Inter- and intrareader agreement for categorization of background parenchymal enhancement at baseline and after training.

OBJECTIVE: Background parenchymal enhancement (BPE) refers to enhancing fibroglandular tissue on initial contrast-enhanced MR images. BPE appears to impact the rate of abnormal MRI interpretation and may correlate with breast cancer risk. There are now minimal data as to the uniformity of radiologists' BPE assessments and no data as to whether training improves agreement. Therefore, for this study, we sought to assess interreader agreement for BPE at baseline and after dedicated training. MATERIALS AND METHODS: This study included 119 breast MRI examinations performed in 119 patients (mean age, 47 years; age range, 25-79 years) in 2008. One week before training, four fellowship-trained breast imagers with 2-12 years' experience independently recorded BPE on a 4-point scale as follows: 1 (minimal, ≤ 25%), 2 (mild, 26-50%), 3 (moderate, 51-75%), or 4 (marked, > 75%). The same 119 cases were reread in a new random order within 1 week and at least 3 weeks after training. Interreader agreement and intrareader agreement were assessed using kappa coefficients. RESULTS: With training, interreader agreement increased from fair (κ = 0.36) to moderate (κ = 0.48). Improvement was sustained at 3 weeks after training (κ = 0.45). Intrareader agreement between time points 2 and 3 (κ: mean, 0.79; range, 0.56-0.98) was greater than between time points 1 and 2 (κ: mean, 0.62; range, 0.45-0.84), indicating readers learned and retained. CONCLUSION: Initial interreader agreement for BPE was fair among breast radiologists but achieved sustained improvement with training, highlighting the importance of education and inclusion of standardized BPE categories in a reference atlas.

Update on imaging of the postsurgical breast.

Oncologic, reconstructive, and cosmetic breast surgery has evolved in the last 20 years. Familiarity with cutting-edge surgical techniques and their imaging characteristics is essential for radiologic interpretation and may help avert false-positive imaging findings. Novel surgical techniques include skin- and nipple-sparing mastectomies, autologous free flaps, autologous fat grafting, and nipple-areola-complex breast reconstruction. These techniques are illustrated and compared with conventional surgical techniques, including modified radical mastectomy and autologous pedicled flaps. The role of magnetic resonance (MR) imaging in surgical planning, evaluation for complications, and postsurgical cancer detection is described. Breast reconstruction and augmentation using silicone gel-filled implants is discussed in light of the Food and Drug Administration's recommendation for MR imaging screening for "silent" implant rupture 3 years after implantation and every 2 years thereafter. Recent developments in skin incision techniques for reduction mammoplasty are presented. The effects of postsurgical changes on the detection of breast cancer are discussed by type of surgery.

Short interval follow-up after a benign concordant MR-guided vacuum assisted breast biopsy--is it worthwhile?

OBJECTIVE: To determine the utility of short-interval follow-up after benign concordant MRI-guided breast biopsy. MATERIALS AND METHODS: Institutional review board approved, retrospective review of consecutive biopsies performed over 3 years (2007-10) yielded 170 women with 188 lesions that were considered benign concordant. Indication for original study, biopsy results, follow-up recommendations, compliance and outcomes of subsequent MRI and mammography examinations were reviewed. RESULTS: The most common indication for breast MRI was high-risk screening 119/170 (70 %). Overall, 59 % of lesions (113/188) had follow-up MRI. Of those lesions (n = 113), 43 % (49/113) presented within 7 months, 26 % (29/113) presented within 8-13 months, 11.5 % (13/113) presented within 14-22 months, and 19 % (22/113) presented after 23 months. At initial follow-up, 37 % of lesions were stable and 61 % were decreased in size. Three lesions were recommended for excision based on follow-up imaging with one malignancy diagnosed 2 years following biopsy. One additional patient had MRI-detected bilateral cancers remote from the biopsy site 3 years after biopsy. CONCLUSION: Overall cancer yield of lesions with follow-up MRI was 0.9 % (1/113); no cancers were detected at 6 months. Our data suggests that 6-month follow-up may not be required and that annual screening MRI would be acceptable to maintain a reasonable cancer detection rate. KEY POINTS: Follow-up recommendations after benign concordant MRI-guided breast biopsy remain controversial. Cancer detection rate was 0.9 % overall with no cancers detected at 6 months. Short-interval follow-up after benign concordant MRI-guided breast biopsy may not be necessary.

Ductal carcinoma in situ of the breasts: review of MR imaging features.

The incidence of ductal carcinoma in situ (DCIS) has increased over the past few decades and now accounts for over 20% of newly diagnosed cases of breast cancer. Although the detection of DCIS has increased with the advent of widespread mammography screening, it is essential to have a more accurate assessment of the extent of DCIS for successful breast conservation therapy. Recent studies evaluating the detection of DCIS with magnetic resonance (MR) imaging have used high spatial resolution techniques and have increasingly been performed to screen a high-risk population as well as to evaluate the extent of disease. This work has shown that MR imaging is the most sensitive modality currently available for identifying DCIS and is more accurate than mammography in evaluating the extent of DCIS. MR imaging is particularly sensitive for identifying high-grade and intermediate-grade DCIS. DCIS may have variable morphologic features on MR images, with non-mass enhancement morphology being the most common manifestation. Less commonly, DCIS may also manifest as a mass on MR images, in which case it is most likely to be irregular. The kinetics of DCIS are also variable, with fast uptake and a plateau curve reported as the most common kinetic pattern. Additional MR imaging tools such as diffusion-weighted imaging and quantitative kinetic analysis combined with the benefit of high field strength, such as 3 T, may increase the sensitivity and specificity of breast MR imaging in the detection of DCIS.

Sonographic features of rare posterior fetal neck masses of vascular origin.

The purpose of this series is to describe the grayscale and color Doppler sonographic characteristics as well as the histopathologic features of rare solid posterior neck masses identified on prenatal sonography in pregnant patients. We conducted a retrospective review of detailed fetal sonographic examinations of second- and third-trimester pregnancies referred to the Center for Fetal Diagnosis and Treatment at the Children's Hospital of Philadelphia for suspected fetal neck masses from June 1998 to December 2011. Eight predominately solid posterior neck masses were identified on 139 studies performed during the study period. Of the 7 cases in which follow-up was available, 6 were confirmed as hemangiomas, and 1 was confirmed as a kaposiform hemangioendothelioma with Kasabach-Merritt syndrome. The most common sonographic features were hypervascularity (7) and calcifications (5). Posterior solid fetal neck masses are rare anomalies. Hemangioma is the most common etiology and should be suggested as the likely diagnosis rather than teratoma, even in the presence of calcifications.

Variable MR imaging appearances of focal nodular hyperplasia in pediatric cancer patients.

BACKGROUND: Focal nodular hyperplasia (FNH) is rare in the general pediatric population but is increasingly found in treated pediatric cancer patients. FNH can be incidentally found on CT and MRI and can be misdiagnosed as liver metastasis in patients with an oncological history. OBJECTIVE: To describe the MR imaging findings of FNH in pediatric cancer patients. MATERIALS AND METHODS: Ten children who had been treated for a primary malignancy and who were diagnosed with FNH from 2003 to 2010 were identified from a search for FNH in our pathology and radiology databases. Patients were included if they were treated for a primary malignancy and had undergone MR imaging of the liver including T1-weighted, T2-weighted and dynamic contrast-enhanced T1-weighted sequences. RESULTS: FNH from all patients (n=10) demonstrated typical homogeneous arterial enhancement on MRI. The FNH was often multiple and small (7/10 patients), lacking a central scar, with variable imaging characteristics including signal hyperintensity on both T1- and T2-weighted images (4/10 patients), especially in the setting of hepatic hemosiderosis. CONCLUSION: FNH has a variable MR appearance in pediatric cancer patients and should be considered in the differential diagnosis of hypervascular liver lesions.

Internal hernia following Roux-en-Y gastric bypass surgery for morbid obesity: evaluation of radiographic findings at small-bowel examination.

PURPOSE: To characterize features of internal hernia (IH) at small-bowel follow-through (SBFT) following Roux-en-Y gastric bypass procedure (RYGBP) for morbid obesity. MATERIALS AND METHODS: The institutional review board approved this HIPAA-compliant retrospective study; informed consent was waived. Radiologic database review revealed 1655 SBFT studies over 6 years in 1282 patients after RYGBP. IH was suggested on 24 studies in 23 patients. Studies were analyzed for atypical bowel configuration, change in bowel or suture position, and obstruction. Chart review was performed to determine clinical course, treatment, and outcome. Studies from a control group of 21 RYGBP patients were similarly analyzed. Statistical comparison was performed with the Fisher exact test. RESULTS: Clinical and/or surgical evidence of IH was found following 21 SBFT studies in 20 of 1282 patients (1.6%). Atypical bowel configuration with clustered small bowel was identified on all studies. Cluster location was lateral to descending colon (n = 10), left upper quadrant (n = 6), left upper and mid abdomen (n = 3), right midabdomen (n = 2), under the gastric pouch (n = 1), and right lower quadrant (n = 1). For two studies, two locations of clustered bowel were identified. Change in jejunojejunal suture position occurred in all cases with radiopaque suture (n = 15). Other signs of IH included displaced colon (n = 19), visible entrance and exit limbs into the hernia (n = 17), stasis in clustered bowel (n = 16), densely matted bowel (n = 12), and a straight left lateral border of clustered bowel (n = 10). Partial obstruction occurred in 16 patients. Findings of atypical bowel configuration, clustered bowel, and staple line change were significant when compared with the control. CONCLUSION: IH following RYGBP is a rare but potentially fatal complication. Radiologists must be aware of this complication and its diagnostic features at SBFT.