Ultrasound of palpable lesions: a pictorial review.

Ultrasound (US) is the imaging modality of choice for evaluation of superficial palpable lesions. A large proportion of these lesions have characteristic sonographic appearance and can be confidently diagnosed with US without the need for biopsy or other intervention. The Society of Radiologists in Ultrasound (SRU) recently published a Consensus Conference Statement on superficial soft tissue masses. The goal of this manuscript is (a) to serve as a sonographic pictorial review for palpable lesions based on the SRU statement, (b) present the typical sonographic features of palpable lesions that can be confidently diagnosed with US, and (c) provide an overview of other palpable lesions with a framework to interpret the US studies and advise on appropriate further management.

Predictors of pain development for contralateral asymptomatic degenerative rotator cuff tears based on features of an ipsilateral painful cuff tear: a prospective longitudinal cohort study.

BACKGROUND: Prior rotator cuff disease natural history studies have focused on tear-related factors that predict disease progression within a given shoulder. The purpose of this study was to examine both patient- and tear-related characteristics of a painful rotator cuff tear that predict future pain development and functional impairment in a shoulder with a contralateral asymptomatic cuff tear. METHODS: This was a prospective longitudinal cohort study of patients aged ≤65 years who underwent surgery for a painful degenerative rotator cuff tear and possessed an asymptomatic contralateral tear. Patients were followed up prospectively by shoulder ultrasound, physical examination, and functional score assessment. The primary outcome was change in the American Shoulder and Elbow Surgeons (ASES) score at 2 years. Secondary outcomes included the Western Ontario Rotator Cuff Index (WORC) score, Patient-Reported Outcomes Measurement Information System (PROMIS) score, Hospital Anxiety Depression Scale (HADS) depression and anxiety scores, and Veterans RAND-12 (VR-12) mental component score (MCS). RESULTS: Sixty-five patients were included, with a mean follow-up period of 37 months (range, 24-42 months). In 17 patients (26%), contralateral shoulder pain developed at a median of 15.2 months (interquartile range [IQR], 10.5 months). No difference in age, sex, Charlson Comorbidity Index, or occupational demand was noted between patients in whom pain developed and those in whom pain did not develop. In the presenting painful shoulder, there was no difference in baseline tear size, muscle degeneration, or biceps pathology between groups. The mean baseline tear length (8.6 mm vs. 3.8 mm, P = .0008) and width (8.4 mm vs. 3.2 mm, P = .0004) were larger in asymptomatic shoulders in which pain subsequently developed compared with those in which pain did not develop. However, there was no difference in mean tear enlargement (P = .51 for length and P = .90 for width). There were no differences in baseline ASES, WORC, Patient-Reported Outcomes Measurement Information System (PROMIS), or HADS depression and anxiety scores between shoulders in which pain developed and those in which pain did not develop; however, patients in whom pain developed reported a lower baseline VR-12 MCS (53.3 vs. 57.6, P = .04). Shoulders in which pain developed had higher visual analog scale pain scores (2.9 [standard deviation (SD), 2.5] vs. 0.6 [SD, 1.0]; P = .016), lower ASES scores 75 [SD, 33] vs. 100 [SD, 11.6]; P = .001), and significant changes in all WORC scales with pain onset compared with those that remained asymptomatic. The study showed no significant difference in changes in the HADS anxiety and depression scores but found a significant increase in the VR-12 MCS in patients in whom pain developed (7.1 [interquartile range, 12.6] vs. -1.9 [interquartile range, 8.7]; P = .036). CONCLUSION: In one-quarter of patients with painful cuff tears, pain developed in a contralateral asymptomatic cuff tear that resulted in a measurable decline in function within 3 years. Our analysis showed that only the baseline tear size of the asymptomatic shoulder was predictive of pain development. There were no tear-related features of the presenting painful rotator cuff tear or indices of mental health and physical function or occupational demand that were predictive of future pain development at short-term follow-up.

Percutaneous Core Biopsy Devices: A Detailed Review and Comparison of Different Needle Designs.

ABSTRACT: Percutaneous core-needle biopsy (PCNB) plays a growing and essential role in many medical specialties. Proper and effective use of various PCNB devices requires basic understanding of how they function. Current literature lacks a detailed overview and illustration of needle function and design differences, a potentially valuable reference for users ranging from early trainees to experts who are less familiar with certain devices. This pictorial aims to provide such an overview, using diagrams and magnified photographs to illustrate the intricate components of these devices. Following a brief historical review of biopsy needle technology for context, we emphasize distinctions in design between 2 major classes of PCNB devices (side- and end-cutting devices), focusing on practical implications for how each device is most effectively used. We believe a nuanced understanding of biopsy device function sheds light on certain lingering ambiguities in biopsy practice, such as the optimal needle gauge in organ biopsy, the benefits and risks associated with coaxial technique, the impact of needle selection and technique on bleeding, and the risk of unsuccessful sampling. In a subsequent pictorial, we will draw on the concepts presented here to illustrate examples of biopsy needle failure and how unrecognized needle failure can be an important and often preventable cause of increased biopsy risk and lower tissue yield.

Contrast-Enhanced Ultrasound for Image-Guided Procedures.

Contrast-enhanced ultrasound (CEUS) uses intravenously injected gas microbubbles as a pure blood pool contrast agent to demonstrate blood flow and tissue perfusion at a much higher sensitivity than color Doppler and power Doppler ultrasound. CEUS has gained traction in abdominal diagnostic imaging for improved lesion detection and characterization and a complementary problem-solving tool to CT and MRI. In addition to its diagnostic applications, CEUS has also proven useful for pre-procedure planning, procedure guidance, and post-procedure evaluation. This review provides a practical overview and guides to the application of CEUS in percutaneous, ultrasound-guided, needle-driven procedures, focusing on 2 common procedures, which illustrate the many benefits of CEUS- core needle biopsy (CNB) and percutaneous hepatic lesion ablation.

International Expert Consensus on US Lexicon for Thyroid Nodules.

Multiple US-based systems for risk stratification of thyroid nodules are in use worldwide. Unfortunately, the malignancy probability assigned to a nodule varies, and terms and definitions are not consistent, leading to confusion and making it challenging to compare study results and craft revisions. Consistent application of these systems is further hampered by interobserver variability in identifying the sonographic features on which they are founded. In 2018, an international multidisciplinary group of 19 physicians with expertise in thyroid sonography (termed the International Thyroid Nodule Ultrasound Working Group) was convened with the goal of developing an international system, tentatively called the International Thyroid Imaging Reporting and Data System, or I-TIRADS, in two phases: (phase I) creation of a lexicon and atlas of US descriptors of thyroid nodules and (phase II) development of a system that estimates the malignancy risk of a thyroid nodule. This article presents the methods and results of phase I. The purpose herein is to show what has been accomplished thus far, as well as generate interest in and support for this effort in the global thyroid community.

Spatiotemporal development of the human T follicular helper cell response to Influenza vaccination.

We profiled blood and draining lymph node (LN) samples from human volunteers after influenza vaccination over two years to define evolution in the T follicular helper cell (TFH) response. We show LN TFH cells expanded in a clonal-manner during the first two weeks after vaccination and persisted within the LN for up to six months. LN and circulating TFH (cTFH) clonotypes overlapped but had distinct kinetics. LN TFH cell phenotypes were heterogeneous and mutable, first differentiating into pre-TFH during the month after vaccination before maturing into GC and IL-10+ TFH cells. TFH expansion, upregulation of glucose metabolism, and redifferentiation into GC TFH cells occurred with faster kinetics after re-vaccination in the second year. We identified several influenza-specific TFH clonal lineages, including multiple responses targeting internal influenza proteins, and show each TFH state is attainable within a lineage. This study demonstrates that human TFH cells form a durable and dynamic multi-tissue network.

Improving the Efficacy of ACR TI-RADS Through Deep Learning-Based Descriptor Augmentation.

Thyroid nodules occur in up to 68% of people, 95% of which are benign. Of the 5% of malignant nodules, many would not result in symptoms or death, yet 600,000 FNAs are still performed annually, with a PPV of 5-7% (up to 30%). Artificial intelligence (AI) systems have the capacity to improve diagnostic accuracy and workflow efficiency when integrated into clinical decision pathways. Previous studies have evaluated AI systems against physicians, whereas we aim to compare the benefits of incorporating AI into their final diagnostic decision. This work analyzed the potential for artificial intelligence (AI)-based decision support systems to improve physician accuracy, variability, and efficiency. The decision support system (DSS) assessed was Koios DS, which provides automated sonographic nodule descriptor predictions and a direct cancer risk assessment aligned to ACR TI-RADS. The study was conducted retrospectively between (08/2020) and (10/2020). The set of cases used included 650 patients (21% male, 79% female) of age 53 ± 15. Fifteen physicians assessed each of the cases in the set, both unassisted and aided by the DSS. The order of the reading condition was randomized, and reading blocks were separated by a period of 4 weeks. The system's impact on reader accuracy was measured by comparing the area under the ROC curve (AUC), sensitivity, and specificity of readers with and without the DSS with FNA as ground truth. The impact on reader variability was evaluated using Pearson's correlation coefficient. The impact on efficiency was determined by comparing the average time per read. There was a statistically significant increase in average AUC of 0.083 [0.066, 0.099] and an increase in sensitivity and specificity of 8.4% [5.4%, 11.3%] and 14% [12.5%, 15.5%], respectively, when aided by Koios DS. The average time per case decreased by 23.6% (p = 0.00017), and the observed Pearson's correlation coefficient increased from r = 0.622 to r = 0.876 when aided by Koios DS. These results indicate that providing physicians with automated clinical decision support significantly improved diagnostic accuracy, as measured by AUC, sensitivity, and specificity, and reduced inter-reader variability and interpretation times.

Evaluation of survivorship of asymptomatic degenerative rotator cuff tears in patients 65 years and younger: a prospective analysis with long-term follow-up.

BACKGROUND: The purpose of this prospective study is to describe the mid- to long-term natural history of untreated asymptomatic degenerative rotator cuff tears in patients 65 years and younger. METHODS: Subjects with an asymptomatic rotator cuff tear in one shoulder and a contralateral painful cuff tear aged 65 years or younger were enrolled in a previously described prospective longitudinal study. Annual physical and ultrasonographic evaluations and surveillance for pain development were performed using independent examiners for the asymptomatic shoulder. RESULTS: Two hundred twenty-nine participants (mean age 57.1 years) were followed for a median of 7.1 (range 0.3-13.1) years. Tear enlargement occurred in 138 (60%) shoulders. Full-thickness tears were at greater risk for enlargement compared with partial-thickness (hazard ratio [HR] 2.93, 95% confidence interval [CI] 1.71-5.03, P < .0001) and control shoulders (HR 18.8, 95% CI 4.63-76.1, P < .0001). Mean survival rates from Kaplan-Meier analyses indicate that full-thickness tears enlarged earlier (mean 4.7, 95% CI 4.1-5.2 years) than partial-thickness (mean 7.4, 95% CI 6.2-8.5 years) and control shoulders (mean 9.7, 95% CI 9.0-10.4 years). Tear presence in the dominant shoulder was associated with a greater enlargement risk (HR 1.70, 95% CI 1.21-1.39, P = .002). Patient age (P = .37) and gender (P = .74) were not associated with tear enlargement. The 2-, 5-, and 8-year survivorship free of tear enlargement for full-thickness tears was 74%, 42%, and 20%, respectively. Shoulder pain developed in 131 (57%) shoulders. Pain development was associated with tear enlargement (HR 1.79, 95% CI 1.24-2.58, P = .002) and was more common in full-thickness tears compared with controls (P = .0003) and partial tears (P = .01). An analysis of progression of muscle degeneration was performed in 138 shoulders with full-thickness tears. Tear enlargement was seen in 104 of 138 (75%) of these shoulders during follow-up (median 7.7 [interquartile range 6.0] years). Progression of muscle fatty degeneration was seen in the supraspinatus in 46 (33%) and the infraspinatus in 40 (29%) shoulders. Adjusting for age, both the presence of fatty muscle degeneration and the progression of muscle changes for both the supraspinatus (P < .0001) and infraspinatus (P < .0001) muscles were associated with tear size. For both the supraspinatus (P = .03) and infraspinatus (P = .03) muscles, tear enlargement was significantly associated with progression of muscle fatty degeneration. Anterior cable integrity was significantly associated with the risk of muscle degeneration progression for both the supraspinatus (P < .0001) and the infraspinatus (P = .005) muscles. CONCLUSIONS: Asymptomatic degenerative rotator cuff tears progress in patient 65 years and younger. Full-thickness rotator cuff tears have a higher risk of continued tear enlargement, progression of fatty muscle degeneration, and pain development than partial-thickness tears.

SARS-CoV-2 Omicron boosting induces de novo B cell response in humans.

The primary two-dose SARS-CoV-2 mRNA vaccine series are strongly immunogenic in humans, but the emergence of highly infectious variants necessitated additional doses and the development of vaccines aimed at the new variants1-4. SARS-CoV-2 booster immunizations in humans primarily recruit pre-existing memory B cells5-9. However, it remains unclear whether the additional doses induce germinal centre reactions whereby re-engaged B cells can further mature, and whether variant-derived vaccines can elicit responses to variant-specific epitopes. Here we show that boosting with an mRNA vaccine against the original monovalent SARS-CoV-2 mRNA vaccine or the bivalent B.1.351 and B.1.617.2 (Beta/Delta) mRNA vaccine induced robust spike-specific germinal centre B cell responses in humans. The germinal centre response persisted for at least eight weeks, leading to significantly more mutated antigen-specific bone marrow plasma cell and memory B cell compartments. Spike-binding monoclonal antibodies derived from memory B cells isolated from individuals boosted with either the original SARS-CoV-2 spike protein, bivalent Beta/Delta vaccine or a monovalent Omicron BA.1-based vaccine predominantly recognized the original SARS-CoV-2 spike protein. Nonetheless, using a more targeted sorting approach, we isolated monoclonal antibodies that recognized the BA.1 spike protein but not the original SARS-CoV-2 spike protein from individuals who received the mRNA-1273.529 booster; these antibodies were less mutated and recognized novel epitopes within the spike protein, suggesting that they originated from naive B cells. Thus, SARS-CoV-2 booster immunizations in humans induce robust germinal centre B cell responses and can generate de novo B cell responses targeting variant-specific epitopes.

Persons with HIV Develop Spike-Specific Lymph Node Germinal Center Responses following SARS-CoV-2 Vaccination.

COVID-19 disproportionately affects persons with HIV (PWH) in worldwide locations with limited access to SARS-CoV-2 vaccines. PWH exhibit impaired immune responses to some, but not all, vaccines. Lymph node (LN) biopsies from PWH demonstrate abnormal LN structure, including dysregulated germinal center (GC) architecture. It is not clear whether LN dysregulation prevents PWH from mounting Ag-specific GC responses in the draining LN following vaccination. To address this issue, we longitudinally collected blood and draining LN fine needle aspiration samples before and after SARS-CoV-2 vaccination from a prospective, observational cohort of 11 PWH on antiretroviral therapy: 2 who received a two-dose mRNA vaccine series and 9 who received a single dose of the Ad26.COV2.S vaccine. Following vaccination, we observed spike-specific Abs, spike-specific B and T cells in the blood, and spike-specific GC B cell and T follicular helper cell responses in the LN of both mRNA vaccine recipients. We detected spike-specific Abs in the blood of all Ad26.COV2.S recipients, and one of six sampled Ad26.COV2.S recipients developed a detectable spike-specific GC B and T follicular helper cell response in the draining LN. Our data show that PWH can mount Ag-specific GC immune responses in the draining LN following SARS-CoV-2 vaccination. Due to the small and diverse nature of this cohort and the limited number of available controls, we are unable to elucidate all potential factors contributing to the infrequent vaccine-induced GC response observed in the Ad26.COV2.S recipients. Our preliminary findings suggest this is a necessary area of future research.

SARS-CoV-2 Omicron boosting induces de novo B cell response in humans.

The primary two-dose SARS-CoV-2 mRNA vaccine series are strongly immunogenic in humans, but the emergence of highly infectious variants necessitated additional doses of these vaccines and the development of new variant-derived ones 1-4 . SARS-CoV-2 booster immunizations in humans primarily recruit pre-existing memory B cells (MBCs) 5-9 . It remains unclear, however, whether the additional doses induce germinal centre (GC) reactions where reengaged B cells can further mature and whether variant-derived vaccines can elicit responses to novel epitopes specific to such variants. Here, we show that boosting with the original SARS- CoV-2 spike vaccine (mRNA-1273) or a B.1.351/B.1.617.2 (Beta/Delta) bivalent vaccine (mRNA-1273.213) induces robust spike-specific GC B cell responses in humans. The GC response persisted for at least eight weeks, leading to significantly more mutated antigen-specific MBC and bone marrow plasma cell compartments. Interrogation of MBC-derived spike-binding monoclonal antibodies (mAbs) isolated from individuals boosted with either mRNA-1273, mRNA-1273.213, or a monovalent Omicron BA.1-based vaccine (mRNA-1273.529) revealed a striking imprinting effect by the primary vaccination series, with all mAbs (n=769) recognizing the original SARS-CoV-2 spike protein. Nonetheless, using a more targeted approach, we isolated mAbs that recognized the spike protein of the SARS-CoV-2 Omicron (BA.1) but not the original SARS-CoV-2 spike from the mRNA-1273.529 boosted individuals. The latter mAbs were less mutated and recognized novel epitopes within the spike protein, suggesting a naïve B cell origin. Thus, SARS-CoV-2 boosting in humans induce robust GC B cell responses, and immunization with an antigenically distant spike can overcome the antigenic imprinting by the primary vaccination series.

Management of Incidentally Detected Gallbladder Polyps: Society of Radiologists in Ultrasound Consensus Conference Recommendations.

Gallbladder polyps (also known as polypoid lesions of the gallbladder) are a common incidental finding. The vast majority of gallbladder polyps smaller than 10 mm are not true neoplastic polyps but are benign cholesterol polyps with no inherent risk of malignancy. In addition, recent studies have shown that the overall risk of gallbladder cancer is not increased in patients with small gallbladder polyps, calling into question the rationale for frequent and prolonged follow-up of these common lesions. In 2021, a Society of Radiologists in Ultrasound, or SRU, consensus conference was convened to provide recommendations for the management of incidentally detected gallbladder polyps at US. See also the editorial by Sidhu and Rafailidis in this issue.

Ultrasonography of Superficial Soft-Tissue Masses: Society of Radiologists in Ultrasound Consensus Conference Statement.

The Society of Radiologists in Ultrasound convened a panel of specialists from radiology, orthopedic surgery, and pathology to arrive at a consensus regarding the management of superficial soft-tissue masses imaged with US. The recommendations in this statement are based on analysis of current literature and common practice strategies. This statement reviews and illustrates the US features of common superficial soft-tissue lesions that may manifest as a soft-tissue mass and suggests guidelines for subsequent management.

SARS-CoV-2 mRNA Vaccination Causes Prolonged Increased Cortical Thickening and Vascularity in Ipsilateral Axillary Lymph Nodes.

OBJECTIVES: To describe the serial grey-scale and color Doppler appearance of ipsilateral axillary lymphadenopathy in response to the Pfizer-BioNTech Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) messenger RNA (mRNA) vaccine over 24 to 28 weeks. METHODS: The data for this study were collected during an observational study to determine whether mRNA vaccination induced a germinal center B cell reaction in blood and draining axillary lymph nodes. The current study evaluated the serial color Doppler and grey-scale sonographic appearance of these lymph nodes. Ten participants who each underwent 6 sonograms and FNAs over 24 to 28 weeks were included in the study. A total of 11 lateral lymph nodes were identified. Cortical thickness was measured and absence or presence of color Doppler flow in the hilum and lymph node cortex was graded (scale: 0-2). RESULTS: Eleven lateral axillary lymph nodes were biopsied over 24 to 28 weeks. Mean thickness varied through time (P < .001) and was greater weeks 2 to 7 compared to weeks 24 to 28 (mean differences of 2.6 to 1.3; P < .006), but weeks 14 to 17 mean thickness was not different from weeks 24 to 28 (0.57; P = .15). Cortical vascularity was increased in all 11 lymph nodes by week 5. Mean vascularity varied through time (P < .001) and was greater weeks 2 to 14 compared to weeks 24 to 28; mean differences ranged from 1.7 to 0.83 (P < .001). CONCLUSIONS: Serial grey-scale and color Doppler appearance of ipsilateral axillary lymph nodes after mRNA vaccination manifest as increased and prolonged cortical thickening and vascularity that diminishes and approaches normal by 24 to 28 weeks.

Survey Study on the Experience, Practice Patterns, and Preferences of the Fellows of the Society of Radiologists in Ultrasound for Evaluation and Management of Gallbladder Polyps Detected With Ultrasound.

ABSTRACT: Gallbladder polyps (GPs) are a common incidental finding on ultrasound; however, important differences in recommended management exist among professional society guidelines.An electronic survey was sent to 189 fellows of the Society of Radiologists in Ultrasound. Main outcomes included preferences and current practice patterns for evaluation, management, and surveillance of GPs as well as personal lifetime experience with gallbladder sonography and GPs.A total of 64 subjects (34%) with experience in gallbladder sonography completed the study. The estimated combined total number of gallbladder scans seen by the responders was 3,071,880. None of fellows had ever seen a pedunculated GP <1 cm detected on ultrasound that was proven to be malignant at the time of detection or during subsequent follow-up. All of the fellows used size as a feature to stratify recommendations. The median size threshold currently used by Society of Radiologists in Ultrasound fellows for recommending ultrasound follow-up was 6 mm, and their preferred threshold was 7 mm. The median size threshold for recommending surgical consultation was 10 mm, and the preferred threshold was 10 mm. Wall thickening and shape were considered important factors by 76% and 67% of respondents, respectively.Society of Radiologists in Ultrasound fellows tend to provide recommendations most similar to the American College of Radiology and Canadian Association of Radiology guidelines for management of GPs. Many would prefer guidelines that result in fewer recommendations for follow-up and surgical consultation. Despite a substantial combined experience, this survey did not uncover any case of a small GP that was malignant.

Germinal centre-driven maturation of B cell response to mRNA vaccination.

Germinal centres (GC) are lymphoid structures in which B cells acquire affinity-enhancing somatic hypermutations (SHM), with surviving clones differentiating into memory B cells (MBCs) and long-lived bone marrow plasma cells1-5 (BMPCs). SARS-CoV-2 mRNA vaccination induces a persistent GC response that lasts for at least six months in humans6-8. The fate of responding GC B cells as well as the functional consequences of such persistence remain unknown. Here, we detected SARS-CoV-2 spike protein-specific MBCs in 42 individuals who had received two doses of the SARS-CoV-2 mRNA vaccine BNT162b2 six month earlier. Spike-specific IgG-secreting BMPCs were detected in 9 out of 11 participants. Using a combined approach of sequencing the B cell receptors of responding blood plasmablasts and MBCs, lymph node GC B cells and plasma cells and BMPCs from eight individuals and expression of the corresponding monoclonal antibodies, we tracked the evolution of 1,540 spike-specific B cell clones. On average, early blood spike-specific plasmablasts exhibited the lowest SHM frequencies. By contrast, SHM frequencies of spike-specific GC B cells increased by 3.5-fold within six months after vaccination. Spike-specific MBCs and BMPCs accumulated high levels of SHM, which corresponded with enhanced anti-spike antibody avidity in blood and enhanced affinity as well as neutralization capacity of BMPC-derived monoclonal antibodies. We report how the notable persistence of the GC reaction induced by SARS-CoV-2 mRNA vaccination in humans culminates in affinity-matured long-term antibody responses that potently neutralize the virus.

SARS-CoV-2 mRNA vaccination elicits a robust and persistent T follicular helper cell response in humans.

SARS-CoV-2 mRNA vaccines induce robust anti-spike (S) antibody and CD4+ T cell responses. It is not yet clear whether vaccine-induced follicular helper CD4+ T (TFH) cell responses contribute to this outstanding immunogenicity. Using fine-needle aspiration of draining axillary lymph nodes from individuals who received the BNT162b2 mRNA vaccine, we evaluated the T cell receptor sequences and phenotype of lymph node TFH. Mining of the responding TFH T cell receptor repertoire revealed a strikingly immunodominant HLA-DPB1∗04-restricted response to S167-180 in individuals with this allele, which is among the most common HLA alleles in humans. Paired blood and lymph node specimens show that while circulating S-specific TFH cells peak one week after the second immunization, S-specific TFH persist at nearly constant frequencies for at least six months. Collectively, our results underscore the key role that robust TFH cell responses play in establishing long-term immunity by this efficacious human vaccine.

Ultrasound-Guided Thrombin Injection for the Treatment of Bleeding Following Kidney and Liver Biopsies.

The purpose of this study was to describe the technique and outcomes of percutaneous thrombin injection into the superficial aspect of actively bleeding liver and kidney biopsy tracks identified with color Doppler ultrasound with the aim of hemorrhage termination. After percutaneous thrombin injection, 15/16 (94%) patients did not require further intervention. Ultrasound-guided thrombin injection into the superficial site of active bleeding is an effective technique for terminating bleeding in the immediate post-procedure period following kidney and liver biopsies and should be considered if active bleeding persists on color Doppler after ≥30 minutes of compression and observation.

Analysis and Classification of Postcatheterization Femoral Arteriovenous Fistulas Based on Color Doppler Examinations.

OBJECTIVE: To analyze and classify arterial supply and venous drainage of postcatheterization femoral arteriovenous fistulas (AVFs). METHODS: A review of extremity Doppler reports identified 77 femoral AVFs in 75 patients. Doppler exams were reviewed retrospectively. Fistulas were classified as above or below the common femoral artery bifurcation and subclassified based on the location of arterial inflow and venous outflow. RESULTS: Arterial inflow originated above the femoral bifurcation in 32 cases. The communication was between the common femoral artery and the superficial circumflex iliac vein in 25 of 32 cases and between a branch of the common femoral or external iliac artery and the common femoral or external iliac vein in 4 of 32 cases. In 3 of 32 cases, AVFs arose from the common femoral artery, but the venous outflow was not determined. Arterial inflow originated from the superficial femoral artery in 23 cases. Venous outflow originated from the common femoral vein in 10 of 23 cases, the femoral vein in 7 of 23 cases, and the lateral circumflex femoral vein in 6 of 23 cases. Arterial inflow originated from the deep femoral artery in 12 cases. Venous outflow originated from the common femoral vein in 6 of 12 cases and from the lateral circumflex femoral vein 6 of 12 cases. In 8 cases, the AVF originated below the bifurcation, but the arterial inflow was not classified. In 2 cases, it was impossible to determine if the AVF originated above or below the bifurcation. CONCLUSIONS: Iatrogenic femoral AVFs arise above the femoral bifurcation more often than previously recognized. Classification based on the arterial inflow and venous outflow provides a straightforward means of describing these fistulas.

Detection and management of bleeding in the setting of image-guided percutaneous needle biopsy.

Image-guided percutaneous needle biopsy (PNB) is an important and increasingly utilized method of minimally invasive tissue sampling for a broad variety of disease processes. While infrequent, major bleeding is a potential complication of PNB and can be life-threatening, especially when unrecognized. On the other hand, prompt recognition and treatment of major bleeding in this setting can prevent significant morbidity or mortality. It is therefore crucial for anyone performing PNB to be familiar with the diagnosis and management of bleeding complications. This article reviews the risk factors for major bleeding in the setting of PNB, the presentation and imaging findings of a spectrum of bleeding complications encountered during and following PNB, and the management of those findings based on experience at a single, high volume, biopsy center.