High Signal Intensity of the Cochlear Modiolus on Unenhanced T1-Weighted Images in Classical Infratentorial Superficial Siderosis.

Background: Superficial siderosis (SS) results from chronic bleeding in the subarachnoid space. SS can be classified as infratentorial SS (i-SS) and supratentorial SS (s-SS). The cochlear modiolus (CM) normally shows low signal intensity (SI) on Tl-weighted images (T1WI). We noticed persistently high SI of the CM on unenhanced thin-sliced T1WI in patients with i-SS. The purpose of this study was to evaluate the correlation between SS and high SI of the CM on unenhanced T1WI. Methods: This retrospective study analyzed three cases with i-SS, eight cases with s-SS, and 23 normal controls (NC) evaluated on unenhanced thin-sliced T1WI with a three-dimensional spoiled gradient-recalled echo sequence. CM-T1SI scores of 0, 1, and 2 indicated low, iso, and high SI, respectively. In cases with scores of 2 evaluated several times, all scores were reviewed for each case. The CM-T1SI ratio was defined as the contrast ratio between the CM and the cerebellum. Differences between the three groups were statistically analyzed based on the CM-T1SI score and ratio. Receiver operative curve (ROC) analysis was used to determine the cut-off values for differentiating the i-SS group from the NC group based on the CM-T1SI ratio. Results: Two patients with i-SS had a score of 2 on all evaluations. The CM-T1SI score and ratio differed significantly between the i-SS and NC groups. The accuracy of the CM-T1SI ratio for discriminating i-SS from NC was 98.9% at a cutoff value of 0.628. Conclusion: High SI of the CM on unenhanced TIWI can be an additional characteristic finding of i-SS.

MRI multiparametric scoring system for pial blood supply of intracranial meningiomas.

Background: Meningiomas are occasionally fed by pial blood supply (PBS). It is postulated that peritumoral flow void (PTFV), peritumoral brain edema (PTBE), and absence of an arachnoid plane (AP) are useful parameters for evaluating PBS. Purpose: To determine whether conventional magnetic resonance imaging (MRI) using a multiparametric scoring system (MSS) is a useful way to predict PBS. Material and Methods: Forty-six patients were included and divided: PBS and non-PBS groups. Differences between the groups in six parameters of MR imaging were analyzed: tumor size, tumor location, PTBE grade, AP grade, PTFV, and MIB1 labeling index (MIB1-LI) grade. Cutoff values were determined using receiver operating characteristic (ROC) curve analysis for the differentiation of both groups based on statistically significant parameters. All cases were scored as 1 (PBS) or 0 (non-PBS) for each parameter according to set thresholds. Individual scores were totaled for each case, yielding a combined score for each case to obtain a cutoff value using ROC curve analysis for the MSS. Results: Peritumoral brain edema grade, AP grade, PTFV, and MIB-LI grade were statistically associated with PBS. Receiver operating characteristic curve analyses showed that PTBE grade 3 or 4, AP grade 3 or 4, and PTFV positivity had the highest accuracy of 69%, 64%, and 68%, respectively. Regarding the MSS, a cutoff value of 2 had the highest accuracy of 71%; PBS diagnosis was indicated by at least two of the three parameters, namely, PTBE grade, AP grade, and PTFV. Conclusion: The MSS is a useful way to predict PBS in intracranial meningiomas on MRI.

Advanced magnetic resonance imaging findings of cerebellar hemangioblastomas: A report of three cases and a literature review.

On conventional magnetic resonance imaging (MRI), hemangioblastomas typically appear as mural nodules with an adjacent surrounding cyst or a solid mass in the cerebellum. However, hemangioblastomas sometimes cannot be reliably distinguished using this imaging technique from other tumors, especially pilocytic astrocytomas and metastatic tumors, because of their similar imaging findings and locations. Herein, we report three cases of cerebellar hemangioblastomas and review their findings on conventional and advanced MRI, including diffusion-weighted imaging (DWI), dynamic susceptibility-weighted contrast-enhanced perfusion-weighted imaging (DSC-PWI), and magnetic resonance spectroscopy (MRS). Solid contrast-enhanced lesions of hemangioblastomas showed increased apparent diffusion coefficient values on DWI, increased relative cerebral blood volume ratio on DSC-PWI, and high lipid/lactate peak on MRS. Therefore, advanced MRI techniques can be helpful in understanding the pathological and metabolic changes of hemangioblastomas and may be useful for their characterization.

Utility of 3T single-voxel proton MR spectroscopy for differentiating intracranial meningiomas from intracranial enhanced mass lesions.

BACKGROUND: Proton magnetic resonance spectroscopy (MRS) provides structural and metabolic information that is useful for the diagnosis of meningiomas with atypical radiological appearance. However, the metabolite that should be prioritized for the diagnosis of meningiomas has not been established. PURPOSE: To evaluate the differences between the metabolic peaks of meningiomas and other intracranial enhanced mass lesions (non-meningiomas) using MR spectroscopy in short echo time (TE) spectra and the most useful metabolic peak for discriminating between the groups. MATERIAL AND METHODS: The study involved 9 meningiomas, 22 non-meningiomas, intracranial enhancing tumors and abscesses, and 15 normal controls. The ranking of the peak at 3.8 ppm, peak at 3.8 ppm/Creatine (Cr), ß-γ Glutamine-Glutamate (bgGlx)/Cr, N-acetyl compounds (NACs)/Cr, choline (Cho)/Cr, lipid and/or lactate (Lip-Lac) at 1.3 ppm/Cr, and the presence of alanine (Ala) were derived. The metabolic peaks were compared using the Mann-Whitney U test. ROC analysis was used to determine the cut-off values for differentiating meningiomas from non-meningiomas using statistically significant metabolic peaks. RESULTS: The ranking of the peak at 3.8 ppm among all the peaks, peak at 3.8 ppm/Cr, bgGlx/Cr, Lip-Lac/Cr, and the presence of Ala discriminated meningiomas from non-meningiomas with moderate to high accuracy. The highest accuracy was 96.9% at a threshold value of 3 for the rank of the peak at 3.8 ppm. CONCLUSION: A distinct elevated peak at 3.8 ppm, ranked among the top three highest peaks, allowed the detection of meningiomas.

Computed Tomography-guided Lung Biopsy: A Review of Techniques for Reducing the Incidence of Complications.

Computed tomography-guided lung biopsy is a well-established method for the histological diagnosis of pulmonary lesions. There is abundant literature regarding the diagnostic yield of and complications associated with computed tomography-guided lung biopsy. Many studies have investigated the risk factors influencing pneumothorax. Conversely, there are a limited number of reports detailing techniques for reducing the incidence of pneumothorax or other complications. This study reviews the indications, diagnostic accuracy, and complications of computed tomography-guided lung biopsy. In addition, techniques for reducing the incidence of these complications were reviewed.

The utility of the combined use of 123I-FP-CIT SPECT and neuromelanin MRI in differentiating Parkinson's disease from other parkinsonian syndromes.

BACKGROUND: Neuromelanin magnetic resonance imaging (NmMRI) and 123I-FP-CIT dopamine transporter single photon emission computed tomography (DAT-SPECT) provide specific information that distinguishes Parkinson's disease (PD) from non-degenerative parkinsonian syndrome (NDPS). PURPOSE: To determine whether a multiparametric scoring system (MSS) could improve accuracy compared to each parameter of DAT-SPECT and NmMRI in differentiating PD from NDPS. MATERIAL AND METHODS: A total of 49 patients, including 14 with NDPS, 30 with PD, and five with atypical parkinsonian disorder (APD) underwent both NmMRI and DAT-SPECT and were evaluated. The average (Ave) and the asymmetry index (AI) were calculated in the substantia nigra compacta area (SNc-area), SNc midbrain-tegmentum contrast ratio (SNc-CR), and specific binding ratio (SBR). Cut-off values were determined, using receiver operating characteristic (ROC) analysis, for the differentiation of PD from NDPS on the statistically significant parameters. All cases were scored as either 1 (PD) or 0 (NDPS) for each parameter according to its threshold. These individual scores were totaled for each case, yielding a combined score for each case to obtain a cut-off value for the MSS. RESULTS: The Ave-SNc-area, Ave-SNc-CR, and Ave-SBR in PD were significantly lower than those in NDPS. The AI-SNc-area and AI-SBR in PD were significantly higher than those in NDPS. Of the five parameters, the highest accuracy was 93% for the Ave-SNc-area. For the MSS, a cut-off value of 3 was the accuracy of 96%. Besides, no significant difference was observed between PD and APD on all parameters. CONCLUSION: An MSS has comparable or better accuracy compared to each parameter of DAT-SPECT and NmMRI in distinguishing PD from NDPS.

The Utility of the Combined Use of 123I-FP-CIT and 123I-MIBG Myocardial Scintigraphy in Differentiating Parkinson's Disease from Other Parkinsonian Syndromes.

BACKGROUND: 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy and 123I-FP-CIT dopamine transporter single photon emission computed tomography (DAT-SPECT) provide specific information that distinguish Parkinson's disease (PD) from parkinsonian syndromes other than PD (non-PD), including atypical parkinsonian disorder (APD) and non-PD other than APD (nPD-nAPD). The purpose of this study was to determine whether combining DAT-SPECT and MIBG myocardial scintigraphy using multiparametric scoring system (MSS) could improve diagnostic test accuracy in discriminating PD from APD or discriminating PD from nPD-nAPD. METHODS: A total of 52 patients, including 36 PD, eight APD and eight nPD-nAPD, underwent both MIBG myocardial scintigraphy and DAT-SPECT, were evaluated. The heart-to-mediastinum (H/M) ratios (early and delayed), washout-rate (WR), the average (Ave) and asymmetry index (AI) of specific binding ratio (SBR) were calculated. Cutoff values were determined, using ROC analysis, for discriminating PD from APD and for discriminating PD from nPD-nAPD, on five parameters. All cases were scored as either 1 (PD) or 0 (nPD-nAPD or APD) for each parameter according to its threshold in each discrimination. These individual scores were summed for each case, yielding a combined score to obtain a cutoff value for the MSS in each discrimination. RESULTS: For discriminating PD from nPD-nAPD, the highest accuracy was 80% at a cutoff value of 19% for the WR and a cut off value of 2 improved diagnostic accuracy to 84% for MSS. For discriminating PD from APD, the highest accuracy was 86% at a cutoff value of 2.8 for the H/M ratio (late) and a cut off value of 2 showed diagnostic accuracy of 86% for MSS. CONCLUSION: A MSS has comparable or better accuracy compared to each parameter of MIBG myocardial scintigraphy and DAT-SPECT in distinguishing PD from nPD-nAPD or distinguishing PD from APD.

Vanishing Parotid Tumors on MR Imaging.

BACKGROUND: Of all parotid gland tumors, only oncocytoma has been reported to appear isointense to the parotid gland, namely vanishing, on fat-saturated T2 and T1 postcontrast gadolinium-enhanced magnetic resonance imaging (MRI). The purpose of this study was to evaluate vanishing of parotid tumors on conventional MRI with and/or without postcontrast gadolinium-enhancement and on diffusion weighted imaging (DWI). METHODS: In 8 of 51 patients, ten parotid gland tumors had homogeneously enhanced lesions and were retrospectively analysed. Comparisons of signal intensity between those parotid tumors and parotid glands and evaluations of vanishing were performed on T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), fat-suppressed T2WI (FS-T2WI), postcontrast gadolinium-enhanced T1WI (CE-T1WI) and fat-suppressed CE-T1WI (FS-CE-T1WI), DWI as well as apparent diffusion coefficient (ADC). RESULTS: Ten parotid gland tumors consisted of five Warthin tumors, two pleomorphic adenomas, two parotid carcinomas (small cell carcinoma and adenoid cystic carcinoma) and one oncocytoma. All tumors showed hypointensity on T1WI and hyperintensity on DWI. Nine of ten tumors showed vanishing on the other MR sequences. All Warthin tumors showed vanishing on FS-T2WI, FS-CE-T1WI and the ADC map. One oncocytoma showed vanishing on FS-T2WI and the ADC map and hyperintensity on FS-CE-T1WI. All pleomorphic adenomas showed vanishing on T2WI and CE-T1WI. One adenoid cystic carcinoma showed vanishing only on CE-T1WI. CONCLUSION: Vanishing of parotid tumors can be observed not only on FS-T2WI and FS-CE-T1WI but also on T2WI, CE-T1WI and ADC mapping.

Differentiating parotid tumors by quantitative signal intensity evaluation on MR imaging.

BACKGROUND: There have been no reports about quantitative evaluations of enhancing components of parotid tumors on conventional MR imaging. PURPOSE: To evaluate the signal intensity of the enhancing components of tumors, including pleomorphic adenomas (PAs), Warthin tumors (WTs) and malignant tumors (MTs), on various MR sequences and to assess the usefulness of quantitative evaluations for differentiation among the three groups of tumors. MATERIAL AND METHODS: A total of 39 histologically proven tumors, including 15 PAs, 17 WTs and 7 MTs, were enrolled in this study. The tumor-to-spinal cord contrast ratio (TSc-CR) was calculated by dividing the signal intensity of the lesion by that of the spinal cord on MR sequences, including T1-weighted imaging (T1WI), T2-weighted imaging (T2WI) and postcontrast gadolinium-enhanced T1WI (CE-T1WI). The mean apparent diffusion coefficient (ADC) value was selected in each tumor. Furthermore, the differences in the TSc-CRs and the ADC values among the three groups of tumors were statistically evaluated. Cutoff values were determined for the prediction of tumor histology. RESULTS: The TSc-CRs of PAs were significantly higher than those of WTs and MTs on T2WI and CE-T1WI. The sensitivities and specificities were 100% and 87.5%, respectively, at a cutoff value of 1.31 for the TSc-CR of T2WI; and 83.3% and 100%, respectively, at a cutoff value of 2.00 for the TSc-CR of CE-T1WI. For the ADC values, sensitivity and specificity for discriminating PAs from WTs or MTs were both 100% when the cutoff value of the ADC was set at 1.40×10-3mm2/s. CONCLUSION: ADC maps and the quantitative evaluations using the TSc-CRs on T2WI and CE-T1WI were useful for discriminating WTs or MTs from PAs. However, discrimination between WTs and MTs was difficult using any MR sequence.

Three cases of neuromyelitis optica spectrum disorder.

Neuromyelitis optica (NMO) is characterized by attacks of optic neuritis and longitudinally extensive transverse myelitis. Cases positive for aquaporin 4 antibodies are classified to NMO spectrum disorder (NMOSD) which includes cases with optic neuritis, transverse myelitis, or with brain lesions typical of NMO. Our three cases with NMO/NMOSD revealed five imaging features: (i) extensive transverse cord lesions, extending more than three vertebral segments, partially persisting as cavitation; (ii) periependymal lesions; (iii) lesions of the corticospinal tracts; (iv) extensive and confluent hemispheric white matter lesions reflecting vasogenic edema and partially involving the cerebral cortices and basal ganglia; and (v) two patterns of serial hemispheric white matter lesions: one is cavitation and another is partial regression or disappearance. Cavitations, in the upper spinal cord and hemispheric white matter, are considered to be caused by severe vasogenic edema and are likely to be one of the characteristic findings in NMOSD.

Three cases of mediastinal pancreatic pseudocysts.

A rare complication of acute or chronic pancreatitis is the formation of a mediastinal pancreatic pseudocyst (MPP), which is caused by tracking of pancreatic fluids through anatomical openings of the diaphragm into the mediastinum. Herein, we report the imaging characteristics of three cases of this condition. Our results revealed three features in common: (i) the connection between the mediastinum and the pancreatic cystic lesion; (ii) the presence of pleural effusions; and (iii) imaging findings consistent with chronic pancreatitis, such as pancreatic atrophy and calcifications and dilatation and/or stricture of main pancreatic duct (MPD). Serial diameter changes of the MPD and of the adjacent pseudocysts were necessary for the determination of the therapeutic strategy used in each case.

Correlation between pathology and neuromelanin MR imaging in Parkinson's disease and dementia with Lewy bodies.

INTRODUCTION: Direct correlation between neuropathological findings and postmortem neuromelanin MR imaging (NmMRI) was performed in the substantia nigra pars compacta (SNc) to clarify the pathological background of the signal changes in normal, Parkinson's disease (PD), and dementia with Lewy bodies (DLB) cases. METHODS: NmMRI of 10 % formalin-fixed autopsied midbrains was performed in three cases (normal control, DLB, and PD) with a 3T imaging system, using a 3D gradient echo T1-weighted sequence with a magnetization transfer contrast pulse. Neuropathological examinations of the midbrains were performed, and the density of neuromelanin-positive neurons (number per square millimeter) was determined. The extent of iron deposition in the midbrain was also evaluated using ferritin immunohistochemistry. Furthermore, we directly correlated the contrast signal ratio in the SNc and the density of neuromelanin-containing neurons. RESULTS: Diffuse hyperintense areas in the SNc reflected well-preserved neuromelanin-containing neurons in the normal control case, whereas an iso-intense area in the SNc showed severe loss of neuromelanin-containing neurons in the DLB and PD cases. Increased signal intensity in the SNc was apparently not influenced by iron deposition. Furthermore, a significant positive correlation between signal intensity and the density of neuromelanin-containing neurons was seen in the SNc. CONCLUSION: Based on the direct correlation between postportem NmMRI and neuropathological findings, signal intensity in the SNc is closely related to the quantity of neuromelanin-containing neurons but is not influenced by iron deposition.

Correlation of apparent diffusion coefficients measured by diffusion-weighted MR imaging and standardized uptake values from FDG PET/CT in metastatic neck lymph nodes of head and neck squamous cell carcinomas.

Both diffusion-weighted magnetic resonance imaging and fluorodeoxyglucose positron emission tomography/computed tomography are oncological imaging techniques. The aim of this study was to assess any correlation between apparent diffusion coefficients and standardized uptake value in metastatic neck lymph nodes of head and neck squamous cell carcinomas.

Significance of apparent diffusion coefficient measurement for the differential diagnosis of multiple system atrophy, progressive supranuclear palsy, and Parkinson's disease: evaluation by 3.0-T MR imaging.

INTRODUCTION: The clinical differentiation of Parkinson's disease (PD) from multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) may be challenging, especially in their early stages. The aim of this study was to evaluate the utility of apparent diffusion coefficient (ADC) measurement to distinguish among these degenerative disorders. METHODS: Twenty-five MSA, 20 PSP, and 17 PD patients and 18 healthy controls were retrospectively studied. Axial diffusion-weighted and T2-weighted images were obtained using a 3-T MR system. Regions of interest (ROIs) were precisely placed in the midbrain, pons, putamen, globus pallidus, caudate nucleus, thalamus, superior cerebellar peduncle, middle cerebellar peduncle, cerebellar white matter, and cerebellar dentate nucleus, and the regional ADC (rADC) value was calculated in each ROI. RESULTS: In MSA, rADC values in the pons, middle cerebellar peduncle, cerebellar white matter, and cerebellar dentate nucleus were significantly higher than in PSP, PD, and controls. Furthermore, rADC values in the posterior putamen were significantly higher in MSA than in PSP and controls. In PSP, rADC values were significantly higher in the globus pallidus and midbrain than in MSA, PD, and controls. Furthermore, rADC values in the caudate nucleus and superior cerebellar peduncle were significantly higher in PSP than in MSA and controls. In PD, there were no significant differences in the rADC values compared to in MSA, PSP, and controls in all regions. CONCLUSION: Evaluation of rADC values in characteristic lesions in MSA, PSP, and PD by placing ROIs using 3-T systems can provide useful additional information for differentiating these disorders.

Comparison of 3 Tesla proton MR spectroscopy, MR perfusion and MR diffusion for distinguishing glioma recurrence from posttreatment effects.

PURPOSE: To compare 3 Tesla (3T) multi-voxel and single-voxel proton MR spectroscopy (MRS), dynamic susceptibility contrast perfusion MRI (DSC), and diffusion-weighted MRI (DWI) for distinguishing recurrent glioma from postradiation injury. MATERIALS AND METHODS: We reviewed all 3T MRS, DSC and DWI studies performed for suspicion of malignant glioma recurrence between October 2006 and December 2008. Maximum Cho/NAA and Cho/Cr peak-area and peak-height ratios were recorded for both multi-voxel and single-voxel MRS. Maximum cerebral blood volume (CBV) and minimum apparent diffusion coefficient (ADC) were normalized to white matter. Histopathology and clinical-radiologic follow-up served as reference standards. Receiver operating characteristic curves for each parameter were compared. RESULTS: Forty lesions were classified as glioma recurrence (n = 30) or posttreatment effect (n = 10). Diagnostic performance was similar for CBV ratio (AUC = 0.917, P < 0.001), multi-voxel Cho/Cr peak-area (AUC = 0.913, P = 0.002), and multi-voxel Cho/NAA peak-height (AUC = 0.913, P = 0.002), while ADC ratio (AUC = 0.726, P = 0.035) did not appear to perform as well. Single-voxel MRS parameters did not reliably distinguish tumor recurrence from posttreatment effects. CONCLUSION: A 3T DSC and multi-voxel MRS Cho/Cr peak-area and Cho/NAA peak-height appear to outperform DWI for distinguishing glioma recurrence from posttreatment effects. Single-voxel MRS parameters do not appear to distinguish glioma recurrence from posttreatment effects reliably, and therefore should not be used in place of multi-voxel MRS.

A novel tract imaging technique of the brainstem using phase difference enhanced imaging: normal anatomy and initial experience in multiple system atrophy.

OBJECTIVES: To develop a new tract imaging technique for visualising small fibre tracts of the brainstem and for detecting the abnormalities in multiple system atrophy of the cerebellar type (MSA-C) using a phase difference enhanced (PADRE) imaging technique, in which the phase difference between the target and surrounding tissue is selectively enhanced. METHODS: Two neuroradiologists compared the high-spatial-resolution PADRE imaging, which was acquired from six healthy volunteers, three patients with MSA-C, and 7 patients with other types of neurodegenerative diseases involving the brainstem or cerebellum. RESULTS: Various fine fibre tracts in the brainstem, the superior and inferior cerebellar peduncles, medial lemniscus, spinothalamic tract, medial longitudinal fasciculus, central tegmental tract, corticospinal tract and transverse pontine fibres, were identified on PADRE imaging. PADRE imaging from MSA-C demonstrated the disappearance of transverse pontine fibres and significant atrophy of the inferior cerebellar peduncles, while the superior cerebellar peduncles were intact. PADRE imaging also demonstrated that the transverse pontine fibres and inferior cerebellar peduncle were not involved in the other neurodegenerative diseases. CONCLUSION: PADRE imaging can offer a new form of tract imaging of the brainstem and may have the potential to reinforce the clinical utility of MRI in differentiating MSA from other conditions.

Usefulness of administration of SPIO prior to RF ablation for evaluation of the therapeutic effect: an experimental study using miniature pigs.

OBJECTIVES: To evaluate the usefulness of administration of superparamagnetic iron oxide (SPIO) and magnetic resonance (MR) imaging for assessing the efficacy of radiofrequency (RF) liver ablation. MATERIAL AND METHODS: Using a protocol approved by the animal research committee of our university, nine RF liver ablations were performed in three miniature pigs. Six ablations were performed after administration of SPIO in two pigs (group A). Three ablations were performed in the other pig without administration of SPIO (group B). All pigs were sacrificed 4 days after the procedure. Harvested livers were scanned with a 1.5T MR system before and after fixation with 10% buffered formalin, and MR images were precisely compared with histological specimens. RESULTS: There were no histological differences between the two groups. All ablated liver lesions showed coagulation necrosis at the external layer. There were no viable cells inside the coagulation necrosis. All ablated lesions had a hypointense rim on fast low angle shot (FLASH) images. The rims of group A were thicker than those of group B. The rims of group B corresponded histologically to congestion and hemorrhagic necrosis area. The rims of the group A corresponded to hemorrhagic necrosis and coagulation necrosis areas. In group A, the hypointense rim reflected necrotic Kupffer cells that took up SPIO before RF liver ablation. CONCLUSION: Administration of SPIO made it possible to precisely evaluate ablated liver parenchyma by hypointense rim on FLASH images. This method is helpful for the evaluation of safety margin after RF ablation for liver tumors.

Three-dimensional gradient echo versus spin echo sequence in contrast-enhanced imaging of the pituitary gland at 3T.

INTRODUCTION: To clarify whether a three-dimensional-gradient echo (3D-GRE) or spin echo (SE) sequence is more useful for evaluating sellar lesions on contrast-enhanced T1-weighted MR imaging at 3.0Tesla (T). METHODS: We retrospectively assessed contrast-enhanced T1-weighted images using 3D-GRE and SE sequences at 3.0T obtained from 33 consecutive patients with clinically suspected sellar lesions. Two experienced neuroradiologists evaluated the images qualitatively in terms of the following criteria: boundary edge of the cavernous sinus and pituitary gland, border of sellar lesions, delineation of the optic nerve and cranial nerves within the cavernous sinus, susceptibility and flow artifacts, and overall image quality. RESULTS: At 3.0T, 3D-GRE provided significantly better images than the SE sequence in terms of the border of sellar lesions, delineation of cranial nerves, and overall image quality; there was no significant difference regarding the boundary edge of the cavernous sinus and pituitary gland. In addition, the 3D-GRE sequence showed fewer pulsation artifacts but more susceptibility artifacts. CONCLUSION: Our results indicate that 3D-GRE is the more suitable sequence for evaluating sellar lesions on contrast-enhanced T1-weighted imaging at 3.0T.

Diffusion-weighted imaging findings of adnexal torsion: initial results.

Our purpose is to clarify the diffusion-weighted (DW) imaging findings of adnexal torsion. We retrospectively analyzed the DW imaging findings in 11 consecutive patients with surgical confirmation of adnexal torsion. We assessed signal intensity of the adnexal mass and fallopian tube thickening, and the location of abnormal signal intensity within the adnexal mass. On DW imaging, thickening of the fallopian tube was apparent as abnormal signal intensity in 8 of 11 patients. Abnormal signal intensity was inhomogeneous in 7 of 8 patients. Abnormal signal intensity on DW imaging was observed in 10 of 11 adnexal masses, and in the walls of 7 out of 8 adnexal cystic lesions. In adnexal torsion, DW imaging showed abnormal signal intensity in the thickened fallopian tube and in the wall of cystic ovarian lesions. These findings would be feasible to diagnose adnexal torsion.