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To investigate whether the neurocognitive function at 4 months could be a relevant primary endpoint in clinical trials dealing with brain metastases, we created a Japanese neurocognitive battery and examined the changes in patients' neurocognitive function for 1 year after their brain radiotherapy. In this prospective pilot study, we enrolled 27 patients (20 patients who received whole-brain radiation therapy [WBRT] and seven who received stereotactic irradiation [STI] alone) between March 2009 and December 2010. The follow-up neurocognitive data at 4, 8 and 12 months were available in 22 (17 WBRT, 5 STI), 19 patients (14 WBRT, 5 STI) and 13 patients (9 WBRT, 4 STI), respectively. Among the patients who received WBRT, significant deterioration in delayed memory compared to the baseline (p = 0.04) was observed at 4 months, and at 8 months, significant improvements were observed in immediate memory compared to the baseline (p = 0.008) and 4-months scores (p = 0.005). At 12 months, however, the immediate memory scores had returned to the baseline. Similar trends were observed in other functions (delayed memory, attention and executive functions). In these patients, the correlations between 4-months scores of neurocognitive functions and 12-months scores were significant in immediate memory (γ = 0.68, p = 0.004), delayed memory (γ = 0.738, p = 0.023) and attention (γ = 0.817, p = 0.007). Among the patients who received STI, no significant changes were observed in any functions. These results suggest that 4-months changes in neurocognitive functions were transient but could also be a premonitory index for predicting the neurocognitive function 1 year or later after brain radiation therapy.

Diffusion tensor imaging (DTI) is considered to be able to non-invasively quantify white matter integrity. This study aimed to use DTI to evaluate white matter integrity in non-geriatric patients with major depressive disorder (MDD) who were free of antidepressant medication. DTI was performed on 19 non-geriatric patients with MDD, free of antidepressant medication, and 19 age-matched healthy subjects. Voxel-based and histogram analyses were used to compare fractional anisotropy (FA) and mean diffusivity (MD) values between the two groups, using two-sample t tests. The abnormal DTI indices, if any, were tested for correlation with disease duration and severity, using Pearson product-moment correlation analysis. Voxel-based analysis showed clusters with FA decrease at the bilateral frontal white matter, anterior limbs of internal capsule, cerebellum, left putamen and right thalamus of the patients. Histogram analysis revealed lower peak position of FA histograms in the patients. FA values of the abnormal clusters and peak positions of FA histograms of the patients exhibited moderate correlation with disease duration and severity. These results suggest the implication of frontal-subcortical circuits and cerebellum in MDD, and the potential utility of FA in evaluation of brain parenchymal integrity. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

Background: Vulnerable and inflamed plaques in the carotid artery are at high risk of ischemic stroke, suggesting the importance of diagnostic modalities to detect them in patients with carotid stenosis with high sensitivity and specificity. Although many investigators have reported that magnetic resonance imaging (MRI) is a useful tool to predict the vulnerable components of carotid plaque, its validity is not established. On the other hand, 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) may be an alternative modality to directly identify the inflamed plaque in carotid artery stenosis. Therefore, this study aimed at evaluating the validity of MRI and FDG-PET to predict vulnerable and inflamed carotid plaque. Methods: This prospective study totally included 25 patients who underwent carotid endarterectomy (CEA) for carotid artery stenosis at our institute between January 2009 and January 2012. Prior to CEA, FDG-PET, black-blood T1-weighted imaging (BB-T1WI), and 3-dimensional time-of-flight (TOF) imaging were performed. The specimens were stained with hematoxylin-eosin to assess the different plaque components (lipid, hemorrhage, calcification, and fibrous tissue). In addition, they were stained with primary antibodies against CD68 (activated macrophages) and matrix metalloproteinase (MMP)-9. Results: High FDG uptake was detected in 13 (52.0%) of 25 patients. All of them had lipid-rich plaque. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) to identify the lipid-rich plaques were all 100% for FDG-PET. More importantly, all of the FDG-positive plaques had strong immunoreactivity against both CD68 and MMP-9. There was a significant correlation between the findings on FDG-PET and those on immunohistochemistry against CD68 and MMP-9 (p = 0.006 and 0.004, respectively). On the other hand, 16 (64.0%) of 25 patients had high signal intensity plaque on BB-T1WI. In 7 of these 16 patients, the lesions also showed high signal intensity on TOF imaging. All of them had a large intraplaque hemorrhage. The sensitivity, specificity, PPV, and NPV to identify a large intraplaque hemorrhage were 70, 100, 100, and 83%, respectively, for MRI. Conclusions: These findings suggest that FDG-PET and MRI are complementary to predict high-risk carotid plaque, such as lipid-rich or hemorrhagic plaque. FDG-PET can accurately predict the lipid-rich and inflamed plaque. MRI is valuable to identify unstable plaque with a large intraplaque hemorrhage. The combination of these two modalities may play an important role in predicting carotid plaque at high risk of ischemic stroke.

Purpose: To evaluate the speed and precision of split renal volume (SRV) measurement (SRV), which is the ratio of unilateral renal volume to bilateral renal volume, using a newly developed software for computed tomographic (CT) volumetry and to investigate the usefulness of SRV for the estimation of split renal function (SRF) in kidney donors. Method: Both dynamic CT and renal scintigraphy in 28 adult potential living renal donors were the subjects of this study. We calculated SRV using the newly developed volumetric software built into a PACS viewer (n-SRV), and compared it with SRV calculated using a conventional workstation, ZIOSOFT (z-SRV). The correlation with split renal function (SRF) using 99mTc-DMSA scintigraphy was also investigated. Results: The time required for volumetry of bilateral kidneys with the newly developed software (16.7 ± 3.9 sec) was significantly shorter than that of the workstation (102.6 ± 38.9 sec, p < 0.0001). The results of n-SRV (49.7 ± 4.0%) were highly consistent with those of z-SRV (49.9 ± 3.6%), with a mean discrepancy of 0.12 ± 0.84%. The SRF also agreed well with the n-SRV, with a mean discrepancy of 0.25 ± 1.65%. The dominant side determined by SRF and n-SRV showed agreement in 26 of 28 cases (92.9%). Conclusion: The newly developed software for CT volumetry was more rapid than the conventional workstation volumetry and just as accurate, and was suggested to be useful for the estimation of SRF and thus the dominant side in kidney donors.

Spinal cord sarcoidosis is a rare manifestation of sarcoidosis. Magnetic resonance imaging (MRI) of spinal cord sarcoidosis sometimes resembles that of the non-inflammatory spinal cord lesion. 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is an effective method to detect both systemic and central nervous system lesions in sarcoidosis. This study compared the standard uptake value (SUV) of FDG-PET between spinal cord sarcoidosis and non-inflammatory spinal cord lesions. We retrospectively reviewed the records of patients who underwent both spinal MRI and FDG-PET scans. We used SUV to evaluate the FDG-PET uptake of the lesion. The region of interest was the center of high-intensity areas on T2-weighted MR images. We included three patients with spinal cord sarcoidosis, five with myelomalacia caused by cervical spondylosis or ossification of the posterior longitudinal ligament, one with spinal cord edema associated with cervical spondylosis, and one with spinal cord edema associated with dural arteriovenous fistula. The spinal cord sarcoidosis group had a significantly higher SUV (mean = 4.38, range 3.30-4.93) than patients with the other diseases (mean = 1.87, range 1.42-2.74). The SUV of FDG-PET thus may be able to distinguish spinal cord sarcoidosis from other non-inflammatory lesions. FDG-PET can play an important role in the diagnosis of spinal cord sarcoidosis because the gadolinium enhancement in MRI is sometimes seen in spondylotic myelopathy or vascular malformation. FDG-PET is informative for the accurate diagnosis of spinal cord sarcoidosis and may enable clinicians to start treatment at an earlier stage.

In most cases of systemic lupus erythematosus (SLE), glomerular lesions are the main renal complication. Although tubulointerstitial lesions are often associated with severe glomerular lesions, predominant or isolated tubulointerstitial injury in the presence of minimal glomerular abnormalities with SLE, so-called predominant tubulointerstitial lupus nephritis, is rare and there is no report on CT and MR imaging findings of predominant tubulointerstitial lupus nephritis. Herein, we describe the case of a 48-year-old woman with SLE who presented with acute renal deterioration attributable to acute tubulointerstitial nephritis with an emphasis on CT and MR imaging findings. CT demonstrated multiple wedge-shaped areas or streaky zones of lesser enhancement that extend from the papilla to the renal cortex. MR images revealed relatively clear corticomedullary junction with slightly irregular cortex on T1-weighted images, and wed-shaped areas of decreased signal intensity corresponding CT findings increased signal intensity in the central parenchyma on T2-weighted image. The enhancement effect was weak and delayed in the central parenchyma on dynamic MR images after bolus administration of contrast. These imaging features seemed to reflect the tubulointerstitial dysfunction and infiltration in this case.

Purpose To evaluate the feasibility of shortening the bed rest time from 4 hours to 2 hours after transfemoral noncardiac angiography with a 4-F sheath (outer diameter, 1.93 mm), a 5-F sheath (outer diameter, 2.27 mm), and a 4-F catheter. Materials and Methods Patients were randomized into two groups, receiving either 2 or 4 hours of bed rest after hemostasis by manual compression of the puncture site. The authors evaluated the frequency of bleeding complications. An interim analysis was performed wherein 40 patients were assigned to each group. After the analysis, a single-arm 2-hour bed rest trial was conducted in an additional 115 procedures. Results In the interim analysis, three of the 40 patients in the 4-hour group and none of the 40 patients in the 2-hour group developed minor bleeding within 2 hours after manual compression ( P = .24). After 2 hours of bed rest, no bleeding complication was observed in either group. In the single-arm 2-hour bed rest trial, minor bleeding developed in one of the 115 procedures (0.8%). Through the study, minor bleeding occurred in four of the 195 total procedures (2%), and no major complications developed. The occurrence of a bleeding complication was significantly higher in patients with platelet counts of less than 100 × 10 9 /L than in the other patients (4/67 vs 0/128, P = .01). Conclusions Two hours of bed rest is feasible for patients undergoing transfemoral noncardiac angiography by using a 4–5-F sheath and/or a 4-F catheter, especially those with a normal platelet count.

Summary Objectives: The objectives of this study were to investigate the transitional probability distribution of medical term boundaries between characters and to develop a parsing algorithm specifically for medical texts. Methods: Medical terms in Japanese computed tomography (CT) reports were identified using the ChaSen morphological analysis system. MeSH-based medical terms (51,385 entries), obtained from the metathesaurus in the Unified Medical Language System (UMLS, 2005AA), were added as a medical dictionary for ChaSen. A radiographer corrected the set of results containing 300 parsed CT reports. In addition, two radiologists checked the medical term parsing of 200 CT sentences. Results: We obtained modified inter-annotator agreement scores for the text corrected by the radiologists. We retrieved the transitional probability as the conditional probability of a uni-gram, bi-gram, and tri-gram. The highest transitional probability P(Ci | Ci - 2*Ci - 1) was 1.00. For an example of anatomical location, the term “pulmonary hilum” was parsed as a tri-gram. Conclusions: Retrieval of transitional probability will improve the accuracy of parsing compound medical terms.

Primary intramedullary spinal cord germinoma is a rare neoplasm and sensitive to radiotherapy and chemotherapy. In this report, a 16-year-old girl presented with pain and numbness of both thighs, difficulty in walking, followed by urinary disturbance. Neurological examination revealed motor weakness, hypotonicity, reduced deep tendon reflexes of both lower limbs, and decrease in sensation below Th12 level. MR examination demonstrated intramedullary mass lesion of the lower thoracic spinal cord. On T2-weighted images, the lesion was heterogeneous but mostly slightly hyperintense. There were small cysts within the tumor. On T1-weighted images, the lesion was mostly hypointense. Mild and heterogeneous enhancement was observed on postcontrast T1-weighted images. No other neoplastic lesion has been found inside and outside the central nervous system. The patient underwent surgery, and the intramedullary lesion was almost totally resected. The lesion was diagnosed as germinoma histologically. Analysis of cerebrospinal fluid (CSF) obtained during operation revealed elevated level of beta-subunit of human chorionic gonadotrophin (beta-hCG). Literature review revealed that MRI findings of intramedullary spinal cord germinomas are frequently nonspecific, but these tumors sometimes have small intratumoral cysts. Germinomas should be included in the differential diagnosis, especially when an intramedullary spinal cord tumor is found in the thoracic or thoraco-lumbar region in a young adult patient. Elevated level of beta-hCG in CSF strongly suggests germinoma.

Objective : Traumatic brain injury causes cognitive disturbances in many cases. Some patients have moderate–severe brain dysfunction despite slight or no abnormality in MRI. The purpose of this study is to investigate whether the loss of neuronal integrity exists in the patients with traumatic brain injury using C-11 flumazenil PET (FMZ-PET) without MRI abnormality. Method : This study included 11 patients with traumatic brain injury and posttraumatic cognitive disturbances. All of the studies were examined at least 6 months later after injury. The dynamic flumazenil PET was studied in all patients. The binding potential of flumazenil (BP) was calculated by reference method. Axial T1WI, T2WI and FLAIR images were obtained with 1.5-T scanner. Coronal images were added in some cases. The BP images were visually interpreted by at least two experienced nuclear physicians by consensus. The lesions were determined as positive if a definite localized area of decreased distribution with respect to the surrounding normal tissue was present except for physiological distribution. Results : All of the patients had normal T1, T2 and FLAIR MRI. Nine patients had memory impairment. The low uptakes of BP images were shown in seven patients (63%). The low uptakes of BP were shown in the medial temporal lobe, the lateral temporal lobe, the temporal base and the frontal lobe in five, one, one and two patients, respectively. There were no patients that had low uptake in the cerebellum. Six of the nine patients who had memory impairment showed low uptakes in BP in the temporal lobe. Conclusion : These results indicated that the loss of the neuronal integrity, which was not able to be detected with MRI, was one of the causes of the cognitive disturbances in patients with traumatic brain injury.

We report a case of 5-fluorouracil (5-FU)-induced leukoencephalopathy in which magnetic resonance imaging (MRI) of the brain, including diffusion-weighted imaging (DWI), was performed serially. The initial T2-weighted and FLAIR images showed diffuse mild hyperintensity in bilateral deep cerebral white matter and corpus callosum, which on T1WI appeared as non-enhanced faint hypointensity. Isotropic DWI disclosed the abnormality as well-conspicuous diffuse hyperintensity with decreased ADC. Serial studies revealed that majority of the abnormal signal intensity on these sequences resolved, and the decreased ADC values approached normal. Some hyperintensity remained in the deep cerebral white matter and the splenium, but no further significant ADC change after normalization was noted. Measurement of ADC along the three orthogonal directions showed the presence of directional dependence of diffusion throughout the length of study. These findings suggest that early stage of 5-FU-induced leukoencephalopathy is associated with reversible restricted diffusion and preservation of anisotropy. Diffusion-weighted imaging may be useful for the diagnosis.

To evaluate the feasibility of arterial spin-labeling (ASL) in head and neck cancer for noninvasive measurement of tumor blood flow (TBF), by comparing 1) the TBF change before and after the treatment, and 2) posttreatment TBF and its reduction rate between residual and nonresidual tumors after treatment.Twenty-two patients with head and neck cancer were evaluated using ASL on 3.0-T magnetic resonance imaging (MRI) before and after nonsurgical treatment. A pulsed ASL sequence with Look–Locker readout was used to calculate quantitative TBF. TBF reduction rates between pre- and posttreatment values were also calculated. Residual tumors were confirmed when present with either histopathologically or clinical follow-up.Pre- and posttreatment mean TBF values were 121.4 ± 27.8 (standard deviation) and 24.9 ± 14.9 mL/100g/min, respectively. Pre- and posttreatment TBF differed significantly. Posttreatment TBF was significantly higher in patients with residual tumors (five patients, 46.9 ± 7.1 mL/100g/min) than in those without (17 patients, 18.4 ± 9.2 mL/100g/min). The TBF reduction rate was significantly lower in patients with residual tumors (0.540.55 ± 0.120.12) than in those without (0.85 ± 0.06).ASL allows quantitative assessment of TBF in head and neck cancer. ASL may be useful for noninvasive assessment of tumor viability in head and neck cancer.

We report magnetic resonance findings in the intramedullary schwannoma of the cervical spinal cord in two patients. In both cases, the solid portions of the tumours enhanced intensely after administration of Gd-DTPA and the enhanced border was sharply delineated from the adjacent spinal cord. Schwannomas should be considered in the differential diagnosis of intramedullary tumours when magnetic resonance images show a strongly enhancing mass with sharply delineated borders.

Electrocardiographic-gated 64-slice multidetector computed tomography (MDCT) was performed on a 30-year-old man who presented with a complete endocardial cushion defect (ECD) and severe pulmonary hypertension diagnosed when he was 3 years old. Multiplanar reconstruction image showed the common atrium without an atrial septum, a large ventricular septum defect, and a small right ventricle due to a complete atrioventricular canal defect. Three-dimensional CT volume-rending imaging showed a patent ductus arteriosus, dilation of the ascending aorta, and an anomalous-origin right coronary artery. This patient also had heterotaxy syndrome with polysplenia and azygos continuation. MDCT proved to be a good noninvasive imaging method for the evaluation of ECD associated with cardiac as well as extracardiac abnormalities.

The purpose of this report is to assess clinically acceptable compression ratios on the detection of brain lesions at magnetic resonance imaging (MRI). Four consecutive T2-weighted and the corresponding T1-weighted images obtained in 20 patients were studied for 109 anatomic sites including 50 with lesions and 59 without lesions. The images were obtained on a 1.5-T MR unit with a pixel size of 0.9 to 1.2 x 0.47 mm and a section thickness of 5 mm. The image data were compressed by wavelet-based algorithm at ratios of 20:1, 40:1, and 60:1. Three radiologists reviewed these images on an interactive workstation and rated the presence or absence of a lesion with a 50 point scale for each anatomic site. The authors also evaluated the influence of pixel size on the quality of image compression. At receiver operating characteristic (ROC) analysis, no statistically significant difference was detected at a compression ratio of 20:1. A significant difference was observed with 40:1 compressed images for one reader (P = .023), and with 60:1 for all readers (P = .001 to .012). A root mean squared error (RMSE) was higher in 0.94- x 0.94-mm pixel size images than in 0.94- x 0.47-mm pixel size images at any compression ratio, indicating compression tolerance is lower for the larger pixel size images. The RMSE, subjective image quality, and error images of 10:1 compressed 0.94- x 0.94-mm pixel size images were comparable with those of 20:1 compressed 0.94- x 0.47-mm pixel size images. Wavelet compression can be acceptable clinically at ratios as high as 20:1 for brain MR images when a pixel size at image acquisition is around 1.0 x 0.5 mm, and as high as 10:1 for those with a pixel size around 1.0 x 1.0 mm.

Gd-DTPA-enhanced magnetic resonance (MR) imaging can depict not only the morphology but also the pathological changes of a nerve root compressed by herniated disc. Enhanced MR imaging was performed on 115 patients treated surgically for lumbar disc herniation. Nerve root enhancement was seen in 39.1% of the patients preoperatively and in 58.7% postoperatively. Preoperative root enhancement reflects the radicular pain intensity rather than the degree of neurological deficits, whereas postoperative enhancement did not correlate with the radicular symptoms. Nerve root enhancement represents an intraneural edema in the affected nerve root. Enhanced MR imaging is a potential method for the identification of an affected nerve root in patients with a discrepancy between the level of disc herniation and neurological manifestations.

Cine-MRI with presaturation bolus tracking was used in patients with syringomyelia associated with a Chiari malformation to study pulsatile movement of the hindbrain, cervical spinal cord, cerebrospinal fluid and the fluid within the syrinx. Nine patients had 13 examinations, 6 preoperative, 3 after syringosubarachnoid shunting and 4 after posterior fossa decompression. Five controls were also examined. Dynamic display of the acquired images demonstrated downward displacement of the presaturation bolus on the cerebellar tonsils and medulla oblongata (or upper cervical cord) at the C1 level in all preoperative examinations and in two patients after syringosubarachnoid shunting but with residual foramen magnum obstruction. Downward displacement of the bolus on the cervical spinal cord was also demonstrated in 7 examinations, but not observed in the controls. Thus, the hind-brain-spinal cord axis showed larger pulsatile movements in patients with foramen magnum obstruction. Based on these observations and a review of the literature, a new theory on the mode of extension of syringomyelia, emphasising the role of increased pulsatile movement of the hind-brain-spinal cord axis is proposed: that the pulsatile movements, together with a one-way valve mechanism in the syrinx cavity act as a "vacuum-pump" to enlarge the syrinx.

The fluid-attenuated inversion recovery imaging sequence is a widely used MRI sequence of the brain. It is an inversion recovery pulse sequence, designed to suppress signals from the cerebrospinal fluid. It is highly sensitive in detection of lesions adjacent to or within the cerebrospinal fluid associated with T(2) prolongation or T(1) shortening. The term "hyperintense cerebrospinal fluid" is used to describe failed suppression, or hyperintensity, of cerebrospinal fluid on fluid-attenuated inversion recovery imaging of the brain. It is often encountered in many important pathological conditions, including subarachnoid haemorrhage, meningitis and leptomeningeal metastasis. However, certain non-pathological states in which there is no definite cerebrospinal fluid abnormality can also present with hyperintense cerebrospinal fluid. Correct interpretation of abnormalities is important to arrive at an appropriate diagnosis. This pictorial review provides fluid-attenuated inversion recovery images of hyperintense cerebrospinal fluid of the brain and describes distinguishing features. Part I features pathological conditions whereas Part II focuses on non-pathological conditions.

We diagnosed unroofed coronary sinus preoperatively by the 3D volume rendering and endocardial views with 64-slice MDCT, and those clearly showed the defect of the roof of the coronary sinus and the relationship with the surrounding structure. MDCT is a good non-invasive tool for the evaluation of unroofed coronary sinus, and the reconstructed endocardial view is useful for preoperative surgical planning.

Primary central nervous system lymphoma (PCNSL) is rare, although its frequency has increased in recent years. Radiographically, almost all PCNSL enhance on CT and/or MRI, and nonenhancing PCNSL has been thought to be extremely rare. We present PCNSL showing multiple nonenhancing lesions on MRI in an immunocompetent patient.

Objective: We assessed the MR appearance of wallerian degeneration following spinal cord injury. Materials and Methods: We retrospectively reviewed the MR examinations of 13 patients with spinal cord injury. Thirty-one MR examinations were performed at various time intervals (1 day to 4 years) following injury. Results: High signal intensity was observed in six patients (11 examinations) at the level of the posterior columns cephalad to the primary injury site on T2-weighted and proton density-weighted imaging at 10 week to 12 month intervals postinjury. In these six patients the posterior column was involved at the primary injury site. Conclusion: The abnormal intensity cephalad to the injury site is thought to represent wallerian degeneration, which should be considered in the differential diagnoses of spinal intramedullary lesions

RATIONALE AND OBJECTIVES. The authors evaluated the effect of hepatic venous occlusion on hepatic arterial embolization in rats. METHODS. A Lipiodol-Iopamidol mixture was injected into the proper hepatic artery in rats during clamping the right side of the hepatic venous confluence. The distribution of Lipiodol-Iopamidol mixture in the sinusoids was analyzed by histological examination with en bloc silver impregnation. The extent of the distribution of Lipiodol-Iopamidol mixture was compared in sinusoids with hepatic venous occlusion and in sinusoids without hepatic venous occlusion. RESULTS. Lipiodol-Iopamidol mixture was more widely distributed in the lobules with hepatic venous occlusion than in the lobules without occlusion. CONCLUSIONS. Hepatic venous occlusion may enhance the effect of hepatic arterial embolization using Lipiodol emulsions and could be useful in the treatment of hepatocellular carcinoma.