Intravoxel incoherent motion for differentiating residual/recurrent tumor from post-treatment change in patients with high-grade glioma.

PURPOSE: To investigate the diagnostic value of f derived from IVIM technique and to correlate it with rCBV derived from DSC for the differentiation of residual/recurrent tumor from post-treatment change in patients with high-grade glioma. MATERIALS AND METHODS: Patients who underwent MR imaging with IVIM and DSC studies for evaluation of high-grade glioma after standard treatment were enrolled in this retrospective study. For qualitative analysis, the f and rCBV maps were interpreted as hypoperfused or hyperperfused in each parameter. Quantitative analysis was performed using ROI analysis in f and rCBV parameters. The lesions were divided into residual/recurrent tumor and post-treatment change groups. RESULTS: Nineteen patients with high-grade glioma were included. In qualitative analysis, the f-map shows higher sensitivity (100.0%) than rCBV map (92.3%), while the rCBV map shows higher specificity (100.0%) than the f-map (83.3%). In quantitative analysis, the optimal cutoff values of 1.19 for f and 1.06 for rCBV are shown to provide high diagnostic value with high sensitivity (91.7%) for both parameters but slightly higher specificity of rCBV (85.7%) than f (71.4%). The correlation between f and rCBV was good with ICC of 0.810. CONCLUSION: The f value measured by IVIM technique, non-contrast perfusion technique, has high diagnostic performance and potential to be an alternative method to CBV measured by DSC for differentiation between residual/recurrent tumor and post-treatment change in patients with high-grade glioma.

Dual-Energy Computed Tomography-Derived Iodine Density and Spectral Attenuation Analysis for Differentiation of Inverted Papilloma and Sinonasal Squamous Cell Carcinoma/Lymphoma.

OBJECTIVE: This study aimed to assess the value of dual-energy computed tomography for differentiation of inverted papilloma from squamous cell carcinoma (SCC)/lymphoma. METHODS: Twenty-eight patients with pathologically diagnosed inverted papilloma or SCC/lymphoma underwent contrast-enhanced dual-energy computed tomography. Qualitative features (laterality, location, enhancement pattern, border, necrosis, hemorrhage, calcification, bone destruction, pterygopalatine fossa extension, adjacent invasion, and perineural spreading) and quantitative features (iodine density and spectral attenuation curve slope) were analyzed. Optimal cutoff thresholds of diagnostic efficacy were generated. RESULTS: Fifteen patients had inverted papilloma, and 13 had malignancy (5 SCC and 8 lymphoma). Computed tomography findings of bilateral lesions, sphenoid sinus involvement, pterygopalatine fossa extension, and adjacent invasion were significantly associated with SCC/lymphoma. The iodine density was significantly higher in SCC/lymphoma (2.46 ± 0.22 mg/mL) than in inverted papilloma (1.42 ± 0.46 mg/mL; P = 0.001). An iodine density threshold of 1.74 mg/mL had a sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of 92.3%, 86.7%, 92.9%, 85.7%, and 90.3%, respectively. The spectral attenuation curve slope was significantly higher in SCC/lymphoma (4.35 ± 0.27 HU/keV) than in inverted papilloma (2.72 ± 0.88 HU/keV; P = 0.001). A spectral attenuation curve slope threshold of 3.34 HU/keV had a sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of 92.3%, 86.7%, 92.9%, 85.7%, and 90.8%, respectively. CONCLUSIONS: Squamous cell carcinoma/lymphoma had a significantly higher iodine density and spectral attenuation curve slope than inverted papilloma. Using optimal quantitative measurement thresholds provides high diagnostic efficacy.

Enlarging biopsy-proven fibroadenoma: Is surgical excision necessary?

PURPOSE: Core biopsy-proven fibroadenomas that enlarge on clinical or imaging follow-up are often surgically excised to exclude an associated malignancy. The purpose of this study was to assess how often malignancy is detected upon excision, and to determine whether excision of enlarging, biopsy-proven, uncomplicated fibroadenomas is still warranted. MATERIALS AND METHODS: Review of our institutional pathology database from 2000 to 2010 identified 1117 cases of fibroadenoma, and retrospective chart review, including review of pathology and imaging findings of all these records, was performed. RESULTS: 1117 cases of fibroadenoma were identified in a population of women ranging from ages 17 to 78. Of these, 378 (33.8%) were diagnosed by ultrasound core needle biopsy and formed the study population. Of the 378 cases, 24 (6.3%) had co-existent atypia and were immediately excised; these cases were excluded. An additional 107 (28%) were lost to follow-up. Of the remaining 247 cases, 201 (81%) showed stability on follow-up imaging (mean 31.5 months), and 46 (18.6%) enlarged on follow-up. Of the 46 biopsy proven fibroadenomas that enlarged, 19 had a biopsy at initial presentation and 27 underwent biopsy after they enlarged. Seventeen of the 19 were excised after enlargement, and pathology confirmed fibroadenoma in all cases (100%); two enlarged on initial follow-up imaging but remained stable for at least three years on continued follow-up. Of the 27 cases which were biopsied after enlargement, 23 revealed fibroadenoma on core biopsy, 3 had fibroadenoma with associated atypia with subsequent surgery revealing fibroadenoma and no associated malignancy, and one showed fibroadenoma with smooth muscle with subsequent surgery showing phyllodes tumor. CONCLUSION: Based on this study, enlarging biopsy proven fibroadenomas are not associated with malignancy; therefore, surgical excision does not seem warranted. For presumed enlarging fibroadenomas on imaging, core biopsy should be performed to exclude associated atypia or phyllodes tumor. Finally, surgical excision is indicated for lesions with associated atypia or suspected phyllodes and for symptomatic lesions or cosmetic reasons.

Interventional MR Imaging for Deep-Brain Stimulation Electrode Placement.

Purpose To investigate the safety and targeting errors of deep-brain stimulation (DBS) electrodes placed under interventional magnetic resonance (MR) imaging, which allows near real-time anatomic placement without physiologic mapping. Materials and Methods Retrospectively evaluated were 10 consecutive patients (five women, five men) with a mean age of 59.9 years (age range, 17-79 years). These patients underwent interventional MR imaging-guided DBS placement for movement disorders from September 2013 to August 2014 for placement of 19 DBS electrodes in cases where traditional frame-based surgery may be challenging because of the following: dystonia resulting in difficulty in placing the patients in frame, patient's inability or unwillingness to tolerate awake surgery, or anatomic anomaly or variant that could increase the risk of bleeding from microelectrode mapping. Outcomes measured included perioperative hemorrhage, death, and stroke, and electrode functionality assessed at 2 weeks after the operation. In addition, the mean radial error and mean trajectory error were calculated. Results No intraoperative neurologic complications (n = 10 [95% confidence interval: 0%, 31%]) were observed. One patient developed aspiration pneumonia in the postoperative period. Mean radial error was 0.7 mm ± 0.4 (standard deviation) and mean trajectory error was 0.5 mm ± 0.4. All leads delivered clinically effective stimulation. Conclusion Interventional MR imaging-guided DBS electrode placement may be a safe and effective alternative to conventional frame-based surgery in well-selected patients. © RSNA, 2016.

Magnetic Resonance Imaging-Guided Spine Interventions.

MR imaging-guided interventions for treatment of low back pain and for diagnosis and treatment of soft tissue and bony spinal lesions have been shown to be feasible, effective, and safe. Advantages of this technique include the absence of ionizing radiation, the high tissue contrast, and multiplanar imaging options. Recent advancements in MR imaging systems allow improved image qualities and real-time guidance. One exciting application is MR imaging-guided cryotherapy of spinal lesions, including treating such lesions as benign osteoid osteomas and malignant metastatic disease in patients who are not good surgical candidates. This particular technique shows promise for local tumor control and pain relief in appropriate patients.

Intra-thoracic rheumatoid arthritis: Imaging spectrum of typical findings and treatment related complications.

Non-cardiac thoracic manifestations of rheumatoid arthritis (RA) cause significant morbidity and mortality among RA patients. Essentially all anatomic compartments in the chest can be affected including the pleura, pulmonary parenchyma, airway, and vasculature. In addition, treatment-related complications and opportunistic infections are not uncommon. Accurate diagnosis of intra-thoracic disease in an RA patient can be difficult as the radiologic findings may be nonspecific and many of these conditions may coexist. This review article serves to highlight the multitude of RA-related intra-thoracic pathological processes, emphasize differential diagnosis, diagnostic conundrums and discuss how tailoring of CT imaging and image-guided biopsy plays a key role in the management of RA-related pulmonary disease.

Imaging in lung transplants: Checklist for the radiologist.

Post lung transplant complications can have overlapping clinical and imaging features, and hence, the time point at which they occur is a key distinguisher. Complications of lung transplantation may occur along a continuum in the immediate or longer postoperative period, including surgical and mechanical problems due to size mismatch and vascular as well as airway anastomotic complication, injuries from ischemia and reperfusion, acute and chronic rejection, pulmonary infections, and post-transplantation lymphoproliferative disorder. Life expectancy after lung transplantation has been limited primarily by chronic rejection and infection. Multiple detector computed tomography (MDCT) is critical for evaluation and early diagnosis of complications to enable selection of effective therapy and decrease morbidity and mortality among lung transplant recipients.

Hyaluronic acid-binding scaffold for articular cartilage repair.

Hyaluronic acid (HA) is an extracellular matrix molecule with multiple physical and biological functions found in many tissues, including cartilage. HA has been incorporated in a number of biomaterial and scaffold systems. However, HA in the material may be difficult to control if it is not chemically modified and chemical modification of HA may negatively impact biological function. In this study, we developed a poly(ethylene glycol) hydrogel with noncovalent HA-binding capabilities and evaluated its ability to support cartilage formation in vitro and in an articular defect model. Chondrogenic differentiation of mesenchymal stem cells encapsulated in the HA-interactive scaffolds containing various amounts of exogenous HA was evaluated. The HA-binding hydrogel without exogenous HA produced the best cartilage as determined by biochemical content (glysocaminoglycan and collagen), histology (Safranin O and type II collagen staining), and gene expression analysis for aggrecan, type I collagen, type II collagen, and sox-9. This HA-binding formulation was then translated to an osteochondral defect model in the rat knee. After 6 weeks, histological analysis demonstrated improved cartilage tissue production in defects treated with the HA-interactive hydrogel compared to noninteractive control scaffolds and untreated defects. In addition to the tissue repair in the defect space, the Safranin O staining in cartilage tissue surrounding the defect was greater in treatment groups where the HA-binding scaffold was applied. In sum, incorporation of a noncovalent HA-binding functionality into biomaterials provides an ability to interact with local or exogenous HA, which can then impact tissue remodeling and ultimately new tissue production.

The postconservation breast: part 1, Expected imaging findings.

OBJECTIVE: The objectives of this article are to discuss the conventional imaging algorithms after breast-conserving surgery and radiation therapy and to review the expected chronologic imaging appearances of the conservatively treated breast. CONCLUSION: Imaging the treated breast presents challenges because of its limited compressibility and the overlapping features of benign posttreatment alterations and tumor recurrence. After lumpectomy and radiation therapy, mammographic findings such as breast edema, skin thickening, fluid collections, architectural distortion, and calcifications have characteristic sequences of evolution toward stability. Awareness of these normal chronologic imaging findings for the conservatively treated breast minimizes unnecessary recall from screening and permits early detection of recurrent breast carcinoma.

The postconservation breast: part 2, Imaging findings of tumor recurrence and other long-term sequelae.

OBJECTIVE: The objectives of this article are to highlight the imaging findings of tumor recurrence and other long-term potential sequelae after breast-conserving surgery and radiation therapy, including increased risk of infection and radiation-induced malignancies. The role of MRI as a problem-solving tool in evaluating the conservatively treated breast will also be discussed. CONCLUSION: Imaging the treated breast presents challenges because of its limited compressibility and overlapping features of benign posttreatment alterations and tumor recurrence. After lumpectomy and radiation therapy, mammographic findings such as breast edema, skin thickening, fluid collections, architectural distortion, and calcifications have characteristic sequences of evolution toward stability. Changes in the imaging appearance after stability has been achieved--including increasing asymmetry, an enlarging mass, increasing edema or skin thickening, and the development of pleomorphic calcifications within or near the operative bed--should alert the radiologist to possible tumor recurrence. When mammography or sonography is indeterminate, MRI may be useful in excluding recurrence or providing a means for biopsy of a suspicious finding.

Enhanced chondrogenesis of mesenchymal stem cells in collagen mimetic peptide-mediated microenvironment.

A new type of synthetic hydrogel scaffold that mimics certain aspects of structure and function of natural extracellular matrix (ECM) has been developed. We previously reported the conjugation of collagen mimetic peptide (CMP) to poly(ethylene oxide) diacrylate (PEODA) to create a polymer-peptide hybrid scaffold for a suitable cell microenvironment. In this study, we showed that the CMP-mediated microenvironment enhances the chondrogenic differentiation of mesenchymal stem cells (MSCs). MSCs were harvested and photo-encapsulated in CMP-conjugated PEODA (CMP/PEODA). After 3 weeks, the histological and biochemical analysis of the CMP/PEODA gel revealed twice as much glycosaminoglycan and collagen contents as in control PEODA hydrogels. Moreover, MSCs cultured in CMP/PEODA hydrogel exhibited a lower level of hypertrophic markers, core binding factor alpha 1, and type X collagen than MSCs in PEODA hydrogel as revealed by gene expression and immunohistochemisty. These results indicate that CMP/PEODA hydrogel provides a favorable microenvironment for encapsulated MSCs and regulates their downstream chondrogenic differentiation.