to the end of systole, as well as duration of systole. Three kinds of dynamic channels could be differentiated along the spinal axis, the lateral, medioventral and mediodorsal channels. Lateral spinal CSF pulse waves show significant craniocaudal propagation. No such significant progression was detected through the medial channels along the spine. Through the medial channels, a cephalic progression was observed from the upper cervical level to the intracranial level. At the craniocervical junction, mediodorsal CSF systole appeared the earliest one whereas in the anterior intracranial basal cistern, CSF systole appeared delayed. In conclusion, spinal CSF pulsations seem to result mainly from intracranial pulsations in the lateral channels, whereas local vascular pulsations could modify CSF pulse wave mainly in the medial channels. At the craniocervical junction, our results suggest that blood volume change in the richly vascularised cerebellar tonsils is the main initiating factor of CSF systole; and that spinal vascular pulsations could be considered as an additional early and variable CSF pump.

Body composition determined with MR in patients with Duchenne muscular dystrophy, spinal muscular atrophy, and normal subjects.

Magnetic resonance imaging was used to determine total fat mass of patients with neuromuscular disorders, accounting for intramuscular fat. Nineteen boys aged 9 to 12 (eight with Duchenne muscular dystrophy, three with type II spinal muscular atrophy and eight control subjects) underwent whole-body magnetic resonance imaging examination and anthropometric measurements. Whole-body fat mass was deduced from automated analysis of images normalized by a reference signal. Intramuscular and subcutaneous fat masses were deduced from manual analysis of twelve reference slices. Affected children significantly differed from control subjects for higher total fat mass, mostly related to intramuscular fat mass. Shorter protocols validated from whole-body data were shown to be more accurate than fat mass estimation derived from anthropometric measurements.

Assessment of deep venous thrombosis in the lower limbs and pelvis: MR venography versus duplex Doppler sonography.

OBJECTIVE: This study was designed to compare the diagnostic value of MR venography and color Doppler sonography in the assessment of deep venous thrombosis. SUBJECTS AND METHODS: MR venograms and color Doppler examinations were obtained in 37 patients either with suspected deep venous thrombosis of the lower limbs or pelvis or with pulmonary embolism. Two-dimensional time-of-flight venography was used for all studies. MR and color Doppler data were collected prospectively and analyzed in a blinded manner. In a subset of 21 patients, MR venography and color Doppler sonography were prospectively compared with contrast-enhanced venography. RESULTS: When compared with contrast-enhanced venography, MR venography was 100% sensitive and 100% specific in the diagnosis of deep venous thrombosis above the knee. Color Doppler imaging depicted 13 of 15 cases of deep venous thrombosis and 5 of 6 venous examinations that had normal results, yielding a sensitivity and a specificity of 87% and 83%, respectively. The differences in sensitivity and specificity between MR venography and color Doppler sonography were not statistically significant. MR venography was 95% sensitive and 99% specific in detecting the extension of deep venous thrombosis, compared with the 46% sensitivity and 100% specificity of color Doppler sonography (differences in sensitivity, p < .01). MR images showed 29 collateral vessels, whereas only 21 were detected by contrast-enhanced venography (p < .04). CONCLUSION: MR venography seems to be more accurate than color Doppler sonography in detecting the extension of deep venous thrombosis. The positive diagnosis and extent of deep venous thrombosis can be easily detected and monitored by a noninvasive technique such as MR venography.

Differentiation between multiple liver hemangiomas and liver metastases of gastrinomas: value of enhanced MRI.

PURPOSE: Hepatic metastases of neuroendocrine tumors are known to mimic hemangiomas on nonenhanced SE MR sequences. The usefulness of MR examination with gadolinium injection to identify lesions was prospectively evaluated. METHOD: Nine patients with multiple liver metastases of gastrinomas were compared with six patients showing multiple liver hemangiomas. Patients underwent unenhanced T2-weighted SE, T1-weighted SE, and FLASH sequences, followed by enhanced sequential FLASH sequences and a 5 min delayed T1-weighted SE sequence. RESULTS: On T2-weighted SE sequence, all hemangiomas displayed the same typical morphology as a sharply defined, homogeneous, high signal intensity lesion, but this pattern was also observed for some or all of the lesions in seven of nine patients with gastrinoma metastases. Dynamic FLASH sequences were accurate for lesions larger than 2 cm, hemangiomas displaying a nodular peripheral enhancement with centripetal filling in, and metastases displaying either an initial homogeneous or a regular peripheral enhancement. Precise assessment of lesions smaller than 2 cm remained equivocal. Delayed T1-weighted. SE sequence (performed at least 5 min after Gd-chelate injection) was the most accurate technique to identify metastases by showing hypo- or isointensity signal, whereas all hemangiomas were hyperintense. CONCLUSION: Postcontrast delayed T1-weighted sequence is the primary technique to differentiate equivocal cases of hemangiomas from metastases of gastrinoma.

[Magnetic resonance angiography of the cervical and superior mediastinal veins]. / Angiographie par résonance magnétique des veines cervicales et du médiastin supérieur.

PURPOSE: To evaluate magnetic resonance venography (MRV) in the detection of cervical/mediastinal venous thrombosis (CMVT). METHODS: MR venograms were performed in 20 patients suspected for CMVT. 2D-TOF MR venography was used for all studies. MR and conventional venographic/surgical data were collected prospectively and analyzed in a blinded manner comparatively to other corroborative studies: venography (n = 8), color-Doppler studies (n = 15), CT (n = 12), and/or surgery (n = 6). RESULTS: MRV was 100% sensitive and 100% specific in the diagnosis of venous thrombosis (VT) of the cervical/mediastinal veins, present in fourteen patients, and 93% accurate in grading the extension of CMVT. MR images showed a greater number of collateral vessels than detected by contrast venography in case of complete cervical/mediastinal venous thrombosis. CONCLUSION: The positive diagnosis and extent of CMVT can be accurately diagnosed by a non-invasive method such as MRV.

Screening of renal artery stenosis: assessment with magnetic resonance angiography at 1.0 T.

The results of MR angiography at 1.0 T with digital intraarterial angiography in the screening of patients with suspected renal hypertension were compared. In this first phase of the study, 10 volunteers underwent examination with both two-dimensional (2D) with traveling saturation time-of-flight (TOF) magnetic resonance angiography (MRA) with various parameters to develop a protocol for evaluation of the renal arteries. In the second phase, 36 patients with suspected renovascular hypertension underwent both 2D TOF MRA and intraarterial digital angiography to evaluate the clinical value of MRA. The degree of stenosis was graded with a two-point scale. In volunteers, using 2D acquisitions C/N ratios indicated the best flip angle as being 55 degrees (p = .02). MRA showed 100% (70/70) of all main arteries and 86% (6/7) of all accessory renal arteries seen on angiography. MRA had a sensitivity of 94% (15/16) and a specificity of 98% (60/61) for detection of stenoses of greater than 50% present in 14 patients. 2D-TOF MRA at 1.0 T shows promise in the noninvasive diagnosis of patients with suspected renovascular hypertension.