Breast biopsy markers have evolved from simple metallic devices to sophisticated multimaterial tools that have become essential for breast cancer care, demonstrating their clinical benefits in surgical planning, radiation targeting, and cost reduction.
Thermal and imaging effects of Feraheme in MR-guided focused ultrasound: a phantom study
Abstract Objective . The use of Feraheme (ferumoxytol) as a contrast agent in MR-guided focused ultrasound (MRgFUS) tumor ablations could enhance treatment safety and efficacy by improving vascular visualization through strong T1 and T2 shortening effects. However, Feraheme impact on MR thermometry and tissue heating is unclear. This study evaluates the feasibility of incorporating Feraheme into MRgFUS by assessing its impact on MR imaging contrast, MR thermometry, and thermal response in tissue-mimicking phantoms. Approach . Tissue-mimicking phantoms with 0 (baseline), 0.25, and 0.5 mM Feraheme concentrations were prepared using a validated recipe. Acoustic attenuation was measured with a commercial diagnostic ultrasound scanner. MR imaging at 1.5 T was performed to assess gradient-recalled-echo (GRE)-based thermometry signal-to-noise-ratio (SNR), relaxation rates, and relaxivities. MRgFUS system integrated with 1.5 T MRI was used to perform multiple sonications in the phantoms. Temperature elevations and focal heating areas were quantified from proton resonance frequency (PRF) shift thermometry. Experiments were repeated three times over the period of eight-weeks. Separately, temperature-dependent nuclear magnetic resonance (NMR) spectroscopy was performed at 3.0 T in saline-diluted Feraheme phantoms (0, 0.25, 0.5, and 1.0 mM) to assess the influence of Feraheme concentration on PRF coefficients used in MR thermometry. Main results . Phantoms showed nuclear relaxation times ( T 1: 1178.1 ± 77.8, T 2: 103.21 ± 2.45 ms) and attenuation coefficients (0.34–0.36 dB cm −1 MHz −1 ) within expected biological tissue ranges. Relaxivities demonstrated a strong linear dependence on Feraheme concentration ( r 1: 17.5 ± 0.2, r 2: 209.2 ± 2.6 s −1 mM −1 ). Relative to baseline (0 mM) phantom, the SNR of GRE-based thermometry increased by 12.6% at 0.25 mM and decreased by 27.1% at 0.5 mM. Sonications in Feraheme-containing phantoms resulted in statistically higher temperature elevations ( p < 0.001 ) although no statistically significant difference was observed between 0.25 and 0.5 mM. All NMR measurements demonstrated stable, linear PRF temperature dependence ( R 2 = 0.996–0.999), with PRF coefficients (between −0.0074 and −0.0082 ppm °C −1 ). The resulting thermometry bias was small and predictable (+0.67 and +1.73 per 20 °C at 3.0 T for 0.25 and 0.5 mM). Significance . These findings demonstrate that MR thermometry remains feasible at moderate Feraheme concentrations and support its potential use to enhance visualization of critical vasculature near targeted tissues during MRgFUS.
Plethysmography compared to ultrasound for the evaluation of chronic venous insufficiency
Background: Chronic venous insufficiency (CVI) can be evaluated using Duplex ultrasonography (US) and air plethysmography (PG), yet comparative performance remains unclear. Methods: We retrospectively identified patients who underwent venous insufficiency US and PG within a 90-day interval from March 1, 2015 through July 31, 2024. CVI severity was classified by the clinical (C) component of the Clinical, Etiologic, Anatomic, and Pathophysiologic (CEAP) classification system and categorized as mild (C0–2), moderate (C3), or severe (C4–6). PG and insufficiency US findings were compared across categories and machine learning models were trained to predict severe CVI. Results: We analyzed 1478 limbs from 839 patients who were predominantly women (62%) with a mean age of 61 years (± 14 years). Severe CVI was present in 32.3% of limbs. US detected venous incompetence in 67.4% of limbs overall and in 75.3% of severe CVI limbs. Abnormal PG findings occurred in 72.9% of limbs overall and in 88.5% of severe CVI limbs. PG parameters in machine learning models outperformed US parameters in predicting severe CVI (area under the receiver operating characteristic curve [AUROC] 0.82 vs 0.65). The top PG model (multilayer perceptron [MLP]) achieved an AUROC of 0.82, versus the best US model (gradient boosting) with an AUROC of 0.65. Limiting PG data to incompetence and obstruction parameters modestly reduced performance but remained higher than US (logistic regression AUROC 0.72). Conclusion: Our findings indicate that PG assessment in CVI offers superior performance compared to US. Overall, these results validate the quantitative whole-limb hemodynamic approach using PG, which provides a more complete understanding of the pathology behind CVI.
Novel Ultrasound Technique to Evaluate the Superior Segment of the Internal Jugular Vein in Normal Subjects
A novel ultrasound technique was used to assess the superior segment of the internal jugular vein (IJV) in healthy individuals, evaluating the feasibility of visualizing this vein through the parotid gland and examining positional changes. Eighty-five patients undergoing unrelated carotid ultrasound were included, excluding those with headaches, migraines, or other neurological symptoms. A transducer was placed over the parotid gland, and gray scale images—with and without diameter measurement—and color and spectral Doppler of the IJV were obtained in neutral and head turned contralaterally. Technical feasibility and quantitative measurements with mean values and standard deviations were reported. Significant positional changes were assessed if paired data were available. Successful diameter measurements were obtained in at least one side in 79% to 80% of patients and bilaterally in 75%. Mean diameters were 5.5 cm (right) and 5 cm (left). Velocities were acquired in 82% (unilaterally) and 78% (bilaterally). Mean peak systolic velocities were 42 cm/s (right) and 32 cm/s (left). With head rotation, mean velocities were 46 cm/s (right) and 38 cm/s (left). In patients with paired measurements, velocities increased by over 50% in 19% to 28% of patients ( P <0.05 for both sides). There was no significant change in the diameter when the head was turned. Visualization of the superior IJV using a parotid window and evaluation of its diameter and internal velocities are feasible with the head in both neutral position and turned contralaterally.
Prospective Assessment of Changes in Target Vessel Peak Systolic Velocity Measurements After Fenestrated-Branched Endovascular Aortic Repair
Objective: Target vessel stenosis or occlusion is a common indication for secondary intervention after fenestrated-branched endovascular aortic repair requiring long-term imaging surveillance including duplex ultrasound (DUS). This study aimed to describe and compare longitudinal changes in peak systolic velocity (PSV) measurements for renal and mesenteric arteries targeted by directional branches (DBs) or reinforced fenestrations (RFs). Methods: Patients enrolled in a prospective, nonrandomized study (2013-2020) had DUS of celiac axis, superior mesenteric artery, and renal arteries (RAs) obtained preoperatively, at 6 to 8 weeks, 6 months, and annually. Vessels with preprocedural stenosis were excluded. Outcomes were variations in PSV over time for target vessels incorporated by DBs or RFs, differences in balloon-expandable stent-grafts (BESGs) and self-expandable stent-grafts (SESGs), PSV measurements prior to secondary interventions related to vessel stenosis, and a predictive value of PSV for stenosis requiring secondary intervention. Results: A total of 419 patients (292 male, mean age 74 ± 8 years old) were enrolled, with 1,311 target vessels analyzed preoperatively, including 607 mesenteric and 704 RAs. Over a median follow-up of 23 months (interquartile range [IQR], 7-36), PSV measurements decreased in the first 6 to 8 weeks after DB incorporation, remained stable, followed by a nonsignificant increase at 5 years. PSV increased in the first 6 months using RFs with postoperative velocities significantly higher ( P < .05) for RFs compared to DBs. Branched mesenteric vessels stented with BESGs had higher velocities than SESGs ( P < .05). Of the 23 target vessels treated by secondary intervention for stenosis, 19 (83%) had velocities above the thresholds for native, nonstented vessels. Furthermore, in RAs (n = 20) PSV effectively predicted clinically relevant stenosis, AUC was 0.98, with a 231 cm/s threshold offering 84% sensitivity with 100% specificity. Conclusion: Longitudinal follow-up shows that velocity changes vary depending on the type of incorporation, vessel, and bridging stent. For DBs, PSV decreased initially, stabilized, and showed a nonsignificant increase at 5 years. In contrast, PSV increased with RFs and remained higher than DBs. Despite these variations, velocities remained below established thresholds for clinically significant stenosis in nonstented vessels. Criteria for in-stent stenosis may differ, and PSV alone should not be the sole indicator for reintervention. Clinical Impact This study provides new insight into duplex ultrasound (DUS) surveillance after fenestrated and branched endovascular aneurysm repair (FB-EVAR). Peak systolic velocity (PSV) trends differed between fenestrations and branches, and stent type influenced flow dynamics. Importantly, most vessels with secondary interventions had elevated PSVs, but many others exceeded native stenosis thresholds without clinical consequence. Despite these variations, velocities remained below established thresholds for clinically significant stenosis in non-stented vessels. Criteria for in-stent stenosis may differ, and PSV alone should not be the sole indicator for reintervention.The reported PSV measurements served as a benchmark for DUS surveillance following FB-EVAR.
Comparative Evaluation of Contrast-enhanced Ultrasound and Indocyanine Green Lymphography for Lymphatic Mapping: A Retrospective Study
Background: Lymphaticovenous anastomosis (LVA) is an effective surgical treatment for extremity lymphedema. Indocyanine green (ICG) fluorescent lymphography, the traditional standard for imaging lymphatic vessels, has limitations, including difficulty depicting deeper or congested lymphatics and contraindication in iodine hypersensitivity. This study evaluated contrast-enhanced ultrasound (CEUS) with microbubbles for identifying lymphatic vessels for LVA and compared it with ICG lymphography. Methods: In this single-center retrospective review, intraoperative CEUS with intradermal injection of microbubble suspension (Lumason, Bracco Diagnostics, Inc.) was used in patients before LVA surgery between October 2019 and February 2023. Pre- or intraoperative ICG lymphography was also used to identify target lymphatic vessels. All patients diagnosed with primary or secondary extremity lymphedema who underwent LVA were included. Technical success rate was defined as lymphatic vessels identified by CEUS that led to successful LVAs. Descriptive statistics were used. Results: Thirty-two patients underwent LVA surgery, with a mean age of 58.5 ± 13.9 years. CEUS identified lymphatic vessels in all 32 patients, including 7 in whom ICG failed. Two patients with ICG allergy underwent CEUS only. CEUS identified more candidate lymphatics per patient (5.3 ± 4.2) compared with ICG (2.5 ± 2.7). Of the 182 anastomoses, 96 (52.8%) were identified by both CEUS and ICG, 75 (41.2%) by CEUS only, and 11 (6%) by ICG only. Conclusions: CEUS is a promising tool for identifying lymphatic vessels in patients with lymphedema undergoing LVA, particularly when ICG lymphography is inadequate or contraindicated.
Summary: Prior studies on contrast-enhanced ultrasound (CEUS) lymphography for preoperative mapping before lymphaticovenous anastomosis surgery in patients with extremity lymphedema have been limited to using only Lumason and Sonazoid as microbubble contrast agents. The purpose of this study was to determine the feasibility of using two other Food & Drug Administration–approved microbubble agents, Optison and Definity, for imaging lymphatic vessels in the upper extremities. Nine female adults with unilateral upper extremity lymphedema anticipating lymphaticovenous anastomosis surgery underwent CEUS lymphography of the unaffected upper extremity randomized to either Lumason, Definity, or Optison. Lymphatic vessels were visualized in all but one case when undilated Definity was used. In the eight upper extremities where lymphatic vessels were visualized, an average of eight intradermal injections of microbubbles were performed in the extremity. Lymphatic vessels could be identified in 57% (36 of 63) of the injections. The effective dilution for each of the microbubble agents is provided. This was the first successful demonstration of lymphatic vessel visualization using either Definity or Optison. Broadening the range of available microbubble agents for CEUS lymphography could improve accessibility to the procedure and provide potentially safer alternatives.
An Allergic Reaction in Contrast-enhanced Ultrasound Lymphography for Lymphovenous Bypass Surgery
Summary: Lymphedema following oncologic intervention can cause significant lifelong morbidity for patients in whom conservative management fails. The associated swelling, discomfort, pain, and recurrent cellulitis greatly diminish quality of life. Surgical procedures, including suction-assisted lipectomy, lymphovenous anastomosis (LVA), and vascularized lymph node transfers, show effectiveness in both volume reduction in affected extremities and symptom relief. However, the success of procedures like LVA is dependent on effective preoperative lymphatic mapping to identify suitable vessels for anastomosis. Traditional superficial lymphatic mapping uses near infrared fluorescence indocyanine green (ICG) imaging. Moreover, recent advances in contrast-enhanced ultrasound (CEUS) lymphography increased lymphovenous bypass target identification for LVA in the extremities.7 CEUS lymphography uses microbubbles as a contrast-enhancing agent injected intradermally into the affected extremity with subsequent identification of superficial collecting lymphatic vessels using ultrasound. Although a recent report noted an uptick in severe and critical adverse drug reactions to an ultrasound contrast agent injected intravenously in stress echocardiography, adverse drug reactions associated with ultrasound contrast-enhancing agents in body ultrasound are rare. The safety profile and potential complications from CEUS lymphography in the lymphedema population have yet to be fully characterized. In this case report, the authors present the first cutaneous adverse drug event following a secondary exposure to the contrast used for CEUS imaging. Mechanisms and justifications for an immune-mediated process are explored, and a review of similar manifestations in other related contrast applications is discussed.
Abstract Osteoarthritis of the knee is a common cause of pain, functional disability, and reduced quality of life in the elderly. Despite its prevalence, there are limited currently available noninvasive treatment options. MRI-guided focused ultrasound (MRgFUS) is a noninvasive thermal ablation method which is used in a spectrum of musculoskeletal conditions. It is FDA approved for the treatment of painful bone metastases and osteoid osteoma, and has been considered for the treatment of other painful conditions such as osteoarthritis. The purpose of this case report is to describe the use of MRgFUS for the treatment of osteoarthritic knee pain in a 72-year-old male. The patient led an active lifestyle, however suffered significant limitations due to lateral knee pain with jogging and walking down the stairs. MRgFUS ablation treatment was performed to the lateral knee, targeting the periosteum in the patients’ area of pain. Following treatment, he experienced considerable reduction in his activity limiting symptoms with a duration of at least 6 months. Similar pain reduction was observed in two small series of MRgFUS treatment of knee pain from Japan. It is important for radiologists to be aware of MRgFUS as an innovative ablation modality. MRgFUS appears promising as a safe, non-invasive treatment option for temporary relief of knee pain. This may be particularly valuable for patients who are unwilling or unable to undergo total knee arthroplasty.