Primary non-Hodgkin lymphoma (NHL) of the breast is a very rare disease, and the mammographic and ultrasonographic findings of breast lymphoma are variable. There are several reports of magnetic resonance (MR) imaging findings in patients with breast lymphomas; however, few reports have described the findings observed on MR spectroscopy or the features of diffusion weighted (DW) imaging. The authors report the findings of classical MR imaging, MR spectroscopy and DW imaging of a 48-year-old woman and a 40-year-old woman with primary non-Hodgkin's lymphoma of breasts. Mammography and breast ultrasonography revealed a mass with circumscribed margin. The mass showed strong enhancement after contrast injection on MR imaging. DW imaging showed reduced diffusion and high-amplitude choline (Cho) peak at 3.22 ppm was detected by single voxel MR spectroscopy which was consistent with malignancy.
Adult ; Breast* ; Choline ; Diffusion* ; Female ; Humans ; Lymphoma ; Lymphoma, Non-Hodgkin* ; Magnetic Resonance Imaging ; Magnetic Resonance Spectroscopy* ; Mammography ; Middle Aged ; Rare Diseases ; Ultrasonography, Mammary

Pancreatic pseudocyst rupture into the portal vein is a very rare complication and only three reported cases were confirmed using MRI. We report the case of a 50-year-old man with fistula formation between the pseudocyst and the portal vein, confirmed noninvasively by MRI. T2-weighted MR images and magnetic resonance cholangiopancreatography showed fluid signal intensity within the portal, superior mesenteric, and splenic veins, and a direct communication between the pseudocyst and the portal vein.
Cholangiopancreatography, Magnetic Resonance ; Fistula* ; Humans ; Magnetic Resonance Imaging ; Middle Aged ; Pancreatic Pseudocyst* ; Pancreatitis ; Portal Vein* ; Rupture ; Splenic Vein ; Venous Thrombosis

The medial longitudinal fasciculus (MLF) is myelinated composite tract, lying near the midline, ventral to periaqueductal grey matter that plays a key role in coordinating eye movements. A lesion of the MLF results in an ipsilateral adduction deficit and a contralateral abducting nystagmus, referred to as an internuclear ophthalmoparesis. The blended tract with adjacent white matter in pons and midbrain is indistinguishable on brain imaging such as CT and MRI. Until now, to the best of our knowledge, MLF is not delineated on in vivo MRI. We present a case showing the whole connecting courses of MLF lesion on MRI in a patient with inflammatory demyelinating disorder.
Deception ; Demyelinating Diseases ; Eye Movements ; Humans ; Magnetic Resonance Imaging* ; Mesencephalon ; Myelin Sheath ; Neuroimaging ; Ophthalmoplegia* ; Pons

PURPOSE: The purpose of this study is to determine whether adding an angled oblique sagittal plane to the routine shoulder MRI improves the diagnostic performance in the evaluation of supraspinatus tendon tears with arthroscopic correlation. MATERIALS AND METHODS: The study included 121 patients who had a shoulder MRI followed by arthroscopy. Two radiologists separately evaluated the supraspinatus tendon for tears on shoulder MRI either with or without the angled oblique sagittal images. Arthroscopy was used as the reference standard. The sensitivity and specificity for diagnosing supraspinatus tendon tears were calculated and compared by using McNemar test. Interobserver and intertechnique variability in the interpretation of supraspinatus tendon tears were calculated as a kappa value. RESULTS: Adding the angled oblique sagittal images to the standard shoulder MRI showed improvement in the sensitivity for diagnosing full-thickness supraspinatus tendon tears and also in the sensitivity, specificity and accuracy for the detection of partial-thickness tears. However, there was no statistically significant difference in all of them between with and without the angled set. Interobserver agreement was substantial to almost perfect and intertechnique agreement was moderate. CONCLUSION: Adding an angled oblique sagittal plane image to the routine shoulder MRI showed no significantly different diagnostic performance in detecting the partial- and full-thickness supraspinatus tendon tears, compared to MRI without angled oblique sagittal plane.
Arthroscopy ; Humans ; Magnetic Resonance Imaging* ; Rotator Cuff ; Sensitivity and Specificity ; Shoulder Joint ; Shoulder* ; Tendon Injuries ; Tendons*

PURPOSE: Spin-echo (SE) technique is most commonly used pulse sequence for T1-weighted MR imaging. T1-weighted fluid-attenuated inversion recovery (T1FLAIR) is a relatively new pulse sequence and it provides higher tissue contrast between the gray matter (GM) and white matter (WM) of the brain than T1-weighted SE (T1SE) sequence. However, there has been controversy for the evaluation of enhancing brain tumors with T1FLAIR compared to T1SE. The purpose of this study was to compare T1FLAIR and T1SE sequences for the evaluation of enhancing intracranial tumors. MATERIALS AND METHODS: Fifty-two patients with enhancing brain tumors were evaluated with contrast-enhanced (CE) T1SE and T1FLAIR imaging. Eight quantitative criteria were calculated: lesion-to-WM contrast ratio (CR) and contrast-to-noise ratio (CNR), lesion-to-GM CR and CNR, lesion-to-CSF CR and CNR, and WM-to-GM CR and CNR. For qualitative evaluation, two radiologists assessed lesion conspicuity on CE T1SE and T1FLAIR sequences with three-scale: 1, T1SE superior; 2, sequence equal; T1FLAIR superior. RESULTS: Seventy-nine tumors (31 primaries, 48 metastases) were assessed. For quantitative measurement, the T1FLAIR lesion-to-GM, lesion-to-CSF, WM-to-GM CR and CNR values were comparable and statistically superior to those of the T1SE images (p < 0.001 in all). However, lesion-to-WM CR and CNR were similar on both two sequences without statistically significant difference (p = 0.661, 0.662, respectively). For qualitative evaluation, both radiologists assessed that T1FLAIR images were superior to T1SE images for the evaluation of lesion conspicuity. CONCLUSION: For the evaluation of enhancing intracranial tumors, T1FLAIR sequence was superior or comparable to T1SE sequence.
Brain ; Brain Neoplasms* ; Evaluation Studies as Topic ; Humans ; Magnetic Resonance Imaging*

PURPOSE: Intramedullary spinal lesions in the conus medullaris (CM), including tumors and vascular lesion, are rarely reported. We reported various MR features of intramedullary spinal cord lesions involving the CM including ependymoma, hemangioblastomas, dermoid cyst, ventriculus terminalis and spinal AVF and tried to discuss them for differential diagnosis. MATERIALS AND METHODS: Six patients (male: female = 4:2, mean age = 44.3 year old) were enrolled from the clinical database of our institute from 2004 to 2010 and their radiological images and clinical symptoms were reviewed retrospectively. All patients had taken initial and postoperative MRI with contrast enhancement using gadopentate dimeglumine (Gd-DTPA). These images were analyzed by tumor size, location, signal intensity relative to the spinal cord, vascular flow voids, syrinx or cyst, edema and enhancement pattern. RESULTS: Contrast enhancement was seen in all intramedullary masses. An eccentric enhancing nodule was noted in two hemangioblastomas and unusual peripheral rim enhancement with septation was seen in ventriculus terminalis. Patchy enhancement of the CM was observed in spinal arteriovenous fistula (AVF). Extensive cord edema adjacent to the intramedullary lesions was seen in four cases and syrinx was noted in three cases. Vascular signal voids were found in two hemangioblastomas and one spinal AVF. CONCLUSION: In evaluation of intramedullary spinal lesions in the CM, it is necessary to consider these unusual MR findings and discriminate various pathologies with prudence and caution.
Arteriovenous Fistula ; Conus Snail* ; Dermoid Cyst ; Diagnosis, Differential* ; Edema ; Ependymoma ; Female ; Hemangioblastoma ; Humans ; Magnetic Resonance Imaging* ; Pathology ; Retrospective Studies ; Spinal Cord

PURPOSE: The aim of this study was to determine the magnetic resonance imaging (MRI) features associated with re-excision due to the presence of a positive margin after breast conserving therapy (BCT) in breast cancer patients. MATERIALS AND METHODS: We reviewed the records of 286 consecutive breast cancer patients who received BCT between January 2006 and December 2007. Among 246 patients who had undergone BCT, 38 (15.4%) underwent immediate further surgery due to positive margin status. We analyzed the MRI findings using chi2 test, Fisher's exact test and t tests. Multivariate logistic regression was conducted for prediction of re-excision. RESULTS: Tumor size (p < 0.001), lesion multiplicity (p = 0.003), and non-mass-like enhancement (NMLE) type on MRI (p < 0.001) were associated with margin involvement in BCT. On preoperative MRI, larger size (> or = 5 cm) (odds ratio = 2.96), NMLE (odds ratio = 3.81), and multifocal lesions (odds ratio = 2.54) were positively associated with re-excision. In cases involving NMLE, segmental distribution was associated with a greater likelihood of immediate re-excision. CONCLUSION: Larger size, multiplicity, and NMLE on MRI are significantly associated with re-excision after BCT in breast cancer patients. For NMLE lesions, the segmental distribution pattern was predictive of re-excision.
Breast ; Breast Neoplasms* ; Humans ; Logistic Models ; Magnetic Resonance Imaging*

PURPOSE: To compare dynamic susceptibility contrast imaging, diffusion-weighted imaging, and susceptibility-weighted imaging (SWI) for the differentiation of tumor recurrence and delayed radiation therapy (RT)-related changes in patients treated with RT for primary brain tumors. MATERIALS AND METHODS: We enrolled 24 patients treated with RT for various primary brain tumors, who showed newly appearing enhancing lesions more than one year after completion of RT on follow-up MRI. The enhancing-lesions were confirmed as recurrences (n=14) or RT-changes (n=10). We calculated the mean values of normalized cerebral blood volume (nCBV), apparent diffusion coefficient (ADC), and proportion of dark signal intensity on SWI (proSWI) for the enhancing-lesions. All the values between the two groups were compared using t-test. A multivariable logistic regression model was used to determine the best predictor of differential diagnosis. The cutoff value of the best predictor obtained from receiver-operating characteristic curve analysis was applied to calculate the sensitivity, specificity, and accuracy for the diagnosis. RESULTS: The mean nCBV value was significantly higher in the recurrence group than in the RT-change group (P=.004), and the mean proSWI was significantly lower in the recurrence group (P<.001). However, no significant difference was observed in the mean ADC values between the two groups. A multivariable logistic regression analysis showed that proSWI was the only independent variable for the differentiation; the sensitivity, specificity, and accuracy were 78.6% (11 of 14), 100% (10 of 10), and 87.5% (21 of 24), respectively. CONCLUSION: The proSWI was the most promising parameter for the differentiation of newly developed enhancing-lesions more than one year after RT completion in brain tumor patients.
Blood Volume ; Brain Neoplasms* ; Diagnosis ; Diagnosis, Differential ; Diffusion ; Follow-Up Studies ; Humans ; Logistic Models ; Magnetic Resonance Imaging ; Perfusion Imaging* ; Recurrence* ; Sensitivity and Specificity

PURPOSE: To efficiently evaluate phased array coil performance using a software tool box with which we can make visual comparison of the sensitivity of every coil element between the real experiment and EM simulation. MATERIALS AND METHODS: We have developed a C++- and MATLAB-based software tool called Phased Array Coil Evaluator (PACE). PACE has the following functions: Building 3D models of the coil elements, importing the FDTD simulation results, and visualizing the coil sensitivity of each coil element on the ordinary Cartesian coordinate and the relative coil position coordinate. To build a 3D model of the phased array coil, we used an electromagnetic 3D tracker in a stylus form. After making the 3D model, we imported the 3D model into the FDTD electromagnetic field simulation tool. RESULTS: An accurate comparison between the coil sensitivity simulation and real experiment on the tool box platform has been made through fine matching of the simulation and real experiment with aids of the 3D tracker. In the simulation and experiment, we used a 36-channel helmet-style phased array coil. At the 3D MRI data acquisition using the spoiled gradient echo sequence, we used the uniform cylindrical phantom that had the same geometry as the one in the FDTD simulation. In the tool box, we can conveniently choose the coil element of interest and we can compare the coil sensitivities element-by-element of the phased array coil. CONCLUSION: We expect the tool box can be greatly used for developing phased array coils of new geometry or for periodic maintenance of phased array coils in a more accurate and consistent manner.
Electromagnetic Fields ; Magnetic Resonance Imaging ; Magnets ; Retrospective Studies*

PURPOSE: To describe how a robust implementation of a radial 3D gradient-echo sequence with stack-of-stars sampling can be achieved, to review the imaging properties of radial acquisitions, and to share the experience from more than 5000 clinical patient scans. MATERIALS AND METHODS: A radial stack-of-stars sequence was implemented and installed on 9 clinical MR systems operating at 1.5 and 3 Tesla. Protocols were designed for various applications in which motion artifacts frequently pose a problem with conventional Cartesian techniques. Radial scans were added to routine examinations without selection of specific patient cohorts. RESULTS: Radial acquisitions show significantly lower sensitivity to motion and allow examinations during free breathing. Elimination of breath-holding reduces failure rates for non-compliant patients and enables imaging at higher resolution. Residual artifacts appear as streaks, which are easy to identify and rarely obscure diagnostic information. The improved robustness comes at the expense of longer scan durations, the requirement for fat suppression, and the nonexistence of a time-to-center value. Care needs to be taken during the configuration of receive coils. CONCLUSION: Routine clinical use of radial stack-of-stars sequences is feasible with current MR systems and may serve as substitute for conventional fat-suppressed T1-weighted protocols in applications where motion is likely to degrade the image quality.
Artifacts ; Cohort Studies ; Humans ; Respiration