Christoph A. Binkert

Three-Dimensional C-arm Cone-beam CT: Applications in the Interventional Suite

C-arm cone-beam computed tomography (CT) with a flat-panel detector represents the next generation of imaging technology available in the interventional radiology suite and is predicted to be the platform for many of the three-dimensional (3D) roadmapping and navigational tools that will emerge in parallel with its integration. The combination of current and unappreciated capabilities may be the foundation on which improvements in both safety and effectiveness of complex vascular and nonvascular interventional procedures become possible. These improvements include multiplanar soft tissue imaging, enhanced pretreatment target lesion roadmapping and guidance, and the ability for immediate multiplanar posttreatment assessment. These key features alone may translate to a reduction in the use of iodinated contrast media, a decrease in the radiation dose to the patient and operator, and an increase in the therapeutic index (increase in safety-vs-benefit ratio). In routine practice, imaging information obtained with C-arm cone-beam CT provides a subjective level of confidence factor to the operator that has not yet been thoroughly quantified.

Bone metastases from prostate cancer: assessing treatment response by using diffusion-weighted imaging and functional diffusion maps--initial observations.

PURPOSE To prospectively investigate and monitor the response to antiandrogen treatment of bone metastases in patients with prostate cancer by using diffusion-weighted (DW) magnetic resonance (MR) imaging with the apparent diffusion coefficient (ADC) and functional diffusion maps (DMs). MATERIALS AND METHODS This study had institutional review board approval; informed consent was obtained from all patients. Nine treatment-naive men (mean age, 73 years; range, 66-86 years) with 20 pelvic bone metastases were included. Imaging was performed before antiandrogen treatment and at 1, 2, and 3 months afterward. Imaging included a DW MR imaging sequence with five b factors (0-800 sec/mm²). Serum prostate-specific antigen (PSA) levels and mean ADCs of each metastasis were measured over time and analyzed by using the general linear model. Pairwise comparisons (paired-samples t tests) of PSA levels and ADCs before and after therapy were performed with the significance level set at P < .017 (Bonferroni correction). To determine the relationship between serum PSA level and the averaged mean ADCs in each patient, the two parameters were correlated across time. In addition, an analysis with functional DMs was performed to evaluate ADC response to treatment on a per-voxel basis. RESULTS Serum PSA levels decreased by more than 90% during therapy. The mean ADCs of metastases were increased significantly at 1 (P < .001), 2 (P = .002), and 3 (P = .011) months after therapy compared with pretreatment values. Heterogeneous response was revealed at functional DM analysis. After 1 month of therapy, 47.3% of all analyzed tumor voxels showed significantly increased ADCs, while 46.5% were unchanged and 6.2% exhibited decreased ADCs in comparison to the pretreatment values. At 3 months after therapy, the proportion of voxels showing ADC decrease was higher (13.7%) than that at 1 month. CONCLUSION DW MR imaging allows monitoring of antiandrogen therapy in bone metastases. PSA level decrease corresponded well with an increase in mean tumor ADC. Heterogeneity of tumor response to therapy was demonstrated by functional DM analysis.

Inferior Vena Cava Filter Removal after 317-day Implantation

A Günther Tulip inferior vena cava (IVC) filter was placed prophylactically in a 22-year-old trauma victim with spinal injuries. Attempts to retrieve the filter at 21 and 25 days after placement were aborted as a result of clot trapped in the filter. Despite the possible risk of an IVC laceration, a third attempt was made 317 days after placement in view of the young age of the patient. The filter started collapsing into the retrieval sheath but could not easily be separated from the IVC. During attempted redeployment, the filter would not reopen. The filter was ultimately retrieved with use of additional force. A mild stenosis of the IVC was noted immediately after retrieval. However, the IVC returned to its preretrieval diameter as seen on a 3-month follow-up venogram.

Treatment of Pelvic Venous Spur (May–Thurner Syndrome) with Self-Expanding Metallic Endoprostheses

AbstractPurpose: The application of self-expanding metallic endoprostheses (stents) to treat symptomatic pelvic venous spurs as an alternative to surgery. Methods: Wallstents with a diameter from 14 to 16 mm and one Cragg stent were placed in the left common iliac vein of eight patients (seven women, one man; mean age 42 years) with a symptomatic pelvic venous spur (left deep venous thrombosis or post-thrombotic leg swelling). Four patients had surgical thrombectomy prior to stent placement. Results: Technical success with immediate reduction of left leg circumference was achieved in all eight patients. A primary patency rate of 100% was observed during an average follow-up of 3 years (range 10–121 months). There were no procedural or stent-related complications. Conclusion: The percutaneous transfemoral placement of self-expanding metallic stents is an effective minimally invasive alternative to surgery in the treatment of symptomatic pelvic venous spur.

MR-guided high-intensity focused ultrasound ablation of breast cancer with a dedicated breast platform.

Optimizing the treatment of breast cancer remains a major topic of interest. In current clinical practice, breast-conserving therapy is the standard of care for patients with localized breast cancer. Technological developments have fueled interest in less invasive breast cancer treatment. Magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) is a completely noninvasive ablation technique. Focused beams of ultrasound are used for ablation of the target lesion without disrupting the skin and subcutaneous tissues in the beam path. MRI is an excellent imaging method for tumor targeting, treatment monitoring, and evaluation of treatment results. The combination of HIFU and MR imaging offers an opportunity for image-guided ablation of breast cancer. Previous studies of MR-HIFU in breast cancer patients reported a limited efficacy, which hampered the clinical translation of this technique. These prior studies were performed without an MR-HIFU system specifically developed for breast cancer treatment. In this article, a novel and dedicated MR-HIFU breast platform is presented. This system has been designed for safe and effective MR-HIFU ablation of breast cancer. Furthermore, both clinical and technical challenges are discussed, which have to be solved before MR-HIFU ablation of breast cancer can be implemented in routine clinical practice.

CT Features of Hepatic Venoocclusive Disease and Hepatic Graft-Versus-Host Disease in Patients After Hematopoietic Stem Cell Transplantation

OBJECTIVE We conducted this study to evaluate whether CT scans could be used to differentiate hepatic venoocclusive disease from hepatic graft-versus-host disease in patients treated with hematopoietic stem cell transplantation. SUBJECTS AND METHODS We retrospectively evaluated 18 patients (eight women, 10 men; mean age, 42.4 years) after hematopoietic stem cell transplantation with biopsy-proven hepatic venoocclusive disease (n = 5), hepatic graft-versus-host disease (n = 6), or both (n = 7). Two radiologists reviewed abdominal and pelvic CT scans for hepatomegaly (> 18 cm), splenomegaly (> 13 cm), size of main portal and right hepatic veins, presence of periportal edema, gallbladder wall edema, hydropic gallbladder, ascites, and small-bowel wall thickening. CT and histopathology findings were correlated using analysis of variance and Fisher-Free-man-Holton tests. RESULTS Ascites and periportal edema were present in all five patients with venoocclusive disease, but of six patients with graft-versus-host disease, ascites was seen in two (p < 0.05) and periportal edema in only one (p < 0.05). Small-bowel wall thickening was encountered in five patients with graft-versus-host disease and in none with venoocclusive disease (p < 0.05). The right hepatic vein diameter in patients with venoocclusive disease (mean, 0.27 cm) was significantly smaller than the right hepatic vein diameter in patients with graft-versus-host disease (mean, 0.87 cm; p < 0.05). CONCLUSION In patients treated with hematopoietic stem cell transplantation, CT findings of periportal edema, ascites, and a narrow right hepatic vein suggest venoocclusive disease rather than graft-versus-host disease. Small-bowel wall thickening suggests graft-versus-host disease.

ECG-Triggered Non-Contrast-Enhanced MR Angiography (TRANCE) versus Digital Subtraction Angiography (DSA) in patients with peripheral arterial occlusive disease of the lower extremities

ObjectiveTo prospectively determine the diagnostic value of electrocardiography-triggered non-contrast-enhanced magnetic resonance angiography (TRANCE) of the lower extremities including the feet versus DSA.MethodsAll 43 patients with symptomatic peripheral arterial occlusive disease (PAOD) underwent TRANCE before DSA. Quality of MRA vessel depiction was rated by two independent radiologists on a 3-point scale. Arterial segments were graded for stenoses using a 4-point scale (grade 1: no stenosis; grade 2: moderate stenosis; grade 3: severe stenosis; grade 4: occlusion). Findings were compared with those of DSA.ResultsIn the 731 vessel segments analysed, intra-arterial DSA revealed 283 stenoses: 33.6% moderate, 16.6% severe and 49.8% occlusions. TRANCE yielded a mean sensitivity, specificity, positive and negative predictive value and diagnostic accuracy to detect severe stenoses or occlusions of 95.6%, 97.4%, 87.2%, 99.2%, 97.1% for the thigh segments and 95.2%, 87.5%, 83.2%, 96.6%, 90.5% for the calf segments. Excellent overall image quality was observed for TRANCE in 91.4% versus 95.7% (DSA) for the thigh and in 60.7% versus 91.0% for the calves, while diagnostic quality of the pedal arteries was rated as insufficient.ConclusionTRANCE achieves high diagnostic accuracy in the thigh and calf regions, whereas the pedal arteries showed limited quality.

Cirse Quality Assurance Document and Standards for Classification of Complications: The Cirse Classification System

Interventional radiology provides a wide variety of vascular, nonvascular, musculoskeletal, and oncologic minimally invasive techniques aimed at therapy or palliation of a broad spectrum of pathologic conditions. Outcome data for these techniques are globally evaluated by hospitals, insurance companies, and government agencies targeting in a high-quality health care policy, including reimbursement strategies. To analyze effectively the outcome of a technique, accurate reporting of complications is necessary. Throughout the literature, numerous classification systems for complications grading and classification have been reported. Until now, there has been no method for uniform reporting of complications both in terms of definition and grading. The purpose of this CIRSE guideline is to provide a classification system of complications based on combining outcome and severity of sequelae. The ultimate challenge will be the adoption of this system by practitioners in different countries and health economies within the European Union and beyond.

Feasibility of small bowel flow rate measurement with MRI

To evaluate whether it is feasible to measure the segmental flux of small bowel content using MR phase‐contrast (PC) pulse sequences.

Compression of the Inferior Vena Cava by the Right Iliac Artery: A Rare Variant of May–Thurner Syndrome

May–Thurner syndrome is known as compression of the left common iliac vein by the right common iliac artery. We describe a case of an atypical compression of the inferior vena cava by the right common iliac artery secondary to a high aortic bifurcation. Despite an extensive collateral network, there was a significant venous gradient between the iliac veins and the inferior vena cava above the compression. After stenting the venous pressure gradient disappeared. Follow-up 4 months later revealed a good clinical response with a patent stent.