Pelvic MRI: Is Endovaginal or Rectal Filling Needed?

Magnetic resonance imaging is the optimal modality for pelvic imaging. It is based on T2-weighted magnetic resonance (MR) sequences allowing uterine and vaginal cavity assessment as well as rectal evaluation. Anatomical depiction of these structures may benefit from distension, and conditions either developing inside the lumen of cavities or coming from the outside may then be better delineated and localized. The need for distension, either rectal or vaginal, and the way to conduct it are matters of debate, depending on indication for which the MR examination is being conducted. In this review, we discuss advantages and potential drawbacks of this technique, based on literature and our experience, in the evaluation of various gynecological and rectal diseases.

DWI in evaluation on biological characteristics of breast invasive ductal carcinoma / 中国医学影像技术

Objective To evaluate the value of DWI in assessing the biological characteristics of breast invasive ductal carcinoma (IDC).Methods Eighty-seven IDC lesions confirmed by postoperative pathology were involved in this retrospective study.The ADC values of IDC were compared among different lymph node status,grades,and molecular subtype.The correlations of ADC value and lymph node status,grades,and molecular subtype were evaluated.Results The ADC value of IDC with positive lymph node was lower than that with negative lymph node (P=0.035),and the ADC value of the high grade IDC was lower than those of medium grade IDC and low grade IDC (P=0.021,0.002).There was no significant difference of ADC value between different molecular subtypes.There was low negative correlation of ADC value with grades (r.s =-0.357,P 0.001) and week negative correlation of ADC value lymph node status and nolecular subtype (rs =-0.227,P=0.034;rs-0.093,P＜0.001).Conclusion DWI can provide useful information in evaluating the biological characteristics of IDC.

Extra-pleural solitary fibrous tumor: imaging and histopathologic features / 实用放射学杂志

Objective To analyze the imaging and histopathologic features of extra-plural solitary fibrous tumor (SFT) and to improve the diagnose diagnostic ability.Methods The images and pathologic features of 32 SFT cases confirmed by pathology were retrospectively reviewed.Results Of 32 SFT cases, there were 5 cases in the head, 3 cases in the orbit, 1 case in the nasal sinuses, 1 case in the bronchus, 2 cases in the stomach,1 case in the pancreas, 3 cases in the kidney, 3 cases in the retroperitoneum, 4 cases in the pelvic cavity, 6 cases in the soft tissues, 3 cases near the vertebra.6 cases were malignant,8 cases were borderline,18 cases were benign.The tumors located in abdominal and pelvic tumors were larger,the average diameter of the tumors was 13.6 cm.The volumes of the other tumors were smaller, the average diameter was 4.2 cm.The majority of the tumors showed clear boundary, smooth edge or lobulated soft tissue mass, partial necrosis, rare cystic degeneration and calcification.MR images showed hypo to isointensity on T1WI and hyper to isointensity on T2WI.After enhanced enhancement, multiple small circuitous vessels could be found in or around the mass.The tumor showed slightly enhanced in the arterial phase and moderately to obviously heterogeneously enhancement in the venous phase.In addition, part of the tumors can could be seen positive-negative signal changes.The positive expression rate of immunohistochemical indexes were: CD34 100%, CD99 68.8%, Bcl-2 62.5%, Vimentin 46.9%, Ki-67>5% 43.8% respectively.

Application and advance of physiological MR imaging of knee articular cartilage / 医学研究生学报

Physiological MR imaging techniques provide abundant information for the diagnosis and research of knee cartilage le -sions.It can not only evaluate the morphology and structure of cartilage , but also analyze the functional , metabolic and biochemical changes quantitatively , to explore the causes of cartilage lesions at the molecular level .Application and advance of physiological MR imaging of knee articular cartilage are reviewed , including sodium imaging , delayed gadolinium enhanced magnetic resonance imaging of cartilage, T1ρ, T2 mapping, chemical exchange saturation transfer , diffusion imaging and so on, aiming at providing references for choosing MR imaging of knee articular cartilage .

Features of long bone diaphysial osteosarcoma on X-ray, CT and MRI / 中华放射学杂志

Objective To explore the findings of diaphysial osteosarcoma in long bone on X-ray,CT and MRI, and discuss their clinical features and manifestations for differential diagnosis. Methods Twenty-eight cases with diaphysial osteosarcoma in long bone proved by surgery and pathology were reviewed retrospectively. Eighteen tumors were located in the femur, 4 in fibula, 4 in humerus and 2 in tibia. All of the patients were examined by X-ray, CT and MRI. The imaging manifestations on X-ray, CT and MRI were analyzed, and the relationship of the imaging features with the pathological types was also observed. The imaging signs were correlated with the pathologic findings with a double blind method. Results Of the 28 cases, there were 16 cases with large bone destruction, 22 cases with periosteal reaction on X-ray and CT. On X-ray, 18 cases showed soft tissue mass and 12 cases with neoplastic bone and tumor calcification.While on CT, 22 cases showed soft tissue mass on plain scan and 2 more cases displayed soft tissue mass after the injection of contrast mediun. Sixteen cases showed neoplastic bone and tumor calcification on CT.On MRI, there were 10 cases with bone destruction and periosteal reaction with iso- and hypo-intense on T1WI and iso- signals on T2WI. Twenty-six cases showed soft tissue edema and bone marrow on MRI. The soft mass were iso-signals on T1 WI and iso-hyperintense signals on T2 WI or STIR. The soft tissue edema was found hyperintense signals on T2WI or STIR. The lesions had heterogeneous enhancement especially in bone marrow with edema and adjcent soft tissue. Conclusion The X-ray, CT and MRI can reflect the pathological changes of diaphysial osteosarcoma in long bone from different aspects. Lower incidence, large bone destruction and no pathological fracture were the features of diaphysial osteosarcoma. The osteogenic type is diagnosed easily, but the osteolytic lesion should be differentiated from Ewing sarcoma, malignant giant cell tumor of bone and so on.

Focal Liver Lesion Detection in Gadoxetic Acid-enhanced Liver MRI: Effects of Scan Delay, Hepatic Function, and Magnetic Field Strength

PURPOSE: To determine the effects of scan delay, hepatic function, and magnetic field strength on the performance of gadoxetic acid enhanced magnetic resonance imaging. MATERIALS AND METHODS: Gadoxetic acid enhanced MRI conducted in 72 patients with 10 minutes and 20 minutes delay were reviewed retrospectively. For quantitative analysis, liver-to-lesion signal difference ratio (SDR) was measured and compared according to scan delay time, hepatic function and magnetic field strength. For qualitative analysis, two board-certificated radiologists reviewed 10-minute delay and 20-minute delay images. The sensitivity and specificity of each reader was compared. RESULTS: The SDR of 20-minute images in non-cirrhotic patients was significantly higher (p 0.05) to 10-min delay images. In comparisons according to the magnetic strength, there was no significant difference between 1.5-T and 3.0-T systems. Comparisons of ROC curves showed no statistically significant differences in sensitivity and specificity between 10-minute and 20-minute delay images. CONCLUSION: An increase in the liver-to-lesion signal difference ratio was dependent on the patients' hepatic function but not dependent on the magnetic strength. There was no significant difference in sensitivity or specificity between the 10-minute and 20-minute delay images.

MR diffusion weighted imaging in evaluating bone mineral density:a pilot study / 中华放射学杂志

Objective To investigate the correlation between vertebral diffusion weigllted imaging (DWI)and dual X-ray absorptiometry(DXA),quantitative computed tomography(QCT)for the evaluation of bone mineral density(BMD).Methods A total of 152 female volunteers[aged from 30 to 80 years,mean age(58.2±14.2)years 1 were recruited in this study.All subjects underwent lateral thoracicolumbar radiographs,dual X-ray absorptiometry(DXA)and quantitative computed tomography(QCT),as well as DWI examination.Lateral spine radiographs(T4-L4)were evaluated with Genant's semiquantitative assessment.BMD was obtained by both DXA and QCT at lumbar spine(L2-L4).Axial vertebral(L2-4)DWI was performed with single shot spin-echo echo-planar imaging(SS-SE-EPI)sequenee (b value=500 s/mm2)after routine MRI examination(saginal T2 WI,T1 WI and axial T2 WI).Apparent diffusion coefficient(ADC)was measured with GE-Functool DWI software.Pearson correlation analysis was used for the statistics.Results There was a decreasing tendency in ADC value with age.A positive correlation was found between ADC(0.241×10-3 mm2/s)and BMD results measured by both DXA (1.038 S/cm3)and QCT(104.2 mg/cm3)examinations(r=0.461,0.731,respectively,P＜0.01).Conclusion DWI is an useful tool for noninvasive evaluation of the pathophysiologic changes of bone marrow in volunteers with difierent bone mineral density.

Dynamic MRI for Breast Cancer: Correlation with the Prognostic factors and the Time-Signal Intensity Curve

PURPOSE: We wanted to evaluate the relation of the kinetic MRI features of dynamic contrast-enhanced MRI with the histopathological prognostic factors of breast cancer. MATERIALS AND METHODS: Fifty-four lesions of breast cancer patients were evaluated with using a 1.5 T MR scanner. The dynamic studies were performed in the axial plane with using T1 High Resolution Isotropic Volume Examination (THRIVE) so we obtained the time signal intensity curves. By considering the early peak signal intensity, the maximal signal intensity, the pre-enhanced signal intensity and the last signal intensity, we calculated the absolute value, percentage, slope of enhancement and the washout. The time of the early peak signal intensity and the time of the maximal signal intensity were obtained. We classified the early and delayed enhancement patterns. The kinetic MR features were correlated with the histopathological findings (the histologic and nuclear grades, estrogen receptor, progesteron receptor, Ki-67, p53 and c-erb B2). RESULTS: The early peak signal intensity slope was significantly correlated with the histologic grade (I versus II, III), and the Ki-67 (p=0.045, p=0.009). Ki-67 was also significantly correlated with the time of the peak signal intensity and the time of the maximal signal intensity (p=0.009, p=0.045). CONCLUSION: Some of the parameters of the time-signal intensity curve of dynamic MRI were associated with the prognostic factors, so these MRI signs may be useful to noninvasively identify prognostic factors in the future.

Functional Localization of Human Swallowing Motor Cortex / 国际脑血管病杂志

The localization of human swallowing cortical area remains unclear,which prevents the understanding of pathophysiologic change of peripheral swallowing apparatus and the development of swallowing rehabilitation.Animal experiments have found that the non-human primates, premotor cortex,sensorimotor area,frontal,parietal and temple operculum,orbitofrontal cortex and cingulate cortex are associated with swallowing function.Recently,by using the advanced techniques such as functional MRI,position emission tomography and magnetoencephalography,it was found that a number of encephalic regions participated in the human swallowing,mostly concentrated in primary sensorimotor cortex,premotor cortex,cingule,insular lobe,and parietal-occipital area.However,the exact functions and roles of various encephalic regions and their correlations between various encephalic regions remain unclear.Further studies are needed to identify them.

A Case of Acute Cerebellitis

Acute cerebellitis, also known as acute cerebellar ataxia, is an inflammatory syndrome of cerebellar dysfunction that may reflect an infectious, post-infectious, or post-vaccination disorder. The clinical presentations are abnormal eye movement, truncal ataxia, dysarthria, nausea, headache, tremor, convulsion and altered mental status. Many patients with cerebellitis are supposed to have normal MRI findings. But hyperintense signals of cerebellar gray matter in T2-weighted sequences of MRI can be used as a strong indication of acute cerebellitis. We report here a case of acute cerebellitis with abnormal MRI findings in 7 years old patient with diplopia and tremor.

Central Nervous System Tuberculoma

The authors present a retrospective analysis of central nervous system(CNS) tuberculoma, describing the clinical manifestations, radiological findings, diagnosis, treatment, and prognosis. Between February 1984 to December 1996, 22 cases of CNS tuberculoma presenting as intracranial space occupying lesions were managed at Seoul National University Hospital. The age of patients ranged from two to 47 (mean, 28) years and the male-to-female ratio was 6 to 16. The diagnosis of CNS tuberculoma was pathologically confirmed in 18 cases, while the remaining four were diagnosed on the basis of clinical manifestations and radiological findings. The duration of follow-up ranged from 10 months to 7 years(median, 2 years). The results of treatment and prognosis were defined according to the status of patients on their final visit to the Outpatients' clinic. The symptoms of CNS tuberculoma were seizure(45% of cases), headache(36%), visual disturbance(18%), and hemiparesis(18%), and in 12 patients(55%), the presence of related pulmonary tuberculosis was noted. The most commom site of CNS tuberculoma was the frontal lobe; multiple lesions were present in five cases, and brain stem lesions in three. In 13 cases, CNS tuberculoma was seen as low signal intensity on T2 weighted magnetic resonance images(MRI). Gadolinium-enhanced T1 weighted MRI showed strong rim enhancement in ten cases and nodular enhancement in five, as well as characteristic grape-like conglomerated lesions in six cases. Surgical removal was performed in 13 cases, stereotactic biopsy in two, and biopsy via craniotomy in three. Although microbiologic study was negative in all 18 cases, diagnosis of CNS tuberculoma was possible on histological examination. After clinical or surgical diagnosis, a course of anti-tuberculosis medication was started in all patients. In 18 cases, intracranial lesions disappeared completely after anti-tuberculosis medication, and during the follow-up period, there was no evidence of recurrence. In three cases the lesions became smaller during treatment and symptoms improved. One patient died in spite of medication and decompressive surgery. Between the group of 13 patients who underwent decompressive surgery or lesionectomy via craniotomy, and the other group of nine, the outcome of treatment was not different(p=1.000, Fisher's exact test). In conclusion, the MRI findings of intracranial CNS tuberculoma are characteristic MRI findings. In cases of CNS tuberculoma, the treatment of choice is anti-tuberculous medication after histologic confirmation, though if sufficient clinical data support this diagnosis, then diagnostic and therapeutic medication without histologic confirmation is recommanded. Stereotactic biopsy is an ideal method for confirming a pathologic diagnosis of intracranial CNS tuberculoma, except in the cases in which intracranial pressure is high.