Are Sonographically Measured Vascular Haemodynamic Parameters Reproducible Using Magnetic Resonance Imaging?

OBJECTIVE/BACKGROUND: Hemodynamic measurements of blood flow in the common femoral vein and artery can be performed readily using duplex sonography. The ratio of venous to arterial volume flow in these vessels, the venous arterial flow index (VAFI), is increased in patients with varicose veins and/or chronic venous disease. The objective was to determine the reproducibility of sonographically measured hemodynamic flow parameters using phase contrast magnetic resonance imaging (MRI). METHODS: Based on hemodynamic volume flow measurements from the common femoral vein and artery the VAFI was calculated in seven patients with varicose veins (C2, Ep, As, Pr) and 32 healthy controls using standard duplex sonography and MRI. RESULTS: Based on duplex sonography, the average VAFI (VAFI_d) was 1.05 ± 0.17. The same ratio, using MRI (VAFI_mri) was 1.05 ± 0.19. There was a significant correlation between the VAFI_d and the VAFI_MRI (p = .0021). In patients with venous disease, the average VAFI_d and VAFI_mri were 1.36 ± 0.21 and 1.36 ± 0.20, respectively. In contrast, in the healthy cohort the VAFI_d was 1.00 ± 0.12 and the VAFI_mri measured 1.01 ± 0.15. As expected, there was a significant difference between the VAFI measured in those with venous disease when compared with that of healthy controls (p < .0001). CONCLUSION: There is a significant correlation between the VAFI measured using sonography and MRI. The study confirmed the elevation of VAFI in patients with chronic venous disease.

Radiotherapy beyond cancer: target localization in real-time MRI and treatment planning for cardiac radiosurgery.

PURPOSE: Atrial fibrillation (AFib) is the most common cardiac arrhythmia that affects millions of patients world-wide. AFib is usually treated with minimally invasive, time consuming catheter ablation techniques. While recently noninvasive radiosurgery to the pulmonary vein antrum (PVA) in the left atrium has been proposed for AFib treatment, precise target location during treatment is challenging due to complex respiratory and cardiac motion. A MRI linear accelerator (MRI-Linac) could solve the problems of motion tracking and compensation using real-time image guidance. In this study, the authors quantified target motion ranges on cardiac magnetic resonance imaging (MRI) and analyzed the dosimetric benefits of margin reduction assuming real-time motion compensation was applied. METHODS: For the imaging study, six human subjects underwent real-time cardiac MRI under free breathing. The target motion was analyzed retrospectively using a template matching algorithm. The planning study was conducted on a CT of an AFib patient with a centrally located esophagus undergoing catheter ablation, representing an ideal case for cardiac radiosurgery. The target definition was similar to the ablation lesions at the PVA created during catheter treatment. Safety margins of 0 mm (perfect tracking) to 8 mm (untracked respiratory motion) were added to the target, defining the planning target volume (PTV). For each margin, a 30 Gy single fraction IMRT plan was generated. Additionally, the influence of 1 and 3 T magnetic fields on the treatment beam delivery was simulated using Monte Carlo calculations to determine the dosimetric impact of MRI guidance for two different Linac positions. RESULTS: Real-time cardiac MRI showed mean respiratory target motion of 10.2 mm (superior-inferior), 2.4 mm (anterior-posterior), and 2 mm (left-right). The planning study showed that increasing safety margins to encompass untracked respiratory motion leads to overlapping structures even in the ideal scenario, compromising either normal tissue dose constraints or PTV coverage. The magnetic field caused a slight increase in the PTV dose with the in-line MRI-Linac configuration. CONCLUSIONS: The authors' results indicate that real-time tracking and motion compensation are mandatory for cardiac radiosurgery and MRI-guidance is feasible, opening the possibility of treating cardiac arrhythmia patients completely noninvasively.

High-Intensity Focused Ultrasound Ablation of Uterine Fibroids - Potential Impact on Fertility and Pregnancy Outcome.

Laparoscopic myomectomy is regarded as the gold standard for women with symptomatic fibroids who wish to become pregnant. High-intensity focused ultrasound (HIFU or MRgFUS) ablation of uterine fibroids is also being discussed as a non-surgical, minimally invasive, therapeutic option. This review examines the available data on the impact of HIFU/MRgFUS on fertility and pregnancy, focusing particularly on potential direct side-effects of this type of intervention on ovaries, fallopian tubes and uterus and potential late effects on pregnancy and birth, based on the current literature. All pregnancies after HIFU/MRgFUS published to date (around 100 cases) were evaluated. The published case series suggest that HIFU/MRgFUS ablation has no impact on the rate of miscarriages or other obstetrical outcome parameters. Because no prospective studies exist which permit firm conclusions to be drawn on the impact of HIFU/MRgFUS on fertility and pregnancy outcome in women with symptomatic fibroids, this approach is currently only recommended for women with suspected fertility problems due to uterine fibroids who either decline surgery or who have an unacceptably high surgical risk.

MR-guided HIFU treatment of symptomatic uterine fibroids using novel feedback-regulated volumetric ablation: effectiveness and clinical practice.

PURPOSE: To evaluate a novel feedback-regulated volumetric sonication method in MR-guided HIFU treatment of symptomatic uterine fibroids. MATERIALS AND METHODS: 27 fibroids with an average volume of 124.9 ± 139.8 cc in 18 women with symptomatic uterine fibroids were ablated using the new HIFU system Sonalleve (1.5 T MR system Achieva, Philips). 21 myomas in 13 women were reevaluated 6 months later. Standard (treatment) cells (TC) and feedback-regulated (feedback) cells (FC) with a diameter of 4, 8, 12, and 16 mm were used and compared concerning sonication success, diameter of induced necrosis, and maximum achieved temperature. The non-perfused volume ratio (NPV related to myoma volume) was quantified. The fibroid volume was measured before, 1 month, and 6 months after therapy. Symptoms were quantified using a specific questionnaire (UFS-QoL). RESULTS: In total, 205 TC and 227 FC were applied. The NPV ratio was 23 ± 15 % (2 - 55). The TC were slightly smaller than intended (-3.9 ± 52 %; range, -100 - 81), while the FC were 20.1 ± 25.3 % bigger (p = 0.02). Feedback mechanism is less diversifying in diameter (p < 0.001). Overall, the FC correlate well with the planned treatment diameter (r = 0.79), other than the TC (r = 0.38). Six months after therapy, the fibroid volume was reduced by 45 ± 21 % (5 - 100) (p = 0.001). The symptoms decreased significantly (p = 0.001). No serious adverse events were recorded. CONCLUSION: Use of volumetric sonication leads to homogenous heating and sufficient necrosis. It is a safe and effective therapy for treating symptomatic uterine fibroids. Successful sonication of feedback cells leads to more contiguous necrosis in diameter and a less diversifying temperature. KEY POINTS: ▶ MR-guided HIFU ablation of symptomatic uterine fibroids is a valuable treatment option. ▶ By non-invasive HIFU fibroid volumes can be reduced and symptoms improved. ▶ The novel feedback-regulated treatment cells offer advantages over standard treatment cells.

[MRI for arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C)]. / MRT bei arrhythmogener rechtsventrikulärer Dysplasie/Kardiomyopathie (ARVD/C).

Arrhythmogenic right ventricular dysplasia/cardiomyopathy is a congenital disease that may present with sudden cardiac death as the first manifestation. Standards for the difficult clinical diagnosis are the so-called modified Task Force criteria that incorporate imaging-based, electrocardiographic and anamnestic information. Cardiac magnetic resonance imaging (MRI) is the standard technique for imaging of the right ventricle and can compliment the recent ARVD/C diagnosis criteria by providing exact information on right ventricular size and function. It is the most reliable modality available for the detection of right ventricular aneurysms and the quantification of ventricular size. Furthermore, MRI is able to identify areas of fatty or fibrous replacement within the right ventricular myocardium in a non-invasive way. However, a suspicion of ARVD/C cannot be confirmed or excluded based on MRI findings alone. In clinical routine cardiac MRI is an enormously important component in the ARVD/C diagnostic toolbox; however, MRI can only act as one part of the diagnostic puzzle and should exclusively be performed by experienced centers using specifically tailored protocols.

MR-guided HIFU treatment of symptomatic uterine fibroids using novel feedback-regulated volumetric ablation: effectiveness and clinical practice.

PURPOSE: To evaluate a novel feedback-regulated volumetric sonication method in MRguided HIFU treatment of symptomatic uterine fibroids. MATERIALS AND METHODS: 27 fibroids with an average volume of 124.9 ± 139.8 cc in 18 women with symptomatic uterine fibroids were ablated using the new HIFU system Sonalleve (1.5 TMR system Achieva, Philips). 21 myomas in 13 women were reevaluated 6 months later. Standard (treatment) cells (TC) and feedback-regulated (feedback) cells (FC) with a diameter of 4, 8, 12, and 16 mm were used and compared concerning sonication success, diameter of induced necrosis, and maximum achieved temperature. The non-perfused volume ratio (NPV related to myoma volume) was quantified. The fibroid volume was measured before, 1 month, and 6 months after therapy. Symptoms were quantified using a specific questionnaire (UFS-QoL). RESULTS: In total, 205 TC and 227 FC were applied. The NPV ratio was 23 ± 15 % (2 ­ 55). The TC were slightly smaller than intended (-3.9 ± 52 %; range, -100 ­ 81), while the FC were 20.1 ± 25.3 % bigger (p = 0.02). Feedback mechanism is less diversifying in diameter (p < 0.001). Overall, the FC correlate well with the planned treatment diameter (r = 0.79), other than the TC (r = 0.38). Six months after therapy, the fibroid volume was reduced by 45 ± 21 % (5 ­ 100) (p = 0.001). The symptoms decreased significantly (p = 0.001). No serious adverse events were recorded. CONCLUSION: Use of volumetric sonication leads to homogenous heating and sufficient necrosis. It is a safe and effective therapy for treating symptomatic uterine fibroids. Successful sonication of feedback cells leads to more contiguous necrosis in diameter

[The thickened left ventricle: etiology, differential diagnosis and implications for cardiovascular radiology]. / Der dicke linke Ventrikel: Ursachen und Differenzialdiagnose der linksventrikulären Hypertrophie und Implikationen für die kardiovaskuläre Radiologie.

Hypertrophy of the left ventricular myocardium is a common finding and can be reliably detected by echocardiography, CT and MRI. Common causes include diseases associated with increased cardiac afterload as well as primary and secondary cardiomyopathy. With the opportunity to determine functional parameters and myocardial mass precisely as well as to detect structural changes of the cardiac muscle simultaneously, cardiac MRI is the most precise imaging method for quantifying left ventricular hypertrophy as well as determining the cause and the exact characterization of the myocardial changes. It is mandatory, however, to create a flexible, individually adapted examination protocol. This review presents useful diagnostic algorithms in relation to different underlying pathologies in patients with left ventricular hypertrophy.

[Tumor and pulmonary cysts - Lice, fleas or both?]. / Tumor und Zysten in der Lunge - Läuse, Flöhe oder beides?

The article reports on a 60-year-old female patient with insulin-dependent diabetes who presented with coughing, chest pains and low-grade fever. Auscultation revealed a vesicular breathing noise bilaterally and the laboratory results showed slightly increased infection parameters. The initial diagnostic work-up included chest x-ray and contrast-enhanced computed tomography (CT). The diagnostics resulted in a pulmonary adenocarcinoma with osseous and hepatic metastases. Furthermore, widespread bilateral pulmonary cystic lesions were observed. Regarding the wide spectrum of differential diagnoses and the clinical pattern, the findings have to be regarded as cystic metastases and not as primary cystic lung disease.

[Consensus recommendations of the German Radiology Society (DRG), the German Cardiac Society (DGK) and the German Society for Pediatric Cardiology (DGPK) on the use of cardiac imaging with computed tomography and magnetic resonance imaging]. / Konsensusempfehlungen der DRG/DGK/DGPK zum Einsatz der Herzbildgebung mit Computertomografie und Magnetresonanztomografie.

Cardiac magnetic resonance imaging (MRI) and computed tomography (CT) have been developed rapidly in the last decade. Technical improvements and broad availability of modern CT and MRI scanners have led to an increasing and regular use of both diagnostic methods in clinical routine. Therefore, this German consensus document has been developed in collaboration by the German Cardiac Society, German Radiology Society, and the German Society for Pediatric Cardiology. It is not oriented on modalities and methods, but rather on disease entities. This consensus document deals with coronary artery disease, cardiomyopathies, arrhythmias, valvular diseases, pericardial diseases and structural changes, as well as with congenital heart defects. For different clinical scenarios both imaging modalities CT and MRI are compared and evaluated in the specific context.

[Non-invasive thermoablation of symptomatic uterine fibroids with magnetic resonance-guided high-energy ultrasound]. / Nichtinvasive Thermoablation symptomatischer Uterusmyome mit MR-gesteuertem hochenergetischem Ultraschall.

Uterine fibroids are the most common benign tumors in postmenopausal women which can cause severe symptoms and considerably reduce the quality of life. Patients are requesting minimally invasive, organ-saving therapies increasingly more often and magnetic resonance-guided focused ultrasound is a promising new technology which even surpasses these requirements as it is a totally non-invasive approach. The possibility of real-time temperature mapping allows a safe and precise thermal ablation of uterine fibroids. The rate of adverse events is low and safety and efficiency have been proven in several clinical studies. Further studies will have to be carried out to demonstrate long-term success and comparability to the established therapies and clarify if focused ultrasound is a safe treatment for women with the desire for future pregnancy. The MR-guided focused ultrasound technique is an effective and gentle treatment for uterine fibroids and holds a great potential for further indications.