Establishment of diagnostic reference levels in cardiac CT in France: a need for patient dose optimisation.

The objective of this study was to propose diagnostic reference levels (DRLs) for coronary computed tomography angiography (CCTA), in the context of a large variability in patient radiation dose, and the lack of European recommendations. Volume Computed Tomography Dose Index (CTDIvol) and dose-length product (DLP) were collected from 460 CCTAs performed over a 3-month period at eight French hospitals. CCTAs (∼50 per centre) were performed using the routine protocols of the centres, and 64- to 320-detector CT scanners. ECG gating was prospective (n = 199) or retrospective (n = 261). The large gap in dose between these two modes required to propose specific DRLs: 26 and 44 mGy for CTDIvol, and 370 and 970 mGy cm for DLP, respectively. This study confirms the large variability in patient doses during CCTA and underlines the need for the optimisation of cardiac acquisition protocols. Availability of national DRLs should be mandatory in this setting.

Dilated cardiomyopathy in patients with mutations in anoctamin 5.

BACKGROUND: Homozygous mutations in ANO5, a gene encoding anoctamin 5, a putative calcium-activated chloride channel, have recently been reported in patients with adult-onset myopathies or isolated high-CK levels. Cardiomyopathy has not previously been reported in these populations despite a proven expression of anoctamin 5 in the cardiac muscle. METHODS: Patients presenting for the management of high-CK levels or overt myopathy with proven ANO5 mutations were prospectively investigated between June 2010 and March 2012 in Pitié Salpêtrière Hospital, according to a standardised protocol. Neurological and cardiological clinical examinations, CK assessment, electrocardiogram (ECG), and echocardiography were performed, as well as cardiac MRI and coronary CT angiography in patients with left ventricular (LV) dysfunction. RESULTS: Our study included 19 consecutive patients (male=15, age=46.2 ± 12.7 years) from 16 families. Five had asymptomatic high-CK levels and 14 had overt myopathy. One patient had a personal history of stable coronary artery disease with normal ventricular function. ECG showed ventricular premature beats in one patient. Echocardiography displayed LV dilatation in two patients, LV dysfunction in one, and both abnormalities in two who fulfilled criteria for dilated cardiomyopathy which was confirmed by cardiac MRI and normal CT angiography. CONCLUSIONS: Dilated cardiomyopathy is a potential complication in patients with myopathies due to mutations in the ANO5 gene whose screening requires specific procedures.

[Contrast enhanced MR angiography: evolving towards whole-body real time acquisitions]. / Angiographie par résonance magnétique avec injection de produit de contraste: évolution vers le corps entier et le temps réel.

MRA includes all techniques used to depict vessels with MR. Gadolinium contrast injection combined with gradient echo sequences is the technique of choice for vascular imaging. Technical advances now allow faster acquisitions. The purpose of this article is to present two main advances with MRA: whole-body MRA and dynamic 3D MRA. Technical considerations, acquisition techniques, advantages and pitfalls based on our experience with a 1.5T MR unit will be discussed in order to promote their use in routine clinical practice.

Cardiac magnetic resonance imaging in systemic sclerosis: a cross-sectional observational study of 52 patients.

OBJECTIVES: To assess the prevalence and patterns of cardiac abnormalities as detected by cardiac magnetic resonance imaging (MRI) in systemic sclerosis (SSc). METHODS: Fifty-two consecutive patients with SSc underwent cardiac MRI to determine morphological, functional, perfusion at rest and delayed enhancement abnormalities. RESULTS: At least one abnormality on cardiac MRI was observed in 39/52 patients (75%). Increased myocardial signal intensity in T2 was observed in 6 patients (12%), thinning of left ventricle (LV) myocardium in 15 patients (29%) and pericardial effusion in 10 patients (19%). LV and right ventricle (RV) ejection fractions were altered in 12 patients (23%) and 11 patients (21%), respectively. LV diastolic dysfunction was found in 15/43 patients (35%). LV kinetic abnormalities were found in 16/52 patients (31%) and myocardial delayed contrast enhancement was detected in 11/52 patients (21%). No perfusion defects at rest were found. Patients with limited SSc had similar MRI abnormalities to patients with diffuse SSc. Seven of 40 patients (17%) without pulmonary arterial hypertension had RV dilatation. CONCLUSIONS: This study shows that MRI is a reliable and sensitive technique for diagnosing heart involvement in SSc and for analysing its mechanisms, including its inflammatory, microvascular and fibrotic components. Compared with echocardiography, MRI appears to provide additional information by visualising myocardial fibrosis and inflammation. RV dilatation appeared to be non-specific for pulmonary arterial hypertension but could also reflect myocardial involvement related to SSc. Further studies are needed to determine whether cardiac MRI abnormalities have an impact on the prognosis and treatment strategy.

[Intravascular lymphoma revealed by generalized arborescent telangiectasia and repeated venous thrombosis]. / Thromboses veineuses récidivantes et télangiectasies arborescentes généralisées révélatrices d'un lymphome intravasculaire.

BACKGROUND: Intravascular lymphoma is a rare form of non-Hodgkin's lymphoma characterized by proliferation of lymphoid cells within the lumen of small veins, small arteries and capillaries. CASE REPORT: A 79-year-old man presented with repeated superficial venous thrombosis of the lower limbs associated with diffuse telangiectasia of the trunk, upper arms and thighs but with normal epidermis. Screening for thrombophilia and neoplasm were negative. The patient subsequently developed abdominal pain, lower-limb oedema, deterioration in performance status and rapidly increasing telangiectasia with the appearance of generalized oedematous cutaneous induration. Increased LDH and anaemia were observed without other blood count anomalies. Intravascular lymphoma was diagnosed on a skin biopsy with telangiectasia and oedema. After eight courses of treatment with rituximab-CHOP the outcome was good. DISCUSSION: A few telangiectasias associated with nodules or infiltrated plaques are often a clinical manifestation of intravascular lymphoma. The dermatological presentation described here is interesting for two reasons: on the one hand, telangiectasias were initially isolated in normal epidermis without any infiltration for more than one year and, on the other hand, the skin infiltration seen subsequently was very extensive and marked. Moreover, although microthrombi are frequent in small and medium-sized blood vessels, thrombosis of large vessels is rarely described in intravascular lymphoma.

[Imaging of the renal arteries: when, how and why?]. / Quand, comment et pourquoi réaliser une exploration des artères rénales?

The objectives of this course are both: to describe acquisition, injection and reconstruction parameters of volumic images for renal arteries examination and specific signs; to discuss the role of the different images in the diagnosis and in the therapeutic management. Ultrasound is one of the best imaging for the analysis of renal arteries in the detection of stenosis even if the sensitivity is less (around 85%)compared to CT Angiography (95%) and MR Angiography (90%). Because of this advantage and of 3D evaluation, CTA and MRA are sometimes in the first line for renal artery evaluation and can assess morphology before angioplasty. Renal scintigraphy with Captopril test and renin dosage are only used for small kidney evaluation. Arteriogram is systematically followed by angioplasty if possible. With the new endovascular materials, complications decrease (less than 5% with a major reduction in cholesterol emboli) and indications of endoprosthesis increase (71% of stenting with half of it in direct stenting technique). This course will give practical tools for imaging acquisition, specifically 3D imaging, for indications and management of lesion in accordance to symptoms and morphology.

Prospective evaluation of magnetic resonance imaging after endovascular treatment of infrarenal aortic aneurysms.

OBJECTIVES: to evaluate the sensitivity and specificity of magnetic resonance imaging (MRI) in the detection of type II endoleaks during follow-up after endovascular treatment of intra-renal aortic aneurysms. DESIGN: prospective study. MATERIAL AND METHODS: between March 1996 and November 1999, 31 patients with infra-renal aortic aneurysms who underwent stentgraft implantation were followed with helical CT and MRI, including magnetic resonance angiography (MRA), at 1 and 6 months after the procedure. Arteriography was performed between 6 and 12 months after intervention. The parameters studied included the change in the maximum anteroposterior and transverse diameters, the nature of the signal on T1 and T2 weighted sequences (homogeneous vs heterogeneous), the presence or absence of Gadolinium uptake on MRI or of contrast uptake on helical CT (early and late phases) in the sac of the aneurysm. On MRA, stentgraft patency and endoleak detection were studied. RESULTS: arteriography demonstrated an endoleak in 19 patients (18 type II, and 1 type I endoleak). MRI at 6 months detected 18/19 endoleaks on T1 weighted sequences after injection of Gadoliniumj; there were 2 false positives. MRA sequences confirmed stentgraft patency in all patients, but did not diagnose type II endoleaks. Helical CT (late phase) at 6 months detected 10/19 endoleaks; there was 1 false positive. The sensitivity of MRI after injection of Gadolinium and of helical CT for the detection of type II endoleaks were 94% and 50% (p=0.003) respectively. The mean maximal anteroposterior and transverse diameters were similar on MRI and on helical CT at 1 month and at 6 months. CONCLUSION: MRI after injection of Gadolinium is more sensitive than helical CT in the detection of type II endoleaks after stentgraft implantation. Its more widespread use may permit earlier intervention in such patients.

Rare variations in renal anatomy and blood supply: CT appearances and embryological background. A pictorial essay.

Helical CT angiography is increasingly used for the evaluation of the kidneys and the renal vessels. Knowledge of the potential variants in renal and renal vascular anatomy and of their appearances on helical CT are thus indispensable for radiologists who perform and interpret such examinations. We report six cases of anatomic variants that we encountered in our tertiary referral centre over the past 5 years, during which time we have performed 4850 helical CT angiograms, including 1432 renal artery examinations. These represent rarer anomalies in renal vascularization, most of which were associated with renal malformations (horseshoe kidney with or without cortical torsion, renal malrotation, single kidney, and thoracic origin of a renal artery). We present the helical CT findings and discuss the possible embryological mechanisms and the practical implications of these abnormalities for the radiologist.

Diagnosis and treatment of type II endoleak after stent placement for exclusion of an abdominal aortic aneurysm.

After endovascular treatment of AAA, regular clinical and radiologic surveillance is necessary for early diagnosis and treatment of mid-term and long-term complications. The purpose of this report was to evaluate the efficacy of magnetic resonance imaging (MRI) in screening for type II endoleaks and assessing the results of treatment by embolization. From March 1996 to November 1999, 64 patients with uncomplicated infrarenal abdominal aortic aneurysm (AAA) were treated by endovascular exclusion with a covered aortic stent. Radiological surveillance included plain abdominal roentgenogram (PAR), CT scan, and pelvioabdominal MRI at 1 month, 3 months, 6 months, and every 6 months thereafter. Arteriography was performed routinely after 1 year or sooner if an endoleak was suspected. Based on the results of this study, MRI seems to be more sensitive than CT scanning for detection of type II endoleaks. The negative predictive value of MRI is also better. In this series, all endoleaks were treated by embolization. In most cases, the maximum transverse diameter and maximum anteroposterior diameter decreased after embolization. Further follow-up will be necessary to confirm these findings.

Endovascular treatment for dissection of the descending aorta.

Surgery for acute ischaemia complicating dissection of the descending aorta is associated with high mortality. We used an endovascular fenestration approach (scissor technique) to treat seven of 12 patients with ischaemic complications of descending aortic dissection; the remaining five patients were treated by stent implantation. Four of the 12 patients died (two in the fenestration group and two in the stenting group) in the days after the procedure. The remaining eight were symptom-free a mean of 9.4 (SD 8) months later. We suggest that the fenestration approach is a promising addition to endovascular treatment for patients with ischaemic complications of descending aortic dissection.

[Intravascular Doppler for the evaluation of renal blood flow: validation and demonstration of vessel reactivity]. / Doppler endovasculaire dans les artères rénales. Validation de la méthode et mise en évidence de la réactivité vasculaire.

AIM: To assess the feasibility and to demonstrate the potential clinical application of intravascular doppler in the evaluation of renal blood flow in patients with hypertension and normal renal arteries. MATERIALS AND METHODS: Intravascular doppler was used to measure renal blood flow in 19 patients (34 kidneys) during arteriography to rule out renovascular hypertension. Arteriography showed no evidence of renal artery stenosis in any patient. Hemodynamic parameters, renal artery diameter, and doppler measurements were undertaken at baseline, after injection of a bolus (10 ml) of normal (0.9%) saline, and after injection of isosorbide dinitrate (1 mg diluted in 10 ml normal saline). RESULTS: Repeated measurements of renal blood flow confirmed the reproducibility of the technique. Basal blood flow was similar in both right and left kidneys; injection of vehicle solution (10 ml normal saline) had no effect on doppler parameters. Injection of isosorbide dinitrate resulted in a significant increase in renal blood flow velocity reflecting an increase in renal blood flow; this demonstrates the existence of a renal flow reserve. The degree of increase in renal blood flow varied significantly between kidneys. CONCLUSIONS: Intravascular doppler is a safe, effective, and reproducible technique for measurement of renal blood flow. It allows evaluation of variations in renal blood flow in response to diverse vasoactive drugs or other vasomotor stimuli. The present study demonstrated the heterogenous response of renal blood flow in response to vasodilator stimuli.