Areas Of Low Signal Research Articles

Magnetic resonance-based visualization of thermal ablative margins around hepatic tumors by means of systemic ferucarbotran administration before radiofrequency ablation: animal study to reveal the connection between excess iron deposition and T2*-weighted hypointensity in ablative margins.

The objective of this study was to demonstrate experimentally that radiofrequency ablation (RFA) of ferucarbotran-accumulated healthy liver tissues causes excess iron deposition in the ablated liver tissues on postablation days and produces sustained T2*-weighted low signals indicative of ablative margins surrounding hepatic tumors. We conducted 3 experiments using 30 rats. In experiment 1, we administered either ferucarbotran (n = 6) or saline (n = 4), acquired T2*-weighted images (T2*-WIs) of the liver by using a 3-T magnetic resonance scanner, and subsequently performed RFA of healthy liver lobes. We acquired follow-up T2*-WIs up to day 7 and histologically analyzed the liver specimens. In another 4 rats, we performed sham operation, instead of RFA, in ferucarbotran-accumulated liver lobes, followed by the same image acquisition and histological analysis. In experiment 2, we administered 59Fe-labeled ferucarbotran, subsequently performed either RFA (n = 4) or sham operation (n = 4) in the liver, and acquired autoradiograms of the liver specimens on day 7. In experiment 3, we conducted RFA treatment for 8 rats bearing orthotopic hepatic tumors after ferucarbotran administration and monitored tumor growth by using serial T2*-WIs. On days 4 and 7 of the experiment 1, T2*-WIs of 6 rats with systemic ferucarbotran administration and subsequent hepatic RFA showed low-signal regions indicative of ablated liver tissues, whereas high-signal areas were seen in 4 saline-administered rats. Neither high nor low signal areas were detected in 4 sham-operated rats. Histologically, larger amounts of iron were observed in the RFA-induced necrotic liver tissues in the ferucarbotran-administered rats than in the saline-administered-rats. The 59Fe autoradiography of the rats in experiment 2 revealed accumulation of ferucarbotran-derived iron in necrotic liver tissues. Among 6 hepatic tumors grown in 6 rats of the experiment 3, a total of 4 tumors were stable in size, but the other 2 increased markedly on day 7. Retrospectively, T2*-WIs showed the former tumor sites surrounded completely by low-signal areas on day 4. The RFA of ferucarbotran-accumulated healthy liver tissues in the rats caused excess iron deposition in the ablated liver tissues and produced sustained T2*-weighted hypointense regions. Similar hypointense regions surrounding hepatic tumors were indicative of ablative margins.

Improving the accuracy of cardiac DTI by averaging the complex data

Background When performing cardiac diffusion tensor imaging (cDTI) multiple averages are typically acquired to compensate for the low signal to noise ratio of the individual images. However, the potential for reducing noise in low signal areas is not fully realized when the averaging is performed on the magnitude data[1]. Averaging the complex cDTI data is not straightforward as the diffusion weighting introduces a different, spatially varying phase across each image. In this work we use simulations to demonstrate the benefits available when using complex averaging and then develop an algorithm for performing complex averaging of in-vivo cDTI data, which accounts for the induced phase variations.

Retrorectal cystic hamartoma (Tailgut cyst)

CASE SUMMARY A 30-year-old asymptomatic female presented for IUD placement 5 months after an uncomplicated C-section. Ultrasound confirmed correct IUD placement but revealed a “complex pelvic mass” in the posterior cul-de-sac. Rectovaginal exam revealed a nontender soft tissue mass, 6-7cm in size, just to the right of the rectum and vaginal apex. Pelvic MRI showed a 7 cm mass deep in the right hemipelvis, felt to possibly represent an endometrioma, which remained unchanged on a 3-month follow-up study. Colonoscopy revealed extrinsic bowel compression but no mucosal changes. Due to recent pelvic surgery, the imaging characteristics of the mass, and the normal appearance of both ovaries, a gossypiboma was considered. Exploratory laparotomy revealed a right perirectal retroperitoneal mass containing copious amounts of keratin. The mass was excised and the patient had an uneventful recovery. IMAGING FINDINGS The initial and follow-up pelvic MR images demonstrated a well-defined, non-enhancing, ovoid lesion within the cul-de-sac which exerted mass effect on the uterus (Figure 1) and was distinct from both ovaries. The lesion exhibited high T2 and low T1 signal as well as several areas of linear low T2 signal internally with a somewhat “whorled” appearance (Figure 2). In addition, there was no signal loss on fat saturated images (Figure 3). Given these findings and the patient’s clinical history, the differential diagnosis included gossypiboma, retrorectal cystic hamartoma, epidermal inclusion cyst and endometrioma.

The MRI Imaging of Cerebral Cavernous Malformation With Practical Use of Diffusion Weighted Image

Aim: To evaluate the significance of diffusion weighted image(DWI) of the cerebral cavernous malformation in clinical practice. Materials and Methods: Thirty patients with 66 lesions (multiple 5 cases) were included in this study. The signal, configuration, anatomical location, size, and the number on each T1WI, T2WI, FLAIR, T2WI*, DWI, Gd (gadolinium)-T1WI,and the sequential signal change of DWI(central and peripheral area in cavernoma)were recorded. Results: The cerebral cavernous malformation (CCM) shows the signal of various phase of hematoma (hemorrhage)on both T1WI and T2WI MRI. On the diffusion weighted imaging (DWI), they showed the marked low (43.3%)and mixed high and low signal intensity (33.3%)even if they were very small appearing as areas of decreased signal (black dots) on T2WI.The low intense signal area on DWI assumed to reflect the hemosiderin or susceptibility effect and blood oxygen level dependent (BOLD)effect by the deoxyhemoglobin and T2 black out effect. The transient high signal foci on DWI were observed in 2(6.7%) cases in whom the intratumoral (re)hemorrhage were suspected. Conclusions: The CCM tends to exhibit almost low signal intensity on DWI.DWI is a useful method like T2*WI and SWI for the detection of the tiny CCM.

OPLL, DISH and HPLL Imaging Presentation

: Posterior longitudinal ligament (PLL) originates at the basiocciput, extends along the posterior aspect of the vertebral bodies and intervertebral discs and inserts into the sacrum. When hypertrophied (HPLL) and ossified (OPLL), the ligament encroaches upon the spinal canal. The OPLL is diagnosed when ossification originates within or spans the space between two discs to involve the ligament overlying the centrum of the vertebral body in between. The HPLL is defined by thickening of the PLL that compresses the dural tube. The differential diagnosis should be made based on the existence of ossification either on the X-rays or the histological findings. The relation between HPLL and OPLL is still controversial, and there is no universal consensus as to whether HPLL evolves into OPLL. For diagnosis, plain films may be useful. MRI should be the initial study for a patient with non-traumatic myelopathy. OPLL appears as an area of low signal and CT-myelogram provides better resolution of osseous anatomy and longitudinal retrovertebral opacity. Etiology of OPLL is unknown, but high incidence of diffuse idiopathic skeletal hyperostosis (DISH) among OPLL patients suggests a hereditary diathesis of spinal ligament ossification. The diagnostic features of DISH are: calcifications and ossifications along the anterolateral aspect of vertebral bodies, osteophytes, preservation of disk height, an absence of excessive disk disease, bony ankylosis, and sacroiliac erosion. Radiography is sufficient for diagnosing DISH. Occasionally, computed tomography (CT) scanning may be performed to evaluate complications. Bone scanning and MRI do not play a significant role.

Treatment of rat with traumatic brain injury and MR tracing in vivo via combined transplantation of bone marrow stromal cells labeled with superparamagnetic iron oxide and Schwann cells.

Transplantation of bone marrow stromal cells (BMSCs) or Schwann cells (SCs) can facilitate axonal regeneration in nerve injuries. The aim of this study was to assess the effect of BMSCs and SCs transplantation on a rat with traumatic brain injury (TBI) and cellular migration in brain, and investigate whether combined BMSCs and SCs transplantations have more advantages than BMSCs transplantation alone. BMSCs were cultured in vitro and then labeled with SPIO. The labeled and unlabeled cells were assayed by MTT inspection to compare the effect of SPIO on growth activity of rat's BMSCs. Sciatic nerve was taken of the rat and striped off epineurium to obtain SCs by carrying out cell culture using mixed enzyme digestion. The SCs were identified by immunofluorescence labeling for S-100 protein and cellular activities were analyzed by MTT growth curves. Improved Feeney method was adopted to make a rat TBI model. In total, 50 male Sprague Dawley (SD) rats weighing 200-250 g were randomly divided into 5 groups: Groups A-E (n = 10 for each group). Injections of nutrient and stereotactic transplantation of BMSCs labeled with SPIO and stereotactic transplantation of SCs and BMSCs labeled with SPIO were administered in these groups 48 hours after TBI modeling. Neurological severity scores (NSS) were implemented at the 3 day, 1 week, 2 week and 4 week, respectively, after transplantation and 7.0T MRI scanning was done to observe migration situation of transplanted cells. After completion of MRI inspection at 4 weeks post transplantation, all rats were sacrificed and their brain tissue sections taken and assayed by HE staining and prussian blue staining. Numerous BMSCs were successfully labeled with SPIO. The labeling efficiency was more than 90%. There was no obvious difference between cellular proliferation of BMSCs labeled and unlabeled with SPIO at different time points. SCs were cultured in vitro and SCs S-100 detected as positive. MRI results show that T2WI was expressed in low signal area and migrated towards injury side after BMSCs labeled with SPIO were transplanted into brain. The combined transplantation had a quicker migration speed than single transplantation. NSS result shows that the combined transplantation group had a low score than single transplantation group after 2 weeks. In conclusion, BMSCs labeled with SPIO can be transplanted into brain and can be used in 7.0T MRI tracing in vivo. Compared to single transplantation, the combined transplantation of BMSCs and SCs has a quicker cellular migration and a better prognosis.

Inferior vermian hypoplasia – preconception, misconception

Inferior vermian hypoplasia – preconception, misconception

A case of primary aldosteronism who experienced cardiopulmonary arrest, was resuscitated and cured

A 45-year-old female went into cardiopulmonary arrest. She was in ventricular fibrillation (VF) and was defibrillated using an automated external defibrillator. After arrival at our hospital, electrocardiography monitoring showed QT prolongation. Serum potassium was low at 2.2mEq/L, and hypokalemia-induced long QT syndrome was considered to be the cause of this patient's VF. An intravenous infusion of potassium and magnesium sulphate was started, which normalized her serum potassium and QTc interval, with no recurrence of ventricular arrhythmias. Endocrinological investigations showed a plasma renin activity of <0.1ng/(mLh) and a plasma aldosterone concentration 258pg/mL. Computed tomography scanning revealed a low signal area 16mm×20mm in size of the right adrenal gland. From the above findings, this patient was diagnosed with a right adrenal tumor and primary aldosteronism. We concluded that the right adrenal tumor was excreting excess amounts of aldosterone from adrenal vein sampling, and performed laparascopic right adrenalectomy. Serum potassium levels rose immediately to normal levels postoperatively. We were able to withdraw her antihypertensive medication 3 months after adrenalectomy. We report a case of primary aldosteronism who experienced cardiopulmonary arrest, was resuscitated, and cured.<Learning objective: When you come across ventricular fibrillation, please consider one of the reasons is caused by hypokalemia due to primary aldosteronism. After an appropriate resuscitation, both hypokalemia and hypertension are completely curable by removing the adrenal tumor.>

Castleman’s disease in the retroperitoneal space mimicking a paraspinal schwannoma: a case report

BackgroundCastleman’s disease is a rare disease characterized by lymph node hyperplasia. Its occurrence in the retroperitoneal space has rarely been reported, making its preoperative diagnosis difficult. Here, we report a case of retroperitoneal Castleman’s disease, which radiologically resembled paraspinal schwannoma.Case presentationA 33-year-old Japanese man with epigastric discomfort underwent abdominal ultrasonic examination revealing a solid mass next to the right kidney. Computed tomography demonstrated a well-circumscribed mass with central calcification in the right psoas muscle. Because the mass presented a dumbbell-like shape extending to the intervertebral foramen, neurogenic tumor was suspected. Both iodine-123 metaiodobenzylguanidine and gallium-67 scintigraphies were negative in the mass, whereas thallium-201 mildly accumulated in the tumor, suggesting blood flow to the tumor. Positron emission tomography revealed accumulation of fluorine-18-2-fluoro-2-deoxy-d-glucose in the tumor at a standard uptake value of 4.7, whereas no other abnormal uptake suggestive of metastatic lesion was noted. On the basis of imaging studies, we mostly suspected paraspinal schwannoma, although malignancy was not completely excluded. Angiography showed feeding vessels from the right lumbar arteries, which were embolized with porous gelatin particles in order to reduce intraoperative bleeding. Surgical resection was performed using a retroperitoneal approach, which revealed the tumor in the swollen psoas muscle. Intraoperative pathological examination of a frozen section revealed no evidence of malignancy; thus, marginal excision of the tumor was performed. The tumor adhered tightly to surrounding muscle tissues, resulting in 940 g of intraoperative blood loss. The pathological examination demonstrated infiltration of lymphocytes surrounding small germinal centers with extensive capillary proliferation. Immunostaining revealed that proliferated lymphocytes were CD3-negative and CD79a-positive.ConclusionsAlthough a dumbbell-shaped mass in a paraspinal region is indicative of a schwannoma for orthopedic surgeons, the possibility of Castleman’s disease should be considered if a central low-signal area in fissured and a radial pattern is detected on computed tomography or magnetic resonance imaging. Appropriate preparation for massive bleeding during the treatment of Castleman’s disease, including angiography and embolization, would be helpful for performing surgical procedures safely.

Imaging evaluation of inflammation in the musculoskeletal system: current concepts and perspectives

Inflammation is the non-specific stereotyped reaction of the musculoskeletal system to various types of aggression, such as infection, tumor, autoimmune diseases, or trauma. Precise evaluation and, increasingly, reliable quantification of inflammation are now key factors for optimal patient management, as targeted therapies (e.g., anti-angiogenesis, anti-macrophages, anti-cytokines) are emerging as everyday drugs. In current practice, inflammation is evaluated mostly using MRI and US on the basis of its non-specific extracellular component due to the increased volume of free water. Inflamed tissue is described as areas of low T1 signal and high T2 signal on magnetic resonance imaging or as hypoechogenic areas on ultrasound imaging, and the evaluation of the increased tissue vascularity can be performed using gadolinium-enhanced MRI or power Doppler US. Emerging new imaging tools, regrouped under the label "cellular and molecular imaging" and defined as the in vivo characterization and measurement of biologic processes at the cellular and molecular level, demonstrate the possible shift of medical imaging from a macroscopic and non-specific level to a microscopic and targeted scale. Cellular and molecular imaging now allows the investigation of specific pathways involved in inflammation (e.g., angiogenesis, cell proliferation, and recruitment, proteases generation, metabolism, gene expression). PET and SPECT imaging are the most commonly used "molecular" imaging modalities, but recent progress in MR, US, and optical imaging has been made. In the future, those techniques might enable a detection of inflammation at its very early stage, its quantification through the definition of biomarkers, and possibly demonstrate the response to therapy at molecular and cellular levels.

内リンパ水腫診断における内耳造影MRIの有用性

Gadolinium (Gd) contrast-enhanced MRI has recently been introduced to clinical practice to detect endolymphatic hydrops. However, since the image depends on the hardware, pulse sequence or the way of Gd administration, the protocol and the evaluating criteria for hydrops on MRI have not yet been standardized. In this study, we assessed the usefulness of the hydrops detection by MRI following the intratympanic or intravenous Gd administration methods, and compared these findings with the electrocochleography and glycerol test. MRI was taken in 27 patients with Meniere's disease or delayed endolymphatic hydrops. All patients had frequent episodes of vertigo attacks which were clinically considered as of unilateral ear origin. Two types of Gd administration were used; injection into the tympanic cavity in 17 patients or intravenous injection in 10 patients. Axial 2D-FLAIR images were obtained with a 3.0T MRI unit, 24 and 4 h after intratympanic or intravenous administration, respectively. The endolymphatic space was detected as a low signal intensity area, while the surrounding perilymphatic space showed high intensity with Gd contrast. Those cases in which low signal areas corresponding to the cochlear duct could be clearly noticed, were classified as cochlear hydrops. When the greater part of the vestibule was occupied by a low signal area in more than half of the images, it was classified as vestibular hydrops. Endolymphatic hydrops was detected in 88% (15/17 cases) by the intratympanic Gd administration method, and 90% (9/10) by the intravenous method. In the contralateral ears, 20% (2/10) showed hydrops, detected by the intravenous method. ECochG and the glycerol test were difficult when the hearing of the patient was severely impaired. Positive results of EcochG and the glycerol test were obtained only in 15 and 6 cases, respectively. However, as far as the waves could be obtained, ECochG showed a high detection rate of 88% (15/17) in the affected ear. In those cases in which both MRI and EcochG could be obtained, including both ears, the results were matched in 78% (21/27ears). For the qualitative detection of hydrops, intratympanic and intravenous Gd administration methods were equivalent. Inner ear Gd contrast-enhanced MRI had higher efficacy in the detection of hydrops than the conventional tests.

MR score system on spatium perilymphaticum gadolinium opacification and its application for diagnosis of Meniere's disease

Objective To propose a MR scoring methods for spatium perilymphaticum gadolinium opacification and explore the value of their diagnosis of Meniere' s disease. Methods Fifty-one asymptomatic and 65 symptomatic patients with Meniere's disease were enrolled in this study.MR imaging ofspatium perilymphaticum after intratypanic gadolinium injection were analyzed with following scoring method. ( 1 ) Semicircular canal not visualized equal to score 0 ; some visualized equal score 1 ; full visualized equal score 2.(2)There were high-signal and low-signal in the vestibule,low-signal areas above the lateral semicircular canal plane equal score 6 ; low signal areas down to lateral semicircular canal plane equal score 3 ; no higher signal in the vestibule area equal score 0.( 3 ) Basal turn of cochlea:full visualized equal score 3; part visualized equal score 2; scala vestibule of basal turn smaller than scala tympani equal score 1 regardless of full or visualized in basal turn; no visualized equal score 0. Medial turn of cochlea:full visualized equal score 2 ; part visualized equal score 1 ; no visualized equal score 0.Apical turn of cochlea: visualized equal score 1 ; no visualized equal score 0. One radiologist scored all cases with double blind. SPSS 17.0 software was used to conduct multiple independent-samples nonparametric tests,multivariate Logistic regression, and ROC curve analysis. Evaluate the sensitivity and specificity for diagnosis of Meniere's disease with the scoring system. Results ( 1 ) Meniere's disease summation score 0 to 12,median 9 (quarter spacing 4.5 ) ; no symptoms group summation score 15 to 18,median 17 (quarter spacing 3),two group differences has statistics significance (Wilcoxon rank and inspection U =-9.118,P =0.00).(2)Based on summation score for the diagnosis of Meniere's disease,tangent point was 14.5,Youden index 0.969,specificity 100.0％,sensitivity 96.9％.( 3 ) Let cochlear,vestibular,semicircular canal scoring for association variable,Logistic regression model:LogitP =61.216 - 7.381 × vestibular -3.056 × canal,based on the P value of ROC curves,diagnostic cut-off point 0.651 (vestibular ≤ 3 or semicircular canals ≤ 4 points ),Youden index 96.9％,specifisity 100.0％, sensitivity 96.9％.Conclusions Perilymphatic space of gadolinium contrast MR score in distinguishing Meniere's disease have practical value,any case meet one of following point could be diagnostic:( 1 ) Perilymphatic space of gadolinium contrast MRI total less than 14.5 ; (2) Vestibular low signal areas down more than lateral semicircular canal plane,namely vestibular score value ≤3;( 3 )Semicircular Canal scoring value ≤4. Key words: Magnetic resonance imaging; Ear, inner; Perilymph ; Gadolinium DTPA

Choroidal changes of macular edema with serous macular detachment in non-proliferative diabetic retinopathy patients

[Objective] To observe the choroidal changes of diabetic macular edema (DME) with serous macular detachment (SMD) in non-proliferative diabetic retinopathy (NPDR) patients by optical coherence tomography (OCT),[Methods] Nine NPDR patients including DME with SMD in one eye (SMD group) and only DME in the other eye (DME group) were enrolled.These 18 eyes were also divided into PRP group (six eyes,received panretinal photocoagulation before) and non-PRP group (12 eyes).Spectral domain EDI (enhance depth imaging)-OCT and fundus photograph were performed in all the eyes.The subfoveal choroidal thickness was measured.The choroidal simulation area acquired by horizontal EDI-OCT scan through the center of the foves was calculated by Image Plus Pro 6.0 software.The difference between DME and SMD group was compared and analyzed with matched t test; the difference between PRP and non-PRP group was compared and analyzed with F test.[Results] In SMD group,spindle-like or dome-like low signal of detachment areas with intact external limiting membrane were found in the retinal detachment region,and the inner and outer segments (IS/OS) were separated from the retinal pigment epithelium (RPE)-Bruch membrane.Both subfoveal choroidal thickness and choroidal simulation area in SMD group were significant greater than those in DME group (t=2.306,2.306 ;P＜0.05).Choroidal simulation area in PRP group was larger than that in non-PRP group (F =5.227,P＜0.05).But there was no significant difference of subfoveal choroidal thickness between PRP and non-PRP group (F =3.276,P＞ 0.05).[Conclusion] EDI-OCT detects spindle-like or dome-like low signal areas in detachment region of SMD with DME in NPDR patients. Key words: Diabetic retinopathy/complications; Macular edema/etiology; Tomography, optical coherence; Diagnostic imaging

Cystic changes in desmoplastic fibroma of bone: A new MRI finding

To evaluate the magnetic resonance imaging features of desmoplastic fibroma (DF) of bone. Two radiologists retrospectively evaluated imaging findings of pathologically confirmed DFs in eight patients. Involved sites and longitudinal location in long bones were evaluated using radiography and computed tomography (CT). At MRI, the presence of low signal areas on T2-weighted images (low-T2), enhancement, cystic changes, and locations of the mass were evaluated. The location of masses was evaluated, based on cortical disruption and adjacent soft-tissue extension. Involved sites were the femur in three patients, the tibia in two, and the humerus, fibula, and pubic bone in one each. Of the seven masses in the long bones, three were located in the epi- and metaphysis, two in the meta- and diaphysis, one in the diaphysis, and one in the epiphysis. Seven masses had areas of low T2-weighted or heterogeneous enhancement, and three (38%) showed cystic changes. cortical disruption was seen at MRI in six of eight patients (88%). DFs contained cystic change. Cortical disruption may also occur, which may cause confusion with malignant lesions.

A Leukocyte-Mimetic Magnetic Resonance Imaging Contrast Agent Homes Rapidly to Activated Endothelium and Tracks With Atherosclerotic Lesion Macrophage Content

Endothelial cell activation is an important mediator of monocyte recruitment to sites of vascular inflammation. We hypothesized that high-affinity dual-ligand microparticles of iron oxide (MPIO), targeted to P-selectin and vascular cell adhesion molecule-1 (PV-MPIO), would identify activated endothelial cells during atherosclerosis progression. In vivo magnetic resonance imaging in apolipoprotein E-deficient mice showed rapid binding of PV-MPIO to the aortic root, which was maximal 30 minutes post-MPIO injection and maintained at 60 minutes. Minimal binding was observed for control IgG-MPIO. Intensely low magnetic resonance signal areas, corresponding to PV-MPIO binding, were detected early (14 weeks), during foam cell formation. Contrast effects increased at 20 weeks during fibrofatty lesion development (P<0.05), but reduced by 30 weeks (P<0.01). Across all lesion severities, magnetic resonance imaging contrast effects correlated with lesion macrophage area quantified by immunohistochemistry (R=0.53; P<0.01). Near-infrared fluorescently labeled PV-MPIO were shown, by flow cytometry, to bind only activated endothelial cells and not to macrophages. Using en face immunofluorescence, we further demonstrate selective PV-MPIO accumulation at atherosclerosis-susceptible sites, with minimal binding to atherosclerosis-spared regions. This high-affinity leukocyte-mimetic magnetic resonance imaging agent reveals endothelial activation. PV-MPIO demonstrate exceptionally rapid in vivo steady state accumulation, providing conspicuous magnetic resonance contrast effects that can be objectively quantified. In atherosclerosis progression, PV-MPIO tracked closely with the burden and distribution of plaque macrophages, not merely plaque size. On a biocompatible platform, this approach has potential for quantitative magnetic resonance imaging of inflammatory disease activity.

Simultaneous bilateral hip joint imaging at 7 Tesla using fast transmit B₁ shimming methods and multichannel transmission - a feasibility study.

The objective of this study was to demonstrate the feasibility of simultaneous bilateral hip imaging at 7 Tesla. Hip joint MRI becomes clinically critical since recent advances have made hip arthroscopy an efficacious approach to treat a variety of early hip diseases. The success of these treatments requires a reliable and accurate diagnosis of intraarticular abnormalities at an early stage. Articular cartilage assessment is especially important to guide surgical decisions but is difficult to achieve with current MR methods. Because of gains in tissue contrast and spatial resolution reported at ultra high magnetic fields, there are strong expectations that imaging the hip joint at 7 Tesla will improve diagnostic accuracy. Furthermore, there is growing evidence that the majority of these hip abnormalities occur bilaterally, emphasizing the need for bilateral imaging. However, obtaining high quality images in the human torso, in particular of both hips simultaneously, must overcome a major challenge arising from the damped traveling wave behaviour of RF waves at 7 Tesla that leads to severe inhomogeneities in transmit B1 (B(1) (+) ) phase and magnitude, typically resulting in areas of low signal and contrast, and consequently impairing use for clinical applications. To overcome this problem, a 16-channel stripline transceiver RF coil was used, together with a B1 shimming algorithm aiming at maximizing B(1) (+) in six regions of interest over the hips that were identified on axial scout images. Our successful results demonstrate that this approach effectively reduces inhomogeneities observed before B1 shimming and provides high joint tissue contrast in both hips while reducing the required RF power. Critical to this success was a fast small flip angle B(1) (+) calibration scan that permitted the computation of subject-specific B1 shimming solutions, a necessary step to account for large spatial variations in B(1) (+) phase observed in different subjects.

Therapeutic effect of transplanting magnetically labeled bone marrow stromal stem cells in a liver injury rat model with 70%-hepatectomy

SummaryBackgroundThere are only few reports about the use of bone marrow stromal stem cells (BMSCs) for the treatment of traumatic liver injury. This study aimed to study the therapeutic effect of fluorescence-labeled BMSCs administered to rats subject to traumatic liver injury.Material/MethodsMale SD rats with a 70% resection of the liver were injected with feridex-labeled BMSCs which could be induced to functional hepatocytes in vitro. Liver function was assayed and the liver scanned by 1.5-T MRI at 12 hrs and on days 1, 3, 5, 7, and 14 post-operation. The pathological changes of liver sections were monitored.ResultsThe serum levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, direct bilirubin, and total bilirubin in the transplantation group were significantly lower than the control group. The MRI showed rats of the transplantation group had an oval low signal area at 12 hr after operation; the low signal range gradually expanded and the signal intensity gradually decreased over 14 days after operation. The low signal range in the control group disappeared 12 hr after the operation. After Prussian blue staining, rats of the transplantation group contained blue granules with no significant hypertrophy or edema in hepatocytes, while the control group showed no blue granules with significant hypertrophy and edema.ConclusionsThe BMSCs transplanted into the injured rat liver gradually migrate to the surrounding liver tissue and partially repair the liver surgical injury in rats. BMSCs may represent an effective therapeutic approach for acute liver injury.

Transplantation of genetically engineered cell lines into hippocampus in rat epileptic model induced by pilocarpine

Objective Transplant genetically engineered cell lines to synthesize and release GABA by immortalized neural progenitor cells (INPCs) in rats, can survive and differentiate in the hippocampus in the epileptic rats model induced by pilocarpine, have ability to suppress spontaneous seizures. Methods The INPCs were transfected with the GABA-synthesizing enzyme GAD (65) cDNA( INPCs-GAD65), Labeled INPCs-GAD65 with superparamagnetic iron oxide (SPIO), SPIO-labeled cells were tracked with 1.5T MRI scanner in vivo; Behavior were monitored for 6 days after surgery;The change examined with the electroencephalogram recording;The differentiation of transplanted cells was observed with immunohisochemistry. Results Animals that received genetically engineered GABA-producing cells had significantly fewer spontaneous seizures than did that the control animals, Epileptiform spikes was suppressed significantly in the electroencephalogram recording; 1.5 Tesia MRI in vivo displayed that remarkable low signal area on T2WI was seen in the fight brain which transplanted with SPIO-labeled cells. SV40Tag-positive cell can change into neurons and astrocytes in the hippocampus. Conclusion These data demonstrate that genetically engineered cells could suppress spontaneous seizures in an accepted model of temporal lobe epilepsy. This is an important step toward defining a clinical potential for this approach in epilepsy. Key words: Epilepsy; Neural progenitor cells; Transplantation; GAD65

Orthopaedic Case of the Month: Painful Lower-leg Mass in a 76-year-old Man

Orthopaedic Case of the Month: Painful Lower-leg Mass in a 76-year-old Man

Inflammatory pseudotumors of the head and neck in pathology-proven cases

The purpose of this case series is to characterize the CT and MRI features of pathology-proven inflammatory pseudotumors in the head and neck. Our search identified three orbital, one maxillary sinus, and one skull base inflammatory pseudotumor. All of the lesions demonstrated some degree of infiltrative features on imaging. On CT, all of the orbital inflammatory pseudotumors were of homogeneous soft tissue density. One of the orbital inflammatory pseudotumors demonstrated bone erosion and two others demonstrated stranding of the orbital fat. The maxillary sinus lesion initially appeared aggressive with bone erosion and orbital invasion. Calcifications were identified in the dural inflammatory pseudotumor. Among the lesions that were given contrast during CT or MRI. All exhibited some degree of enhancement. The two pseudotumors that underwent MRI were isointense on T1 and T2, with scattered areas of low signal. The orbital inflammatory pseudotumors underwent orbitotomy. However, the maxillary sinus and skull base lesions regressed with steroid therapy. Inflammatory pseudotumors of the head and neck regions typically manifest as enhancing soft tissue masses associated with infiltrative changes. Despite their sometimes-aggressive appearance, these lesions may respond well to steroid treatment. Imaging plays an important role in diagnosing and following inflammatory pseudotumors.