T2-weighted Fast Spin-echo MR Imaging Research Articles

Threshold-based quantification of fatty degeneration in the supraspinatus muscle on MRI as an alternative method to Goutallier classification and single-voxel MR spectroscopy

BackgroundConventional fat quantification methods for rotator cuff muscles have various limitations, such as inconsistent reliabilities of the Goutallier grades and need for advanced techniques in quantitative MRI sequences. We aimed to examine a threshold-based fat quantification method in the supraspinatus muscle on standard T1-weighted MR images and compare the threshold-based method with Goutallier grades and MR spectroscopy.MethodsWe retrospectively examined 38 symptomatic patients, who underwent T1 and T2-weighted fast spin-echo MR imaging and a single voxel spin-echo MR spectroscopy. The supraspinatus muscle and fossa were manually segmented in T1-weighted sagittal images and clustering-based thresholding was applied to quantify the fat fractions in the segmented areas using custom MATLAB software. Threshold-based fat fractions were compared with the Goutallier grades and MR spectroscopy fat/water ratios. A one-way analysis of variance and Pearson correlation were tested in the MATLAB software.ResultsInter-observer reliability of threshold-based fat fractions for the supraspinatus muscle and fossa were 0.977 and 0.990 respectively, whereas the reliability of the Goutallier grading was 0.798. Threshold-based fat fractions in the supraspinatus fossa were significantly different between various Goutallier grades (one-way ANOVA, p < 0.001). Threshold-based fat fractions in the supraspinatus muscle strongly correlated with the MR spectroscopy fat/water ratio (Pearson correlation R-square = 0.83).ConclusionsThreshold-based fat quantification on standard T1-weighted MR images was highly reliable and produced comparable results to conventional Goutallier grades and MR spectroscopy fat/water ratios and could serve as an alternative method for accurate fat quantification in rotator cuff muscles.

Fully Automated Diagnosis of Anterior Cruciate Ligament Tears on Knee MR Images by Using Deep Learning.

To investigate the feasibility of using a deep learning-based approach to detect an anterior cruciate ligament (ACL) tear within the knee joint at MRI by using arthroscopy as the reference standard. A fully automated deep learning-based diagnosis system was developed by using two deep convolutional neural networks (CNNs) to isolate the ACL on MR images followed by a classification CNN to detect structural abnormalities within the isolated ligament. With institutional review board approval, sagittal proton density-weighted and fat-suppressed T2-weighted fast spin-echo MR images of the knee in 175 subjects with a full-thickness ACL tear (98 male subjects and 77 female subjects; average age, 27.5 years) and 175 subjects with an intact ACL (100 male subjects and 75 female subjects; average age, 39.4 years) were retrospectively analyzed by using the deep learning approach. Sensitivity and specificity of the ACL tear detection system and five clinical radiologists for detecting an ACL tear were determined by using arthroscopic results as the reference standard. Receiver operating characteristic (ROC) analysis and two-sided exact binomial tests were used to further assess diagnostic performance. The sensitivity and specificity of the ACL tear detection system at the optimal threshold were 0.96 and 0.96, respectively. In comparison, the sensitivity of the clinical radiologists ranged between 0.96 and 0.98, while the specificity ranged between 0.90 and 0.98. There was no statistically significant difference in diagnostic performance between the ACL tear detection system and clinical radiologists at P < .05. The area under the ROC curve for the ACL tear detection system was 0.98, indicating high overall diagnostic accuracy. There was no significant difference between the diagnostic performance of the ACL tear detection system and clinical radiologists for determining the presence or absence of an ACL tear at MRI.© RSNA, 2019Supplemental material is available for this article.

Non-alcoholic fatty liver disease in underweight patients with inflammatory bowel disease: A case-control study.

Non-alcoholic fatty liver disease (NAFLD) was shown to also occur in lean and underweight patients. So far, the prevalence of NAFLD in underweight individuals with and without inflammatory bowel disease (IBD) is insufficiently enlightened. In this cross-sectional age, gender and disease-matched case-control study, underweight patients (BMI<18.5 kg/m2) with inflammatory bowel disease (IBD), who underwent abdominal MRI at 1.5 T/3 T with fat-saturated fast-spin-echo imaging from 10/2005-07/2018 were analysed (control-to-case-ratio 1:1, n = 130). All patients were additionally investigated for duration, history of surgery, medical treatment, laboratory values, liver and spleen diameters. On MRI, liver fat was quantified by two observers based on the relative signal loss on T2-weighted fast spin-echo MR images with fat saturation compared to images without fat saturation. The prevalence of NAFLD/liver steatosis, defined as a measured intrahepatic fat content of at least 5%, was significantly higher in underweight IBD patients than in normal weight patients (87.6% versus 21.5%, p<0.001). Compared to the cases, the liver fat content of the controls was reduced by -0.19 units on average (-19%; 95%Cl: -0.20; -0.14). Similar results were obtained for the subgroup of non-IBD individuals (n = 12; -0.25 units on average (-25%); 95%Cl: -0.35; -0.14). Patients with extremely low body weight (BMI <17.5 kg/m2) showed the highest liver fat content (+0.15 units on average (+15%) compared to underweight patients with a BMI of 17.5–18.5 kg/m2 (p<0.05)). Furthermore, underweight patients showed slightly increased liver enzymes and liver diameters. There were no indications of significant differences in disease duration, type of medications or surgery between cases and controls and also, there were no significant differences between observers or field strengths (p>0.05). The prevalence of liver steatosis was higher among underweight IBD and non-IBD patients compared to normal weight controls. Also, underweight patients showed slightly increased liver enzymes and liver diameters, hinting at initial metabolic disturbances.

High-Resolution 3-T Endorectal Prostate MRI: A Multireader Study of Radiologist Preference and Perceived Interpretive Quality of 2D and 3D T2-Weighted Fast Spin-Echo MR Images.

The goal of this study was to compare the perceived quality of 3-T axial T2-weighted high-resolution 2D and high-resolution 3D fast spin-echo (FSE) endorectal MR images of the prostate. Six radiologists independently reviewed paired 3-T axial T2-weighted high-resolution 2D and 3D FSE endorectal MR images of the prostates of 85 men in two sessions. In the first session (n = 85), each reader selected his or her preferred images; in the second session (n = 28), they determined their confidence in tumor identification and compared the depiction of the prostatic anatomy, tumor conspicuity, and subjective intrinsic image quality of images. A meta-analysis using a random-effects model, logistic regression, and the paired Wilcoxon rank-sum test were used for statistical analyses. Three readers preferred the 2D acquisition (67-89%), and the other three preferred the 3D images (70-80%). The option for one of the techniques was not associated with any of the predictor variables. The 2D FSE images were significantly sharper than 3D FSE (p < 0.001) and significantly more likely to exhibit other (nonmotion) artifacts (p = 0.002). No other statistically significant differences were found. Our results suggest that there are strong individual preferences for the 2D or 3D FSE MR images, but there was a wide variability among radiologists. There were differences in image quality (image sharpness and presence of artifacts not related to motion) but not in the sequences' ability to delineate the glandular anatomy and depict a cancerous tumor.

Annular tears, fissures or HIZ?

Low back pain (LBP) is an acute or chronic pain in the lumbar or sacral regions [1], is highly prevalent and has substantial socioeconomic implications [2]. Jensen et al noted that low back pain is the second most common reason that patients seek medical care in the United States and that the estimated annual cost of related medical care is more than $8 billion [3]. Robertson noted also that the rate of low back–related disability has grown at a rate 14 times that of the population during the last 30 years [3]. MRI is established as the investigation of choice for assessing patients presenting with low back pain (LBP) and sciatica; recognised causes of nerve root compression include disc herniation and spinal stenosis, however many patients presenting with LBP and pain referred to the lower limb(s) show no evidence on imaging studies of nerve root compression, suggesting that there are other factors involved in the production of pain [4]. One of the prominent somatic sources of low back pain is the internal disc disruption of the lumbar spine, the socalled discogenic lumbar pain, which is the condition causing back pain without radiculopathy [5]. The annulus fibrosus is innervated by the recurrent meningeal nerve and by the small branches from the ventral ramus of the somatic spinal nerve; a proposed mechanism for such pain is inflammation of nerve roots (chemical radiculopathy) from leak of degenerative nuclear material through full-thickness annular tears [4, 5]. Compared with asymptomatic disks, painful disrupted lumbar intervertebral disks have higher concentrations of sensory fibers in their endplates and nucleus; this high concentration of sensory fibers, combined with increased levels of proinflammatory mediators such as IL-8 and PGE2, provides a substrate for hyperalgesia and presumably pain [6]. In this hyperalgesic state, even normal mechanical loading will be painful [6]. The concept of diskogenic pain caused by nocioceptive ingrowth into annular fissures has been supported only indirectly by observing a strong correlation between pain provocation and the presence of annular fissure during provocation diskography and subsequent CT imaging; annular fissures reaching the outer annular fibers are in fact the source of symptoms in patients suffering from chronic diskogenic LBP [6]. Discogenic lumbar pain is characterized by nonradicular pain, has a somatotropic rather than dermatomal pattern of pain projection; therefore, the use of symptoms and clinical findings to localize the level of abnormality is difficult; the source of discogenic pain is still unknown [7]. Ideally, a history and physical examination would consistently diagnose the source of a patient’s low back pain, and, if one diagnosed pain secondary to the intervertebral disc, one would be able to identify the exact level or levels involved; in reality, however, the exact source of low back pain is often illusive, because discogenic pain projects in a somatotropic rather than a dermatomal pattern, confirming and localizing a discogenic source, much less the exact level, using clinical findings alone remains unproven [8]. MR imaging provides an unique means to evaluate the morphologic status of intervertebral disks and their relationship to neural structures in patients with low back pain; moreover, the technique allows assessment of the biochemical status of the disk on T2-weighted spin-echo and fast spin-echo MR images [7]. One of the first structural abnormalities that predicted concordant pain provocation during disc stimulation was high-signal-intensity zones (HIZ) at first described by Aprill and Bogduk in 1992 [8]. HIZ are defined as small foci of high signal intensity at:

Differentiation between cavernous hemangiomas and untreated malignant neoplasms of the liver with free-breathing diffusion-weighted MR imaging: Comparison with T2-weighted fast spin-echo MR imaging

To test interobserver variability of ADC measurements and compare the diagnostic performances of free-breathing diffusion-weighted (FBDW) with that of T2-weighted FSE (T2WFSE) MR imaging for differentiating between cavernous hemangiomas and untreated malignant hepatic neoplasms. Thirty-five patients with cavernous hemangiomas and 35 with untreated hepatic malignant neoplasms had FBDW and T2WFSE MR imaging. Hepatic lesions were characterized with ADC measurement and visual evaluation. Interobserver agreement for ADC measurement was calculated. Association between ADC value and lesion type was assessed using univariate analysis. Sensitivity, specificity and accuracy of ADC values and visual evaluation of MR images for the diagnosis of untreated malignant hepatic neoplasm were compared. ADC measurements showed excellent interobserver correlation (intraclass correlation coefficient=0.980). Malignant neoplasms had lower ADC values than hemangiomas for the two observers (1.11×10(-3) mm2/s±.21×10(-3) vs. 1.77×10(-3) mm2/s±.29×10(-3) for observer 1 and 1.11×10(-3) mm2/s±.19×10(-3) vs. 1.79×10(-3) mm2/s±.32×10(-3) for observer 2) and univariate analysis found significant correlations between lesion type and ADC values. Depending on ADC threshold value, accuracy for the diagnosis of malignant neoplasm varied from 82.9% to 94.3%. Using visual evaluation, FBDW showed better specificity and accuracy than T2WFSE MR images for the diagnosis of malignant neoplasm (97.1% vs. 77.1% and 94.3% vs. 62.9%, respectively). FBDW imaging provides reproducible quantitative information and surpasses the value of T2WFSE MR imaging for differentiating between cavernous hemangiomas and untreated malignant hepatic neoplasms.

Preoperative detection of hepatic metastases: Comparison of diffusion-weighted, T2-weighted fast spin echo and gadolinium-enhanced MR imaging using surgical and histopathologic findings as standard of reference

Purpose The purpose of this study was to retrospectively compare the respective sensitivities of diffusion-weighted (DW), T2-weighted fast spin-echo (T2WFSE) and gadolinium chelate-enhanced MR imaging in the preoperative detection of hepatic metastases using intraoperative ultrasonographic and histopathologic findings as the standard of reference. Materials and methods Twenty-seven patients with 64 surgically and histopathologically proven hepatic metastases had MR imaging of the liver, including DW, T2WFSE and dynamic gadolinium chelate-enhanced MR imaging. Images from each MR sequence were separately analyzed by two readers with disagreements resolved by consensus readings. The findings on MR images were compared with intraoperative ultrasonographic and histopathologic findings on a lesion-by-lesion basis to determine the sensitivity of each MR sequence. Statistical review of the lesion-by-lesion analysis was performed with the McNemar test. Results DW, T2WFSE and gadolinium chelate-enhanced MR imaging allowed the depiction of 54/64 (84.4%; 95% CI: 73.1–92.2%), 44/64 (68.8%; 95% CI: 55.9–79.8%), and 51/64 (79.7%; 95% CI: 67.8–88.7%) hepatic metastases respectively. DW MR images allowed depiction of significantly more hepatic metastases than did T2WFSE and was equivalent to gadolinium chelate-enhanced MR imaging ( P = .002 and P = .375, respectively). Conclusion DW MR imaging is superior to T2WFSE imaging and equivalent to gadolinium chelate-enhanced MR imaging for the preoperative detection of hepatic metastases. Further studies however are needed to determine at what extent DW MR imaging can be used as an alternative to gadolinium chelate-enhanced MR imaging for the preoperative depiction of hepatic metastases.

Polycystic Kidney Disease Evaluation by Magnetic Resonance Imaging in Ischemia-Reperfusion Injured PKD1 Knockout Mouse Model

To investigate the efficacy of true fast imaging with steady state precession (true-FISP) compared with T2-weighted fast spin echo (T2W-FSE) in monitoring changes in cyst volume and renal expansion in an ischemia reperfusion (IR) injured PKD1 knockout (IKO) mouse model. The animal study was approved by the local institutional authority. A total of 24 mice (14 PKD1 IKO mice and 10 control mice) were sequentially scanned on a 4.7-T scanner from 4 to 12 weeks after IR injury and the cysts and kidney volumes were measured from true-FISP and T2W-FSE MR images. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated for the images generated from both methods. Cyst SNR and CNR in true-FISP images were significantly higher than in images employing the T2W-FSE sequence (P < 0.05). Both methods demonstrated kidney volume increase as well as cyst growth after IR injury in the mouse model. The kidney and cysts volume at different time points were strongly correlated between true-FISP and T2W-FSE measurements (r(kidney) = 0.99, r(cysts) = 0.97). The true-FISP method offers shorter scan times and higher cyst SNR and cyst to kidney tissue contrast than T2W-FSE. Both sequences have identical accuracy in measuring the cysts and kidney volume changes in mice with PKD.

Effect of T1 Shortening on T2-Weighted MRI Sequences: Comparison of Hepatic Mass Conspicuity on Images Acquired Before and After Gadolinium Enhancement

The purpose of this study was to compare the conspicuity of hepatic lesions on T2-weighted fast-recovery fast spin-echo MR images obtained before and after administration of gadolinium. We reviewed T2-weighted fast-recovery fast spin-echo images before and after gadolinium enhancement for 84 patients with 118 focal liver lesions. Solid lesions (22 hepatomas, seven ablated hepatomas, 12 metastatic lesions, six cases of focal nodular hyperplasia, five dysplastic nodules, one adenoma) were proved pathologically or with multiple follow-up studies. Nonsolid lesions were diagnosed as hemangiomas (n = 33) or cysts (n = 32) on the basis of imaging features. Two blinded radiologists interpreted the images independently, reading unenhanced images first and gadolinium-enhanced images at least 2 weeks later. Lesion conspicuity was ranked as follows: 1, poor; 2, moderate; 3, good; 4, excellent. The sign test was used for qualitative scoring of imaging pairs (unenhanced and gadolinium enhanced). The Fisher's exact test was used for subgroup analysis of solid and nonsolid lesions. On gadolinium-enhanced T2-weighted images, 21 (17.8%) of 118 of the lesions had improved conspicuity, 86 (72.9%) had no difference in conspicuity, and 11 (9.3%) appeared worse. No statistically significant difference was found between unenhanced and enhanced images (p = 0.11), but a trend toward improved conspicuity with gadolinium enhancement was observed. Subgroup analysis showed that on gadolinium-enhanced T2-weighted images, visualization of solid hepatic lesions (28.3%) was significantly better than that of nonsolid lesions (9.2%) (p = 0.01). Compared with unenhanced T2-weighted images, gadolinium-enhanced T2-weighted images had a trend toward improved conspicuity of focal liver lesions. Subgroup analysis showed that visualization of solid lesions benefited significantly more from use of gadolinium-enhanced T2-weighted sequences than did visualization of nonsolid lesions.

FDG-PET findings of the brain in lymphomatoid granulomatosis

A 44-year-old man with a history of sudden onset short-term disorientation was admitted to our hospital. T2-weighted fast spin-echo MR images of the head showed increased signal intensity in the bilateral frontal and parietal white matter. Gadolinium-enhanced T1-weighted spin-echo images showed multiple areas with punctate and linear enhancement scattered in the bilateral frontal and parietal white matter. Although 18F-fluorodeoxyglucose positron emission tomography ([18F]FDG-PET) did not display a significant increase in FDG accumulation in the bilateral frontal and parietal white matter, kinetic analysis of this scan showed increased hexokinase activity in the lesions compared to the unaffected occipital white matter. Diagnosis was made by open biopsy of the right frontal lobe and pathologic specimen was positive for lymphomatoid granulomatosis (LYG). The patient received high-dose methotrexate with CHOP (cyclophosphamide, doxorubicin hydrochloride, vincristine sulfate, and prednisolone) chemotherapy and follow-up MRI showed improvement of the lesions. [18F]FDG-PET study with kinetic analysis may be useful to diagnose LYG in the central nervous system.

Differentiation between hepatic cyst and hemangioma: Additive value of breath‐hold, multisection fluid‐attenuated inversion‐recovery magnetic resonance imaging using half‐Fourier acquisition single‐shot turbo‐spin‐echo sequence

To evaluate the additive value of breath-hold, multisection fluid-attenuated inversion-recovery (FLAIR) magnetic resonance imaging (MRI) using half-Fourier acquisition single-shot turbo-spin-echo (HASTE) sequence as supplements to moderately and heavily T2-weighted fast-spin-echo (FSE) sequences in differentiating hepatic cyst from hemangioma. A total of 183 lesions (127 hepatic cysts, 56 hepatic hemangiomas) in 117 patients were evaluated in this study. Three radiologists independently reviewed FLAIR MR images using a HASTE sequence and T2-weighted FSE MR images. Each radiologist used a five-point scale to rate his confidence in determination of hepatic cyst and hemangioma. All three reviewers were significantly better able to differentiate hepatic cyst from hepatic hemangioma with the combination of FLAIR imaging using HASTE and moderately and heavily T2-weighted FSE images (area under the receiver operating characteristic (ROC) curve, 0.99 for each reader) than with moderately and heavily T2-weighted FSE images alone (0.82-0.93; P < 0.05). FLAIR-HASTE imaging in addition to T2-weighted FSE sequences improved the diagnostic performance, including the sensitivity, specificity, accuracy, and confident diagnosis in the differentiation between hepatic hemangiomas and cysts. FLAIR-HASTE imaging is useful for distinguishing hepatic hemangioma from hepatic cyst without the use of contrast-enhanced MR images.

Crohn disease with endoscopic correlation: single-shot fast spin-echo and gadolinium-enhanced fat-suppressed spoiled gradient-echo MR imaging.

To compare T2-weighted breath-hold single-shot fast spin-echo (SE) and gadolinium-enhanced spoiled gradient-echo (GRE) MR imaging with contrast material administered orally and rectally for evaluating patients with Crohn disease. Twenty-eight patients with Crohn disease received 2% barium sulfate and water enema. The abdomen and pelvis were imaged with transverse and coronal single-shot fast SE and gadolinium-enhanced spoiled GRE MR imaging. Two radiologists reviewed the two types of images for bowel disease. The extent, severity, and conspicuity of the disease were determined. Proof of bowel disease at MR imaging was compared with that at endoscopy, barium study, and surgery. Statistical analysis was performed with the McNemar test. Twenty-five of 28 patients had proven abnormal bowel segments. The per-patient sensitivity of gadolinium-enhanced spoiled GRE MR imaging for the two radiologists was 100% and 96% versus 60% and 60% (P <.05) with single-shot fast SE MR imaging. Gadolinium-enhanced spoiled GRE MR images depicted more segments (54 and 52 of 61 segments; sensitivity, 89% and 85%, respectively) of the diseased bowel than did single-shot fast SE MR images (31 and 32 of 61 segments; sensitivity, 51% and 52%, respectively; P <.001). Severity of Crohn disease was correctly depicted at gadolinium-enhanced spoiled GRE imaging in 93% of patients versus in 43% of patients at single-shot fast SE imaging. In patients with Crohn disease, gadolinium-enhanced fat-suppressed spoiled GRE MR imaging better depicted the extent and severity of intestinal disease compared with single-shot fast SE imaging.

Liver lesion conspicuity: T2-weighted breath-hold fast spin-echo MR imaging before and after gadolinium enhancement--initial experience.

To evaluate the effect of a gadolinium chelate on T2-weighted breath-hold fast spin-echo magnetic resonance images of focal hepatic lesions. In 21 patients with focal hepatic lesions, identical T2-weighted breath-hold fast spin-echo images were obtained before and after gadolinium enhancement and were compared regarding lesion-to-liver contrast-to-noise ratio, signal-to-noise ratio, lesion conspicuity, and vascular pulsation artifact. Image review was performed independently, in random order, by two experienced radiologists. For solid lesions, the lesion-to-liver contrast-to-noise ratio on enhanced images was significantly higher (P <.05) than that on nonenhanced images. For nonsolid lesions, however, there was no significant difference (P =.07). For both readers, lesion conspicuity for solid lesions on enhanced images was significantly higher than on nonenhanced images (P <.05). Severity of vascular pulsation artifact was not significantly different. Solid-lesion contrast on T2-weighted breath-hold fast spin-echo images improves after administration of a gadolinium chelate. These images should be obtained after, rather than before, gadolinium enhancement.

Detection of hepatocellular carcinoma: comparison of T2-weighted breath-hold fast spin-echo sequences and high-resolution dynamic MR imaging with a phased-array body coil.

The purpose of our study was to compare T2-weighted breath-hold fast spin-echo sequence (BHFSE) and high-resolution dynamic MR imaging (HR-DMRI) in the detection of hepatocellular carcinoma (HCC). Short and long T2-weighted BHFSE sequences and biphasic HR-DMRI including arterial-dominant and delayed phase images with a phased-array body coil were performed in 30 consecutive patients with 37 HCCs. The lesion-to-liver contrast-to-noise ratio (CNR) was quantitatively measured. The lesion conspicuity and delineation was qualitatively rated according to a four-point scale. The lesion-to-liver CNR was highest with the arterial-dominant phase HR-DMRI and was significantly higher than those obtained with both short and long T2-weighted BHFSE and those obtained with unenhanced and delayed HR-DMRI. The CNR obtained with short T2-weighted BHFSE was significantly higher than those obtained with long T2-weighted BHFSE and with unenhanced and delayed HR-DMRI. The sensitivity for the sequences was 78.4% (29/37) for short T2-weighted BHFSE, 67.6% (25/37) for long T2-weighted BHFSE, 37.8% (14/37) for unenhanced HR-DMRI, 97.3% (36/37) for arterial-dominant phase HR-DMRI, and 43.2% (16/37) for delayed HR-DMRI. The sensitivity of serial dynamic MR imaging combined with unenhanced, arterial-dominant phase imaging and delayed phase imaging was 100% (37/37). The score in the qualitative analysis of the lesion conspicuity and delineation was highest for the arterial-dominant phase HR-DMRI and was significantly higher than that for the short T2-weighted BHFSE. The score for the short T2-weighted BHFSE was significantly higher than that for the long T2-weighted BHFSE and that for the unenhanced HR-DMRI. Arterial-dominant phase HR-DMRI is superior to the T2-weighted BHFSE technique, and also HR-DMRI combined with unenhanced, arterial-dominant and delayed phases is the most sensitive technique in the detection of HCC.

T2-weighted fast spin-echo MR imaging of liver.

T2-weighted fast spin-echo MR imaging of liver.

Diagnostic performance characteristics of architectural features revealed by high spatial-resolution MR imaging of the breast.

Our objective was twofold: to determine which architectural features revealed by high spatial-resolution MR imaging of the breast contribute to diagnostic accuracy and to evaluate the diagnostic performance characteristics of those architectural features. Eligible patients with suspicious mammographic or palpable findings or both underwent MR imaging. Ninety-three patients whose MR images revealed lesions that corresponded to the mammographically visible or palpable findings were included in the study. Patients were examined with sagittal T1-weighted spin-echo MR imaging, fat-saturated T2-weighted fast spin-echo MR imaging, and dynamically enhanced fat-saturated fast gradient-echo MR imaging. All patients underwent subsequent excisional biopsy or cyst aspiration. Lesions were identified initially by an experienced radiologist who was aware of the patient's clinical or mammographic information. Two radiologists who were unaware of the patients' histories and who had less experience in MR imaging of the breast then independently evaluated each lesion for the architectural-features and predicted each lesion's potential for malignancy. Architectural features that were highly predictive of benign disease included smooth or lobulated borders (97-100%), the absence of mass enhancement (100%), and enhancement that was less than the enhancement of surrounding breast fibroglandular tissue (93-100%). Nonenhancing internal septations were specific for the diagnosis of fibroadenoma. Architectural features that were highly predictive of malignant disease included spiculated borders (76-88%) and peripheral rim enhancement in the presence of central lesion enhancement (79-92%). Architectural features revealed by high spatial-resolution MR imaging of the breast can help distinguish benign from malignant disease.

Symptomatic vertebral hemangiomas: MR findings.

V ertebral hemangiomas are common benign lesions of the spinal column that often are discovered incidentally. Rarely, vertebral hemangiomas behave as aggressive neoplasms that directly or indirectly compress adjacent neural structures. The diagnosis of symptomatic lesions can be elusive on any imaging study but can be especially difficult on MR imaging studies. Because symptomatic hemangiomas typically show marked hypervascularity on spinal angiography, knowledge of the diagnosis before biopsy or surgery is invaluable. The purpose of this essay is to highlight the MR findings in representative cases of symptomatic hemangiomas and to provide clues that may distinguish them from other, more common neoplasms. Moreover, in an era dominated by the use of MR imaging for the evaluation of myelopathy, the importance of basic diagnostic radiologic examinations (plain radiographs and CT scans) in the evaluation of vertebral neoplasms should not be overlooked. Hemangiomas are slowly growing lesions that are commonly found in the vertebral bodies. Histopathologically, they consist of thinwalled, blood-filled vessels and sinuses lined by endothelium and interspersed among the longitudinally (vertically) oriented trabeculae of bones. The dilated vascular channels are set in a substratum of fatty marrow. The accumulation of lipid material is a common secondary and retrogressive phenomenon seen in several types of benign bone lesions. Characteristic plain radiographic findings for asymptomatic vertebral hemangiomas consist of either parallel linear streaks or a honeycomb pattern. CT scans show a speckled (“polka dot”) pattern because the accentuated vertical trabeculae are imaged in cross section [ 1-5]. Asymptomatic vertebral hemangiomas classically show a distinctive appearance on MR images; high signal intensity is seen on spin-echo T I -weighted and T2-weighted images. The shortened Tl relaxation time reflects the fatty component of the tumors. Because fat shows a high signal intensity on T2-weighted fast spin-echo MR images, vertebral hemangiomas remain hyperintense with this pulse sequence [1]. Symptomatic (compressive) vertebral hemangiomas are rare lesions that can gradually compress the spinal cord, nerve roots, or both, thereby producing myelopathy or racliculopathy [1-8]. Compression of neural elements may be related to vertebral fracture, extraosseous extension of the tumor or, less frequently, enlargement of adjacent blood yessels (Figs. 1-4). Diagnosis of these lesions may be much more elusive than that of asymptomatic hemangiomas because many of the aforementioned radiographic characteristics may be absent [ 1-8]. Because MR imaging does not directly visualize bone, the diagnosis can be particularly difficult with this imaging technique. Moreover, in the current era, plain films and CT scans may not be obtained for the evaluation of patients with myelopathy. Ninety percent of vertebral hemangiomas having extraosseous extension occur in the thoracic region; approximately 75% occur between T3 and T9 (Figs. 1-3). A slight predominance in women exists. Cervical lesions are extremely rare [2, 6]. Other authors have described an inverse relationship between the amount of intraosseous fatty stroma and the aggressiveness of the lesion; this relationship accounts for the low signal intensity of most compressive vertebral hemangiomas on Tl-weighted images [6] (Figs. 1 and 3). Consequently, multiple lesions can simulate metastatic disease [SI (Fig. I). Although extremely unusual, an extensive amount of intraosseous fatty stroma and extraosseous extension of a neoplasm can occur simultaneously (Fig. 2); in these cases,

Acute occlusive ischemia of the rat intestine: early detection by MR imaging with polylysine-Gd-DTPA enhancement.

The purpose of this study was to assess the potential role of MR imaging with polylysine-Gd-DTPA enhancement in the early detection of acute occlusive intestinal ischemia in a rat model. After devascularization of the distal ileum in 12 rats, T2-weighted fast spin-echo MR images were acquired, followed by T1-weighted images before and after IV administration of 0.1 mmol/kg polylysine-Gd-DTPA. The signal intensity of the ischemic intestine did not differ significantly from that of the normal intestine before the administration of the contrast material. No mucosal or submucosal edema or hemorrhage was found in the ischemic intestine at histologic examination. After the administration of polylysine-Gd-DTPA, the ischemic intestine lacked enhancement and its signal intensity was significantly lower than that of the normal intestine. MR imaging with polylysine-Gd-DTPA enhancement can detect acute occlusive ischemia of the rat intestine at an early stage.

Breath-hold fast spin-echo MR imaging of the liver: a technique for high-quality T2-weighted images.

HomeRadiologyVol. 194, No. 2 PreviousNext Breath-hold fast spin-echo MR imaging of the liver: a technique for high-quality T2-weighted images.J W ReinigJ W ReinigJ W ReinigPublished Online:Feb 1 1995https://doi.org/10.1148/radiology.194.2.7824701MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In Article HistoryPublished in print: 1995 FiguresReferencesRelatedDetailsCited ByAbdominal RadiologyEuropean Radiology, Vol. 31, No. 11Pediatric Radiology, Vol. 47, No. 5Radiologic Clinics of North America, Vol. 53, No. 3Korean Journal of Radiology, Vol. 16, No. 5Academic Radiology, Vol. 17, No. 3Hepatic Lesions: Improved Image Quality and Detection with the Periodically Rotated Overlapping Parallel Lines with Enhanced Reconstruction Technique—Evaluation of SPIO-enhanced T2-weighted MR Images1Yuusuke Hirokawa, , Hiroyoshi Isoda, , Yoji S. Maetani, , Shigeki Arizono, , Kotaro Shimada, , Tomohisa Okada, , Toshiya Shibata, , and Kaori Togashi, 1 May 2009 | Radiology, Vol. 251, No. 2Journal of Magnetic Resonance Imaging, Vol. 26, No. 2American Journal of Roentgenology, Vol. 184, No. 2Magnetic resonance imaging: TechniquesClinics in Liver Disease, Vol. 6, No. 1Journal of Magnetic Resonance Imaging, Vol. 16, No. 2Magnetic Resonance in Medicine, Vol. 47, No. 3Surgical Oncology, Vol. 10, No. 4Liver Lesion Conspicuity: T2-weighted Breath-hold Fast Spin-Echo MR Imaging before and after Gadolinium Enhancement—Initial Experience1Yong Yeon Jeong, , Donald G. Mitchell, , and George A. Holland, 1 May 2001 | Radiology, Vol. 219, No. 2Clinical Imaging, Vol. 25, No. 2Journal of the American Society of Nephrology, Vol. 11, No. 8Magma: Magnetic Resonance Materials in Physics, Biology, and Medicine, Vol. 9, No. 1-2Chirurgie, Vol. 124, No. 2Journal of Magnetic Resonance Imaging, Vol. 8, No. 3Clinical Imaging, Vol. 22, No. 3Magnetic Resonance Imaging Clinics of North America, Vol. 5, No. 2Journal of Magnetic Resonance Imaging, Vol. 6, No. 4Magnetic Resonance in Medicine, Vol. 36, No. 5Recommended Articles RSNA Education Exhibits RSNA Case Collection Vol. 194, No. 2 Metrics Altmetric Score PDF download

Diagnosis of choledocholithiasis: value of MR cholangiography.

T2-weighted fast spin-echo MR imaging (MR cholangiography) of the right upper quadrant of the abdomen depicts the biliary tree in considerable detail. We studied the value of this procedure for detecting stones in the common bile duct in a series of patients with proved calculi. MR images of 10 consecutive patients with stones in the common bile duct were retrospectively reviewed. The diagnosis of choledocholithiasis was proved by stone extraction in all cases. Axial, coronal, and oblique images were obtained by using heavily T2-weighted fast spin-echo sequences, and the images were processed by using a maximum-intensity-projection (MIP) algorithm and a commercially available multiplanar reformatting software. Two reviewers who were not blinded to the diagnosis analyzed hard copy images and reformatted images at the MR console. The rate of stone detection was evaluated for each acquisition plane. The mean stone/bile signal-intensity ratio and the number and size of stones were recorded. In all patients, the entire length of the extrahepatic bile ducts was visualized, and the diagnosis of choledocholithiasis could be made on the basis of findings on MR images. Eight stones, including two that were impacted in the ampulla, were located in the distal part of the common bile duct. On the hard copy films, the stones were visible in eight of 10 coronal images, six of 10 axial images, and four of 10 oblique images. On the three-dimensional (3D) MIP reconstructions, the stones were seen in five of the coronal sets and in six of the axial sets. The best results were obtained when the multiplanar reconstruction software was used: nine of the 10 coronal sets and eight of the 10 axial sets showed stones in the bile ducts. By use of a combination of 3D MIP and multiplanar reconstruction, choledocholithiasis was detected in all 10 patients. The mean signal intensity of the stones was 58 (range, 18-87). The mean stone/bile signal-intensity ratio was 0.15 (range, 0.05-0.24). In this preliminary study, we showed that MR cholangiography, based on T2-weighted fast spin-echo sequences, could be an important imaging technique for patients with suspected bile duct obstruction and equivocal sonography and/or CT results. However, a large prospective clinical trial is needed to confirm these results.