Jessica B. Robbins

Flat (Nonpolypoid) Colorectal Lesions Identified at CT Colonography in a U.S. Screening Population

RATIONALE AND OBJECTIVES The aim of this study was to investigate the clinical importance and height definition of flat (nonpolypoid) colorectal lesions detected on screening computed tomographic colonography (CTC). MATERIALS AND METHODS Results from prospective screening CTC in 5107 consecutive asymptomatic adults (mean age, 56.9 years) at a single center were analyzed. All detected colorectal lesions > or = 6 mm were prospectively categorized as polypoid or flat (nonpolypoid). The maximal height of all flat lesions was measured to assess the suggested 3-mm threshold definition. RESULTS Of 954 polyps measuring > or = 6 mm identified on screening CTC, 125 lesions (13.1%) in 106 adults were prospectively categorized as flat, with a mean size of 12.7 mm (range, 6-80 mm), including 73 lesions 6 to 9 mm, 42 lesions 10 to 29 mm, and 10 lesions > or = 3 cm (carpet lesions). For polyps between 6 and 30 mm in size, flat lesions were less likely than polypoid lesions to be neoplastic (25.0% vs 60.3%, P < .001), histologically advanced (5.4% vs 12.1%, P = .07) or malignant (0% vs 0.5%, P = NS). Two of 10 carpet lesions (20%) were malignant, compared to 50% of polypoid masses > or = 3 cm. Of nine flat lesions seen only on colonoscopy (false-negatives on CTC), two were neoplastic (tubular adenomas), and none was histologically advanced. For all flat lesions between 6 and 30 mm, the maximal height averaged 2.2 mm and was < or =3 mm in 86.1%, including 93.2% of small 6-mm to 9-mm flat lesions. CONCLUSION In a US screening population, flat colorectal lesions detected on CTC demonstrated less aggressive histologic features compared to polypoid lesions. Excluding carpet lesions, a maximal height of 3 mm appears to be a reasonable definition.

Colorectal Polyps: Stand-alone Performance of Computer-aided Detection in a Large Asymptomatic Screening Population

PURPOSE To evaluate stand-alone performance of computer-aided detection (CAD) for colorectal polyps of 6 mm or larger at computed tomographic (CT) colonography in a large asymptomatic screening cohort. MATERIALS AND METHODS In this retrospective, institutional review board-approved, HIPAA-compliant study, a CAD software system was applied to screening CT colonography in 1638 women and 1408 men (mean age, 56.9 years) evaluated at a single medical center between March 2006 and December 2008. All participants underwent cathartic preparation with stool tagging; electronic cleansing was not used. The reference standard consisted of interpretation by experienced radiologists in all cases. This interpretation was further refined for the subset of cases with positive findings by using subsequent colonoscopic or CT colonographic confirmation, as well as retrospective expert localization of polyps with CT colonography. This test set was not involved in training the CAD system. The Fisher exact test was used to evaluate significance; 95% confidence intervals (CIs) were obtained by using the exact method. RESULTS Per-patient CAD sensitivities were 93.8% (350 of 373; 95% CI: 90.9%, 96.1%) and 96.5% (137 of 142; 95% CI: 92.0%, 98.8%) at 6- and 10-mm threshold sizes, respectively. Per-polyp CAD sensitivities for all polyps, regardless of histologic features, were 90.1% (547 of 607; 95% CI: 88.0%, 92.8%) and 96.0% (168 of 175; 95% CI: 91.9%, 98.4%) at 6- and 10-mm threshold sizes, respectively; CAD sensitivities for advanced neoplasia and cancer were 97.0% (128 of 132; 95% CI: 92.4%, 99.2%) and 100% (13 of 13; 95% CI: 79.4%, 100%), respectively. The mean and median false-positive rates were 4.7 and 3 per series, respectively (9.4 and 6 per patient). Among 373 patients with a positive finding at CT colonography, CAD marked an additional 15 polyps of 6 mm or larger, including four large polyps, that were missed at the prospective three-dimensional reading by an expert but were found at subsequent colonoscopy. CONCLUSION Stand-alone CAD demonstrated excellent performance for polyp detection in a large screening population, with high sensitivity and an acceptable number of false-positive results.

Characterization of hepatic adenoma and focal nodular hyperplasia with gadoxetic acid

To characterize imaging features of histologically proven hepatic adenoma (HA) as well as histologically and/or radiologically proven focal nodular hyperplasia (FNH) using delayed hepatobiliary MR imaging with 0.05 mmol/kg gadoxetic acid.

Accuracy of Diagnostic Mammography and Breast Ultrasound During Pregnancy and Lactation

OBJECTIVE The purpose of this article is to determine the accuracy of mammography and sonography in evaluating pregnant, lactating, and postpartum women. MATERIALS AND METHODS We retrospectively reviewed diagnostic breast imaging examinations of 155 pregnant, lactating, and postpartum women with 164 lesions presenting to our breast imaging department from 2004 to 2005. Records were reviewed for clinical presentation, reported sonographic or mammographic findings with BI-RADS assessment, histologic results, and clinical outcomes. Examinations rated as BI-RADS categories 4 and 5 were considered positive. One hundred thirty-four (82%) of 164 lesions had pathology results available or longer than 12 months follow-up in our study group. Of these lesions, 12 (9%) were evaluated by mammography alone, 49 (37%) were evaluated by ultrasound alone, and 73 (54%) were evaluated by both techniques. RESULTS Of 134 lesions, 87 (65%) were in patients who presented during lactation, 34 (25%) who presented during pregnancy, and 13 (10%) who presented postpartum. The presenting symptom for 86 lesions (64%) was a palpable mass. Biopsies were performed for 40 lesions. Of these lesions, four were malignant and 36 were benign. Mammograms were dense or heterogeneously dense in 88% of patients. All four malignancies were BI-RADS category 4 or 5 according to both mammography and ultrasound. For the 85 lesions evaluated with mammography, there was 100% sensitivity, 93% specificity, 40% positive predictive value, and 100% negative predictive value. For the 122 lesions evaluated with sonography, there was 100% sensitivity, 86% specificity, 19% positive predictive value, and 100% negative predictive value. CONCLUSION Among lactating and pregnant women, both mammography and sonography had a negative predictive value of 100% and accurately revealed the few cancers that were present in our study group.

CT-Guided Lung Biopsies: Pleural Blood Patching Reduces the Rate of Chest Tube Placement for Postbiopsy Pneumothorax

OBJECTIVE The objective of our study was to determine whether pleural blood patching reduces the need for chest tube placement and hospital admission for pneumothorax complicating CT-guided percutaneous lung biopsy. MATERIALS AND METHODS We reviewed 463 CT-guided lung biopsies performed between August 2006 and March 2010 to determine whether intervention for pneumothorax was required and patient outcome. Intervention was categorized as simple aspiration, aspiration and intrapleural blood patching, or chest tube placement and hospital admission. The technique for pleural blood patching consisted of complete pneumothorax aspiration, immediate placement of up to 15 mL of peripheral autologous blood into the pleural space, and positioning the patient in the ipsilateral decubitus position for 1 hour after the procedure. RESULTS Intervention for pneumothorax was necessary in 45 of 463 patients (9.7%) and 19 of 463 patients (4.1%) required chest tube placement. Pleural blood patching as a method to treat a postbiopsy pneumothorax and avoid further intervention was associated with a significantly higher success rate than simple aspiration: 19 of 22 (86.4%) vs seven of 15 (46.7%) (odds ratio = 7.2, p = 0.03), respectively. CONCLUSION Aspiration with intrapleural blood patching is superior to simple aspiration to treat pneumothorax associated with CT-guided lung biopsy. Pleural blood patching reduces the need for chest tube placement and hospital admission in this patient population.

Nature, timing, and severity of complications from ultrasound‐guided percutaneous renal transplant biopsy

We sought to review our kidney transplant biopsy experience to assess the incidence, type, presenting symptoms, and timing of renal transplant biopsy complications, as well as determine any modifiable risk factors for postbiopsy complications. This is an observational analysis of patients at the University of Wisconsin between January 1, 2000, and December 31, 2009. Patients with an INR ≥1.5 or platelet counts less than 50 000 were not biopsied. An 18‐gauge needle was used for biopsy. Over the study period, 3738 biopsies were performed with 66 complications (1.8%). No deaths occurred. A total of 0.7% were mild complications, 0.7% were moderate complications, 0.21% were severe complications, and 0.19% were life‐threatening. Most complications occurred within the 4‐h postbiopsy period, although serious complications were often delayed: 67% of complications requiring surgical intervention presented greater than 4 h after biopsy. Biopsy within 1 week of transplant had a 311% increased risk of a complication. Postbiopsy reduction in hematocrit and hemoglobin at 4 h was associated with a complication. In conclusion, life‐threatening complications after renal allograft biopsy occurred in 0.19% of patients. Most complications occurred within 4 h postprocedure; however, many serious complications occurred with a time delay after initially uneventful monitoring. The only clinically significant laboratory predictor of a complication was a fall in the hematocrit or hemoglobin within 4 h. Patients biopsied within a week of transplant were at the highest risk for a complication and should therefore be most closely monitored.

MRI of Pregnancy-Related Issues: M??llerian Duct Anomalies

OBJECTIVE Müllerian duct anomalies can adversely affect pregnancy outcomes and can result in clinical symptoms. This article will review the appropriate management of patients with müllerian duct abnormalities. CONCLUSION Whereas uterine and vaginal septa, vaginal agenesis, and unicornuate uterus can be managed surgically, other uterine anomalies tend to be managed clinically. Hence, appropriate management depends on a reliable assessment of pelvic anatomy. MRI can accurately display female pelvic anatomy and is, therefore, useful in guiding therapy.

Müllerian duct anomalies: Embryological development, classification, and MRI assessment

Müllerian duct anomalies (MDA) occur due to abnormal development of the uterus, cervix, and vagina, many times affecting a womans ability to conceive and carry a pregnancy to term. The spectrum of possible abnormalities are related to the development of two separate Müllerian systems, which then fuse and subsequently undergo degeneration of the fused segments. This multiphasic development explains the multiple variations within the scheme of MDA classification. The purpose of this article is to review the embryologic development of the Müllerian ducts, relate the development to the most commonly used classification system, and review the magnetic resonance imaging (MRI) assessment of Müllerian duct anomalies. A brief review of the treatment options, as they relate to the imaging diagnosis, will be provided as well. J. Magn. Reson. Imaging 2015;41:1–12.

24/7/365 in-house radiologist coverage: effect on resident education.

RATIONALE AND OBJECTIVES To compare programs with and without 24-hour/7 days a week/365 days a year (24/7/365) in-house radiologist coverage regarding resident perceptions of their on-call experience, volume of resident dictations on call, and report turnaround time. MATERIALS AND METHODS Residents from six academic radiology departments were invited to participate in an 11-item online survey. Survey items were related to workload, level of autonomy, faculty feedback, comfort level, faculty supervision, and overall educational experience while on call from 8 pm to 8 am. Each site provided data on imaging volume, radiologist coverage, volume of examinations dictated by residents, number of residents on call, and report turnaround time from 8 pm to 8 am. F-ratios and eta-squares were calculated to determine the relationships between dependent and independent variables. A P value < .05 was considered statistically significant. RESULTS A total of 146 (67%) of 217 residents responded. Residents in programs with 24/7/365 in-house radiologist coverage dictated a lower percentage of examinations (46%) compared with other residents (81%) and rated faculty feedback more positively (mean 3.8 vs. 3.3) but rated their level of autonomy (mean 3.6 vs. 4.5) and educational experience (mean 3.6 vs. 4.2) more negatively (all P < .05). Report turnaround time was lower in programs with 24/7/365 coverage than those without (mean 1.7 hours vs. 9.1 hours). The majority of resident comments were negative and related to loss of autonomy with 24/7/365 coverage. CONCLUSION More rapid report turnaround time related to 24/7/365 coverage may come at the expense of resident education.

PET/CT and MRI in the imaging assessment of cervical cancer.

Imaging plays a central role in the evaluation of patients with cervical cancer and helps guide treatment decisions. The purpose of this pictorial review is to describe magnetic resonance (MR) imaging and positron emission tomography (PET)/computed tomography (CT) assessment of cervical cancer, including indications for imaging, important findings that may result in management change, as well as limitations of both modalities. The International Federation of Gynecology and Obstetrics cervical cancer staging system does not officially include imaging; however, the organization endorses the use of MR imaging and PET/CT in the management of patients with cervical cancer where these modalities are available. MR imaging provides the best visualization of the primary tumor and extent of soft tissue disease. PET/CT is recommended for assessment of nodal involvement, as well as distant metastases. Both MR imaging and PET/CT are used to follow patients post-treatment to assess for recurrence. This review focuses on the current MR imaging and PET/CT protocols, the utility of these modalities in assessing primary tumors and recurrences, with emphasis on imaging findings which change management and on imaging pitfalls to avoid. It is important to be familiar with the MR imaging and PET/CT appearance of the primary tumor and metastasis, as well as the imaging pitfalls, so that an accurate assessment of disease burden is made prior to treatment.