Magnetization transfer ratio for the assessment of perianal fistula activity in Crohn's disease.

OBJECTIVES: Assessment of perianal fistulas is important to guide management of Crohn's disease (CD). Our objectives were to analyze the feasibility of magnetization transfer (MT) imaging to assess fistulas and to evaluate its contribution in assessing disease activity. METHODS: During 15 months, all patients referred for perianal fistulas in CD underwent 3T-MRI including diffusion, T2/T1-weighted gadolinium-enhanced sequences and MT sequences (one with an off-resonance saturation pulse of 800 and one with 1200 Hz). We collected Van Assche score, fistula activity signs by analyzing T2, diffusion and contrast enhancement. We calculated MT ratio (MTR) with a ROI in the largest fistula. RESULTS: Twenty-nine patients (mean 34.9 years, range 17-53) were included. Van Assche score was 11.7, range 4-21. In 22 patients, the fistula presented with a bright T2 and diffusion signal with contrast enhancement, and was characterized as active. Mean MTR was respectively 47.2 (range 12-68) and 34.3 (range 11-57) at 800 and 1200 Hz. MTR at 800 Hz was significantly lower in non-active (34, range 12-55) than in active fistulas (51, range 24-68) (p < 0.02). CONCLUSIONS: MTR is feasible for the assessment of fistulas in CD and in the future could be used to help identify active and non-active fistulas. KEY POINTS: • MTR is feasible for the assessment of perianal fistulas in CD. • MT allows quantitative imaging of perianal fistula activity in CD. • MTR could be used to help identify active and non-active fistulas in CD.

Direct Aspiration versus Combined Technique for Distal Medium-Vessel Occlusions: Comparison on a Human Placenta Model.

BACKGROUND AND PURPOSE: Mechanical thrombectomy appears to be a promising option for distal medium-vessel occlusions, for which intravenous thrombolysis is effective but may be insufficient when used alone. This study aimed to determine the optimal technique for these distal mechanical thrombectomies using the human placenta model. MATERIALS AND METHODS: Twenty-four procedures were performed, allowing comparison of direct aspiration (n = 12) versus the combined technique (n = 12). Two positions of the aspiration catheter were tested for each of these techniques: in direct contact with the clot and at a distance from it (5-10 mm). Two types of clots were tested: red blood cell-rich clots and fibrin-rich clots. First-pass recanalization and induced arterial collapse and traction were assessed. RESULTS: The first-pass recanalization was less frequent for direct aspiration than for the combined technique, without reaching statistical significance (41.7% versus 75.0%, P = .098). Full collapse (P < .001) and extended arterial traction (P = .001) were significantly less frequent for direct aspiration. For direct aspiration with the aspiration catheter not in direct contact with the clot, there was not a single first-pass recanalization and there was systematic arterial collapse, resulting in a no-flow in the aspiration syringe. CONCLUSIONS: The combined technique appears to be more harmful, and although direct aspiration has a lower rate of first-pass recanalization, it seems appropriate to try direct aspiration as a first-line procedure. However, if the aspiration catheter cannot reach the clot, it is not useful or even risky to try aspiration alone. These results need to be confirmed by clinical studies.

Magnetic resonance colonography in severe attacks of ulcerative colitis.

OBJECTIVES: To evaluate the ability of MR colonography (MRC) to detect lesions in severe attacks of ulcerative colitis (UC) and to assess its concordance with rectosigmoidoscopy. METHODS: Eighteen patients underwent MRC and rectosigmoidoscopy. MRC consisted of a water-filled colonic procedure followed by T1/T2w images. Image quality was recorded. Inflammatory lesions and the existence of signs of severity were analysed. We calculated MR accuracy in the diagnosis of inflammatory lesions, as well as per segment and per patient concordance depending on the presence or absence of severe lesions. RESULTS: The MR image quality of the 108 segments was satisfactory. Endoscopy was used to study 36 segments (rectum and sigmoid). MRC had a positive predictive value of 100% and a sensitivity of 64% in the diagnosis of inflammatory lesions. Concordance for the diagnosis of severe lesions was excellent for the rectum (k = 0.85) and good for the sigmoid (k = 0.64). MRC diagnosed signs of severity in all patients affected at endoscopy. MRC also disclosed signs of severity located higher in the colon in four patients with nonsevere lesions at rectosigmoidoscopy. CONCLUSIONS: MRC can accurately diagnose inflammatory lesions in severe attacks of UC and significantly correlates with rectosigmoidoscopy in the diagnosis of severe lesions.

ESPR uroradiology task force and ESUR paediatric working group: imaging recommendations in paediatric uroradiology, part IV: Minutes of the ESPR uroradiology task force mini-symposium on imaging in childhood renal hypertension and imaging of renal trauma in children.

Two new recommendations of the European Society of Radiology task force and the European Society of Uroradiology workgroup on paediatric uroradiology are presented. One deals with diagnostic imaging in children after trauma to the urinary tract-renal trauma, in particular. The other concerns the evaluation of suspected renal hypertension. Available data in the paediatric literature are either unsatisfactory or controversial for both of these clinical settings. Therefore, the following consensus-based proposals aim at outlining effective imaging algorithms to reduce invasive imaging procedures while optimising diagnostic accuracy. The objective of following a more uniform imaging approach is to facilitate future meta-analysis as well as multicentre and other more evidence-based studies. The practise in paediatric radiology is typically based on local availability and on the limitations of professional expertise and equipment, balanced against the perceived needs of the individual child. Although this is unlikely to change in the near future, it does not release the physicians in charge of diagnostic imaging from their responsibility in choosing and providing state-of-the-art imaging and management protocols that are adapted specifically for use in children.

[Hyperattenuating renal mass]. / Nodule rénal spontanément hyperdense.

Leiomyoma is a frequently uterine tumour. Its location on the urinary tract is rare, making its iconographic diagnosis difficult. The ablation is often realized, allowing the histological confirmation. Renal leiomyoma have good prognosis. In our patient, the CT scan discovered a spontaneously hyperattenuating renal mass, raising after injection of contrast, at a 48-year-old patient. MRI revealed in particular a hyposignal T2. Because of its capsular location, the possibility of a renal leiomyoma had been envisaged without being able to eliminate a malignant lesion. The histological exam confirms this benign hypothesis. So leiomyoma is a rarely renal tumour, of excellent prognosis. The progress of the imaging allows the characterization of these hurts today and could, can be, in a near future, be an alternative at surgery.

MR delayed enhancement imaging findings in suspected acute myocarditis.

The purpose of the study was to prospectively assess the clinical impact of routinely performed delayed enhancement imaging in suspected acute myocarditis. A two-centre prospective study was performed in patients with suspected acute myocarditis. The protocol included horizontal long axis, vertical long axis and short axis ciné MR and delayed enhancement imaging after Gd-DTPA infusion (0.2 mmol/kg). Sixty consecutive patients were enrolled (aged 49.4 +/- 17.8 years). MRI demonstrated delayed enhancement sparing the subendocardicardial layer in 51.6% of patients, concordant with the diagnosis of acute myocarditis; 16.7% of patients exhibited delayed enhancement involving the subendocardial layer with irregular margins, concordant with the diagnosis of acute myocardial infarction; 31.7% of patients had delayed enhancement imaging that was considered normal. Routine imaging to identify delayed enhancement provided crucial information in suspected acute myocarditis by reinforcing the diagnosis in 51.6% of patients and correcting a misdiagnosed acute myocardial infarction in 16.7% of patients.

[Chronic constrictive pericarditis: MR imaging features]. / Comment je fais une IRM pour péricardite chronique constrictive?

Chronic constrictive pericarditis is defined by an increase in the rigidity of the pericardium resulting in impairment of the ventricular filling conditions. Cardiac MR is both a morphological and functional study always complemented by multi-detector CT. Morphological analysis is based on axial, longitudinal long axis and short axis views on Turbo (fast) SE Dark Blood and CINE sequences. Functional analysis is based on real-time acquisitions in the short axis at the base of the ventricles by comparing spontaneous breathing and deep breathing. The excursion of the interventricular septum is a reliable sign of constriction. The study is supplemented by phase contrast acquisitions. In the setting of persistent inflammation or free pericardial fluid, delayed enhancement 3D and 2D sequences including Phase Sensitive Inversion Recovery (PSIR) are useful.

[Multiple ovarian fibromas in a patient with Gorlin syndrome: US and MR imaging features with pathological correlation]. / Fibromes ovariens multiples chez une patiente atteinte du syndrome de Gorlin.

We report a case of multiple ovarian fibromas in a 23 year old woman with Gorlin syndrome. We describe the US and MR imaging features with pathological correlation. The fibrous component of the tumors were hypoechoic and attenuating on US with corresponding T2W hypointensity whereas myxoid components were hypoechoic with increased through transmission on US with corresponding T2W hyperintensity.

A-mode ultrasound in the diagnosis of maxillary sinusitis in ventilated patients.

PROBLEMS/OBJECTIVES: The diagnosis of maxillary sinusitis in intensive care patients remains problematic. However, it is essential since maxillary sinusitis causes numerous complications and there is an effective treatment. The aim of this study was to compare A-mode ultrasound with sinus computed tomography (CT) for the diagnosis of maxillary sinusitis in intubated patients in critical care undergoing mechanical ventilation. METHODOLOGY: Prospective clinical study in 140 maxillary sinuses in the surgical ICU of a university hospital. In each intubated and mechanically ventilated patient undergoing cerebral CT scan for any reason, a bedside A-mode ultrasonography of the maxillary sinuses was performed the same day. The A-mode ultrasound result was compared with the result of the sinus CT scan for the diagnosis of maxillary sinusitis. RESULTS: Sensitivity, specificity, positive predictive value and negative predictive value of A-mode ultrasound compared with CT were 66.7%, 94.7%, 75.0% and 92.2% respectively. All the empty sinuses were correctly identified as being empty. CONCLUSIONS: Given its very good specificity and negative predictive value, bedside A-mode ultrasound may be a useful first-line examination for intubated and mechanically ventilated patients in intensive care, especially to eliminate suspicion of maxillary sinusitis.

Pediatric cardiac computed tomography angiography: Expert consensus from the Filiale de Cardiologie Pédiatrique et Congénitale (FCPC) and the Société Française d'Imagerie Cardiaque et Vasculaire diagnostique et interventionnelle (SFICV).

This article was designed to provide a pediatric cardiac computed tomography angiography (CCTA) expert panel consensus based on opinions of experts of the Société Française d'Imagerie Cardiaque et Vasculaire diagnostique et interventionnelle (SFICV) and of the Filiale de Cardiologie Pédiatrique Congénitale (FCPC). This expert panel consensus includes recommendations for indications, patient preparation, CTA radiation dose reduction techniques, and post-processing techniques. The consensus was based on data from available literature (original papers, reviews and guidelines) and on opinions of a group of specialists with extensive experience in the use of CT imaging in congenital heart disease. In order to reach high potential and avoid pitfalls, CCTA in children with congenital heart disease requires training and experience. Moreover, pediatric cardiac CCTA protocols should be standardized to acquire optimal images in this population with the lowest radiation dose possible to prevent unnecessary radiation exposure. We also provided a suggested structured report and a list of acquisition protocols and technical parameters in relation to specific vendors.

Differentiation between Fabry disease and hypertrophic cardiomyopathy with cardiac T1 mapping.

PURPOSE: To evaluate the potential of non-contrast myocardial T1 mapping on cardiovascular magnetic resonance examination (CMR) in differentiating patients with Fabry disease (FD) from those with hypertrophic cardiomyopathy (HCM) and healthy control subjects. MATERIALS AND METHODS: Seventeen patients with FD (8 men, 9 women; mean age, 48 ±18 [SD] years; [range: 19-73 years]; 53% with left ventricular hypertrophy [LVH]) were matched with 36 patients with hypertrophic cardiomyopathy (HCM) (22 men, 14 women; mean age, 57±16 [SD] years; [range: 22-85 years]) and 70 healthy control subjects (34 men, 36 women; mean age, 38 ±15 [SD] years; [range: 18-65 years]). Cardiac T1 mapping was performed using the modified Look-Locker inversion (MOLLI®) sequence on a 1.5-T magnet. T1 values were calculated, on midventricular section, for septal left ventricular segments (S8-S9) and all mid-ventricular ones (global T1 values; S7-S12). Statistical analysis included unpaired Mann-Whitney test, receiver operating characteristic curve and likelihood ratios. RESULTS: Septal native T1 values were significantly decreased in patients with FD (889±61 [SD] ms; range: 784-980ms) compared to those with HCM (995±48 [SD] ms; range: 935-1125ms) (P<0.001) and versus healthy controls (965±29 [SD] ms; range: 910-1028ms) (P<0.001). Global native T1 values were also significantly decreased in patients with FD (891±49 [SD] ms; range 794-970ms) compared to those with HCM (995±34 [SD] ms; range: 952-1086ms) (P<0.001) and versus healthy controls (966±27 [SD] ms; range: 920-1042ms) (P<0.001). A septal left ventricular native T1 cutoff value of 940ms could distinguish FD from HCM with 88% sensitivity (95% CI: 73-100%) and 92% specificity (95% CI: 83-100%). Positive likelihood ratio was 11, negative likelihood ratio was 0.12. Compared to controls, the same threshold could distinguish FD with 88% sensitivity (95% CI: 73-100%) and 86% specificity (95% CI: 78-94%). Positive likelihood ratio was 6.3, negative likelihood ratio was 0.14. T1 value was abnormal in 4 of 8 (50%) of FD patients who did not have LVH. CONCLUSION: Native T1 values are significantly lower in patients with FD by comparison with those with HCM and healthy volunteers.

Joint Position Paper of the Working Group of Pacing and Electrophysiology of the French Society of Cardiology (SFC) and the Société française d'imagerie cardiaque et vasculaire diagnostique et interventionnelle (SFICV) on magnetic resonance imaging in patients with cardiac electronic implantable devices.

Magnetic resonance imaging (MRI) has become the reference imaging for the management of a large number of diseases. The number of MR examinations increases every year, simultaneously with the number of patients receiving a cardiac electronic implantable device (CEID). A CEID was considered an absolute contraindication for MRI for years. The progressive replacement of conventional pacemakers and defibrillators by MR-conditional CEIDs and recent data on the safety of MRI in patients with "MR-nonconditional" CEIDs have progressively increased the demand for MRI in patients with a CEID. However, some risks are associated with MRI in CEID carriers, even with "MR-conditional" devices because these devices are not "MR-safe". A specific programing of the device in "MR-mode" and monitoring patients during MRI remain mandatory for all patients with a CEID. A standardized patient workflow based on an institutional protocol should be established in each institution performing such examinations. This joint position paper of the Working Group of Pacing and Electrophysiology of the French Society of Cardiology and the Société française d'imagerie cardiaque et vasculaire diagnostique et interventionnelle (SFICV) describes the effect and risks associated with MRI in CEID carriers. We propose recommendations for patient workflow and monitoring and CEID programming in MR-conditional, "MR-conditional nonguaranteed" and MR-nonconditional devices.

Usefulness of multislice computerized tomography angiography in preoperative diagnosis of ruptured cerebral aneurysms.

OBJECTIVE: Non-invasive imaging methods have become primordial in subarachnoid hemorrhage. The aim of our study was to evaluate the sensitivity and specificity of multislice computed tomographic angiography (MSCTA) for the diagnosis of cerebral aneurysm. METHODS: The 28 included consecutive patients with SAH underwent both MSCTA and digital subtraction angiography (DSA). The MSCTA studies were interpreted by two independent readers (A and B) for the presence, the location and size of the aneurysm comparatively to the DSA as reference examination. RESULTS: In 20 patients, 38 aneurysms were diagnosed and in eight no aneurysm was found. Per patient basis, the diagnostic sensitivity and specificity were excellent. Per aneurysm basis, the diagnostic sensitivity and specificity of MSCTA were, respectively, 97.4 and 100% for reader A, 100 and 100% for reader B. For aneurysms less than 3mm, sensitivity was 100% for both readers. Interobserver agreement was excellent for the detection of aneurysm (kappa=0.98, 95% CI [0.96-1]). Intertechnique and interobserver agreements were excellent for the measurement of aneurysms (slope=0.86, r=0.91 p=3.1x10(-7) and slope=1.04, r=0.99, p<10(-6), respectively). CONCLUSION: MSCTA was an accurate and reproducible non-invasive imaging technique for preoperative diagnosis of ruptured cerebral aneurysm. The MSCTA may be proposed in first intention after the diagnosis of SAH was established, with special care regarding injection procedure and a strict reading method using native images and thin MPR.

[Recommendations for training in cross-sectional cardiac imaging]. / Recommandations pour la formation en imagerie en coupes du coeur et des vaisseaux.

The recent and future advancements that are known in the field of cardiac imaging imply an optimal training of the operators. This training concerns medical specialists whether originating from radiology or cardiology. The training of the medical specialists in cardiac imaging entitles 3 main essential steps: The basic training taking place within each specialty, allowing the fellow to get acquainted with the clinical and technical basics. The specialized training, delivered principally in post-residency. This training must include an upgrading of each specialty in the domain that does not concern it (a technical base for the cardiologist, a physio-pathological and clinical base for the radiologist). It must include a specific theoretical training covering all aspects of cardiac imaging as well as practical training in a certified training centre. The continuous medical training and maintenance of skills that allow a sustained activity in the field and the obligation to regularly participate in the actions of specific validated training. The different aspects of these rules are exposed in this chapter.

[Functional MR urography in children]. / Uro-IRM fonctionnelle chez l'enfant.

MR Urography (MRU) provides both morphologic and functional information without radiation exposure. It enables the assessment of split renal function, excretion, and quantification of obstruction. MRU is thus complementary to ultrasonography in the assessment of pre- and post-natal obstructive uropathies in children. If available, MRU should be definitely preferred to intravenous urography.

[Imaging of acute pelvic pain in women]. / Imagerie de la douleur pelvienne aiguë

Acute pelvic pain in women is a routine situation in any emergency unit. The radiologist should know how to explore the patient with regards to the history and clinical findings. Ultrasonography is the primary and sometimes the only necessary imaging tool in the assessment of acute pelvic pain in women. MRI is the preferred technique in pregnant or young women. CT is more valuable for assessing nongynecologic disorders or post-partum and post-operative infections. This article reviews the contribution of each imaging technique in this clinical situation. Emphasis is put on the importance of age and clinical findings in the diagnostic strategy.

[Early imaging features after sleeve gastrectomy]. / Imagerie précoce de la réduction gastrique type gastrectomie en gouttière.

PURPOSE: Sleeve gastrectomy is a new bariatric surgical procedure with promising early results and low morbidity and mortality. We have evaluated the early imaging findings and value of upper GI study (UGI) and CT. PATIENTS AND METHODS: Twenty five patients (mean age=38.9 years, mean BMI=51.5 kg/m2) following sleeve gastrectomy for morbid obesity underwent UGI at day 1. CT was immediately performed in patients with suspected leak or as a follow-up examinations in patients with suspected complication. The different imaging features observed were recorded. RESULTS: UGI demonstrated 13 normal examinations (52%), an abnormal appearance in 11 cases (44%) with opacification of a lateral pouch, and one complication (leak confirmed on CT). Two patients underweent CT (day 3 and day 15) for suspected complication, with demonstration of leak in both cases. CONCLUSION: An abnormal appearance after sleeve gastrectomy is frequently observed on UGI. Routine UGI at day 1 is useful to detect large leaks. CT with oral contrast should be performed in all patients with imaging or clinical suspicion of leak.

Multidetector computed tomography sizing of aortic annulus prior to transcatheter aortic valve replacement (TAVR): Variability and impact of observer experience.

PURPOSE: To evaluate intra- and inter-observer variability of multidetector computed tomography (MDCT) sizing of the aortic annulus before transcatheter aortic valve replacement (TAVR) and the effect of observer experience, aortic valve calcification and image quality. METHODS: MDCT examinations of 52 consecutive patients with tricuspid aortic valve (30 women, 22 men) with a mean age of 83±7 (SD) years (range: 64-93 years) were evaluated retrospectively. The maximum and minimum diameters, area and circumference of the aortic annulus were measured twice at diastole and systole with a standardized approach by three independent observers with different levels of experience (expert [observer 1]; resident with intensive 6 months practice [observer 2]; trained resident with starting experience [observer 3]). Observers were requested to recommend the valve prosthesis size. Calcification volume of the aortic valve and signal to noise ratio were evaluated. RESULTS: Intra- and inter-observer reproducibility was excellent for all aortic annulus dimensions, with an intraclass correlation coefficient ranging respectively from 0.84 to 0.98 and from 0.82 to 0.97. Agreement for selection of prosthesis size was almost perfect between the two most experienced observers (k=0.82) and substantial with the inexperienced observer (k=0.67). Aortic valve calcification did not influence intra-observer reproducibility. Image quality influenced reproducibility of the inexperienced observer. CONCLUSION: Intra- and inter-observer variability of aortic annulus sizing by MDCT is low. Nevertheless, the less experienced observer showed lower reliability suggesting a learning curve.

Distribution of left ventricular trabeculation across age and gender in 140 healthy Caucasian subjects on MR imaging.

PURPOSE: The purpose of this study was to quantify the distribution of trabeculated (T) and compact (C) left ventricular (LV) myocardium masses in a healthy Caucasian population against age, gender and LV parameters, and to provide normal values for T, C and T/C. MATERIALS AND METHODS: One hundred and forty healthy subjects were prospectively recruited and underwent cardiac MRI at 1.5T with a stack of short-axis cine sequences covering the entire LV. End-diastolic volume (EDV), C and T masses were quantified using a semi-automatic method. Ejection fraction (EF) and T/C ratio were computed. RESULTS: We included 70 men and 70 women with a mean age of 44±14 (SD) years (range: 20-69 years). The mean EF was 63.7±6.3 (SD) % (range: 50.7-82.0%), the mean EDV was 75.9±16.2 (SD) mL/m2 (range: 36.4-112.2mL/m2), the mean C mass was 53.9±11.2 (SD) g/m2 (range: 26.5-93.4g/m2) and the mean T mass was 4.9±2.4 (SD) g/m2 (range: 1.1-11.4g/m2). The T/C ratio was 9.2±4.5% (range: 2.0-29.4%). Multivariate ANOVA test showed that the compact mass was influenced by EDV (P<0.0001), EF (P=0.001) and gender (P<0.0001), and the trabeculated mass depended on EDV (P<0.0001), gender (P=0.002) and age (P<0.0001), while the T/C ratio was only influenced by age (P=0.0003). Spearman test showed a correlation between EDV and C (r=0.60; P<0.0001),T (r=0.46; P<0.0001) and T/C ratio (r=0.26; P=0.0023).T and T/C ratio correlated with EF (r=-0.18, P=0.0373; r=-0.18, P=0.0321, respectively). CONCLUSION: While the compact and trabeculated myocardium masses appear to relate separately to the cardiac function, age and gender, their ratio T/C appears to only decrease with age. Furthermore, we propose here normal values for T, C and T/C in a cohort of healthy Caucasians subjects.

[The first campaign to evaluate interns in radiodiagnosis in 2005: national results]. / Première campagne d'évaluation des internes de radiodiagnostic en 2005: résultats nationaux.

Teaching cannot exist without evaluation for three main reasons: it is indispensable to know interns' skills in radiodiagnosis and medical imaging during their training; it is useful to encourage excellence in interns to stimulate their learning; and finally, it is indispensable to provide feedback to teaching personnel so as to modify or correct teaching techniques, modalities, and programs. In September 2005, 260 interns in training participated voluntarily in the first national evaluation campaign. We will attempt to delineate the main lines of this initial experience as well as its limitations.