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Endothelium plays a key role in maintenance of vascular homeostasis. Cardiovascular risk factors promote development of endothelial dysfunction, characterized by increased vasoconstriction and by procoagulant/pro-inflammatory endothelial activities. In coronary artery, endothelium-dependent dilation improves blood flow, while the occurrence of endothelial dysfunction reduces myocardial perfusion, so new methods have been developed for assessment of endothelial function in coronary and peripheral arteries. The quantitative angiography with intracoronary infusion of acetylcholine remains the "gold standard" to assess the endothelium-dependent vasodilatation. The use of this technique is restricted to patients who have a clinical indication for coronary angiography, so new imaging methods have been considered for noninvasive diagnosis of coronary microvascular disease, such as magnetic resonance imaging phase contrast and positron emission tomography. The advent of new techniques has facilitated testing of endothelial dysfunction in peripheral arteries with non-invasive methods. This review presents available in-vivo and ex-vivo methods for evaluating endothelial function with special focus on more recent ones. The diagnostic tools include local vasodilatation by venous occlusion plethysmography and assessment of flow-mediated dilatation, arterial pulse wave analysis and pulse amplitude tonometry, laser Doppler flowmetry. The possibility to detect endothelial dysfunction as an early marker of atherosclerosis makes these instruments useful for early stratification of patients at risk for cardiovascular events. Aim of this review is to summarize the characteristics of non-invasive assessment of endothelial function in order to optimize cardiovascular risk management.

Bicuspid aortic valve (BAV) is the most common congenital cardiac malformation, affecting 1-2% of the general population. BAV is frequently associated with significant aortic pathology (valve regurgitation, endocarditis, severe aortic stenosis, aortic aneurysm and dissection) accounting for considerable morbidity and mortality. Despite its clinical relevance, the pathogenesis of BAV disease and its complications remain largely unknown. The purpose of this paper is to discuss and summarize our current understanding of BAV in terms of epidemiology, genetics and clinics.

Schizophrenia is a disease with heterogeneous features and often a disabling longitudinal outcome. In order to achieve a better understanding of the disease, a detailed characterization and definition of symptomatology, social functioning and cognitive performance of patients is required. Imaging techniques may allow to identify measurable markers of different subgroups of patients, who share common clinical course and, probably, a similar hereditary pathway. The review offers a description of cross-sectional, predictive and longitudinal studies on the relationship between biological, clinical and psychosocial features of patients with schizophrenia. Patients with a more severe and disabling course of illness present larger ventricles, smaller prefrontal, temporal and occipital cortices and smaller subcortical regions such as basal ganglia, the thalamus and limbic areas. These alterations are predictive of a worse prognosis, as observed in predictive and longitudinal studies, both on chronic and first episode patients. The detection of more homogenous groups of patients with schizophrenia will help neurobiological research progress in this field. Furthermore, patients with similar clinical and biological features could undergo more tailored therapeutic and rehabilitative strategies.

Cerebral aneurysm in autosomal dominant polycystic kidney disease (ADPKD) is an uncommon event (documented in 6-13% of cases) but frequently characterized by severe neurological sequelae and potentially fatal in case of rupture. The arterial vascular wall of the anterior cerebral circulation is most frequently involved. Experimental data showed the expression of polycystins (the proteins modified by the mutation in this disease) in the affected arterial vascular wall and some mutations apparently give rise to greater susceptibility to the complication. The risk factors that cause the predisposition to this condition and the natural history are poorly understood. This lack of information complicates the clinical management of these patients because many pivotal questions still need an answer: Are cerebral aneurysms to be screened for in the ADPKD population? If so, at which intervals? In which cases where an aneurysm has been detected is correction needed? Which type of correction technique is to be preferred, interventional neuroradiology or neurosurgery? The three authors compare their partially discordant positions on this highly controversial topic.

Background: The aim of the study was to report a single-center experience about early and mid-term complications in carotid artery stenting., Methods: From June 2005 to April 2009, 148 significant carotid artery stenoses were treated with carotid artery stenting in 140 patients. Preprocedural evaluation was performed with Duplex scan, angio-computed tomography scan or magnetic resonance imaging. Low-profile material was used with curves dedicated to bovine arch. Dual antiplatelet therapy was administered to all patients before and after the procedure., Results: Technical success was achieved in 144 procedures. Four patients (2.7%) required surgical conversion. The rate of neurological complications was 2% at 30 days (0.6% major stroke and 1.3% minor stroke/ transient ischemic attack). After 3 years of follow-up, 2 cases of restenosis occurred (1.3%), one of them necessitating endovascular reintervention., Conclusions: Data from our retrospective experience show that carotid artery stenting is a safe and effective procedure with technical results similar to those of surgery. Neurological complications represent a serious problem and their incidence rate is hard to reduce. At 3-year follow-up, the restenosis rate was low.

Purpose: The authors performed a preliminary study with blood-pool contrast-enhanced magnetic resonance angiography (MRA) in evaluating the degree of carotid artery stenosis and plaque morphology, comparing the diagnostic performance of first-pass (FP) and steady-state (SS) acquisitions with 64-slice computed tomography angiography (CTA) and using digital subtraction angiography (DSA) as the reference standard., Materials and Methods: Twenty patients with >or=50% carotid artery stenosis at Doppler sonography underwent blood-pool contrast-enhanced MRA, CTA and DSA. Two independent radiologists evaluated MRA and CTA examinations to assess the degree of stenosis and characterise plaque morphology. Accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for FP, SS and CTA. The McNemar and Wilcoxon tests were used to determine significant differences (p<0.05) between the diagnostic performance of the three modalities., Results: Forty carotid bifurcations were studied. For stenosis grading, accuracy, sensitivity, specificity, PPV and NPV were 90%, 89%, 90%, 89% and 90%, respectively, at FP; 95%, 95%, 95%, 95% and 95%, respectively, at SS; and 97.5%, 95%, 100%, 100% and 95%, respectively, at CTA. SS and CTA were superior to FP for evaluating the degree of stenosis (p<0.05). For evaluating plaque morphology, accuracy, sensitivity, specificity, PPV and NPV were 87.5%, 89%, 86%, 85% and 90%, respectively, at FP; 97.5%, 100%, 95%, 95% and 100%, respectively, at SS; and 100%, 100%, 100%, 100% and 100%, respectively, at CTA. There were no significant differences between FP, SS and CTA for plaque assessment (p>0.05)., Conclusions: Blood-pool contrast-enhanced MRA with SS sequences allow improved diagnostic evaluation of the degree of carotid stenosis and plaque morphology compared with FP and is substantially equal to CTA and DSA.

Aim: The results may be related to the relative delay in diagnosis and thus in treatment. The authors hope that their paper will help make physicians who work in emergency rooms more aware of the increase in stroke in children., Methods and Results: The study a departmental study in the Children's Hospital, carried out at the Giannina Gasslini Children's Hospital of Genoa, Italy. The authors report on 23 children with stroke who were admitted at onset to the pediatric emergency department. The incidence of patients with stroke at the Institute between 2001 and 2005, was 0.8% among neurology patients and 0.02% among all pediatric patients. This incidence would appear to be lower than the rates reported in the literature. This is most likely due to the fact that patients who presented at the Emergency Department at onset of the stroke were not taken in consideration. In the last few years, children with stroke have been treated empirically by anticoagulant or antiplatelet therapy. Patients with sickle cell disease, with venous stroke, or with heart disease are all treated in a rather homogeneous manner., Conclusions: These cases represent the different types of presentation of stroke in children and also clearly display the different therapeutic strategies that have been applied. In fact, the patients were treated on the basis of an individual protocol which was decided case by case but a critical review of these cases establishes a necessary multidisciplinary protocol.

Aortic coarctation accounts for 5%-10% of all congenital heart diseases and represents 7% of critically ill infants with heart disease. Magnetic resonance (MR) imaging allows the study of this disease with several advantages in comparison with conventional angiography, transesophageal echocardiography, and computed tomography. The MR protocol applied at our institution for both diagnosis and follow-up after surgical or endovascular treatment consists of four steps: morphologic study, cine MR study, flow analysis, and MR angiography (MRA). The first three sequences are acquired during breath-hold and with electrocardiographic gating. Anatomy is well depicted with dark-blood half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences. Cine true-fast imaging with steady-state precession (true-FISP) sequences show not only morphologic features but also blood-flow changes inside the aorta. Gradient-echo sequences for phase-velocity mapping allow flow analysis. Application of Bernoulli's equation--here briefly presented and discussed--allows for calculation of the pressure gradient caused by the coarctation. MRA, acquired with a breath-hold three-dimensional T1-weighted gradient-echo sequence and intravenous administration of paramagnetic contrast material, allows for optimal depiction of the aortic lumen, with a panoramic view of the whole aorta, its main branches and possible collateral circulation.

Chemodectomas are uncommon neoplasms, born by glomic cell of extra-adrenegic system. Usually, these neoplasms are benign and non functioning, but when they are more than 4 cm can induce a neuro-vascular compressive syndrome. In this study the Authors propose the guidelines for diagnostic, clinical and therapeutic management, of these tumors according to their experience.

The objective of this study was to evaluate the potential role of newly developed, advanced magnetic resonance (MR) imaging techniques (spectroscopy, diffusion and perfusion imaging) in diagnosing brain gliomas, with special reference to histological typing and grading, treatment planning and posttreatment follow-up. Conventional MR imaging enables the detection and localisation of neoplastic lesions, as well as providing, in typical cases, some indication about their nature. However, it has limited sensitivity and specificity in evaluating histological type and grade, delineating margins and differentiating oedema, tumour and treatment side-effects. These limitations can be overcome by supplementing the morphological data obtained with conventional MR imaging with the metabolic, structural and perfusional information provided by new MR techniques that are increasingly becoming an integral part of routine MR studies. Incorporation of such new MR techniques can lead to more comprehensive and precise diagnoses that can better assist surgeons in determining prognosis and planning treatment strategies. In addition, the recent development of new, more effective, treatments for cerebral glioma strongly relies on morphofunctional MR imaging with its ability to provide a biological interpretation of these characteristically heterogeneous tumours.

Purpose: The aim of this study was to directly compare the results of magnetic resonance cholangiopancreatography (MRCP) with those of ultrasonography (US) and multislice computed tomography (MSCT) in the diagnosis of pancreaticobiliary diseases., Materials and Methods: A total of 70 patients (41 men, 29 women) aged 22-89 years were studied either before (n=59) or after cholecystectomy (n=11) for biliary lithiasis. Clinical signs and symptoms were jaundice (n=15), abdominal pain (n=37) and proven biliary lithiasis (n=18). MRCP was performed in all patients, whereas abdominal US was performed in 55 (group 1) and MSCT in 37 (group 2) patients. A regional evaluation of the main structures of the pancreaticobiliary system was performed: gallbladder and cystic duct, intra- and extrahepatic bile ducts and main pancreatic duct. Histology (n=27), biopsy (n=5), endoscopic retrograde cholangiopancreatography (ERCP) (n=28) and/or clinical-imaging follow-up (n=10) were considered standards of reference. In particular, patients were classified as showing benign (n=47) or malignant (n=12) lesions or normal biliary anatomy (n=11)., Results: In group 1, the results of MRCP and US were concordant in the majority (92%) of cases; however, statistically significant discordance (p<0.01) was found in the evaluation of the extrahepatic ducts, with nine cases (16%) of middle-distal common bile duct stones being detected on MRCP only. In group 2, the results of MRCP and MSCT were also concordant in most cases (87%). However, findings were significantly discordant when the intra- and extrahepatic ducts were analysed, with seven (19%) and six (16%) cases, respectively, of lithiasis being detected on MRCP only (p<0.01 for both)., Conclusions: The results of our study confirm the diagnostic potential of MRCP in the study of the pancreaticobiliary duct system. In particular, the comparison between MRCP and US and MSCT indicates the superiority of MRCP in evaluating bile ducts and detecting stones in the common bile duct.

Batson's epidural venous plexus plays a crucial role for the generation of vascular back pain, in particular in those conditions characterized by venous congestion, such as heart failure or pregnancy. Except some rudimentary cuspids, the vertebral venous system is considered to be a valveless anastomotic system; as a result the blood is supposed to flow in either direction depending on changes of cardiovascular conditions during the day. Within the narrow boundaries of the neural canal, the epidural veins can therefore get congested, inducing low back pain. The aim of this case report was to highlight a correlation between lumbar superficial veins in patients with chronic low back pain and epidural deep venous plexus congestion. The patients selected underwent a morphologic examination of venous epidural plexus (included its connections with lumbar superficial blood vessels) through a 3D dynamic contrast-enhanced Magnetic Resonance Angiography. The Authors found two different radiological behaviours: total and partial congestion of the vertebral deep venous system. Clinical consequences were discussed and therapeutic strategies were suggested.

Purpose: This study was undertaken to evaluate the usefulness of perfusion-weighted imaging (PWI) in the differential diagnosis of ring-enhancing cerebral lesions, including abscesses, high-grade gliomas and metastases., Materials and Methods: Nine cerebral abscesses (five pyogenic, four from Toxoplasma gondii), ten glioblastomas and five cerebral metastases in 19 patients were studied with gadolinium-enhanced magnetic resonance imaging, diffusion-weighted imaging (DWI) including calculation of mean apparent diffusion coefficient (ADC) of the lesion core, and PWI. At PWI, the mean of the maximum regional cerebral blood volume (rCBV) was calculated in the gadolinium-enhancing peripheral solid areas and compared with that of the contralateral normal-appearing white matter [ratio=rCBV (lesion)/rCBV (contralateral normal-appearing white matter)]., Results: DWI achieved the differential diagnosis in all cases except for the four Toxoplasma abscesses. At PWI, the mean ratio of the rCBV of the capsular portion was 0.72+/-0.08 (range 0.60-0.82) in the pyogenic abscesses, 0.84+/-0.07 (range 0.75-0.91) in the Toxoplasma abscesses, 4.45+/-1.5 (range 2.9-8.0) in the high-grade gliomas and 3.58+/-0.68 (range 3.28-4.27) in the metastases., Conclusions: PWI seems to be useful in the differential diagnosis of ring-enhancing cerebral lesions. High rCBV values in the peripheral areas appear to indicate the possibility of a necrotic tumour, whereas low values tend to indicate an abscess.

Purpose: This study was undertaken to evaluate the accuracy of contrast-enhanced magnetic resonance angiography (CE-MRA) in detecting renal artery stenosis using intra-arterial digital subtraction angiography (DSA) as the gold standard., Materials and Methods: Thirty-five consecutive patients with possible renovascular hypertension were prospectively studied; 26 of them underwent both MRA and DSA. In these 26 cases, two readers assessed the number of renal arteries, the presence of stenoses and their degree. Results were compared with DSA, and sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of MRA were determined. Interobserver variability was also calculated., Results: DSA showed 51 main renal arteries (one patient had a single kidney) and six accessory arteries (total number of arteries 57) in the 26 patients considered. Both MRA readers detected all of the 51 main renal arteries and only one accessory vessel. When the presence of stenosis was considered, the readers' results, respectively, were as follows: sensitivity 77% and 72%, specificity 69% and 69%, PPV 86% and 85%, NPV 55% and 50% and diagnostic accuracy 75% and 71%. When the detection of significant stenosis was considered, the results, respectively, were: sensitivity 83% and 83%, specificity 73% and 78%, PPV 60% and 65%, NPV 90% and 91%, and diagnostic accuracy 76% and 80%. Interobserver variation was good when considering stenosis detection (kappa=0.69) and excellent when considering detection of significant stenosis (kappa=0.85)., Conclusions: MRA results do not appear as positive as in the majority of papers in the literature. Multiple reasons can probably be invoked to explain this difference. The mean age of our patients, higher than in many other studies, should be noted and may have accounted for their possible poor cooperation. Moreover, all of the missed significant stenoses were distally located, and therefore, the failure to detect them might be related to the suboptimal spatial resolution of MRA. Nevertheless, MRA showed a high NPV for detecting significant stenoses, a finding of considerable clinical relevance in that it allows patients with normal MRA findings to be spared additional more invasive procedures.

Purpose: Our study aimed to assess the role of magnetic resonance imaging (MRI) in the characterisation of musculoskeletal tumours and to identify specific perfusion patterns for the different tumours., Materials and Methods: Between January 2003 and September 2005, we evaluated the conventional and perfusion MRIs of 39 patients with musculoskeletal tumours. Dynamic MRI was performed with a 1.5-T and 1.0-T MRI unit before and after the intravenous administration of contrast material, using dedicated phased-array coils appropriate for the region to be studied and fast and ultrafast consecutive sequences. Postprocessing was done on an independent workstation (Advantage Windows, GE Medical System), with Functool (GE) software, which allowed a quantitative evaluation of enhancement as a function of time. The results were compared with the histopathological diagnoses obtained by biopsy or surgery., Results: The lesions identified in the 39 patients included 23 soft tissue tumours (12 benign, 11 malignant) and 16 bone tumours (ten benign, six malignant). Comparing the time-intensity diagrams of lesions of the same histological type, we found typical enhancement patterns for some bone tumours only, especially for bone, cartilaginous, fibrohistiocytic and pseudoinflammatory lesions. No typical enhancement pattern could be detected for any of the histological types of soft tissue tumour. Analysis of the slope of the time-intensity curves has a sensitivity and specificity of 64%-58% for soft tissue tumours and 86%-67% for bone tumours in determining the biological aggressiveness of the lesions., Conclusions: Perfusion MRI had moderate sensitivity and specificity in the differential diagnosis between lesions with high or low biological activity. Only in a few cases was it possible to find some correlation between perfusion patterns and lesion histology. The slope values should therefore be used in combination with conventional spin-echo images and other imaging and clinical data in order to narrow the field of the possible differential diagnoses and reliably predict the nature of the lesion.

Purpose: The aim of this study was to identify and characterise by magnetic resonance imaging (MRI) carotid plaque constituents such as lipid-rich necrotic core, intraplaque haemorrhage and calcification in patients treated with carotid endarterectomy (CEA) using histological evaluation as the reference standard., Materials and Methods: Nineteen patients (13 men and six women) scheduled for CEA between March and August 2004 were imaged on a 1.5-T scanner (Magnetom Symphony, Siemens, Erlangen, Germany). The protocol included four types of sequences [T1, T2, proton density (PD) and three-dimensional time of flight (3D-TOF)]. Images were reviewed for integrity of the fibrous cap, presence of lipid-rich necrotic core, intraplaque haemorrhage and calcification. Signal intensity was assessed relative to the adjacent sternocleidomastoid muscle. Four cross-sections for each lesion were compared with the corresponding histological specimens and independently reviewed by two radiologists and one pathologist., Results: MRI detected lipid-rich necrotic core with a sensitivity and specificity of 91.6% and 95.0%, respectively, whereas it defined intraplaque haemorrhage alone with a sensitivity and specificity of 91.6% and 100%, respectively. Calcification was recognised with a sensitivity and specificity of 80% and 93.7%, respectively., Conclusions: MRI is able to identify signs of carotid plaque instability with a high sensitivity and specificity. Therefore, it may be useful in evaluating and guiding the treatment of haemodynamically nonsignificant stenoses with a potential embolic risk and, in the future, to assess coronary plaque.

Conventional coronary angiography is the gold standard for the diagnosis of coronary artery anomalies. Coronary anomalies are relatively rare findings in patients undergoing conventional coronary angiography for suspected obstructive coronary artery disease. Recently, the increasing performance of diagnostic techniques, such as electron beam tomography (EBT), magnetic resonance (MR) and, more recently, multislice computed tomography (MSCT), has enabled their application to cardiac imaging. MSCT, in particular, has a prominent role in coronary imaging due to its spatial and temporal resolution and three-dimensional capabilities. We report the incidence and pathophysiology of coronary artery anomalies based on the capabilities of recent diagnostic tools with the aim of improving an accurate and noninvasive diagnostic approach.

Purpose: This study prospectively compares Doppler ultrasound (Doppler US) and contrast-enhanced magnetic resonance angiography (CE-MRA) with digital subtraction angiography (DSA) and endarterectomy findings to determine the accuracy in assessing carotid artery stenosis., Materials and Methods: Thirty-two patients underwent carotid endarterectomy, 21 studied with Doppler US, CE-MRA and DSA and 11 with Doppler US and CE-MRA. In 41 carotid arteries, the degree of stenosis was analysed with Doppler US and CE-MRA and compared with DSA by using the Spearman rank correlation coefficient. Nine out of 32 endarterectomies were done using the eversion technique, and it was possible to compare Doppler US, CE-MRA and DSA with the specimen measurement. Twenty-three out of 32 endarterectomies were done using the standard technique, and the presence of ulcers was documented., Results: There was a significant Doppler US/DSA (Rs=0.86; p<0.001) and CE-MRA/DSA (Rs=0.81; p<0.001) correlation for the degree of stenosis. The diagnostic accuracy of the three methods was the same (89%). Ulcers were most frequently seen at CE-MRA, with a diagnostic accuracy of 85%., Conclusions: These data suggest that endarterectomy on the basis of Doppler US and CE-MRA can be considered appropriate. CEMRA was the best noninvasive imaging modality to detect plaque ulceration.

Purpose: One the main reasons for the limited use of MRI in the evaluation of aortic dissection in emergency conditions is its long execution time. The authors report their experience regarding a new MRI sequence that reduces execution time and avoids the use of contrast medium., Materials and Methods: Eighteen haemodynamically stable patients with suspected (16 cases, 3 with confirmed diagnosis of aneurysm) or known aortic dissection (2 cases) underwent in emergency conditions 1.5T MRI with Steady-State sequence (Fast Imaging Employing Steady-State Acquisition: GRE 2D; TR 3.5, TE 1.6; Flip Angle 45, bandwidth 125, matrix 224x224, NEX 1, acquisition time per slice 7 s, thickness 6-8 mm, FOV 38; 2D-GE breath-hold sequence requiring cardiac triggering). The results obtained were compared in terms of diagnostic accuracy and execution time with those of classical MRI examination (black blood T1, FSE T2 and 3D MR-angiography) or multislice CT., Results: The diagnostic accuracy of MRI, both with Steady-State sequence and the ''classical'' technique, and multislice CT in the diagnosis of dissection or aneurysm is equal (100%), whereas execution time is 6, 25 and 6 minutes, respectively. Multislice CT proved to be more accurate than Steady-State MRI in evaluating the renal parenchyma and the extension of the dissection to the renal arteries., Conclusions: The Steady-State MRI sequence provides a diagnosis of aortic dissection or aneurysmal dilatation in a short time and may represent a valuable alternative to CT in emergency settings, especially in patients with reported contraindications to iodinated contrast media.

The purpose of this study was to compare magnetic resonance angiography with duplex ultrasound for defining anatomical features relevant to performing lower limb revascularisation. From June 2003 to June 2004, 30 consecutive patients with chronic lower limb ischaemia underwent magnetic resonance angiography and duplex ultrasound investigations before undergoing lower limb revascularisation procedures. The mean age was 72 years (range: 45-93). Indications for the procedure included resting pain (6 cases), ischaemic ulcer (8 cases), and gangrene (16 cases). We compared magnetic resonance angiography and duplex ultrasonography findings and the differences in the aorto-iliac, femoro-popliteal and infrapoliteal segments were noted. Magnetic resonance angiography and duplex ultrasound findings agreed in 13/15 cases (86%) in the aorto-iliac segment, in 14/17 (82%) in the femoro-popliteal segment, and in 8/11 (74%) in the infrapopliteal segment. In all, duplex ultrasound agreed with intraoperative findings in 97% of cases while magnetic resonance angiography agreed in 81%. These data show that magnetic resonance angiography is less accurate than duplex ultrasound in the infrapopliteal segment. Adeguate training is necessary before duplex ultrasound can be used as the only preoperative imaging procedure.

Purpose: To evaluate the role and the effectiveness of interventional radiology in the treatment of renal transplant complications., Materials and Methods: From 1996 to 2004 a total of 288 kidney transplants from cadavers were performed in our Institute. The kidney was always collocated in iliac fossa by creating a vascular anastomosis with the external iliac artery and vein; in all cases the ureter was implanted into the recipient bladder. During the follow-up, 34 complications were observed. Twenty-seven complications in 25 patients (20 males and 5 females; age 35-65 years) were treated by a radiologic procedure: 9 renal artery stenosis and 1 native external iliac artery stenosis (by PTA), 5 ureteral obstructions (by nephrostomy and ureteral stenting), 8 ureteral leaks (by nephrostomy, in 2 cases associated to ureteral stenting) and 4 limphoceles (by percutaneous ultrasound-guided catheter drainage)., Results: Primary technical success was obtained in 20/27 cases (74%). Success was obtained with a second interventional procedure in 3/27 cases, 2 limphoceles and 1 ureteral fistula (secondary technical success: 85.2%), with a clinical final success in 23/27 cases (85.2%). We observed a peri-procedural complication rate of 3.7% (1 renal artery post-PTA dissection during a restenosis treatment). Four cases (1 renal arterial post-PTA dissection, 1 ureteral obstruction, 1 ureteral leak and 1 limphocele) needed a surgical correction (14.8%)., Conclusions: Interventional radiology is the first therapeutic approach to treat renal transplant complications. It shows good technical and clinical results and a low complication rate. Surgery had to be considered only if minimally invasive procedures are infeasible or ineffective.

Renovascular disease (RVD) is detected with increasing frequency because with an aging population, atherosclerosis and its consequences are seen more frequently. RVD has three component parts: renal artery stenosis (RAS), renovascular hypertension (RVH), and ischemic nephropathy (IN). Each component should be recognized by the appropriate diagnostic tool. The proper techniques and procedures to establish an anatomical RAS diagnosis are: computed tomography angiography, magnetic resonance (MR) angiography and catheter angiography, which is the gold standard. The presence of RAS can also be disclosed through increased systolic blood flow velocity at the level of the narrowed renal artery by an echo color-Doppler. Once the presence of RAS is demonstrated the diagnosis of RVH and/or IN should be performed. The RVH diagnosis needs to demonstrate a causal link between RAS and blood pressure (BP) increase; a causal link between RAS and the reduction in glomerular filtration rate (GFR) is mandatory for the IN diagnosis. Techniques and procedures suggesting that BP is increased and/or GFR is reduced based on RAS are captopril enhanced renoscintigraphy, BP gradient across the stenosis, captopril modification of Doppler parameters and captopril modification of MR curves. The resistive index obtained by color-Doppler could be a structural damage marker of the intrarenal arterioles. A rational approach to the problem demands that each technique is chosen according patient clinical characteristics.

In recent years the technological development of computed tomography (CT) and magnetic resonance (MR) has promoted new improvements in diagnosis by means of imaging. In particular the introduction of multislice CT and MR angiography (MRA) has broadened the non-invasive diagnostic possibilities in the vascular study of the thorax. The new technological developments of CT and MR enable functional studies as well. Recent studies have demonstrated that CT and MR are as accurate in finding the vascular anomalies as digital subtraction angiography, while they are more precise in recognising possible associated pathologies which modify therapeutic treatment (for example of the trachea, bronchi, oesophagus etc.). There are many vascular structures in the thorax which need to be considered (aorta, pulmonary and coronary arteries, pulmonary veins, vena cava). The field of associated pathologies is also broad, and includes congenital vascular anomalies, vascular malformations, aorta dissection, vascular compression syndromes, atherosclerotic stenosis or occlusions, and pulmonary embolism. In pulmonary embolism some authors have demonstrated the utility of CT, in showing pulmonary segmental perfusion defects, and MRA, in identifying sub-segment pulmonary embolism. In this paper we analyse the most important CT and MR applications for the study of vascular thoracic diseases and compare them with other diagnostic techniques. We also evaluate the morpho-functional capabilities of CT and MR in this field.

Purpose: To investigate the diagnostic accuracy of non-enhanced Colour-Doppler US and enhanced power-Doppler US in the diagnosis of renal artery stenosis compared with breath-hold Gd-DOTA-enhanced MR-angiography. Digital subtraction angiography (DSA) provided the gold standard., Materials and Methods: A total of 51 patients (19 women and 32 men, age ranging from 29 to 76 years) with clinical suspicion of renovascular hypertension underwent Colour-Doppler US of the renal artery; 11 subjects (21.6%) were excluded from the study as a complete and bilateral depiction of renal artery was not obtained. The remaining 40 subjects (14 women and 26 men) were investigated with power-Doppler US with time-intensity renal enhancement curve and with MR-Angiography. All of these subjects were also studied by DSA which provided the gold standard., Results: As stated, in 11 of 51 patients the diagnostic work-up was not completed because the initial US examination failed to depict the renal arteries. DSA showed renal artery stenosis in 16 of the remaining 40 patients. The sensitivity and specificity in diagnosing stenoses were 75% and 79.1% for conventional colour-Doppler US, 100% and 87.5% for enhanced power-Doppler US and 100% and 91.6% for MR-angiography., Conclusions: MR-angiography is the most reliable technique in the diagnosis of renal artery stenosis. The sensitivity and specificity of enhanced power-Doppler US are superior to those of colour-Doppler US. Although MR-Angiography enables a better evaluation of renal artery stenosis, the good diagnostic accuracy of enhanced power-Doppler US, its greater acceptance by the patients and its wider diffusion support the use of this technique in the screening of patients with clinical suspicion of renovascular hypertension.

Purpose: To assess the effectiveness of routine MSCT in the planning of endovascular and open surgery of AAA., Patients and Methods: A series of 42 consecutive patients was prospectively examined by MSCT (Siemens Sensation 16, arterial phase, bolus tracking threshold=200 HU, 75 mm collimation) for AAA surgery planning. MPR, MIP and VRT reconstructions were routinely obtained. In four cases previous DSA was available for comparison., Results: AAA was classified infrarenal (28/42), juxtarenal (10/42), pararenal (2/42) and thoraco-abdominal (Crawford type IV (2/42). In 27/42 AAA maximum diameter was greater than 45 mm; involvement of a single iliac artery (6/42) or both (7/42) was also observed. Vascular anomalies were detected in 54.8% of patients. Overall, 22 accessory renal arteries, 4 visceral aneurysms (2 renal arteries, 1 celiac trunk, 1 SMA) and 1 retroaortic renal vein were detected. Patency of IMA was demonstrated in 25/42 AAA. Based on MSCT data 11 patients were treated (7 by open surgery, 4 by endovascular approach). No discrepancy was observed concerning the planned infrarenal clamping, all accessory renal arteries were identified at surgery. In all AAA, endovascular treatment planning matched the actual geometry of vessels., Conclusions: Although this series is limited, information provided by axial images, MPR, MIP and VRT reconstructions fulfilled all requirements for routine planning of both open and endovascular treatment of AAA. Moreover, VRT reconstructions enable a more precise assessment of accessory renal arteries origin and course and spatial orientation of AAA neck.

The anatomic anomalies of the supra-aortic trunks and their branches are comparatively frequent observations. They often remain asymptomatic throughout life although in some cases, especially if nothing is known of them, they may complicate surgical interventions involving that anatomical region. The case of a female patient who, during thyroidectomy, suffered the ligature of her external carotid artery which was taken mistakenly for the thyroid, is reported. Dissection of the area made it possible to identify an anomaly of the vascular structures with a carotid bifurcation which turned out to be very low, a very deep internal carotid artery on the prevertebral fascia and an absent lower thyroid artery. In the postoperative period, the patient was subjected to MR of the neck. This showed an anatomical anomaly of the left carotid bifurcation which was much lower than normal. An attempt was made to reconstruct the external carotid artery with a saphenous vein but unsuccessfully. The incident did not have serious complications for the patient but it might be asked whether, given the low cost and the absolute non-invasiveness of the examination, it might not be worth while to carry out a duplex scan of the supra-aortic trunks before going ahead with any operation in the cervical region, in consideration above all of the dangerous nature of these vascular structures and of the usefulness of studying pathologies that often remain silent until the occurrence of an event which might well be catastrophic.

Purpose: To analyse the major radiological and clinical features of dissections of the epiaortic vessels and evaluate the potential of imaging techniques on the basis of the findings reported in the literature over the last few years., Materials and Methods: We evaluated 9 dissections (7 carotid lesions and 2 vertebral lesions) in 9 patients (5 women and 4 men; age range: 30-56 years) who came to our attention between September 1999 and June 2002. These were all stenoses and obstructions located in the cervical region and, in two patients, extended intracranially. The morphologic features were assessed in each case by colour-Doppler US, CT, MR or conventional angiography and correlated with clinical, therapeutic and distant progression patterns. Colour-Doppler US of the neck vessels was performed in 4 patients; CT angiography of neck and intracranial vessels was performed in 4 patients using a single-slice spiral scanner and a single contrast medium bolus injection, following unenhanced examination of the brain; MR angiography was performed in 6 patients after baseline examination using flow-dependent and/or angiographic sequences; conventional angiography was performed in 7 patients. Clinical manifestations at onset were peripheral neurological lesions in 5 cases and central ischaemic lesions in the remaining 4 cases. All patients underwent medical therapy (anticoagulants or antiaggregants). The follow-up was done by colour-Doppler US, MR and/or MR angiography; follow-up conventional angiography at 6-9 months was also performed in 6 patients. Distant progression was assessed on the basis of the degree of vascular re-canalization and the residual signs and symptoms., Results: MR- and CT-angiography were diagnostic in all cases. In particular, diagnosis was obtained by MR-angiography in 4 patients and by CT-angiography in 3 patients. Conventional angiography yielded a diagnosis in 2 cases which had previously undergone non-contrast brain CT or MR without examination of neck vessels alone. Colour-Doppler US revealed non-specific wall and flow alterations in 2 cases, thus requiring further diagnostic studies. In patients with central neurological symptoms at onset the diagnosis was obtained within 48-72 hours, whereas in patients with initial peripheral neurological symptoms the time to diagnosis was significantly longer (up to 10 days) due to the poor specificity of the clinical picture and/or failed detection of the warning symptoms. Medical treatment gave rise to no major complications. Overall, distant progression was good: 6 patients recovered completely and 3 had mild to moderate residual neurological deficits., Discussion and Conclusions: Dissection of epiaortic vessels should always be considered as a probable cause of cerebral ischaemia in adults aged 20-50 years, particularly in the absence of vascular risk factors. Clinical assessment is fundamental for the diagnosis and treatment. Currently, CT and MR imaging techniques providing similar information are reliable diagnostic tools that can rapidly and non-invasively clarify suspicious clinical cases. Nevertheless, angiography continues to have an important role in the overall evaluation of disease severity in view of the possible endovascular or surgical treatment of complications.

Purpose: To evaluate the diagnostic accuracy, sensitivity and specificity of MRA (3D TOF) in comparison to contrast-enhanced MRA using DSA as the gold standard in the study of steno-occlusive disease of the internal carotid artery, in order to determine if this technique still has a diagnostic value., Materials and Methods: Three radiologists blindly and independently evaluated either the unenhanced MRA, CE MRA, or DSA images of 23 consecutive patients, assessing the stenosis based on a NASCET five-class classification., Results: The sensitivity, specificity, and diagnostic accuracy of CE MRA and unenhanced MRA were 100% and 100%, 100% and 95.5% and 100% and 93.2%, respectively. These differences were not statistically significant., Conclusions: Unenhanced MRA should be still considered a valid alternative for studying the extracranial section of the internal carotid arteries especially in patients who refuse or whose laboratory results exclude the use of contrast medium or in patients in whom continuous monitoring of a clinical condition is required but a repeated and/or frequent use of contrast medium is not possible.

Purpose: The purpose of this study was to compare contrast enhanced MR angiography (MRA) with gadopentetate dimeglumine (Gd-DTPA) to MRA with gadobenate dimeglumine (Gd-BOPTA), a high relaxivity paramagnetic contrast agent., Materials and Methods: Twelve patients referred for carotid artery stenosis were examined with MR angiography using a fast spoiled gradient echo sequence. Gd-DTPA and Gd-BOPTA enhanced MR angiography were performed within 48-72 hours using a dose of 0.1 mmol/kg for Gd-BOPTA and 0.2 mmol/kg for Gd-DTPA, at a flow rate of 2 ml/s. Images were evaluated by two blinded radiologists. Qualitative and quantitative evaluations were performed comparing the sets of images from the two examinations., Results: Qualitative evaluation demonstrated superior arterial contrast enhancement and vessel conspicuity with Gd-BOPTA compared with Gd-DTPA. Quantita-tive evaluation showed an improvement in both signal intensity and contrast to noise ratio with Gd-BOPTA., Conclusion: The greater relaxivity of Gd-BOPTA, at lower doses, compared with Gd-DTPA, provides higher intravascular signal and signal to noise ratio. Gd-BOPTA appears to be an optimal contrast agent for contrast enhanced MRA.

Aim: The aim of this study is to evaluate the indications for a carotid-carotid bypass and its therapeutic efficacy., Methods: Between January 1995 and December 2001, 42 out of 782 patients with obstructive lesions of carotid vessels were submitted to carotid-carotid bypass. Preoperative investigations included Duplex scanning, transcranial Doppler and cerebral CT in all the patients, angiography in 24, spiral CT in 8, MR angiography in 6. Carotid bypass was planned pre-operatively in 13 cases due to internal carotid occlusion in 4, to pseudo-occlusion in 8 and to restenosis in 1. In the remaining 29, due to a too thin residual wall or to the lack of a good clivage plane, a carotid bypass was planned intraoperatively. A PTFE graft was employed in 30 cases while the autologous saphenous vein in 12. Four patients were lost in a 12-80-month follow-up. No intra or postoperative mortality was recorded., Results: Three patients died during the follow-up. In 1 patient the death followed an ischemic stroke due to bypass occlusion. Four bypasses became occluded, in 3 cases without clinical signs. Eight patients suffered by transient superior laryngeal nerve iniury., Conclusions: Carotid bypass, as an alternative to CEA, provides good results in the treatment of the patients with carotid stenosis, pseudo-occlusion or segmental occlusion. In most of the cases the surgical technique is planned intraoperatively but in selected cases angiographic findings, spiral CT and color flow duplex can suggest in the preoperative phase that carotid bypass is the best choice.

This study evaluates the role of cerebral MR Angiography (MRA), as a part of the flowchart for the assessment of the brain in childhood. This noninvasive technique provides intra- and extra-cranial anatomic and physiologic vascular information, with a level of precision almost equal to that of arterial angiography. Indeed, MRA has reached a level of diagnostic accuracy such that the need for arterial angiography can be avoided, in most cases of cerebrovascular disorder. Therefore arterial angiography could be performed at the subacute (and more neurologically stable) stage, or presurgically, yielding additional morphologic and hemodynamic insights into cerebrovascular disease. MRA is also indicated at follow-up examination, and in treatment planning.

Purpose: Spontaneous dissection of the carotid and vertebral arteries represents a rare pathology. Its pathogenesis, probably multi-factorial, can be related to neck trauma and to a genetic basis, extensively demonstrated in the cases of association with type IV fibromuscular dysplasia, Ehlers-Danlos syndrome, Marfan's syndrome, pseudoxanthoma elasticum and osteogenesis imperfecta. Onset symptoms include neck, facial pain and diffuse headache. Cranial nerve palsy has been also described. The aim of this study was to evaluate MR angiography and MR findings in a population of patients with carotid and vertebral artery dissections., Materials and Methods: We reviewed the MR angiography and MR exams of 15 patients (10 males, 5 females, average age 42.0, age range 30-55) with carotid and/or vertebral artery dissection; the serial MR follow-up studies were also examined., Results: Twelve internal carotid arteries (ICA) showed the presence of an irregular stenosis; three of these showed complete occlusion. In two patients both ICA were involved. Six vertebral arteries (VA) showed irregular stenosis (only one patient suffered from both CI and VA dissection); in one case there was also a pseudoaneurysm of the VA. Follow-up studies showed vessel lumen re-opening in 5/11 ICA (one patient underwent vascular stent positioning) and in 3/6 VA., Conclusions: The present study confirms the usefulness of MR angiography and MR in the diagnosis and follow-up of patients with carotid and vertebral artery dissection.

The new diagnostic options offered by the continuous development of CT and MR imaging of the heart must be periodically reviewed. This review article aims to outline the main developments in CT and MR technology and to evaluate the results and indications in CAD (coronary artery disease) patients.