Clinical Axillary Staging in Breast Cancer Patients Using Ultrasound Imaging.

Introduction: The presence of axillary lymph node involvement is an important prognostic factor and has a major impact on treatment decisions in early breast cancer patients. This study aimed to determine the role of cortical thickness in axillary ultrasound (AUS) as an indicator of lymph node metastasis. Methods: 766 patients with primary breast cancer who received AUS during clinical work-up were selected for this retrospective study. Lymph nodes were defined as suspicious if they showed a cortical thickness of >3.0 mm at 11-15 MHz harmonic imaging ultrasound. Lymph node involvement was assessed by core needle biopsy (n = 150), sentinel node dissection or axillary dissection. Extensive axillary spread (EAS) was diagnosed if more than two lymph nodes showed metastatic disease in histology. Results: AUS for detecting all lymph node metastases had a sensitivity of 62.27%, a specificity of 93.15% and a negative predictive value of 81.74%. However, the resulting negative predictive value for transcapsular growth was 93.97%, and for EAS 97.52%. Conclusion: EAS - in contrast to non-palpable involvement of 1 or 2 lymph nodes - contributes relevantly to the individualization of breast cancer treatment. In combination with SNB, AUS using cortical thickness as the main distinctive parameter seems to be an easily available, robust tool of diagnosing extensive axillary metastases. If AUS proves negative, it helps to reduce the number of classic axillary dissections.

Towards risk stratification in systemic atherosclerosis: value of myocardial function and viability imaging as an adjunct to MR angiography.

OBJECTIVES: To longitudinally assess the value of cardiac functional and viability imaging as a supplement to MR angiography in patients with atherosclerotic disease. METHODS: Cardiac MRI was performed in 195 consecutive patients with symptomatic peripheral arterial disease. Of these, 186 patients were followed for 22 +/- 5 months for the presence of cardiac events (cardiac death, acute coronary syndrome and hospitalisation as a result of congestive heart failure). RESULTS: Myocardial viability imaging showed a high prevalence of known (n = 31) and occult myocardial infarctions (MI) (n = 26). Cardiac events occurred more often in patients with reduced ventricular function (ejection fraction (EF) less than 40%, cardiac event in 4/8 patients; EF 40-55%, cardiac event in 10/40 patients; EF greater than 55%, cardiac event in 15/138 patients) as well as in patients with occult MI (8/25 patients) and known MI (11/30 patients). In patients with normal function, the detection of a previous MI was of high relevance to prognosis. CONCLUSIONS: Both reduced EF and the presence of MI influence patients' prognoses. Performing cardiac MRI in this patient population may influence further patient management including intensified risk factor intervention.

Three-dimensional cine MRI in free-breathing infants and children with congenital heart disease.

BACKGROUND: Patients with congenital heart disease frequently have complex cardiac and vascular malformations requiring detailed non-invasive diagnostic evaluation including functional parameters. OBJECTIVE: To evaluate the morphological and functional information provided by a novel 3-D cine steady-state free-precession (SSFP) sequence. MATERIALS AND METHODS: Twenty consecutive children (mean age 2.2 years, nine boys) were examined using a 1.5-T MR system including 2-D cine gradient-recalled-echo sequences, static 3-D SSFP and 3-D cine SSFP sequences. RESULTS: Measurement of ventricular structures and volumes showed close agreement between the 3-D cine SSFP sequence and the 2-D cine gradient-recalled-echo and static 3-D SSFP sequences (left ventricular volumes mean difference 1.0-1.9 ml and 8.8-11.4%, respectively; right ventricular volumes 1.7-2.1 ml and 9.9-16.9%, respectively). No systematic bias was observed. CONCLUSION: 3-D cine MRI provides anatomic as well as functional information with sufficient spatial and temporal resolution in free-breathing infants with congenital heart disease.

Comparison between a linear versus a macrocyclic contrast agent for whole body MR angiography in a clinical routine setting.

BACKGROUND: Previous experiences of whole body MR angiography are predominantly available in linear 0.5 M gadolinium-containing contrast agents. The aim of this study was to compare image quality on a four-point scale (range 1-4) and diagnostic accuracy of a 1.0 M macrocyclic contrast agent (gadobutrol, n = 80 patients) with a 0.5 M linear contrast agent (gadopentetate dimeglumine, n = 85 patients) on a 1.5 T whole body MR system. Digital subtraction angiography served as standard of reference. RESULTS: All examinations yielded diagnostic image quality. There was no significant difference in image quality (3.76 +/- 0.3 versus 3.78 +/- 0.3, p = n.s.) and diagnostic accuracy observed. Sensitivity and specificity of the detection of hemodynamically relevant stenoses was 93%/95% in the gadopentetate dimeglumine group and 94%/94% in the gadobutrol group, respectively. CONCLUSION: The high diagnostic accuracy of gadobutrol in the clinical routine setting is of high interest as medical authorities (e.g. the European Agency for the Evaluation of Medicinal Products) recommend macrocyclic contrast agents especially to be used in patients with renal failure or dialysis.

Impact of Papillary Muscle Infarction on Ischemic Mitral Regurgitation Assessed by Magnetic Resonance Imaging.

OBJECTIVE: Ischemic mitral regurgitation is a predictor of heart failure resulting in increased mortality in patients with chronic myocardial infarction. It is uncertain whether the presence of papillary muscle (PM) infarction contributes to the development of mitral regurgitation in patients with chronic myocardial infarction (MI). The aim of the present study was to assess the correlation of PM infarction depicted by MRI with mitral regurgitation and left ventricular function. METHODS AND MATERIALS: 48 patients with chronic MI and recent MRI and echocardiography were retrospectively included. The location and extent of MI depicted by MRI were correlated with left ventricular function assessed by MRI and mitral regurgitation assessed by echocardiography. The presence, location and extent of PM infarction depicted by late gadolinium enhancement (LGE-) MRI were correlated with functional parameters and compared with patients with chronic MI but no PM involvement. RESULTS: PM infarction was found in 11 of 48 patients (23 %) using LGE-MRI. 8/11 patients (73 %) with PM infarction and 22/37 patients (59 %) without PM involvement in MI had ischemic mitral regurgitation. There was no significant difference between location, extent of MI and presence of mitral regurgitation between patients with and without PM involvement in myocardial infarction. In 4/4 patients with complete and in 4/7 patients with partial PM infarction, mitral regurgitation was present. The normalized mean left ventricular end-diastolic volume was increased in patients with ischemic mitral regurgitation. CONCLUSION: The presence of PM infarction does not correlate with ischemic mitral regurgitation. In patients with complete PM infarction and consequent discontinuity of viable tissue in the PM-chorda-mitral valve complex, the probability of developing ischemic mitral regurgitation seems to be increased. However, the severity of mitral regurgitation is not increased compared to patients with partial or no PM infarction. KEY POINTS: · No correlation between ischemic mitral regurgitation and presence of papillary muscle infarction. · Complete papillary muscle infarction results in dysfunction associated with ischemic mitral regurgitation. · Severity of mitral regurgitation not increased in patients with complete PM infarction. CITATION FORMAT: · Bretschneider C, Heinrich H, Seeger A et al. Impact of Papillary Muscle Infarction on Ischemic Mitral Regurgitation Assessed by Magnetic Resonance Imaging. Fortschr Röntgenstr 2018; 190: 42 - 50.

Cardiac magnetic resonance imaging in patients undergoing percutaneous mitral valve repair with the MitraClip system.

BACKGROUND: Percutaneous mitral valve repair (MVR) with the MitraClip(®) system in patients with mitral regurgitation (MR) is known to reduce symptoms and to improve cardiac morphology and function. MitraClip has been approved for cardiac magnetic resonance imaging (MRI). To date, however, no systematic analysis exists on cardiac MRI in patients undergoing the MitraClip procedure. OBJECTIVE: The aim of this study was to (1) prove feasibility and robustness of cardiac MRI and (2) visualize effects of the procedure on cardiac morphology and function by cardiac MRI. METHODS: 27 consecutive patients (age 77.5 ± 7.6 years) with symptomatic moderate to severe MR undergoing the MitraClip(®) procedure were prospectively included. Cardiac MRI at 1.5 T was performed before and at 3 months after intervention. Cardiac morphology and function were evaluated using steady-state free precession (SSFP) cine sequences by assessment of left ventricular enddiastolic and endsystolic diameters (LVEDD, LVESD) and volumes (EDV, ESV), ejection fraction (LVEF) and stroke volume (SV), diameter of mitral annulus, and myocardial mass (MM). Planimetry of the left atrium (LA) was performed in identical slices in a four-chamber view. RESULTS: Around the clip an extinction artifact was observed which did not disturb the evaluation of cardiac morphology and function. At follow-up, we observed significant decreases of LVEDD (58.0 to 53.3 mm, p < 0.0001), EDV (167 to 159 mL, p = 0.0006) and ESV (101 to 89 mL, p < 0.0001), diameter of mitral annulus (41.4 to 37.9 mm, p < 0.0001), myocardial mass (148.4 to 144.5 g, p = 0.0004) and LA size (40.2 to 37.6 cm(2), p < 0.0001). LVEF improved (43.3 to 46.7 %, p = 0.0041). CONCLUSIONS: Cardiac MRI is feasible and robust in patients with MitraClips. The clinical benefit of a successful MitraClip intervention is paralleled by significant improvements of cardiac morphology and function which can be monitored and validated using MRI in clinical follow-up examinations.

Diagnostic value of high spatial and temporal resolution time-resolved MR angiography in the workup of peripheral high-flow vascular malformations at 1.5 Tesla.

To evaluate the feasibility and diagnostic impact of time-resolved MR angiography (TR-MRA) combined with parallel imaging and low contrast dose for the assessment of peripheral high-flow vascular malformations (VM) at 1.5 Tesla (T). Twelve consecutive patients (7 female, 5 male, mean age 24.7 ± 11.1 years) with known or suspected high-flow VM underwent time-resolved MRA. Two readers individually assessed image quality, diagnostic confidence as well as hemodynamic features. Digital subtraction angiography (DSA) correlation was available in 9 patients. TR-MRA provided a comprehensive assessment of all VMs with good quality images, allowing reliable differentiation of the early and main arterial phases and of at least the early venous phase. Based on hemodynamic features VM were classified as predominantly arterial malformations in 5 cases (42%), or arteriovenous malformations in the remaining 7 cases (58%). The high-flow component of a VM was confirmed by DSA in 9/9 (100%) cases during the interventional treatment procedure. TR-MRA of peripheral VMs with temporal interpolation and stochastic spiral trajectories is feasible, allowing the assessment of dynamic inflow and vessel-specific information similar to conventional DSA. Therefore, TR-MRA represents a reasonable alternative imaging technique for the pre-treatment evaluation of high-flow VMs.

Fusion of MR coronary angiography and viability imaging: feasibility and clinical value for the assignment of myocardial infarctions.

PURPOSE: To investigate the feasibility of image fusion of MR-coronary angiography (MRCA) and delayed gadolinium enhancement imaging (LGE) and to assign areas of myocardial infarction to the corresponding supplying coronary arteries. MATERIALS AND METHODS: An interactive segmentation of the coronary arteries was performed in MRCA data sets (n=25). The LGE slices were matched onto the vessel segmentation to perform a fused analysis of coronary artery anatomy and LGE. The results were compared to the segmental model recommended by the American Heart Association (AHA). Standard of reference was the identification of the culprit lesion in the invasive coronary angiography (CA) (n=20). RESULTS: The fused analysis allowed the assignment of MI to the supplying coronary artery in 13/20 patients. The sensitivities/specificities for the assignment of MI to the three main vessels were: LAD 63%/100%, LCX 75%/100%, and RCA 56%/100%, respectively. Using the AHA segmental model the sensitivities/specificities for the correct assignment of MI to the three main vessels were: LAD 88%/58%, LCX 94%/75%, and RCA 77%/73%, respectively. CONCLUSION: Fusion images of MRCA and LGE provides added diagnostic information in the effort to determine the epicardial vessels responsible for the postischemic myocardial injury and therefore might be helpful to establish appropriate future therapeutic steps.

Low-dose, time-resolved, contrast-enhanced 3D MR angiography in the assessment of the abdominal aorta and its major branches at 3 Tesla.

RATIONALE AND OBJECTIVES: The aims of this study were to evaluate the effectiveness of low-dose, contrast-enhanced (CE), time-resolved, three-dimensional magnetic resonance angiography (MRA) in the assessment of the abdominal aorta and its major branches at 3 T and to compare the results with those of high-spatial resolution CE MRA. MATERIALS AND METHODS: Twenty-two consecutive patients (eight men, 14 women; mean age, 43.9 +/- 17.9 years) underwent CE time-resolved three-dimensional MRA and high-spatial resolution three-dimensional MRA. Studies were performed using a 3-T magnetic resonance system; gadolinium-based contrast medium was administered at a dose of 3 to 5 mL for time-resolved MRA, followed by 0.1 mmol/kg gadopentetate dimeglumine for single-phase CE MRA. For analysis purposes, the abdominal arterial system was divided into 11 arterial segments, and image quality as well as the presence and degree of vascular pathology were evaluated by two independent magnetic resonance radiologists. RESULTS: A total of 242 arterial segments were visualized with good image quality. Time-resolved MRA was able to visualize the majority of arterial segments with good definition in the diagnostic range. Vascular pathologies (stenosis, occlusion) or abnormal vascular anatomy was detected in 19 arterial segments, with good interobserver agreement (kappa = 0.78). All image findings were detected with time-resolved CE MRA by both observers and were confirmed by correlative imaging. CONCLUSION: Low-dose, time-resolved MRA at 3 T yields rapid and important anatomic and functional information in the evaluation of the abdominal vasculature. Because of its limited spatial resolution, time-resolved MRA is inferior to CE MRA in demonstrating fine vascular details.

Determination of unknown high-grade atherosclerotic lesions by whole-body cardiovascular imaging: assessment of patients with symptomatic atherosclerotic disease of peripheral arteries.

RATIONALE AND OBJECTIVES: The long-term prospects for patients with peripheral-arterial-occlusive disease (PAOD) must be considered in the context of coexistent generalized atherosclerosis. We sought to determine the added clinical information of noninvasive magnetic resonance imaging (MRI) for detecting asymptomatic atherosclerotic disease in patients already at high risk. MATERIALS AND METHODS: Eighty-four patients (64 men, mean age 66.2 + or - 10.0 years, range 34-84 years) with suspected or known PAOD were examined using a comprehensive cardiovascular MRI protocol. Two experienced observers reviewed all MRIs for the presence of "relevant findings," which were defined as pathology requiring immediate therapy or mid-term follow-up. RESULTS: Assessment of cardiac structures and function in 84 study patients yielded new pathology in 40 (48%) patients, whereas cerebral imaging revealed new findings in 45 (54%) patients. Previously unsuspected vascular findings were evident in 46 (55%) patients. Using the information from the MRIs, in 54 (64%) of patients mid-term follow-up was required, whereas in 7 (8%) patients a change of therapy or immediate treatment was necessary. CONCLUSION: Whole-body cardiovascular MRI is able to detect symptomatic and unsuspected findings in patients with PAOD. This technique was able to detect several vascular abnormalities that necessitated immediate medical attention and intervention in patients already identified as high-risk patients and, therefore, may show an increasing impact to determine individual therapeutic and follow-up concepts.

Impact of restrictive physiology on intrinsic diastolic right ventricular function and lusitropy in children and adolescents after repair of tetralogy of Fallot.

BACKGROUND: Restrictive right ventricular (RV) physiology is a phenomenon considered potentially beneficial when detected in children and adolescents with repaired tetralogy of Fallot (ToF). It is typically characterised by antegrade flow in the pulmonary artery in late diastole at the time of atrial contraction. However, little is known about the impact of restrictive physiology on intrinsic diastolic RV function or lusitropy. METHODS: Diastolic function was prospectively assessed at baseline level and during dobutamine infusion using the pressure-volume conductance system. End diastolic forward flow in the pulmonary artery was measured by MRI. RESULTS: Twenty-five patients aged 17.9±7.5 years were studied. Although the end diastolic RV pressure, the time constant of isovolumic RV relaxation (τ) and dP/dtmin were similar between both groups, the slope of the end diastolic pressure-volume relationship (Eed) was significantly higher in the restrictive group indicating increased diastolic stiffness in these patients (0.14±0.05 vs 0.06±0.01, p=0.03). Dobutamine stress, however, led to an increase in Eed in the entire ToF cohort indicating an abnormal diastolic response to catecholamines in these patients. CONCLUSIONS: Diastolic RV stiffness of repaired ToF patients with restrictive physiology is increased. The lusitropic response of the RV to ß adrenergic agents is abnormal after ToF repair regardless of whether restrictive physiology is present or not. This has potential implications, particularly for postoperative drug management.

Atherosclerotic disease: whole-body cardiovascular imaging with MR system with 32 receiver channels and total-body surface coil technology--initial clinical results.

In this prospective study, the feasibility of a comprehensive cardiovascular imaging protocol with a dedicated whole-body 1.5-T magnetic resonance (MR) imager with 32 receiver channels in 34 patients with peripheral arterial occlusive disease was evaluated. Informed consent and institutional review board approval were obtained. Three-dimensional MR angiographic data sets were acquired with adapted injection protocol. Cardiac functional imaging and delayed-enhancement imaging were performed, as were fluid-attenuated inversion-recovery imaging of the brain and time-of-flight MR angiography of the intracranial blood vessels. Sensitivity and specificity for depiction of significant vascular stenosis (> 70%) were 96%, with conventional digital subtraction angiography as the standard. Substantial microangiopathic tissue alterations (n = 4) and/or cerebral infarction (n = 4) were diagnosed in seven patients. In seven patients, subendocardial or transmural delayed enhancement was detected in corresponding regions, indicating prior myocardial infarction. Previously unknown findings diagnosed with MR imaging required midterm follow-up or therapy in 24 patients, whereas change of therapy or immediate treatment was necessary in three. For patients suspected of having systemic atherosclerotic disease, comprehensive risk assessment is feasible within 30 minutes.