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Karen Schwenk Johnson

Associate Professor of Radiology
Radiology, Breast Imaging
Box 3808 Med Ctr, Durham, NC 27710
Dept of Radiology, Durham, NC 27710

Selected Publications


Screening the Implant-Augmented Breast with Digital Breast Tomosynthesis: Is Tomosynthesis Necessary for Non-implant-Displaced Views?

Journal Article J Breast Imaging · May 27, 2024 OBJECTIVE: To determine cancer visualization utility and radiation dose for non-implant-displaced (ID) views using standard protocol with digital breast tomosynthesis (DBT) vs alternative protocol with 2D only when screening women with implant augmentation ... Full text Link to item Cite

Now or Later? Patient Satisfaction and Anxiety Among Women Undergoing Breast Biopsies Performed the Same Day as Recommended Versus a Later Day.

Journal Article J Am Coll Radiol · March 2024 PURPOSE: The aim of this study was to determine differences in patient satisfaction and anxiety among women undergoing core-needle breast biopsies performed the same day as recommended versus a future date. METHODS: After institutional review board exempti ... Full text Link to item Cite

Retained Biopsy Site Markers After Breast Lesion Surgical Resection: Associations With Residual Malignancy.

Journal Article AJR Am J Roentgenol · January 2024 BACKGROUND. Biopsy site markers (BSMs) placed during image-guided core needle biopsy (CNB) are typically targeted for surgical excision, along with the breast imaging abnormality. Retained BSMs raise concern of incomplete resection of the breast abnormalit ... Full text Link to item Cite

Learning from errors: Implementation of a resident-oriented radiology morbidity and mortality conference as an educational tool.

Journal Article Clin Imaging · April 2022 PURPOSE: Our diagnostic radiology (DR) program lacked a formalized, structured process for residents to learn from errors. Prior DR residency Accreditation Council for Graduate Medical Education (ACGME) survey results additionally demonstrated opportunity ... Full text Link to item Cite

Role of digital breast tomosynthesis in the evaluation of focal breast pain.

Journal Article Clin Imaging · February 2022 RATIONAL AND OBJECTIVE: To investigate the utility of digital breast tomosynthesis (DBT) in the evaluation of focal breast pain, considering breast density and breast cancer risk. METHODS: Ninety-one cases of focal breast pain evaluated with DBT and ultras ... Full text Link to item Cite

Molecular Subtypes of Breast Cancer: A Review for Breast Radiologists.

Journal Article J Breast Imaging · January 26, 2021 Gene expression profiling has reshaped our understanding of breast cancer by identifying four molecular subtypes: (1) luminal A, (2) luminal B, (3) human epidermal growth factor receptor 2 (HER2)-enriched, and (4) basal-like, which have critical difference ... Full text Link to item Cite

Breast Imaging: Screening for New Breast Cancers and for Cancer Recurrence

Chapter · January 1, 2021 Breast cancer survivors require a unique breast imaging approach to identify new cancers as well as cancer recurrences. In this patient population, appropriate imaging requires some combination of digital mammography, digital breast tomosynthesis, ultrasou ... Full text Cite

Awareness of implicit bias mitigates discrimination in radiology resident selection.

Journal Article Med Educ · July 2020 OBJECTIVES: Implicit bias is common and is thought to drive discriminatory behaviour. Having previously demonstrated discrimination against specific applicant demographics by academic radiology departments in a simulated resident selection process, the aut ... Full text Link to item Cite

Bias in Radiology Resident Selection: Do We Discriminate Against the Obese and Unattractive?

Journal Article Acad Med · November 2019 PURPOSE: To evaluate for appearance-based discrimination in the selection of radiology residents. METHOD: A deception study simulating the resident selection process examined the impact of attractiveness and obesity on resident selection. Seventy-four core ... Full text Link to item Cite

A Proposal to Define Three New Breast Calcification Shapes: Square, Sandwich, and Teardrop, Pill & Capsule.

Journal Article J Breast Imaging · September 4, 2019 OBJECTIVE: To define and illustrate three new descriptors for microcalcification morphology on mammography, and provide a preliminary assessment of their potential clinical value. METHODS: The institutional review board approved this retrospective study an ... Full text Link to item Cite

Hybrid Interactive and Didactic Teaching Format Improves Resident Retention and Attention Compared to Traditional Lectures.

Journal Article Acad Radiol · September 2019 PURPOSE: To compare the traditional lecture to a hybrid interactive and didactic teaching format with regards to radiology resident short- and long-term retention, as well as attention. MATERIALS AND METHODS: The tested hybrid format consists of a 30-minut ... Full text Link to item Cite

Optimizing the Patient Experience during Breast Biopsy.

Journal Article J Breast Imaging · June 4, 2019 For years, breast imaging has been the model in radiology for patient communication, and more recently, it has been a leader in the growing patient- and family-centered approach to care. To maintain high levels of patient satisfaction during image-guided c ... Full text Link to item Cite

Normal Axillary Lymph Node Variability Between White and Black Women on Breast MRI.

Journal Article Acad Radiol · March 2018 RATIONALE AND OBJECTIVES: This study aimed to determine if there were differences in the imaging features of normal lymph nodes between white and black women using magnetic resonance imaging. MATERIALS AND METHODS: Following institutional review board appr ... Full text Link to item Cite

Positive and negative mood following imaging-guided core needle breast biopsy and receipt of biopsy results.

Journal Article Psychol Health Med · December 2017 Positive and negative mood are independent psychological responses to stressful events. Negative mood negatively impacts well-being and co-occurring positive mood leads to improved adjustment. Women undergoing core needle breast biopsies (CNB) experience d ... Full text Link to item Cite

Relationships Between MRI Breast Imaging-Reporting and Data System (BI-RADS) Lexicon Descriptors and Breast Cancer Molecular Subtypes: Internal Enhancement is Associated with Luminal B Subtype.

Journal Article Breast J · September 2017 The aim of this study was to determine the associations between breast MRI findings using the Breast Imaging-Reporting and Data System (BI-RADS) lexicon descriptors and breast cancer molecular subtypes. In this retrospective, IRB-approved, single instituti ... Full text Link to item Cite

Suspicious breast calcifications undergoing stereotactic biopsy in women ages 70 and over: Breast cancer incidence by BI-RADS descriptors.

Journal Article Eur Radiol · June 2017 OBJECTIVES: To determine the malignancy rate overall and for specific BI-RADS descriptors in women ≥70 years who undergo stereotactic biopsy for calcifications. METHODS: We retrospectively reviewed 14,577 consecutive mammogram reports in 6839 women ≥70 yea ... Full text Link to item Cite

Focal Breast Pain: Does Breast Density Affect the Need for Ultrasound?

Journal Article Acad Radiol · January 2017 RATIONALE AND OBJECTIVES: This study aimed to determine the utility of directed ultrasound and digital mammogram for evaluating focal breast pain in women with different mammographic breast densities. MATERIALS AND METHODS: This institutional review board- ... Full text Link to item Cite

Predicting false negative errors in digital breast tomosynthesis among radiology trainees using a computer vision-based approach

Journal Article Expert Systems with Applications · September 1, 2016 Purpose Digital breast tomosynthesis (DBT) can improve lesion visibility in comparison to mammography by eliminating breast tissue superimposition. While the benefits of DBT in breast cancer screening rely on well trained radiologists, the optimal training ... Full text Cite

Imaging-Guided Core-Needle Breast Biopsy: Impact of Meditation and Music Interventions on Patient Anxiety, Pain, and Fatigue.

Journal Article J Am Coll Radiol · May 2016 PURPOSE: To evaluate the impact of guided meditation and music interventions on patient anxiety, pain, and fatigue during imaging-guided breast biopsy. METHODS: After giving informed consent, 121 women needing percutaneous imaging-guided breast biopsy were ... Full text Link to item Cite

Radiology Trainee Performance in Digital Breast Tomosynthesis: Relationship Between Difficulty and Error-Making Patterns.

Journal Article J Am Coll Radiol · February 2016 PURPOSE: The aim of this study was to better understand the relationship between digital breast tomosynthesis (DBT) difficulty and radiology trainee performance. METHODS: Twenty-seven radiology residents and fellows and three expert breast imagers reviewed ... Full text Link to item Cite

Identification of error making patterns in lesion detection on digital breast tomosynthesis using computer-extracted image features

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2016 Digital breast tomosynthesis (DBT) can improve lesion visibility by eliminating the issue of overlapping breast tissue present in mammography. However, this new modality likely requires new approaches to training. The issue of training in DBT is not well e ... Full text Cite

Recurrence-free survival in breast cancer is associated with MRI tumor enhancement dynamics quantified using computer algorithms.

Journal Article Eur J Radiol · November 2015 PURPOSE: The purpose of this study is to investigate the association between breast cancer recurrence-free survival and breast magnetic resonance imaging (MRI) tumor enhancement dynamics which are quantified semi-automatically using computer algorithms. ME ... Full text Link to item Cite

Abbreviated screening protocol for breast MRI: a feasibility study.

Journal Article Acad Radiol · September 2015 RATIONALE AND OBJECTIVES: To compare the performance of two shortened breast magnetic resonance imaging (MRI) protocols to a standard MRI protocol for breast cancer screening. MATERIALS AND METHODS: In this Health Insurance Portability and Accountability A ... Full text Link to item Cite

Frequency of Malignancy and Imaging Characteristics of Probably Benign Lesions Seen at Breast MRI.

Journal Article AJR Am J Roentgenol · August 2015 OBJECTIVE: The purposes of this study were to evaluate the frequency, follow-up compliance, and cancer rate of MRI BI-RADS category 3 lesions and to determine the cancer rate for individual BI-RADS descriptors. MATERIALS AND METHODS: A retrospective review ... Full text Link to item Cite

Lobular breast cancer series: imaging.

Journal Article Breast Cancer Res · July 11, 2015 The limitations of mammography in the detection and evaluation of invasive lobular carcinoma (ILC) have long been recognized, presenting real clinical challenges in treatment planning for these tumors. However, advances in mammography, ultrasound, and magn ... Full text Link to item Cite

Does Breast Imaging Experience During Residency Translate Into Improved Initial Performance in Digital Breast Tomosynthesis?

Journal Article J Am Coll Radiol · July 2015 PURPOSE: To determine the initial digital breast tomosynthesis (DBT) performance of radiology trainees with varying degrees of breast imaging experience. METHODS: To test trainee performance with DBT, we performed a reader study, after obtaining IRB approv ... Full text Link to item Cite

Interobserver Variability Between Breast Imagers Using the Fifth Edition of the BI-RADS MRI Lexicon.

Journal Article AJR Am J Roentgenol · May 2015 OBJECTIVE: The purpose of this study was to assess the interobserver variability of users of the MRI lexicon in the fifth edition of the BI-RADS atlas. MATERIALS AND METHODS: Three breast imaging specialists reviewed 280 routine clinical breast MRI finding ... Full text Link to item Cite

Can breast cancer molecular subtype help to select patients for preoperative MR imaging?

Journal Article Radiology · February 2015 PURPOSE: To assess whether breast cancer molecular subtype classified by surrogate markers can be used to predict the extent of clinically relevant disease with preoperative breast magnetic resonance (MR) imaging. MATERIALS AND METHODS: In this HIPAA-compl ... Full text Link to item Cite

Incorporating breast tomosynthesis into radiology residency: Does trainee experience in breast imaging translate into improved performance with this new modality?

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2015 Digital breast tomosynthesis (DBT) is a powerful new imaging modality that has the potential to transform breast cancer screening practices. The advantages over mammography include improved sensitivity and specificity as well as the detection of additional ... Full text Cite

Lobular breast cancer series: Imaging

Journal Article Breast Cancer Research · 2015 © 2015 Johnson et al.The limitations of mammography in the detection and evaluation of invasive lobular carcinoma (ILC) have long been recognized, presenting real clinical challenges in treatment planning for these tumors. However, advances in mammography, ... Full text Cite

Predictors of pain experienced by women during percutaneous imaging-guided breast biopsies.

Journal Article J Am Coll Radiol · July 2014 PURPOSE: The purpose of this study was to evaluate pain experienced during imaging-guided core-needle breast biopsies and to identify factors that predict increased pain perception during procedures. METHODS: In this institutional review board-approved, HI ... Full text Link to item Cite

Cancelation of MRI guided breast biopsies for suspicious breast lesions identified at 3.0 T MRI: reasons, rates, and outcomes.

Journal Article Acad Radiol · May 2013 RATIONALE AND OBJECTIVES: To determine the cancelation rate of magnetic resonance imaging (MRI)-guided procedures in suspicious breast lesions initially detected at 3.0 Tesla (T) MRI. MATERIALS AND METHODS: With institutional review board approval, a Healt ... Full text Link to item Cite

Suspicious breast lesions detected at 3.0 T magnetic resonance imaging: clinical and histological outcomes.

Journal Article Acad Radiol · June 2012 RATIONALE AND OBJECTIVES: To evaluate the imaging features and histological and clinical outcomes of a series of suspicious, mammographically occult breast lesions detected at 3.0 T magnetic resonance imaging (MRI). MATERIALS AND METHODS: Approval was obta ... Full text Link to item Cite

Using the BI-RADS lexicon in a restrictive form of double reading as a strategy for minimizing screening mammography recall rates.

Journal Article AJR Am J Roentgenol · April 2012 OBJECTIVE: The purpose of this article is to determine the potential reduction in screening recall rates by strictly following standardized BI-RADS lexicon for lesions seen on screening mammography. MATERIALS AND METHODS: Of 3084 consecutive mammograms per ... Full text Link to item Cite

Minimal Screening Mammography Recall Rates Using Standardized BI-RADS Criteria

Journal Article AMERICAN JOURNAL OF ROENTGENOLOGY · May 1, 2007 Link to item Cite

Ultrasound of the thyroid and parathyroid glands.

Journal Article Ultrasound Q · December 2003 Ultrasound plays a prominent role in the management of thyroid disease and parathyroid adenomas. It can detect clinically impalpable thyroid nodules and characterize them as cystic, solid, or complex. Determining that a nodule is definitively benign or mal ... Full text Link to item Cite

Sympathetic response to intracranial NGF infusion in the absence of afferent input: axonal sprouting without neurotransmitter production.

Journal Article Exp Neurol · September 1996 The anatomical relationships between postganglionic sympathetic neurons, their targets, and their afferent inputs provide an opportunity to experimentally distinguish between the anterograde and the retrograde influences on neuronal responsivity to growth ... Full text Link to item Cite