Fat-suppressed T2-weighted Images Research Articles

Comparison of image quality between conventional VIBE and radial VIBE in free-breathing paediatric abdominal MRI

To compare the image quality between conventional volume interpolated breath-hold examination (VIBE) and radial VIBE in contrast-enhanced fat-suppressed T1-weighted images of paediatric abdominal magnetic resonance imaging (MRI) during free-breathing. Images from paediatric patients who underwent contrast-enhanced abdominal MRI with a 3T magnet using conventional VIBE (conventional group) and radial VIBE (radial group) while freely breathing were reviewed retrospectively. For objective analysis, the mean values of noise and signal-to-noise ratio (SNR) in the liver on contrast-enhanced fat-suppressed T1-weighted images were compared. For subjective analysis, overall image quality, respiratory motion, portal vein clarity, and hepatic margin sharpness were assessed using four-point scales. Nine patients (mean age of 2.8±2.3 years) in the conventional and 17 patients (mean age of 2.4±2.8 years) in the radial groups were included. According to the objective analysis, the noise was significantly lower and the SNR was significantly higher in the radial group than those in the conventional group (all, p<0.001). In the subjective analysis, overall image quality, respiratory motion, portal vein clarity, and hepatic margin sharpness were all significantly higher in the radial group (all, p<0.001). Paediatric abdominal MRI images with radial VIBE showed lower noise with higher SNR in objective analysis and higher image quality in subjective analysis, compared to conventional VIBE.

Effect of steatosis on liver signal and enhancement on multiphasic contrast-enhanced magnetic resonance imaging

To investigate the effect of steatosis on liver signal and enhancement in multiphasic contrast-enhanced (MCE) MRI. In this IRB-approved, HIPAA-compliant, retrospective, observational study, 1217 MCE abdominal MRIs performed during 2014 at a single institution were reviewed. Of these, 1085 were excluded, due to potential factors other than steatosis that may affect liver signal intensity and/or enhancement. In the remaining 132, liver fat fraction (FF) was calculated from the in- and opposed-phase 2D T1-weighted images. Liver signal intensity, absolute enhancement, and relative enhancement on fat-suppressed (Dixon method) 3D T1-weighted images before and after injection of gadobutrol (arterial, portal venous, and equilibrium phases) were plotted against co-localized FF values and the linear trend was evaluated by Pearson correlation coefficient (r). P values <0.05 were considered statistically significant. Liver signal intensity negatively correlated with FF for all phases (r=-0.388 to -0.544, p<0.001). Absolute enhancement negatively correlated with FF for the portal venous and equilibrium phases (r=-0.286 and -0.289, respectively, p<0.001), but not for the arterial phase (r=-0.042, p=0.632). Relative enhancement did not significantly correlate with FF for any phase (p≥0.125). Steatosis reduces liver signal intensity in MCE MRI. This effect of steatosis was reduced in calculated absolute enhancement and eliminated in calculated relative enhancement.

Evaluation of Adhesive Capsulitis of the Shoulder With Fat-Suppressed T2-Weighted MRI: Association Between Clinical Features and MRI Findings.

The purpose of this study was to examine the association between clinical features and MRI findings in adhesive capsulitis of the shoulder. This study included 103 patients (41 men, 62 women) with adhesive capsulitis. The MRI findings were correlated with pain intensity, range of motion, and clinical stage. Joint capsule edema in the axillary recess, extracapsular edema, obliteration of the subcoracoid fat triangle, and effusion in the long head biceps tendon sheath were assessed by two radiologists using fat-suppressed T2-weighted images. Joint capsule thickness in the axillary recess and degree of external rotation during MRI were also measured. Intraclass correlation coefficient and kappa values were obtained. Associations between MRI findings and clinical features were assessed by statistical analyses. Anterior extracapsular edema was associated with range of motion on external rotation and abduction (p < 0.01). Joint capsule edema in the humeral portion of the axillary recess was associated with range of motion on external rotation (p = 0.01). Joint capsule thickness in the humeral portion of the axillary recess and height of the axillary recess were associated with pain intensity (p < 0.05). Joint capsule edema in the humeral portion of the axillary recess and obliteration of the subcoracoid fat triangle were significantly more common in the early stages of adhesive capsulitis (p < 0.05). Joint capsule thickness in the humeral portion of the axillary recess at stage 1 (4.67 ± 1.73 mm) was significantly different from the thickness at the later stages (stage 2, 3.73 ± 1.49 mm; stages 3 and 4, 3.67 ± 1.44 mm) (p < 0.05). MRI is useful for assessing clinical impairment and predicting the clinical stage of adhesive capsulitis.

Quantitative diffusion-weighted magnetic resonance imaging for the diagnosis of partial-thickness rotator cuff tears

This study investigated diffusion-weighted (DWI) magnetic resonance imaging (MRI) as an alternative to fat-suppressed T2-weighted imaging (FS-T2WI) for assessment of partial-thickness rotator cuff tears (RCTs). Patients with arthroscopy proven partial-thickness RCTs who also received MRI (FS-T2WI and DWI) before surgery were prospectively included. Receiver operating characteristic curves were used to compare DWI vs. FS-T2WI using lesion-to-muscle signal intensity ratios. A cutoff point for predicting partial-thickness tears was determined using the Youden index. Included were 146 patients, with a mean age of 48.3 years (range, 19-86 years), of whom 43 had full-thickness RCTs, 67 had partial-thickness RCTs, and 36 had no tears. Areas under receiver operating characteristic curves for diagnosing partial-thickness tears were significantly higher for DWI (0.910) than for FS-T2WI (0.822, P = .016). Lesion-to-muscle signal intensity ratio cutoff values were 1.06 for DWI vs. 1.65 for FS-T2WI, respectively. The sensitivity and accuracy of DWI (89.1% [98 of 110] and 87.7% [128 of 146], respectively) for diagnosing partial-thickness and full-thickness tears were higher than for FS-T2WI (65.5% [72 of 110] and 72.6% [106 of 146], respectively). FS-T2WI, however, had higher specificity (94.4% [34 of 36]) than DWI (83.3% [30 of 36]). DWI is more accurate and sensitive than FS-T2WI for diagnosing partial-thickness RCTs.

Bone Metastases of Hepatocellular Carcinoma: Appearance on MRI Using a Standard Abdominal Protocol.

The purpose of this study is to describe the MRI features of hepatocellular carcinoma (HCC) bone metastases. Thirty-three consecutive patients were included. Two radiologists performed qualitative and quantitative analysis. The coordinator searched for clinical and epidemiologic features related to patients and their primary liver tumors. Earlier MRI studies were also reviewed to determine whether bone metastases were already present and prospectively identified. Descriptive statistics and the Lin concordance correlation coefficient were used. Chronic hepatitis C virus infection was the most common cause of liver disease (20/32; 62.5%), and diffuse and multifocal HCC were the most frequent types of liver HCCs (28/33; 84.8%). Most lesions were located at the spine (109/155; 70.3%), with high signal intensity on fat-suppressed T1-weighted (54/62; 87.1%) and T2-weighted (53/62; 85.5%) images. Bone metastases were predominantly nodular (48/62; 77.4%), confined to the vertebral body (40/60; 66.7%), and best visualized at the arterial phase (40/62; 64.5%). The ring pattern of enhancement was present in 23 of 62 lesions, and the remaining lesions showed diffuse enhancement. Thirty-five of 62 (56.4%) bone metastases showed arterial peak of enhancement. In 13 of 33 (39.9%) patients, bone metastases were not prospectively reported. Most patients with bone metastases had chronic hepatitis C virus infection and diffuse or multifocal HCC. Metastases are most commonly appreciated as hypervascular focal moderately intensely enhancing nodular masses on the hepatic arterial dominant phase images, with concomitant moderately high signal intensity on fat-suppressed T1- and T2-weighted images.

Duplication of chromosome segment 12q13-15 in a lipomatous tumor with minimal nuclear atypia: A case report.

Ordinary lipoma is cytogenetically characterized by structural rearrangements, particularly translocations, of 12q13-15. By contrast, atypical lipomatous tumors exhibit supernumerary ring or giant marker chromosomes that are composed mainly of amplified material from the 12q13-15 chromosome segment. The present study describes the cytogenetic and molecular cytogenetic findings from a lipomatous tumor with minimal nuclear atypia that was identified in a 49-year-old female patient. Magnetic resonance imaging of the right shoulder revealed a 13-cm fatty mass in the subcutaneous layer that possessed only pencil-line septa. Contrast-enhanced fat-suppressed T1-weighted images demonstrated faint enhancement. A marginal excision was performed. Histologically, the tumor was composed of lobules that consisted of mature adipocytes separated by thin fibrous septa. There was minimal nuclear atypia in certain cells, and a small number of binucleated cells were also observed within the tumor. Immunohistochemically, the tumor cells did not reveal the expression of murine double-minute 2 (MDM2). Cytogenetic analysis revealed a complex karyotype with several numerical and structural alterations, including 12q rearrangements. Spectral karyotyping demonstrated a duplication of chromosome segment 12q13-15. Interphase fluorescence in situ hybridization analysis revealed no MDM2 gene amplification. The present case indicates that duplication of 12q may be associated with minimal nuclear atypia in a subset of lipomatous tumors.

Perineural Spread in Noncutaneous Head and Neck Cancer: New Insights into an Old Problem.

Head and neck malignancies have the propensity to invade nerves. Perineural tumor invasion is common, with some series reporting rates of 30 to 100%. Squamous cell carcinoma and adenoid cystic carcinoma are the most commonly involved tumors. The most commonly involved nerves are the trigeminal (cranial nerve [CN] V) and facial (CN VII) and their branches. Neural spread away from a tumor is encountered less often and usually causes specific symptoms such as pain, muscle weakness, and atrophy, depending on the involved nerves. While clinical symptoms and physical examination may suggest the presence of neural invasion, specific imaging modalities such as fat-suppressed T1-weighted magnetic resonance images, should be utilized to identify perineural tumor spread in its early phases. Perineural tumor spread should be considered and addressed in the treatment planning of patients with head and neck or skull base cancers as it can influence the extent of surgery, and the dosage and fields of radiation therapy. In the current review, we discuss the clinical course of perineural tumor spread and its therapeutic implications.

Abstract 21: Hypo-intensity of MRI Vessel Wall Imaging Indicates Advanced Intracranial Atherosclerosis With Lipid Core

Objective: Although Magnetic Resonance Imaging (MRI) vessel wall imaging could visualize the pathology of intracranial arterial disease, signal changes are poorly interpreted due to lacking of cerebral artery specimens. Based on a MRI-histology comparison study on a series of post-mortem cerebral arteries, we aimed to examine the occurrence of hyper-, iso- and hypo-intensity on T1-weighted fat-suppressed images of MCA plaques, which might be suggestive of different plaque components. Methods: Fifty-eight pairs of MCAs were imaged at 1.5T MRI with T1-weighted Table 1: The distribution of different atherosclerotic phenotypes among MCA plaques with iso-, hyper- and hypo-intensity on T1-weighted fat-suppressed images fat-suppressed- and T2-weighted sequence. MRI was performed in the postmortem brains to scan the cross-sections of MCAs with barium expanding the artery lumen. The MCAs were then removed for histopathologic processing and atherosclerotic plaque classification, which was used as a reference standard to interpret the signal changes on MRI pictures. Results: A total of 76 MRI vessel wall images were adequate for signal changes interpretation. On T1-weighted fat-suppressed images of MCA plaques, hyper-intensity was revealed on 34 vessels (44.7%), iso-intensity on 24 vessels (31.6%) and hypo-intensity was revealed on 18 samples (23.7%). There was a trend that iso-intensity indicated lower grade atherosclerosis and hypo-intensity represented advanced atherosclerosis, while hyper-intensity was suggestive of median grade atherosclerotic plaques. Further analysis demonstrated that nearly all hypo-intensity was found to be histology-verified advanced atherosclerosis with lipid core formation. Interpretation: Signals of hypo-intensity on T1-weighted fat-suppressed images of MCA plaques may be useful in stratification of stroke patients with intracranial atherosclerosis.

Pathological correlation of Magnetic Resonance Imaging features in a classical case of lipomatous meningioma

Meningiomas are common tumors, constituting about 20% of all primary brain tumors.[4] The histological subtype of lipomatous meningioma, resulting from lipid accumulation within meningothelial cells, is a well-described but uncommon entity, representing approximately 0.3% of meningiomas.[2,3] In the World Health Organization (WHO) classification of tumors of the nervous system (2000), meningiomas with lipomatous changes were classified as metaplastic meningiomas (WHO Grade 1), and it has been documented that the clinical features, surgical management, and prognosis of lipomatous meningiomas are no different from those of other WHO Grade 1 meningiomas.[2] We report the case of a middle-aged women presenting with magnetic resonance imaging (MRI) features of a classical “lipomatous” meningioma and correlate the radiological findings with the histopathological features of this uncommon tumor. A 44-year-old female presented with history of long-standing generalized tonic-clonic seizures of 9 years duration on antiepileptic medications. MRI of the brain revealed a well-demarcated, extra-axial, dural-based, right anterior one-third, parasagittal lesion with predominant areas of intrinsic T1- and T2-weighted hyperintensity [Figure ​[Figure1a1a and ​andb].b]. Hyperostosis of the overlying calvarium was evident. On fat-suppressed fluid attenuation inversion recovery (FLAIR) images, the areas of T1-weighted hyperintensity were suppressed that corresponded to the fat content [Figure 1c]. Moderate edema was evident in the underlying right frontal lobe. On susceptibility weighted imaging, extensive susceptibility (or blooming) was noted within the lesion [Figure 1d]. Postcontrast T1 magnetization prepared rapid gradient-echo axial and sagittal images revealed intense heterogeneous enhancement within the lesion with a dural tail [Figure ​[Figure1e1e and ​andf].f]. The patient underwent right frontal parasagittal craniotomy and Simpson Grade 1 excision of the tumor. The tumor on gross appearance was bright yellow and greasy [Figure 2a]. Histopathology revealed large lobules of mature adipose tissue within which were nesting islands of meningothelial cells forming whorls [Figure ​[Figure2a2a–c], characteristic of a metaplastic (lipomatous) meningioma. Fine intracellular vacuolation was evident within meningothelial cells [Figure 2d]. On close examination, these vacuolations were highlighted on Oil red O stain, confirming its neutral lipid nature [Figure 2d, inset]. At follow-up (1 year), patient is asymptomatic. Figure 1 Magnetic resonance imaging findings in a classical case of lipomatous meningioma. (a) T1-axial, (b) T2-axial, (c) fluid attenuation inversion recovery-axial, (d) susceptibility weighted imaging-axial, (e) T1 magnetization prepared rapid gradient-echo-axial, ... Figure 2 (a) Gross appearance of the tumor that is bright yellow and greasy; (b) scanner view of tumor reveals large lucent areas (*) separating islands of tumor cells; (c) microscopy reveals lobules of mature adipose tissue (*) separating whorls of meningothelial ... Lipomatous meningioma is a subtype of metaplastic meningioma, which was first described by Bailey and Bucy in 1931.[4] On imaging, lipomatous meningiomas have characteristic MRI findings, which, if taken into consideration, can provide preoperative diagnosis of this uncommon entity.[1,3,5] The tumor shows high intensity on T1- and T2-weighted MRI and the high-intensity area on T1-weighted MRI is changed to a low-intensity area on fat-suppressed T1-weighted imaging. Despite this, in the majority of cases, lipomatous meningioma is not diagnosed preoperatively and is often a histopathological diagnosis.[4] The preoperative differential diagnoses considered, in our case, were lipoma, dermoid cyst, teratoma, or xanthomatous meningioma. The classical “dural tail” sign, intense contrast enhancement of the lesion, and hyperostosis of the overlying calvarium were highly suggestive of meningioma; the suppression of T1-weighted hyperintense areas on FLAIR imaging indicated the lipomatous nature of the meningioma. Our report highlights the distinct MRI findings correlating with characteristic histopathological findings in a “classical case” of lipomatous meningioma. Financial Support and Sponsorship Nil. Conflicts of Interest There are no conflicts of interest.

Quantitative Comparison of 2D and 3D MRI Techniques for the Evaluation of Chondromalacia Patellae in 3.0T MR Imaging of the Knee

Methods: Seventy-five knee MRI exams of 69 adult consecutive patients were included in the study. Fat-saturated T2-weighted (FST2), fat-saturated proton density (FSPD), water-only T2-weighted DIXON (T2mD), T2-weighted 3 dimensional steady state (3DT2FFE), merged multi-echo steady state (3DmFFE), and water selective T1-weighted fatsuppressed (WATSc) images were acquired. Quantitative comparison of grade 1 and grade 5 lesions were made using contrast-to-noise (CNR) ratios. Grade 2-4 lesions were scored qualitatively and scorings of the lesions were compared statistically. Analysis of variance and Tukey’s tests were used to compare CNR data. Two sample z-test was used to compare the ratio of MR exams positive for grade 1 lesions noted on T2-mapping and other conventional sequences. Paired samples t-test was used to compare two different pulse sequences. Results: In detecting grade 1 lesions, FSPD, FST2 and T2mD images were superior in comparison to other sequences. FSPD and FST2 images were statistically superior in detecting grade 2-4 lesions. Although all grade 5 lesions were noted in every single sequence, FST2 images have the highest mean CNR followed by 3DT2FFE images. Conclusion: FST2 sequence is equal or superior in detecting every grade of patellar chondromalacia in 3.0T MR imaging of the knee in comparison to FSPD, T2mD, WATSc, 3DT2FFE, and 3DmFFE images.

Acute Myositis of the Tibialis Anterior Muscle after Performance of 108 Prostrations

Exercise-induced muscle damage (EIMD) can be caused by novel or unaccustomed exercise resulting in a temporary decrease in muscle function, increased muscle soreness and swelling, and an increase in muscle proteins in blood. A 38-year-old female presented with a 2-week history of bilateral lower leg pain and swelling that developed suddenly after performing 108 prostrations. Fat-suppressed contrastenhanced T1-weighted magnetic resonance imaging showed bilateral symmetric high signal intensity of the tibialis anterior muscles. Our patient was diagnosed with acute myositis and treated with naproxen. History of physical exertion and acute onset of typical clinical findings of myositis were key elements in the diagnosis. Acute myositis related to exercise is a common and self-limiting condition which fully resolves after 2 to 3 weeks. However, other causes of myositis should be excluded in patients with atypical clinical features.

Clinical Features and Prognosis of Sudden Sensorineural Hearing Loss Secondary to Intralabyrinthine Hemorrhage.

Background and ObjectivesA number of etiologies of idiopathic sudden sensorineural hearing loss (ISSNHL) have been proposed, including viral infection, vascular disturbance, and immune-mediated mechanisms. Intralabyrinthine hemorrhage (ILH) as a cause of SSNHL is extremely rare, and there have been no studies defining the characteristics of hearing impairment and prognosis in patients with ISSNHL due to ILH. This study aimed to investigate the difference in impaired hearing patterns and prognosis for hearing recovery between patients with ISSNHL due to ILH confirmed by magnetic resonance imaging (MRI) and sex- and age-matched patients with ISSNHL due to causes other than ILH.Subjects and MethodsWe compared the results of audiometry and MRI in 12 patients who had ILH on MRI (hemorrhage group) and in 23 sex- and age-matched controls without abnormal findings related to their hearing loss on MRI (non-hemorrhage group). Initial hearing impairment, progression, and recovery of hearing loss were compared between the two groups.ResultsA majority of patients (92%) in the hemorrhage group complained of dizziness. Initial hearing impairment was more frequent in the hemorrhage group than in the non-hemorrhage group (94.09±35.9 vs. 66.66±30.1, p-value=0.036). The final recovery threshold in the hemorrhage group was worse (78.19±46.26 vs. 37.17±31.96, p-value=0.014) than that in the non-hemorrhage group. In the hemorrhage group, hearing recovery seemed to occur less often at high frequencies (2,000, 4,000, and 8,000 Hz) than at low frequencies (250, 500, and 1,000 Hz).ConclusionsThe presence of ILH was associated with poor hearing prognosis and the occurrence of vertigo. The abrupt onset of hearing loss associated with vertigo and the presence of hyperresonance on fat-suppressed T1-weighted MRI images of labyrinthic fluid strongly suggests acute intralabyrinthine hemorrhage, and is predictive of considerable hearing impairment and poor prognosis.

Superior Cervical Sympathetic Ganglion: Normal Imaging Appearance on 3T-MRI.

ObjectiveTo identify superior cervical sympathetic ganglion (SCSG) and describe their characteristic MR appearance using 3T-MRI.Materials and MethodsIn this prospective study, we recruited 53 consecutive patients without history of head and neck irradiation. Using anatomic location based on literature review, both sides of the neck were evaluated to identify SCSGs in consensus. SCSGs were divided into definite (medial to internal carotid artery [ICA] and lateral to longus capitis muscle [LCM]) and probable SCSGs based on relative location to ICA and LCM. Two readers evaluated signal characteristics including intraganglionic hypointensity of all SCSGs and relative location of probable SCSGs. Interrater and intrarater agreements were quantified using unweighted kappa.ResultsNinety-one neck sites in 53 patients were evaluated after exclusion of 15 neck sites with pathology. Definite SCSGs were identified at 66 (73%) sites, and probable SCSGs were found in 25 (27%). Probable SCSGs were located anterior to LCM in 16 (18%), lateral to ICA in 6 (7%), and posterior to ICA in 3 (3%). Intraganglionic hypointensity was identified in 82 (90%) on contrast-enhanced fat-suppressed T1-weighted images. There was no statistical difference in the relative location between definite and probable SCSGs of the right and left sides with intragnalionic hypointensity on difference pulse sequences. Interrater and intrarater agreements on the location and intraganglionic hypointensity were excellent (κ-value, 0.749–1.000).Conclusion3T-MRI identified definite SCSGs at 73% of neck sites and varied location of the remaining SCSGs. Intraganglionic hypointensity was a characteristic feature of SCSGs.

Possibilities of multiparametric MRI in the differential diagnosis of histological types of cervical cancer in the preoperative period

Magnetic resonance imaging (MRI) is sensitive and specific method of study in patients with cervical cancer (CC). A number of studies have demonstrated the possibility to determine histological type (squamous cell cancer and adenocarcinoma) and the degree of differentiation of this type of tumor by using the apparent diffusion coefficient maps (ADC-map) compiled on the basis of diffusion-weighted images (DWI) (p <0.05). We have tested whether a more accurate assessment of the histological type and tumor grade in the preoperative stage is possible, by using a wide range of MRI techniques. According to multiparametric MRI, which included T2-weighted imaging (WI), DWI with reconstruction of ADC-maps and dynamic MRI with contrast enhancement, performed in 90 patients with histologically verified cervical cancer, it was shown that adenocarcinoma is characterized by a high intensity and less heterogeneity of MRI signal in fat-suppressed T2WI images as compared to squamous cell carcinoma. Furthermore, patients with adenocarcinomas who underwent dynamic MRI with contrast enhancement had curves with gradually higher change in MRI-signal intensity on T1WI images in 15 seconds after detection of the magnetic resonance contrast agent (MRCA) in tumor, continuous increase in MRI signal intensity (when observing for about 2.5 minutes) after detection of MRCA in tumor, while in case of squamous cell cancer – a lower variation in MRI signal intensity in T1WI mode to 10-20 second after detection of MRCA in the tumor followed by a biphasic course of the curve, dependence of MRI-signal on time and formation of the “plateau” or the same signal decrease down to 125 sec (about 2.5 min) as well as less signal heterogenecity in the period from 10-20 sec to 125 sec (about 2.5 min) after MRCA detection in tumor. The differences were statistically significant (p <0.05), and had sensitivity and specificity up to 0.76 and 0.75, respectively for particular signs. According to binary logistic regression that combines all the relevant parameters in a complex – up to 0.80 and 0.86 or 0.96 and 0.67, respectively. For poorly- and well differentiated adenocarcinomas it was shown significant difference in heterogeneity of MRI signal of the tumor compared to unaffected tissue with the following sensitivity and specificity: ≈1.00; 0.83 (poorly differentiated) and 0.75; 0.96 (well differentiated) respectively.

Magnetic Resonance Imaging Features of a Juxtaglomerular Cell Tumor.

Objective:To retrospectively determine whether magnetic resonance imaging (MRI) findings can help differentiate a juxtaglomerular cell tumor (JCT) from clear cell renal cell carcinoma (ccRCC).Materials and Methods:Eight patients with JCTs and 24 patients with pathologically proven ccRCC were included for image analysis. All patients underwent unenhanced MRI and dynamic contrast-enhanced MRI. Fat-suppressed T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), in- and opposed-phase imaging, and fat-suppressed preliver acquisitions with volume acceleration sequences were performed before enhancement. After the administration of contrast, dynamic imaging was performed in the corticomedullary, nephrographic, and excretory phases. Student's t-test, t′-test, Chi-square test, and nonparametric Kruskal–Wallis H-test were used to determine the significance of the difference between the two groups. The sensitivity and specificity of the MRI findings were calculated.Results:In patients with a JCT, a cystic part of the lesion of <10%, isointensity or mild hyperintensity on T2WI, heterogeneous hyperintensity on DWI, less signal drop (<10%) in in- and opposed-phase imaging, and a degree of enhancement <200% in the corticomedullary phase showed statistically significant differences compared with those of ccRCC (P < 0.05). After combining a lower apparent diffusion coefficient (ADC) value (heterogeneous hyperintensity) on DWI and a degree of enhancement <200% in the corticomedullary phase using a parallel test, the sensitivity and specificity were 90.9% and 91.7%, respectively.Conclusions:Isointensity or mild hyperintensity on T2WI, a lower ADC value (heterogeneous hyperintensity) on DWI, and a degree of enhancement <200% in the corticomedullary phase are the major MRI findings for JCTs, combined with relative clinical manifestations and excluding other renal masses. A main solid tumor, less signal drop (<10%) in in- and opposed-phase imaging, and a less-washout pattern of <10% in the delayed phase are secondary MRI findings for JCTs.

Fibroglandular tissue and quantitative background parenchymal enhancement on magnetic resonance breast images are inversely correlated with menopause in Thai women

Background: There are limited data regarding background parenchymal enhancement (BPE) in breast magnetic resonance imaging (MRI) for Asian women. Objectives: To determine relationships between the amount of fibroglandular tissue (FGT) and BPE in breast MRI. Methods: A retrospective review identified 95 MRI examinations of women with normal breasts between March 2012 to July 2014 for inclusion in this study. BPE and MRI-FGT were assessed on precontrast T1-weighted fatsuppressed images by consensus and described according to the American College of Radiology Breast Imaging Reporting and Data System. We analyzed BPE, including early and peak enhancement (Eearly, Epeak), and the signal enhancement ratio (SER). Spearman rank correlations between MRI-FGT and BPE and menopausal status were compared using Mann–Whitney U tests. Results: Fourteen premenopausal and 81 postmenopausal women had scattered and heterogeneous FGT (74%) and minimal to mild BPE (84%). There was a significant correlation between age and amount of MRI-FGT (r = –2.63; P = 0.01), but not BPE or enhancement kinetics. There was no significant correlation between FGT, BPE, and enhancement kinetics. There was a significant inverse relationship between menopause and the amount of FGT, BPE, and Epeak (P pre and postmenopausal Eearly and SER (P > 0.05). Conclusions: There is no significant correlation between the amount of FGT and BPE in either premenopausal or postmenopausal women. The amount of FGT, degree of BPE, and Epeak were higher in premenopausal women. Keywords: Background parenchymal enhancement (BPE), breast MRI correlation, fibroglandular tissue (FGT), menstruation, Thai women

T1-hyperintense renal lesions: can high signal predict lack of enhancement?

To establish highly specific criteria for predicting non-enhancement in T1-hyperintense non-fat-containing (T1-high) renal lesions using unenhanced fat-suppressed T1-weighted (T1-FS) images. This IRB-approved, HIPAA-compliant, retrospective study included T1-high renal lesions found between 7/1/2012 and 7/1/2014. The largest lesion diameter and heterogeneity, mean signal intensity of lesion, and adjacent renal cortex were recorded from T1-FS images. The presence/absence of lesion enhancement was determined from subtraction images. T1 signal ratio (T1-SR) was calculated as (mean SI of lesion)/(mean SI of cortex). Logistic regression with binary outcome of the presence or absence of lesion enhancement was performed. Cut-off T1-SR to maximize specificity was established from receiver operator curve analysis. There were 101 patients (58 [57.4%] male) with non-enhancing lesions and 80 patients (51 [63.8%] male) with enhancing lesions, mean ages 64.0 ± 13.3 and 62.1 ± 13.8 years, respectively. Median sizes were 11 mm (IQR 8-16) and 20.5 mm (IQR 15-29) for non-enhancing and enhancing lesions, respectively (p < 0.0001). 19/101 (18.8%) of non-enhancing and 56/80 (70.0%) of enhancing lesions were heterogeneous (p < 0.0001). T1-SR was 1.77 ± 0.6 and 1.25 ± 0.42 for non-enhancing and enhancing lesions, respectively (p < 0.0001). For each increase of 0.5 in T1-SR, odds ratio for non-enhancement was 3.3 (95% CI 1.85-5.79), adjusted for lesion size and heterogeneity. T1-SR alone had area under the curve of 0.88 (95% CI 0.78-10.89) for non-enhancement. T1-SR ≥ 2.15 had positive likelihood ratio of 9.5 for non-enhancement. Signal ratio of lesion to cortex ≥ 2.15 on unenhanced T1-weighted images is a highly specific predictor for non-enhancement.

Use of fat-suppressed T2 -weighted sagittal images after infusion of excess saline into the subarachnoid space as a new diagnostic modality for cerebrospinal fluid hypovolemia: technical note

The diagnosis of CSF hypovolemia remains controversial. The primary diagnostic factor relies on confirmation of leakage of the CSF based on reduced spinal fluid pressure. Determining the specific leakage site is the most important issue for effective treatment but remains a difficult task. Although CT myelography, radioisotope cisternography, and MRI are commonly performed in the diagnosis of CSF hypovolemia, these techniques can rarely identify the precise leakage site. Therefore, an epidural blood patch is performed in the lumbar spine in many cases. This study reports a new diagnostic modality that can help to confirm the leakage site. Fat-suppressed T2-weighted sagittal images were compared before and after the infusion of 20 ml of saline into the subarachnoid space of the lumbar region to detect the specific leakage site with high probability. Three patients were successfully treated by the epidural blood patch based on data obtained with the new diagnostic modality. Two patients were treated in the cervical region and 1 in the lumbar region. The use of fat-suppressed T2-weighted sagittal images after saline infusion could be a relevant diagnostic modality compared with images obtained by CT myelography, radioisotope cisternography, and ordinary MRI to achieve accurate diagnosis and effective treatment of patients with CSF hypovolemia.

Diffusion-weighted MRI findings in Sjögren's syndrome: a preliminary study.

Parotid glands diffusion-weighted imaging (DWI) in Sjögren's syndrome patients have provided conflicting results currently. To determine if parotid gland DWI using a small region of interest (ROI) can provide diagnosis and assess therapeutic efficacy in Sjögren's syndrome. Twenty-three women with Sjögren's syndrome, five with dry mouth who did not meet diagnostic criteria for Sjögren's syndrome, and 11 healthy volunteers (controls) were evaluated with DWI. All participants received routine T1-weighted (T1W) imaging and T2-weighted (T2W) fat-suppressed imaging, and DWI. The SI ratios (SIRs) and ADC ratios (ADCRs) for parotid gland/spinal cord were then calculated. Approximately 8-10 round ROIs measuring approximately 5 mm(2) were placed on each lobe of the parotid gland, and the signal intensity (SI) was measured while avoiding fat, ducts, and blood vessels. A ROI encompassing the entire lobe of the parotid gland was also used to measure SI. Using 5 mm(2) ROIs significantly higher DWI SIRs were noted in participants with Sjögren's syndrome compared with either participants with dry mouth without Sjögren's syndrome or healthy volunteers (all, P <0.001). The difference was not related to the presence of fat. No differences were noted when the larger ROI was used. In addition, parotid gland from untreated Sjögren's participants showed significantly higher SIRs compared with those from treated participants (P = 0.015). A small ROI DWI can provide morphological and functional information on the parotid gland in Sjögren's syndrome patients, and can aid in the diagnosis and evaluation of therapeutic efficacy.

MR imaging findings of pilomatricomas: a radiological-pathological correlation.

Magnetic resonance imaging (MRI) findings of pilomatricomas have yet to be determined. To assess the correlation between MRI and pathological findings of pilomatricomas. MR images were obtained on patients with histologically proven pilomatricomas using a 1.5-T MR scanner. The images were retrospectively reviewed for size, signal intensity compared with skeletal muscles, and enhancement patterns. Furthermore, we assessed the presence of a reticular appearance, a ring-like appearance, and peritumoral fat stranding. We included 11 consecutive patients with 12 histologically proven pilomatricomas (3 boys/men, 8 girls/women; age range, 4-76 years; mean age, 20 years; median age, 14 years). The tumors were located in the head and neck (n = 6), upper extremities (n = 5), and lower extremities (n = 1). The maximum tumor diameter was in the range of 7-32 mm (mean, 16.5 mm). On T2-weighted (T2W) images, five tumors showed homogeneous hypointensity, whereas six showed reticular hyperintensity and one showed cystic hyperintensity. On fat-suppressed T2W images, nine tumors showed reticular hyperintensity, eight showed ring-like hyperintensity, and five showed peritumoral fat stranding. On fat-suppressed gadolinium-enhanced T1-weighted (T1W) images, one tumor showed no enhancement, whereas three showed reticular enhancement and five showed ring-like enhancement. Histologically, edematous and fibrous stroma was observed in 10 tumors, tumor capsules in 11, and inflammatory cell infiltration of the peritumoral fat tissue in nine. MRI features of pilomatricomas included reticular and ring-like hyperintensities on fat-suppressed T2W images and reticular and ring-like enhancement on fat-suppressed gadolinium-enhanced T1W images.