Renal Magnetic Resonance Angiography Research Articles

The utility of magnetic resonance angiography in children with nutcracker syndrome

Background/aim The presented study aimed to evaluate the utility of magnetic resonance angiography (MRA) in the pediatric population with nutcracker syndrome.Materials and methods Patients with suggestive clinical symptoms and laboratory findings and got the diagnosis of nutcracker syndrome with Doppler ultrasonography between January 2011–2019 were included in the study. In addition, children who had renal MRA due to hypertension were evaluated as the control group. MRA images of all patients were examined retrospectively by three radiologists at different levels of experience, and the superior mesenteric artery angle, aorta-mesenteric distance, left renal vein diameter both in the regions of aorta-mesenteric, and renal hilum were recorded. ResultsForty-five patients diagnosed with nutcracker syndrome were included in the study. The mean age of patients was 12 (4–16) and 30 (67%) were female. As the control group, 25 patients with hypertension who had MRA were included and they had a mean age of 12 (1–18) and 19 (76%) were male. The mean superior mesenteric artery angle was 26.5 ° (16–73 ± 12) in the patient group and 57.8 ° (25–139, ± 33) in the control group (p < 0.001); the mean aorta-mesenteric distance was 3.3 mm (1.7–6.5, ± 1.1) in the patient group and 8 mm (3.4–32, ± 5.9) in the control group (p < 0.001). MRA measurements of three radiologists were consistent with each other.ConclusionMRA imaging can be applied as an alternative diagnostic method for Doppler ultrasonography and multidetector CT examinations by radiologists with different experience levels in pediatric patients with nutcracker syndrome.

Comparison of contrast-enhanced magnetic resonance angiography and digital subtraction angiography in the evaluation of renal artery stenosis and detecting of accessory and polar arteries

Objectives: Renal artery stenosis (RAS) is the most common cause of secondary hypertension. RAS may cause renal insufficiency, uncontrolled hypertension and is associated with increased cardiovascular morbidity and mortality. We aimed to evaluate the accuracy of contrast enhanced Flash 3D Renal Magnetic Resonance Angiography (MRA) in the depiction of the RAS also detecting of accessory and polar renal arteries with intraarterial digital subtraction angiography (DSA) still serving as the reference standard. Methods: In this retrospective case-control study, we reviewed contrast enhanced Flash 3D Renal MRA and DSA of 71 patients who were suspected of having RAS and underwent DSA after MRA within 15 days. DSA was accepted as gold standart and the specificity, sensitivity and accuracy of MRA were determined. Results: Overall sensitivity and specificity values of contrast enhanced Flash 3D Renal MRA in detecting stenosis were 96.1% and 76.3% respectively. Conclusions: Contrast enhanced Flash 3D Renal MRA is a reliable noninvasive imaging modality in the diagnosis of RAS.

Birt-Hogg-Dub\xe9 syndrome with simultaneous hyperplastic polyposis of the gastrointestinal tract: case report and review of the literature

BackgroundBirt-Hogg-Dubé syndrome (BHDS) is a rare autosomal dominant genodermatosis characterized by benign growth of the hair follicles, the presence of pulmonary cysts, spontaneous pneumothorax, and bilateral renal tumors that are usually hybrid oncocytic or multifocal chromophobe renal cell carcinoma. The diagnosis is confirmed by the presence of a pathogenic variant in the tumor suppressor folliculin (FLCN) gene mapped at 17p11.2. Although the dermatological lesions typical of BHDS are benign and only cause aesthetic concerns, and the pulmonary manifestations are controllable, the greater tendency of patients with this syndrome to present benign or malignant renal tumors, often bilateral and multifocal, makes the diagnosis of this syndrome important for the prognosis of the patients. The objective was to report the case of a patient with BHDS, without pulmonary manifestations and with hyperplastic polyposis of the gastrointestinal tract, and to perform a literature review.Case presentationA 60-year-old man complained of abdominal pain and diarrhoea for 2 months. Physical examination was normal except for the presence of normochromic papules in the frontal region of the face associated with hyperkeratotic and hyperchromic papules in the dorsal region. The excisional biopsies of the skin lesions indicated trichodiscomas. Esophagogastroduodenoscopy, enteroscopy, and colonoscopy showed the presence of hyperplastic polyps in the stomach, duodenum, jejunum, colon, and rectum. Computed tomography (CT) and magnetic resonance imaging (MRI) of the abdomen revealed multiple expansive solid lesions in both kidneys, with necrotic and calcified areas. Renal magnetic resonance angiography also showed a solid lesion in the right kidney measuring 5 cm in diameter and another solid lesion in the left kidney measuring 8 cm in diameter, both suggestive of renal angiomyolipoma. CT scans of the skull, chest, and temporal bones were normal. The genetic study revealed the presence of a variant of FLCN in the intron 13.ConclusionsTo the best of our knowledge, this is the first reported case of BHDS with the simultaneous finding of gastrointestinal hyperplastic polyposis, which may represent a possible phenotypic expression of this syndrome that has not yet been described.

Comparison of axial and coronal acquisitions by non-contrast-enhanced renal 3D MR angiography using flow-in time-spatial labeling inversion pulse

ObjectiveWe evaluated image quality differences between axial and coronal non-contrast-enhanced renal three-dimensional (3D) magnetic resonance angiography (MRA) acquisitions, using time-spatial labeling inversion pulse (Time-SLIP) with flow-in balanced steady-state free precession (bSSFP).Materials and methodsAxial and coronal images were acquired in 128 subjects using non-contrast-enhanced 3D-MRA with Time-SLIP flow-in bSSFP on a clinical 1.5-T MRI system. Visualization of source and maximum intensity projection (MIP) images of renal arteries were compared between the axial and coronal acquisitions using a four-point scale. For quantitative analysis, vessel-to-background contrast ratios of aorta and renal arteries were calculated.ResultsBoth acquisitions yielded similarly excellent quality. In source image evaluation, coronal acquisitions showed significantly more motion degradation (p < 0.01) than did axial acquisitions. In MIP image evaluation, coronal acquisitions yielded superior image quality, less motion degradation, and better visualization of the number of renal branches than did axial acquisition. The renal artery to background signal contrast was greater in coronal than in axial acquisitions (p < 0.01).ConclusionCoronal acquisition provides superior contrast between the renal arteries and background and allows more persistent visualization than axial acquisitions in non-contrast-enhanced MRA using flow-in bSSFP with Time-SLIP. First-line screening of renal non-contrast-enhanced MRA should involve coronal acquisition.

Unenhanced renal magnetic resonance angiography in patients with chronic kidney disease & suspected renovascular hypertension: Can it affect patient management?

Background & objectives:Renal artery stenosis (RAS) is an important cause of severe hypertension in patients with chronic kidney disease (CKD). It is important to detect RAS early as it can reverse hypertension and stop rapid deterioration of renal function. The potential drawbacks of various imaging modalities used to detect RAS including contrast-related adverse effects associated with diagnostic angiography have led to increasing interest in unenhanced magnetic resonance (MR) renal angiography. The aim of this study was to detect and grade RAS in patients with CKD and suspected renovascular hypertension using unenhanced MR angiography (UMRA) and to identify patients with significant RAS (>70%) who would subsequently require further investigation and revascularization.Methods:Thirty five CKD patients with suspected RAS were subjected to UMRA using non-contrast MR angiography of ArTery and VEins 3D True fast imaging with steady state precession technique over a three year period. Patients with RAS >70 per cent on UMRA were subjected to digital subtraction angiography (DSA) with intervention if indicated.Results:In all, 76 renal arteries were evaluated using UMRA in 35 patients, of which 18 arteries showed stenosis and 11 were haemodynamically significant (eight patients). Seven patients (10 renal arteries) underwent DSA.Interpretation & conclusions:An association between UMRA and DSA findings was obtained in six patients (nine renal arteries), and these patients were stented. Post-procedure follow up showed good improvement in blood pressure and renal function. UMRA was found to be a useful non-invasive imaging modality to detect RAS in CKD patients. It can identify patients who require further invasive angiography and revascularization.

Contrast enhanced renal MR angiography at 7 Tesla: How much gadolinium do we need?

ObjectivesTo investigate whether a dose reduction of Gadobutrol for renal magnetic resonance angiography (MRA) at 7 Tesla (T) is feasible while preserving diagnostic image quality. MethodsTen healthy volunteers were enrolled for a renal MRA on a 7T scanner. Fast low angle shot (FLASH) MRA data sets were obtained utilizing three different doses of Gadobutrol (0.1, 0.05 and 0.025mmol/kg body weight [BW]). Contrast ratios (CR) were measured in the aorta as well as in the intra- and extraparenchymal arteries compared to the psoas muscle. Qualitative analysis regarding the delineation of vessel structures was performed using a four-point-scale. ResultsAll doses of Gadobutrol allowed for a good delineation of the aorta and renal arteries. For the extra- and intraparenchymal segmental arteries higher values were observed for full and half dose in comparison to quarter dose. No significant difference was observed for full and half dose. A lower CR was observed for quarter compared to half dose (p<0.05) for the renal arteries. ConclusionsWhile best results were observed for half and full dose, a dose reduction to 0.025mmol/kg BW is justifiable, maintaining a diagnostic image quality. This may be of high interest considering patients with renal impairment.

7T renal MRI: challenges and promises.

The progression to 7 Tesla (7 T) magnetic resonance imaging (MRI) yields promises of substantial increase in signal-to-noise (SNR) ratio. This increase can be traded off to increase image spatial resolution or to decrease acquisition time. However, renal 7 T MRI remains challenging due to inhomogeneity of the radiofrequency field and due to specific absorption rate (SAR) constraints. A number of studies has been published in the field of renal 7 T imaging. While the focus initially was on anatomic imaging and renal MR angiography, later studies have explored renal functional imaging. Although anatomic imaging remains somewhat limited by inhomogeneous excitation and SAR constraints, functional imaging results are promising. The increased SNR at 7 T has been particularly advantageous for blood oxygen level-dependent and arterial spin labelling MRI, as well as sodium MR imaging, thanks to changes in field-strength-dependent magnetic properties. Here, we provide an overview of the currently available literature on renal 7 T MRI. In addition, we provide a brief overview of challenges and opportunities in renal 7 T MR imaging.

Optimization of non-contrast-enhanced MR angiography of the renal artery with three-dimensional balanced steady-state free-precession and time-spatial labeling inversion pulse (time-SLIP) at 3T MRI, in relation to age and blood velocity.

To determine the optimal inversion time (TI) value of three-dimensional (3D) balanced steady-state free-precession time-spatial labeling inversion pulse (time-SLIP) technique for visualization of the renal artery at 3T MRI, and to assess whether the optimal TI is affected by the subject's age and blood velocity. Forty-two healthy volunteers (range 20-67 years) were enrolled in the study and subjected to non-contrast-enhanced renal MR angiography. Five different TI values (1200, 1400, 1600, 1800, and 2000 ms) were selected for evaluation. For quantitative evaluation, the relative signal intensity (SI) of the main renal artery was compared with that of the renal medulla (Vessel-to-Kidney ratio; VKR). Blood velocity of the abdominal aorta was measured using 2D phase contrast technique. For qualitative evaluation, two radiologists scored the depiction of the renal pelvis and the quality of visualization of the renal artery. VKR is the highest at TI = 1600 ms. A strong negative correlation between age and blood velocity was demonstrated. Regarding the qualitative evaluation, the overall image scores of renal arteries were the highest at a TI = 1800 ms for both readers. The optimal TI values in subjects below 50 years of age were 1600 and 1800 ms, whereas in subjects above 50 years of age, the optimal TI value was 1800 ms. The optimal TI value for the visualization of renal arteries using time-SLIP technique at 3T MRI was 1800 ms. Subjects' age affected optimal TI and this is likely due to differences in the blood velocity of the abdominal aorta.

Systemic vasculitis in a child mimicking mercury poisoning

Results A 12 year-old girl was admitted to our hospital with complaints of weakness, weight loss (10 kg in the last month), excessive sweating, and abdominal and joint pains. Her complaints started 6 weeks prior to admittance when she began to suffer from intermittent fever, acrodynia and back and abdominal pain. Also she was found to have red painful hands, a blood pressure 170/120 mm Hg, and tachycardia. In laboratory examinations, acute phase reactants were very high while viral markers, ANA and ANCA were negative. Renal doppler ultrasound and MR angiography were normal. We found sensorial neuropathy in her legs. Her blood pressure was controlled with 2 different antihypertensive medicines. The patient’s symptoms were not controlled with steroid treatment, we continued our research. A blood mercury concentration of 12.4 Mcg/L (ref value 0,3 mcg/L )and spot urine mercury concentration of 18.8 Mcg/L (ref value 0.15 Mcg/L) were discovered. The girl was treated with metalcaptase 25 mg/kg three times daily for 5 days, then every 12 hours for another 2 weeks (total duration, 19 days).

Nonenhanced renal MR angiography using steady-state free precession (SSFP) and time-spatial labeling inversion pulse (Time-SLIP): repeatability and comparison of different tagging location

To prospectively determine the repeatability of noncontrast-enhanced renal arterial angiography with steady-state free precession (SSFP) and time-spatial labeling inversion pulse (Time-SLIP), and to compare the visibility of renal artery and its branches when different locations of tagging pulse were placed. Thirty-six young healthy volunteers were enrolled in this study and were twice examined by noncontrast-enhanced renal arterial angiography with SSFP and Time-SLIP in 1.5T MR scanner. Measurement error and repeatability were assessed for each of the five major parameters [vessel-to-kidney ratio (VKR), grade of renal arterial branching, grading of image quality, diameter and area of the main renal artery] using the Bland-Altman plot. Two independent observers recorded the values of the parameters; Inter- and intra-observer agreement was assessed using the intraclass correlation coefficients (ICCs). The same parameters, acquired at the tagging pulse placed just above the superior poles of both kidneys or closer to the main renal arteries, were compared using the Wilcoxon signed-rank test. Grading of arterial branching by the Time-SLIP SSFP was satisfactorily reproducible with the mean score of greater 3.83 indicating the visibility of branches within the renal parenchyma. The image quality was excellent for Segment I (the main trunk of renal artery) and good for Segment II (segmental branches pre renal parenchyma) and III (vessels within the renal parenchyma) with a satisfying repeatability between two examinations and a good inter- and intra-observer agreement. The ICCs for the inter- and intra-observer measurements of both diameter and area of the main arteries ranged from 0.781 to 0.934, indicating very good agreement. The repeatability of VKR was poor between the two examinations and at the two different tagging pulse locations. The position of tagging pulse in the origination of the main renal arteries was better than in the superior poles of kidneys as it provided a better visualization of arterial branches. Noncontrast-enhanced renal artery angiography with SSFP and Time-SLIP yields reliable and reproducible visualization of normal renal arteries. Localization of the tagging pulse closer to the main renal arteries provides better visibility of renal artery and its branches than the tag placement just above the superior poles of both kidneys.

Adaptive online self‐gating (ADIOS) for free‐breathing noncontrast renal MR angiography

To develop a respiratory self-gating method, adaptive online self-gating (ADIOS), for noncontrast MR angiography (NC MRA) of renal arteries to overcome some limitations of current free-breathing methods. A NC MRA pulse sequence for online respiratory self-gating was developed based on three-dimensional balanced steady-state free precession (bSSFP) and slab-selective inversion-recovery. Motion information was derived directly from the slab being imaged for online gating. Scan efficiency was maintained by an automatic adaptive online algorithm. Qualitative and quantitative assessments of image quality were performed and results were compared with conventional diaphragm navigator (NAV). NC MRA imaging was successfully completed in all subjects (n = 15). Similarly good image quality was observed in the proximal-middle renal arteries with ADIOS compared with NAV. Superior image quality was observed in the middle-distal renal arteries in the right kidneys with no NAV-induced artifacts. Maximal visible artery length was significantly longer with ADIOS versus NAV in the right kidneys. NAV setup was completely eliminated and scan time was significantly shorter with ADIOS on average compared with NAV. The proposed ADIOS technique for noncontrast MRA provides high-quality visualization of renal arteries with no diaphragm navigator-induced artifacts, simplified setup, and shorter scan time.

Three‐dimensional through‐time radial GRAPPA for renal MR angiography

PurposeTo achieve high temporal and spatial resolution for contrast‐enhanced time‐resolved MR angiography exams (trMRAs), fast imaging techniques such as non‐Cartesian parallel imaging must be used. In this study, the three‐dimensional (3D) through‐time radial generalized autocalibrating partially parallel acquisition (GRAPPA) method is used to reconstruct highly accelerated stack‐of‐stars data for time‐resolved renal MRAs.Materials and MethodsThrough‐time radial GRAPPA has been recently introduced as a method for non‐Cartesian GRAPPA weight calibration, and a similar concept can also be used in 3D acquisitions. By combining different sources of calibration information, acquisition time can be reduced. Here, different GRAPPA weight calibration schemes are explored in simulation, and the results are applied to reconstruct undersampled stack‐of‐stars data.ResultsSimulations demonstrate that an accurate and efficient approach to 3D calibration is to combine a small number of central partitions with as many temporal repetitions as exam time permits. These findings were used to reconstruct renal trMRA data with an in‐plane acceleration factor as high as 12.6 with respect to the Nyquist sampling criterion, where the lowest root mean squared error value of 16.4% was achieved when using a calibration scheme with 8 partitions, 16 repetitions, and a 4 projection × 8 read point segment size.Conclusion3D through‐time radial GRAPPA can be used to successfully reconstruct highly accelerated non‐Cartesian data. By using in‐plane radial undersampling, a trMRA can be acquired with a temporal footprint less than 4s/frame with a spatial resolution of approximately 1.5 mm × 1.5 mm × 3 mm. J. Magn. Reson. Imaging 2014;40:864–874. © 2014 Wiley Periodicals, Inc.

Renal Transplant Imaging Using Magnetic Resonance Angiography With a Nonnephrotoxic Contrast Agent

In renal allograft recipients presenting with graft dysfunction, it is critical to determine the patency of the transplant vasculature to guide clinical management. Conventional modalities such as Doppler ultrasound, contrast-enhanced computed tomography, magnetic resonance angiography (MRA), and noncontrast MRA are each of limited use because of technical factors and toxicity of standard contrast agents. The purpose of this study was to retrospectively review our institutional experience with renal transplant MRA using ferumoxytol (a nonnephrotoxic medication) as a contrast agent and evaluate its use in the assessment of allograft vascular patency in patients with graft dysfunction, either delayed or slow graft function within hours to days after kidney transplantation or acute kidney injury weeks to months after kidney transplantation. Sixteen kidney transplant recipients were retrospectively identified who underwent ferumoxytol-enhanced MRA after a nondiagnostic ultrasound for kidney dysfunction after transplantation. Image evaluation was performed by two radiologists, and clinical follow-up data were collected. In 1 of 16 subjects, MRA with ferumoxytol demonstrated complete arterial occlusion of an allograft. In 2 of 16 subjects, MRA detected moderate to severe anastomotic stenoses, which were confirmed at catheter angiography and successfully treated, resulting in the improvement of graft function. In 13 of 16 subjects, MRA demonstrated normal graft vasculature, and an alternative cause of allograft dysfunction was ultimately confirmed. Our study suggests that ferumoxytol-enhanced MRA may be a novel, safe method to accurately detect graft artery abnormalities in renal transplant recipients without the risk of nephrotoxicity, when transplant ultrasound is nondiagnostic.

First-pass contrast-enhanced renal MRA at 7 Tesla: initial results

The aim of this study was to assess the feasibility of first-pass contrast-enhanced renal MR angiography (MRA) at 7 T. In vivo first-pass contrast-enhanced high-field examinations were obtained in eight healthy subjects on a 7-T whole-body MRI. A custom-built body transmit/receive radiofrequency (RF) coil and RF system suitable for RF shimming were used for image acquisition. For dynamic imaging, gadobutrol was injected intravenously and coronal unenhanced, arterial and venous data sets using a T1-weighted spoiled gradient-echo sequence were obtained. Qualitative image analysis and assessment of artefact impairment were performed by two senior radiologists using a five-point scale (5 = excellent, 1 = non-diagnostic). SNR and CNR of the perirenal abdominal aorta and both main renal arteries were assessed. Qualitative image evaluation revealed overall high-quality delineation of all assessed segments of the unenhanced arterial vasculature (meanunenhanced 4.13). Nevertheless, the application of contrast agent revealed an improvement in vessel delineation of all the vessel segments assessed, confirmed by qualitative (meanunenhanced 4.13 to meancontrast-enhanced 4.85) and quantitative analysis (SNR meanunenhanced 64.3 to meancontrast-enhanced 98.4). This study demonstrates the feasibility and current constraints of ultra-high-field contrast-enhanced renal MRA relative to unenhanced MRA.

Non-contrast-enhanced renal and abdominal MR angiography using velocity-selective inversion preparation.

Non-contrast-enhanced MR angiography is a promising alternative to the established contrast-enhanced approach as it reduces patient discomfort and examination costs and avoids the risk of nephrogenic systemic fibrosis. Inflow-sensitive slab-selective inversion recovery imaging has been used with great promise, particularly for abdominal applications, but has limited craniocaudal coverage due to inflow time constraints. In this work, a new non-contrast-enhanced MR angiography method using velocity-selective inversion preparation is developed and applied to renal and abdominal angiography. Based on the excitation k-space formalism and Shinnar-Le-Roux transform, a velocity-selective excitation pulse is designed that inverts stationary tissues and venous blood while preserving inferiorly flowing arterial blood. As the magnetization of the arterial blood in the abdominal aorta and iliac arteries is well preserved during the magnetization preparation, artery visualization over a large abdominal field of view is achievable with an inversion delay time that is chosen for optimal background suppression. Healthy volunteer tests demonstrate that the proposed method significantly increases the extent of visible arteries compared with the slab-selective approach, covering renal arteries through iliac arteries over a craniocaudal field of view of 340 mm.

Combined renal MRA and perfusion with a single dose of contrast

Both anatomical and functional scans are often performed when diagnosing renovascular diseases, which in many cases require two separate contrast injections. With nephrogenic systemic fibrosis being associated with gadolinium, minimizing contrast injection dosage is desirable. In this study, a technique which performs time-resolved renal magnetic resonance angiography (MRA) and perfusion with a single scan and single dose of contrast has been evaluated in six healthy volunteers. A previously developed three-dimensional MRA technique called Contrast-enhanced Angiography with Multi-Echo and Radial k-space (CAMERA) has been used to acquire images, and perfusion analysis was performed using deconvolution methods. Time-resolved MRA, as well as renal blood flow, renal volume of distribution and mean transit time maps, were acquired.

Multiple renal arteries and non-contrast magnetic resonance angiography in transplant renal artery stenosis.

The reported incidence of transplant renal artery stenosis (TRAS), as high as 23% in earlier decades [1], ranges between 1.2 and 3.9% in more recent reports [2–5]. TRAS is a frequent cause of refractory hypertension and allograft dysfunction [5], but it is often treatable with percutaneous angioplasty. Therefore, its early recognition is critical. We describe the incidence of TRAS in our center over a 10-year period and report a case of TRAS to illustrate the complexity of the diagnosis in patients with slowly recovering graft function, multiple renal arteries and high immunologic risk for rejection. We highlight the utility of a novel non-contrast renal magnetic resonance angiography.

Dynamically applied B1+ shimming solutions for non‐contrast enhanced renal angiography at 7.0 tesla

The purpose of this study was to detail a strategy for performing non-contrast enhanced renal magnetic resonance angiography studies at 7.0 T. It is demonstrated that with proper B1+ management, these studies can be successfully performed at ultrahigh field within local specific absorption rate constraints. An inversion prepared gradient echo acquisition, standard for non-contrast renal magnetic resonance angiography studies, required radiofrequency pulse specific B 1+ shimming solutions to be dynamically applied to address the field dependent increases in both B(0) and B1+ inhomogeneity as well as to accommodate limitation in available power. By using more efficient B1+ shimming solutions for the inversion preparation and more homogeneous solutions for the excitation, high quality images of the renal arteries were obtained without venous and background signal artifacts while working within hardware and safety constraints. Finite difference time domain simulations confirmed in vivo measurements with respect to B1+ distributions and homogeneity for the range of shimming strategies used and allowed the calculation of peak local specific absorption rate values normalized by input power and B1+. Increasing B1+ homogeneity was accompanied by decreasing local specific absorption rate per Watt and increasing maximum local specific absorption rate per [B1+](2), which must be considered, along with body size and respiratory rate, when finalizing acquisition parameters for a given individual.

Comparative study of kidney affection in SLE patients with and without antiphospholipid syndrome

Aim of the workTo evaluate the incidence, clinical associations and outcome of APS nephropathy in SLE patients with 2ry APS. Patients and methodsWe studied 64 female SLE patients with nephritis; 32 of them had 2ry APS (group 1) and the rest without 2ry APS (group 2). Demographic, clinical and serological data were prospectively evaluated. Systemic lupus erythematosus disease activity index (SLEDAI) and Systemic Lupus International Collaboration Clinics/ACR damage index (SLICC) were assessed. Renal duplex, renal 99mTc-dimercaptosuccinic) scan (DMSA scan) and renal magnetic resonance angiography (MRA) were all used to detect renal vascular affection. ResultsThere were statistically significant differences between the two examined groups regarding damage index (p=0.000), hypertension (p=0.02), thrombocytopenia (p=0.000), ↓LDL (p=0.008), ↓C3 (p=0.01) and TMA (p=0.04). In group 1: MR angiography detected 7 patients with RAS: 5 patients with renal artery thrombosis that showed a significant association with TMA and proteinuria (p=0.002, p=0.004: p<0.001, p=0.02, respectively). Patients with RAS had ↑DBP, ↑s.creatinine and ↑TGs (p=0.004, p=0.005 and p=0.0003, respectively). Renal DMSA detected 6 patients with cortical scar which showed a significant association with TMA, proteinuria, livedoreticularis and arthritis (p=0.001, p=0.01, p=0.04 and p=0.03, respectively) those patients had ↑DBP and ↑RI (p=0.000 and p=0.006, respectively). ConclusionaPL testing should become a routine investigation in patients evaluated for RAS or renal infarctions especially with hypertension and unexplainable deteriorating renal function. To confirm our results we propose that larger scale, multicentre studies with longer evaluation periods.

Non-Contrast Renal MR Angiography: Value of Subtraction of Tagging and Non-Tagging Technique

The aim of this study was to examine the usefulness of the subtraction technique of non-contrast renal magnetic resonance angiography (MRA) between tagged and non-tagged data collection. We performed renal MRA on eleven healthy volunteers using a 3T MRI unit. For renal MRA, a three dimensional balanced type steady-state free precession (SSFP) sequence (True FISP, Siemens) was used with diaphragmatic navigator gating. We tried to acquire selective arterial images by subtracting black-blood images (tagged images, on which arterial longitudinal magnetization was nearly zero by selective inversion of upper-stream aortic flow) from bright-blood images (non-tagged images, on which arterial flow is bright due to inflow effect). For analysis, two radiologists independently evaluated the visual quality of the axial and coronal targeted maximum intensity projection images (MIP) of original bright-blood MRA and subtraction MRA. Visualization of the main stem of the renal arteries and their 1st branches were satisfactory on both techniques, and there was no statistically significant difference. The score of 2nd branch appeared superior with the subtraction method, but only the right side showed a statistically significant difference (P <0.01). Visualization of small intraparenchymal arteries was significantly superior with subtraction method on both sides. We tried to improve selective demonstration of renal arterial branches using subtraction technique. Although full sequence optimization was not performed, this pilot study showed this technique to be slightly time-consuming but superior in visualization of peripheral branches and possibly more sensitive in detecting small vessel abnormalities.