MR imaging of splenic masses

It has been reported that MR imaging of the spleen is unsuccessful in detecting focal lesions because there is not a significant difference in relaxation times between most tumors and surrounding normal spleen. We reviewed the MR imaging of 15 patients (5 cysts, 2 abscesses, 1 hemangioma, 5 malignant lymphomas, 2 metastatic tumors). In all cases, the difference in signal intensities between splenic tissue and mass lesions permitted detection of splenic lesions on MR images. But, malignant lesions were less visible than benign lesions.     

Preoperative evaluation of adnexal masses

This is a large multicenter trial designed to determine the efficacy of second stage diagnostic testing when the primary diagnostic test has provided an uncertain diagnosis of a benign or malignant adnexal mass. Women with adnexal masses were evaluated using ultrasonography. Clinical and ultrasonographic data were employed to determine the risk of malignancy using 11 statistical models and their performance was evaluated based on histologic findings at surgery. Overall, the ultrasound examiner's subjective evaluation had the highest area under the curve and specificity, with respect to diagnostic performance. Of the mathematical models evaluated, LR1 performed the best, with an area under the curve of 0.95, a sensitivity of 92% and a specificity of 84%. The accuracy of subjective evaluation did not improve with the addition of any second stage test. If the LR1 model was used as the primary diagnostic test, the addition of subjective evaluation as a secondary test was found to be beneficial.     

Pelvic masses in childhood: ultrasonographic imaging

The echographic appearance of pelvic masses in children was examined in 38 patients. Sonography was correct in determining the site of origin in all cases. Cystic uterine masses and cystic ovarian masses were the most specific, representing hydrometrocolpos and benign ovarian cysts. A nonspecific sonographic pattern was encountered with complex masses, which proved to be ovarian teratomas, hemorrhagic ovarian cysts and pelvic abscesses. Although a number of characteristic features of teratomes have been described, these signs were seen very rarely in children.     

MR imaging of adenomyosis

MR imaging characteristics of adenomyosis were studied in nine women (five diffuse type, four focal type) who underwent hysterectomy. In all cases, MR images were correlated with surgical/pathologic findings. On T2-weighted images, diffuse type appeared as a thickening of the junctional zone, because it was often isointense with this zone. Focal type appeared as a low signal intensity, round or oval shaped mass poorly marginated from the adjacent myometrium.     

四肢软组织肿瘤MRI影像特征分析

目的:探讨四肢软组织肿瘤的MRI特征,以提高诊断准确性.方法:收集经病理证实的四肢软组织肿块38例,分析其MRI征象.结果:38例软组织肿块包括良性肿块31例,恶性肿块7例.除脂肪瘤、脂肪肉瘤及血肿机化在T1WI、T2WI上表现为高信号外,其余肿块T1WI多为等或低信号,T2WI多为高信号或以高信号为主的混杂信号.良性组一般边界清楚,部分病变具有特征性MRI征象.恶性组体积较大,信号不均匀,其中6例邻近组织受侵.结论:MRI能清楚地显示肿瘤的范围、信号特征及与周围组织的关系.某些特征性MRI征象对软组织肿块的正确诊断及鉴别诊断具有重要意义.     

Fast MR imaging and ultrafast MR imaging of fetal central nervous system abnormalities

The aims of this study were two: (1) to compare the efficacy of fast MRI (breath-hold fast spin-echo T2-weighted and fast gradient-echo T1-weighted sequence) and ultrafast MRI (half-Fourier acquisition single-shot turbo spin-echo sequence) in evaluation of fetal central nervous system (CNS) abnormalities at late gestational age, and (2) to compare the capability of fast MRI and ultrafast MRI to assess fetal CNS abnormalities with that of prenatal ultrasonography (US). Forty-nine women with fetuses at gestational ages of 26-39 weeks underwent fast MRI (29 patients) or ultrafast MRI (20 patients). In detection of motion artifact, visualization of the lateral and 4th ventricles, and differentiation between gray and white matter in cerebral hemispheres, ultrafast MRI was significantly superior to fast MRI (p< 0.0001, Mann-Whitney U test). In 25 of 43 cases, US and MR diagnoses were the same and consistent with postnatal diagnosis. In 10 of 43 cases, MRI demonstrated findings additional to or different from those of US, and MR findings were confirmed postnatally. MRI, particularly ultrafast MRI, is useful for demonstrating CNS abnormalities in situations in which US is suggestive but not definitive.     

Arthrosonography in the evaluation of osteoarticular and soft-tissue structures in rheumatology

BACKGROUND: Real-time ultrasonography is a widely available, reliable, diagnostically sensitive and specific noninvasive modality which allows measuring of the thickness of different anatomical landmarks which form joints, of the periarticular soft tissue and connective tissue structures, of their echogenicity and the amount of joint effusion. The present study was designed to assess the clinical and diagnostic applicability of high-frequency ultrasonography in rheumatology. METHODS: We used SONOACE 1500 (Medison Europe GmbH) with a 7.5 MHz transducer. RESULTS: We demonstrate the most characteristic ultrasonographic patterns which have diagnostic significance in the seven most common rheumatologic disorders. DISCUSSION: The pathological ultrasonographic patterns of the joints, periarticular and soft-tissue structures in rheumatologic disorders we present give an insight into the clinical applicability of arthrosonography and its inherent advantages over the conventional radiological examination--namely, ultrasonography is noninvasive, uses no radiation, which allows reproducibility and follow-up, widely available and relatively inexpensive and as such can be performed at bedside or on an outpatient basis.     

MR imaging of cerebellar infarct

Twenty-six patients with cerebellar infarct were studied with MR imaging at 1.5 T. Thirty-one infarctions were observed. Both T1- and T2-weighted images were useful for diagnosing cerebellar infarct. Large cerebellar infarcts were most frequently observed at the PICA territory. Small cerebellar infarcts were located in the border-zone between the SCA and the PICA territories. It was concluded that MR imaging is very useful for diagnosing cerebellar infarct.     

MR imaging of the arm

Thirty arms of healthy adults were studied with MR imaging using surface coil. Fine structures of the arm, such as muscular bundles, small vessels and nerves were clearly demonstrated. Deep fascia dividing muscular bundles appeared as high intensity on T1-weighed image due to fat deposition beneath the fascia. Aponeurosis is also flat sheet of densely arranged collagen fibers. With rather thicker layer of collagen fibers than fascia, aponeurosis appeared as low intensity sheet that was frequently demonstrated on MR images of the extremities.     

MR imaging of brainstem infarction

Thirty-three patients with old brainstem infarct were studied with MR imaging at 1.5T. T1-weighted images were most useful for diagnosing brainstem infarct. Brainstem infarcts were most frequently observed at the central portion of the mid pons. All of the lesions of three patients with medullary infarct were right sided. Both of the lesions of two patients with midbrain infarct were relatively large. Brainstem infarcts frequently accompanied supratentorial lacunar infarcts and subcortical arteriosclerotic encephalopathy.     

脑膜瘤的磁共振诊断

目的：探讨脑膜瘤的磁共振表现及其诊断、方法：回顾性分析20例经手术病理证实的脑膜瘤MRI影像资料,记录病灶的位置、数目及信号特点、强化特征等。结果：脑膜瘤边界清晰,多为类圆形,在T2WI上呈稍高信号,T1WI上呈等或稍低信号,占位效应明显,增强后强化均匀。结论：磁共振时脑膜瘤具有良好的诊断价值。     

Intracranial lipoma; MR imaging

Reported here are five patients with intracranial lipoma. Three of these had pericallosal lipoma. One patient had a lipoma in the quadrigeminal cistern. The remaining one had a lipoma in the interpeduncular cistern. All of these tumors were clearly demonstrated and were homogeneously hyperintense on T1-weighted MR images. One patient with a pericallosal lipoma had also partial agenesis of the corpus callosum. However, all patients had no symptoms relating these tumors. It was concluded that MR imaging is useful for diagnosing intracranial lipomas and associating anomalies.     

Cine MR imaging in valvular heart disease

Cine MR Imaging was carried out using FLASH (fast low angle shot) which employees TE of 16 msec and TR of 30-40 msec. Regurgitant jet was visible as discrete area of low signal intensity extending from the incompetent valve into the respective cardiac chamber. In 20 patients with mitral regurgitation, the correlation of the length and area of mitral jet by cine MR and color doppler mapping was 0.74 and 0.71, respectively. Cine MR imaging is a promising modality for detection and quantification of valvular heart disease.     

MR imaging of basilar artery aneurysms

Eight patients with basilar artery aneurysms (five fusiform, two saccular and one giant aneurysm) were studied by MRI at 1.5 tesla. Dilated lumen of basilar artery was detected in seven of eight patients on T2-weighted axial images. Deformity of pons was demonstrated in six of eight patients on T1-weighted midsagittal images. A fusiform aneurysm, 5 mm in diameter, could not be diagnosed by MRI. It was therefore concluded that MR imaging is relatively useful for diagnosing basilar artery aneurysms.     

MR imaging of the brain in Wilson's disease

Two cases of Wilson's disease, who had been treated for eight years, were examined by MRI at 1.5 tesla. MRI of both cases demonstrated lesions with prolonged T1, prolonged T2 and partially shortened T2 in bilateral lentiform nuclei. Lesions with prolonged T1 & T2 may reflect small cavitary lesions. On the other hand, shortened T2 area may be caused by copper deposits.