Comparative Effectiveness of Tacrolimus and Infliximab in Hospitalized Patients With Ulcerative Colitis.

INTRODUCTION: Cyclosporine or infliximab (IFX) have been used to avoid surgery in patients with severe refractory ulcerative colitis (UC). Tacrolimus (Tac) is occasionally used as an alternative to cyclosporine; however, the comparative efficacy of Tac and IFX has not been reported. We aimed to compare the effectiveness of Tac and IFX in hospitalized patients with UC. METHODS: In a propensity score-matched cohort derived from a large nationwide database, 4-year effectiveness was compared between patients initiated on Tac and those initiated on IFX. The primary outcome was the colectomy rate during the index hospitalization. We also analyzed the cumulative medication discontinuation, UC-related rehospitalization, and colectomy rates after discharge. RESULTS: Among 29,239 hospitalized patients, 4,565 were extracted for eligibility, of whom 2,170 were treated with Tac and the remaining 2,395 with IFX. After propensity score matching, 1,787 patients were selected for each group. During the index hospitalization, excluding patients who switched to another molecular-targeted agent, the colectomy rate was higher in the Tac group than in the IFX group (7.8% vs 4.2%, P < 0.01). Among patients discharged without colectomy, the cumulative medication discontinuation (28.4% vs 17.1%, P < 0.01) and rehospitalization (22.4% vs 15.4%, P < 0.01) rates were higher in the Tac group than in the IFX group; however, there was no difference in the cumulative colectomy rate (3.3% vs 2.7%). DISCUSSION: Although Tac and IFX were effective for avoiding surgery in hospitalized patients with UC, IFX was more effective than Tac. IFX also had higher long-term effectiveness. Future prospective studies comparing the efficacy of Tac and IFX are warranted.

Three-dimensional vessel wall imaging with 1.5-T MRI to visualize invisible occluded cerebral artery.

BACKGROUND: Endovascular thrombectomy (EVT) is performed for acute ischemic stroke (AIS) caused by large vessel occlusion; therefore, preoperative visualization of the occluded invisible vessel course reduces complications and ensures success. Three-dimensional (3D) proton density-weighted (PDW) vessel wall imaging (VWI) using variable refocusing flip angle pulse-turbo spin-echo sequences (VRFA-TSE) with 3.0-T magnetic resonance imaging (MRI) can provide this information. PURPOSE: To assess the effectiveness of 3D PDW-VWI using 1.5-T MRI without VRFA function. MATERIAL AND METHODS: Five consecutive patients with AIS caused by large vessel occlusion underwent EVT in our institute. VWI with 1.5-T MRI using 3D PDW-fast spin echo (FSE) technique was added to conventional brain imaging. RESULTS: PDW-FSE was successfully performed in all cases. 3D PDW-FSE was useful to visualize both the anterior and posterior circulations by clearly revealing invisible vessels but could not demonstrate the length and size of the clot in all five cases. CONCLUSION: 3D PDW-FSE with 1.5-T MRI without VRFA could clearly depict the course of the invisible occluded artery and might support favorable outcomes after EVT in patients with AIS.

Reduced antiviral seropositivity among patients with inflammatory bowel disease treated with immunosuppressive agents.

BACKGROUND: Although live-attenuated vaccines are contraindicated under immunosuppression, the immune status of patients with inflammatory bowel disease (IBD) has not been fully assessed prior to immunosuppressive therapy. AIMS: To investigate antiviral serostatus against viruses requiring live vaccines for prevention in IBD patients undergoing immunosuppressive therapy. METHODS: This multicenter study included IBD patients who were aged <40 years and were treated with thiopurine monotherapy, molecular-targeted monotherapy, or combination therapy. Gender- and age-matched healthy subjects (HS) living in the same areas were included as control group. Antibody titers against measles, rubella, mumps, and varicella were measured by enzyme-linked immunosorbent assays. RESULTS: A total of 437 IBD patients (163 ulcerative colitis [UC] and 274 Crohn's disease [CD]) and 225 HS were included in the final analysis. Compared with HS, IBD patients had lower seropositivity rates for measles (IBD vs. HS = 83.91% vs. 85.33%), rubella (77.55% vs. 84.89%), mumps (37.50% vs. 37.78%), and varicella (91.26% vs. 96.44%). Gender- and age-adjusted seropositivity rates were lower in UC patients than in both CD patients and HS for measles (UC, CD, and HS = 81.60%, 85.29%, and 85.33%), rubella (76.40%, 78.23%, and 84.89%), mumps (27.16%, 43.70%, and 37.78%), and varicella (90.80%, 91.54%, and 96.44%); the difference was significant for all viruses except measles. Divided by the degree of immunosuppression, there were no significant differences in seropositivity rates among IBD patients. CONCLUSIONS: IBD patients, especially those with UC, exhibit reduced seropositivity rates and may benefit from screening prior to the initiation of immunosuppressive therapy.

Long-term effectiveness of ustekinumab comparable to antitumor necrosis factor agents in patients with Crohn's disease.

BACKGROUND: Ustekinumab (UST), an antibody against the p40 subunit of interleukin-12/23, has been proven to be effective in patients with Crohn's disease (CD). However, large, long-term comparative studies of UST against anti--tumor necrosis factor (TNF) agents are lacking. We compared the effectiveness of anti-TNF agents and UST in CD patients without prior use of biologics. METHODS: We used a large nationwide anonymized Japanese database containing administrative medical claims data and various related patient data. In a propensity score-matched cohort with similar clinical characteristics, 2-year effectiveness was compared between patients treated with infliximab or adalimumab (anti-TNF group) and those treated with UST (UST group). Primary outcomes were cumulative rates of hospitalization, surgery, and persistence. RESULTS: Among 53 540 CD patients, 7047 were extracted for eligibility, of which 5665 were treated with an anti-TNF agent and 1382 with UST. After propensity score matching, the cumulative hospitalization rates were comparable between anti-TNF and UST groups (P = 0.85; 25.3% vs 26.5% at 1 year, 33.8% vs 39.8% at 2 years). The cumulative surgery rates were also comparable between these groups (P = 0.46; 5.5% vs 5.1% at 1 year, 8.3% vs 8.4% at 2 years). The persistence rate at 1 year was higher in UST group (90.8% vs 92.5%), and that at 2 years was higher in anti-TNF group (81.2% and 74.6%); however, there was no significant difference in the cumulative persistence rate (P = 0.55). CONCLUSIONS: Anti-TNF agents and UST appear to have comparable effectiveness for CD patients without prior use of biologics.

Prolonged Diarrhea Following COVID-19 Vaccination: A Case Report and Literature Review.

Vaccination against coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is currently underway across countries worldwide. However, the prevalence and characteristics of prolonged adverse events lasting for several months after receiving the vaccine remain largely unknown. We herein report a 46-year-old woman with prolonged diarrhea and vomiting after receiving the BNT162b2 mRNA vaccine for COVID-19. She had no notable medical history, including that of gastrointestinal diseases. She developed vomiting several hours after receiving the first vaccine dose and further developed severe diarrhea after 7 days. Several days after the second vaccine dose, her condition deteriorated, unrelieved by symptomatic therapies, including anti-diarrheal drugs. Abdominal computed tomography (CT) revealed inflammatory changes in the entire segment of the small intestine with wall thickening. The upper and lower gastrointestinal and capsule endoscopies were unremarkable. The patient's symptoms persisted for more than 6 months after the second vaccine dose. A Vaccine Adverse Event Reporting System (VAERS) database search suggested that diarrhea is observed in approximately 3% of all vaccine recipients, but a literature review indicated that prolonged gastrointestinal symptoms lasting for several months is very rare. In summary, a case of prolonged unexplained gastrointestinal symptoms, possibly based on inflammatory changes in the small intestine, is described. A literature search revealed that this type of manifestation is very rare, and further evidence is needed to determine the causality between vaccination and gastrointestinal symptoms.

Ulcerative colitis-related postoperative enteritis treated with anti-tumor necrosis factor therapy: two case reports and a literature review.

Several case reports have described severe postoperative enteritis shortly after total colectomy for ulcerative colitis. The very low incidence of this condition makes diagnosis and treatment difficult, and the appropriate treatment strategy is unclear. We report two cases of enteritis after surgery for ulcerative colitis, which were treated with anti-tumor necrosis factor-α therapy. Case 1 involved a 22-year-old man with symptoms, such as nausea 40 days after total colectomy. Gastrointestinal endoscopy revealed patchy obliteration of the vascular pattern, erosions in the duodenum, and superficial ulcers in the small intestine. His symptoms and endoscopic findings immediately improved upon administration of infliximab; clinical remission lasted 5 years with continuous administration. Case 2 involved a 64-year-old man, who had a large amount of watery diarrhea from ileostomy that increased 5 days after total colectomy; gastrointestinal endoscopy revealed extensive ulcers in the small intestine. Symptoms and endoscopic findings improved with prednisolone, but relapsed with tapering of the corticosteroid. Administration of adalimumab resulted in marked improvement of enteritis. However, the small intestine developed a pinhole stricture, and partial resection of the small intestine was performed. Our experience with two cases indicates that anti-tumor necrosis factor-α therapy may play an important role in ulcerative colitis-related postoperative enteritis.

Presynaptic inhibition of dopamine neurons controls optimistic bias.

Regulation of reward signaling in the brain is critical for appropriate judgement of the environment and self. In Drosophila, the protocerebral anterior medial (PAM) cluster dopamine neurons mediate reward signals. Here, we show that localized inhibitory input to the presynaptic terminals of the PAM neurons titrates olfactory reward memory and controls memory specificity. The inhibitory regulation was mediated by metabotropic gamma-aminobutyric acid (GABA) receptors clustered in presynaptic microdomain of the PAM boutons. Cell type-specific silencing the GABA receptors enhanced memory by augmenting internal reward signals. Strikingly, the disruption of GABA signaling reduced memory specificity to the rewarded odor by changing local odor representations in the presynaptic terminals of the PAM neurons. The inhibitory microcircuit of the dopamine neurons is thus crucial for both reward values and memory specificity. Maladaptive presynaptic regulation causes optimistic cognitive bias.

Neurochemical Organization of the Drosophila Brain Visualized by Endogenously Tagged Neurotransmitter Receptors.

Neurotransmitters often have multiple receptors that induce distinct responses in receiving cells. Expression and localization of neurotransmitter receptors in individual neurons are therefore critical for understanding the operation of neural circuits. Here we describe a comprehensive library of reporter strains in which a convertible T2A-GAL4 cassette is inserted into endogenous neurotransmitter receptor genes of Drosophila. Using this library, we profile the expression of 75 neurotransmitter receptors in the brain. Cluster analysis reveals neurochemical segmentation of the brain, distinguishing higher brain centers from the rest. By recombinase-mediated cassette exchange, we convert T2A-GAL4 into split-GFP and Tango to visualize subcellular localization and activation of dopamine receptors in specific cell types. This reveals striking differences in their subcellular localization, which may underlie the distinct cellular responses to dopamine in different behavioral contexts. Our resources thus provide a versatile toolkit for dissecting the cellular organization and function of neurotransmitter systems in the fly brain.

Tango knock-ins visualize endogenous activity of G protein-coupled receptors in Drosophila.

G protein-coupled receptors (GPCRs) represent a family of seven-pass transmembrane protein receptors whose ligands include neuropeptides and small-molecule neuromodulators such as dopamine and serotonin. These neurotransmitters act at long distances and are proposed to define the ground state of the nervous system. The Drosophila genome encodes approximately 50 neuropeptides and their functions in physiology and behavior are now under intensive studies. Key information currently lacking in the field is the spatiotemporal activation patterns of endogenous GPCRs. Here we report application of the Tango system, a reporter assay to detect GPCR activity, to endogenous GPCRs in the fly genome. We developed a method to integrate the sensor component of the Tango system to the C-terminus of endogenous genes by using genome editing techniques. We demonstrate that Tango sensors in the Sex-peptide receptor (SPR) locus allow sensitive detection of mating-dependent SPR activity in the female reproductive organ. The method is easily applicable to any GPCR and will provide a way to systematically characterize GPCRs in the fly brain.

Effect of a dietary supplement on peri-implant bone strength in a rat model of osteoporosis.

PURPOSE: Osteoporosis contributes to impaired bone regeneration and remodeling through an imbalance of osteoblastic and osteoclastic activity, and can delay peri-implant bone formation after dental implant surgery, resulting in a prolonged treatment period. It poses several difficulties for individuals with large edentulous areas, and decreases their quality of life. Consequently, prompt postoperative placement of the final prosthesis is very important clinically. Peri-implant bone formation may be enhanced by systemic approaches, such as the use of osteoporosis supplements, to promote bone metabolism. We aimed to confirm whether intake of synthetic bone mineral (SBM), a supplement developed for osteoporosis, could effectively accelerate peri-implant bone formation in a rat model of osteoporosis. METHODS: Thirty-six 7-week-old ovariectomized female Wistar rats were randomly assigned to receive a standardized diet with or without SBM (Diet with SBM group and Diet without SBM group, respectively; n=18 for both). The rats underwent implant surgery at 9 weeks of age under general anesthesia. The main outcome measures, bone mineral density (BMD) and pull-out strength of the implant from the femur, were compared at 2 and 4 weeks after implantation using the Mann-Whitney U test. RESULTS: Pull-out strength and BMD in the Diet with SBM group were significantly greater than those in the Diet without SBM group at 2 and 4 weeks after implantation. CONCLUSIONS: This study demonstrated that SBM could be effective in accelerating peri-implant bone formation in osteoporosis.

Improved Bone Micro Architecture Healing Time after Implant Surgery in an Ovariectomized Rat.

The present animal study investigated whether oral intake of synthetic bone mineral (SBM) improves peri-implant bone formation and bone micro architecture (BMA). SBM was used as an intervention experimental diet and AIN-93M was used as a control. The SBM was prepared by mixing dicalcium phosphate dihydrate (CaHPO4·2H2O) and magnesium and zinc chlorides (MgCl2 and ZnCl2, respectively), and hydrolyzed in double-distilled water containing dissolved potassium carbonate and sodium fluoride. All rats were randomly allocated into one of two groups: a control group was fed without SBM (n = 18) or an experimental group was fed with SBM (n = 18), at seven weeks old. At 9 weeks old, all rats underwent implant surgery on their femurs under general anesthesia. The implant was inserted into the insertion socket prepared at rats' femur to a depth of 2.5 mm by using a drill at 500 rpm. Nine rats in each group were randomly selected and euthanized at 2 weeks after implantation. The remaining nine rats in each group continued their diets, and were euthanized in the same manner at 4 weeks after implantation. The femur, including the implant, was removed from the body and implant was pulled out by an Instron universal testing machine. After the implant removal, BMA was evaluated by bone surface ratio (BS/BV), bone volume fraction (BV/TV), trabecular thickness (TbTh), trabecular number (TbN), trabecular star volume (Vtr), and micro-CT images. BS/BV, BV/TV, TbTh and Vtr were significantly greater in the rats were fed with SBM than those were fed without SBM at 2 and 4 weeks after implantation (P < 0.05). The present results revealed that SBM improves the peri-implant formation and BMA, prominent with trabecular bone structure. The effect of SBM to improve secondary stability of the implant, and shortening the treatment period should be investigated in the future study.

Direct monitoring of bias-dependent variations in the exciton formation ratio of working organic light emitting diodes.

In typical operation of organic light emitting diodes (OLEDs), excitons are assumed to generate with a ratio of 1:3 for singlet and triplet excitons, respectively, based on a simple spin statistics model. This assumption has been used in designing efficient OLEDs. Despite the larger generation ratio of triplet excitons, physical properties of fluorescent OLEDs are usually evaluated only through the electroluminescence (EL) intensity from singlets and the behaviors of triplets during the LED operation are virtually black-boxed, because the triplets are mostly non-emissive. Here, we employ transient spectroscopy combined with LED-operation for directly monitoring the non-emissive triplets of working OLEDs. The spectroscopic techniques are performed simultaneously with EL- and current measurements under various operation biases. The simultaneous measurements reveal that the relative formation ratio of singlet-to-triplet excitons dramatically changes with the magnitude of bias. The measurements also show that the generation efficiency of singlets scales with the bias, whereas that of triplets is nearly bias-independent. These features of the formation ratio and efficiency are compatibly explained by considering the yield of intersystem crossing and the energy separation of excitons from electron-hole pairs. The obtained findings via the spectroscopic measurements enable prediction of the formation pathways in OLEDs.

Two adult cases of extralobar pulmonary sequestration: A non-complicated case and a necrotic case with torsion.

BACKGROUND: This case report describes two cases of extralobar pulmonary sequestration in adults with and without torsion/necrosis. CASE REPORTS: Non-complicated extralobar pulmonary sequestration was found incidentally in a 50-year-old asymptomatic woman (Case 1), diagnosed with the presence of a branching structure in a mass lesion and blood supply from the right inferior phrenic artery. Another case of a 38-year-old woman presented with a sudden onset of back pain caused by extralobar pulmonary sequestration with torsion/necrosis (Case 2). A 4-cm fusiform mass in the paravertebral region showed enhancement in the peripheral rim only, and no feeding artery. These were the same as it had been reported typical findings in extralobar pulmonary sequestration with necrosis. On magnetic resonance imaging, the masses in both cases showed inhomogeneous low signal and branching high signal on T2-weighted images. That was characteristic for a stroma without dilated alveoli as a solid part and dilated alveoli as fluid regions. CONCLUSIONS: By comparing those two cases, we came to a conclusion that only T2-weighted imaging reflects the native structure, even after infarction. Although differentiation from a cystic tumor with hemorrhage or infection can be problematic, inhomogeneous low signal and branching high signal on T2-weighted images may help us distinguish extralobar pulmonary sequestration from other cystic lesions.

An automatic system using mobile-agent software to model the calculation process of a chemical vapor deposition film deposition simulator.

We have developed an automatic modeling system for calculation processes of the simulator to reproduce experimental results of chemical vapor deposition (CVD), in order to decrease the calculation cost of the simulator. Replacing the simulator by the mathematical models proposed by the system will contribute towards decreasing the calculation costs for predicting the experimental results. The system consists of a mobile agent and two software resources in computer networks, that is, generalized modeling software and a simulator reproducing cross-sections of the deposited films on the substrates with the micrometer- or nanometer-sized trenches. The mobile agent autonomously creates appropriate models by moving to and then operating the software resources. The models are calculated by partial least squares regression (PLS), quadratic PLS (QPLS) and error back propagation (BP) methods using artificial neural networks (ANN) and expresses by mathematical formulas to reproduce the calculated results of the simulator. The models show good reproducibility and predictability both for uniformity and filling properties of the films calculated by the simulator. The models using the BP method yield the best performance. The filling property data are more suitable to modeling than film uniformity.

An automatic modeling system of the reaction mechanisms for chemical vapor deposition processes using real-coded genetic algorithms.

The identification of appropriate reaction models is very helpful for developing chemical vapor deposition (CVD) processes. In this study, we have developed an automatic system to model reaction mechanisms in the CVD processes by analyzing the experimental results, which are cross-sectional shapes of the deposited films on substrates with micrometer- or nanometer-sized trenches. We designed the inference engine to model the reaction mechanism in the system by the use of real-coded genetic algorithms (RCGAs). We studied the dependence of the system performance on two methods using simple genetic algorithms (SGAs) and the RCGAs; the one involves the conventional GA operators and the other involves the blend crossover operator (BLX-alpha). Although we demonstrated that the systems using both the methods could successfully model the reaction mechanisms, the RCGAs showed the better performance with respect to the accuracy and the calculation cost for identifying the models.

Ectopic posterior pituitary high signal in preoperative and postoperative macroadenomas: dynamic MR imaging.

BACKGROUND AND PURPOSE: In patients with macroadenoma, posterior pituitary high signal (PPHS) on T1-weighted magnetic resonance (MR) imaging is sometimes observed in an ectopic location. The present study compared incidences of ectopic PPHS before and after macroadenoma surgery using MR imaging, including dynamic MR imaging to ascertain whether this ectopic change is irreversible. MATERIALS AND METHODS: MR imaging was performed preoperatively in 111 cases of macroadenoma, and then repeated more than 1-year postoperatively in 47 patients. Enhancement of PPHS was assessed using dynamic MR imaging. Areas of enhanced hyperintensity were considered true PPHS, and the relationship between presence and location of true PPHS and adenoma volume was analyzed. Moreover, changes in the presence and location of true PPHS were ascertained among the patients who underwent postoperative follow-up MR imaging. RESULTS: Preoperatively, PPHS was seen only in the normal location in 29 patients (Group A: 26.1%). High signal was detected only in an ectopic location in 58 patients, and early enhancement of this ectopic high signal was confirmed by dynamic MR imaging in 56 patients (Group B: 50.5%). No PPHS was observed in 24 patients (Group C: 21.6%). Adenoma volume was significantly greater for Group B than for Group A (p<0.001). Among the Group B patients who underwent MR imaging postoperatively (n=31), the location of PPHS was not changed, except for two patients in whom PPHS was absent. Postoperatively, PPHS was not observed in the normal location in any patient in the Group B. CONCLUSIONS: Greater volume of adenoma is associated with a higher incidence of ectopic PPHS, and the ectopic change is irreversible.

Age-related signal intensity changes in the corpus callosum: assessment with three orthogonal FLAIR images.

The presence of age-related hyperintensities of the corpus callosum has not been thoroughly evaluated. Fifty-two patients of 50 years of age or older (mean, 71 years; range, 50-87 years) were included in this study. Fluid-attenuated inversion recovery images were obtained in three orthogonal planes. Periventricular hyperintensities (PVHs) and deep white matter hyperintensities (DWMHs) were graded according to Fazekas' rating scale. Correlations between the presence of hyperintensities in the corpus callosum and age, and the grade of PVH and DWMH were statistically analyzed. PVH was categorized as grade 0 (n=4), grade 1 (n=28), grade 2 (n=10), or grade 3 (n=10). DWMH was categorized as grade 0 (n=4), grade 1 (n=25), grade 2 (n=8), or grade 3 (n=15). Hyperintensity was considered present in the corpus callosum in 31 of the 52 patients (60%). In these 31 patients, PVH was categorized as grade 1 (n=16), grade 2 (n=7), or grade 3 (n=8), while DWMH was categorized as grade 0 (n=1), grade 1 (n=10), grade 2 (n=7), or grade 3 (n=13). The presence of callosal hyperintensities was significantly correlated with age (p=0.001), and with PVH (p=0.04) and DWMH grades (p=0.004). Hyperintensities may be present in the corpus callosum with aging, and are correlated with PVH and DWMH.

Dynamic MR imaging in Tolosa-Hunt syndrome.

OBJECTIVE: To evaluate the cavernous sinuses with dynamic magnetic resonance (MR) imaging in patients with Tolosa-Hunt syndrome (THS). METHODS: The sellar and parasellar regions of five patients with THS and 12 control subjects were examined with dynamic MR (1.5 T) imaging in the coronal plane. Dynamic images were obtained with spin-echo (SE) sequences in three patients, and with fast spin-echo (FSE) sequences in two patients and control subjects. Conventional MR images of the cranium including sellar and parasellar regions were also obtained on T1-weighted pre- and post-contrast SE, and T2-weighted FSE sequences in the coronal plane. RESULTS: MR images revealed affected cavernous sinus with bulged convex lateral wall in three patients and concave lateral wall in two patients. In all control subjects, cavernous sinuses were observed with concave lateral wall. The signal intensity on T1- and T2-weighted images and contrast enhancement on post-contrast images of the affected cavernous sinuses in patients were similar to those of the unaffected cavernous sinuses in patients and control subjects. The dynamic images in all patients disclosed small areas adjacent to the cranial nerve filling-defects within the enhanced venous spaces of the affected cavernous sinus, which showed slow and gradual enhancement from the early to the late dynamic images. No such gradually enhancing area was observed in control subjects except one. The follow-up dynamic MR images after corticosteroid therapy revealed complete resolution of the gradually enhancing areas in the previously affected cavernous sinus. CONCLUSION: Dynamic MR imaging may facilitate the diagnosis of THS.

MRI and CT findings of neurohypophyseal germinoma.

OBJECTIVE: Magnetic resonance (MR) imaging and computed tomography (CT) findings of neurohypophyseal germinoma have not previously been described in detail. The purpose of the present study was to establish the spectrum of MR imaging and CT findings in neurohypophyseal germinomas. MATERIALS AND METHODS: MR and CT images of 13 consecutive patients (seven males, six females; mean age: 15 years; range: 6-31 years) with neurohypophyseal germinoma were retrospectively analyzed. The diagnosis had been made either histologically (n=8) or clinically according to established criteria (n=5). All patients had been examined using MR imaging and CT before treatment. RESULTS: On MR imaging, infundibular thickening (up to 16 mm) was observed in all 13 cases. Hyperintensity of the posterior pituitary on T1-weighted image was absent in all 13 cases (100%) and 12 of the 13 displayed central diabetes insipidus. Ten germinomas (77%) were isointense to cerebral cortex on T1-weighted image, but variable intensities were exhibited on T2-weighted image. MR images revealed intratumoral cysts in six cases (46%), most of which demonstrated intra-third ventricular extension. Eleven of the 13 cases (85%) revealed hyperdense solid components on unenhanced CT. Calcification was absent in all cases (100%). CONCLUSION: Infundibular thickening, absence of the posterior pituitary high signal on T1-weighted image, lack of calcification and hyperdensity on unenhanced CT are common imaging features of neurohypophyseal germinoma.

MR contrast of ferritin and hemosiderin in the brain: comparison among gradient-echo, conventional spin-echo and fast spin-echo sequences.

OBJECTIVE: To compare the magnetic resonance image contrasts due to ferritin and hemosiderin in the brain tissue among different pulse sequences. MATERIALS AND METHODS: Fourteen patients with cavernous hemangioma in the brain prospectively underwent MR imaging with T2*-weighted gradient-echo (GRE), T2-weighted conventional spin-echo (SE) and fast spin-echo (FSE) sequences. The relative contrast ratios (CRs) of the hypointense part of cavernous hemangioma, globus pallidus and putamen to the deep frontal white matter were measured on each pulse sequence and statistically analyzed using analysis of variance followed by paired t-test. RESULTS: In the hypointense part of cavernous hemangioma, relative CRs were significantly lower on T2*-weighted GRE than on T2-weighted SE images (P=0.0001), and on T2-weighted SE than on T2-weighted FSE images (P=0.0001). In the globus pallidus, relative CRs were significantly lower on T2-weighted SE than on T2*-weighted GRE images (P=0.002), and on T2*-weighted GRE than on T2-weighted FSE images (P=0.0002). In the putamen, relative CRs were significantly lower on T2-weighted SE than on T2*-weighted GRE images (P=0.001), and there was no significant difference between CRs on T2-weighted FSE and T2*-weighted GRE images (P=0.90). CONCLUSION: Hemosiderin showed best image contrast on T2*-weighted GRE images but ferritin showed more prominent image contrast on T2-weighted SE than on T2*-weighted GRE images, which may help to determine an appropriate pulse sequence in neurological diseases associated with excessive ferritin accumulation.