Primary intraosseous cavernous hemangioma of the clivus: A case report and literature review.

Background: The radiographic presentation of the primary intraosseous cavernous hemangiomas (PICHs) is nonspecific. We report a case of clival PICH mimicking a chordoma with a literature review. Case Description: A 57-year-old woman presented with diplopia that started a few days before the presentation. She had transient diplopia at the right lateral gaze and upper gaze with normal eye movement. The symptoms disappeared spontaneously 1 week later. She had no other complaints or neurological deficits. Computed tomography revealed an intraosseous mass lesion and bone erosion of the middle and lower clivus, extending laterally to the right occipital condyle. Magnetic resonance imaging (MRI) showed hyperintense and hypointense components on T2- and T1-weighted images, respectively. The lesion was larger than on MRI performed 10 years earlier. Chordoma or chondroma was considered a possible preoperative diagnosis. An endoscopic transsphenoidal approach removed the tumor. In the operating view, the lesion appeared as "moth-eaten" bony interstices filled with vascular soft tissue. Histologically, an intraosseous cavernous hemangioma was diagnosed. Conclusion: Diagnosis before surgery is difficult without characteristic radiographic findings. When making a differential diagnosis of malignant skull lesions, PICH should be considered.

Enhancing Cerebral Amyloid Angiopathy-Related Inflammation Diagnosis With PET Using Pittsburgh Compound B.

ABSTRACT: Cerebral amyloid angiopathy-related inflammation is a rare encephalopathy characterized by inflammation against amyloid protein accumulated in cerebral small vessels. A 50-year-old man was presented with a subacute consciousness disorder. Brain MRI revealed high intensity lesions in the white matter of the right parietal and occipital lobes on fluid-attenuated inversion recovery sequences and cerebral microbleeds in the right parietal and occipital lobes on T2*-weighted images. Pittsburgh compound B-PET demonstrated accumulation in the right temporoparietal lobe, confirming a potential diagnosis of probable cerebral amyloid angiopathy-related inflammation without brain biopsy. Steroid pulse therapy was initiated, with good results.

Contrast-enhanced double inversion recovery sequence for patients with multiple sclerosis: feasibility of subtraction images between pre- and post-contrast images.

BACKGROUND: Few reports have examined the feasibility of a post-contrast double inversion recovery (DIR) magnetic resonance (MR) sequence in patients with multiple sclerosis (MS) because of partial or complete signal loss of enhancing MS lesions. PURPOSE: To compare subtracted images of DIR (pre-contrast - post-contrast DIR images) with contrast enhanced T1-weighted (CE-T1W) images in the depiction of contrast enhancement of MS lesions. MATERIAL AND METHODS: In total, 27 patients were included. Two neuroradiologists interpreted both images of CE-T1W imaging and subtracted DIR, and interpretation of the images was classified into a score of 1-5 (from 5, definitely superior contrast of lesions on DIR subtraction compared to conventional CE-T1W imaging, to 1, definitely superior contrast of lesions on CE-T1W imaging. The interrater agreement (κ coefficient) was measured. The signal-to-noise ratio (SNR) and contrast-noise-ratio (CNR) of the lesion were compared. RESULTS: A significant difference (P < 0.001) in scoring was seen between conventional CE-T1W imaging (2.1 ± 1.5 with one reviewer and 2.4 ± 1.5 with the other) and DIR subtraction (4.4 ± 1.0 with one reviewer and 4.7 ± 0.8 with the other). SNR from conventional CE-T1W imaging (24.8 ± 14.7) was significantly superior to that from DIR subtraction (4.0 ± 1.0; P < 0.001). CNR in DIR subtraction (326.4 ± 250.0) was significantly superior to that in conventional CE-T1W imaging (0.8 ± 5.5; P < 0.001). For interrater agreement in the evaluation of contrast enhancement of the lesions, κ coefficients were 0.84 for conventional CE-T1W imaging and 0.72 for DIR subtraction. CONCLUSION: Subtracted DIR image enables more obvious contrast enhancement of the MS lesions compared with conventional CE-T1W imaging.

18 F-Fluorodeoxy Glucose and 11 C-Methionine Accumulation in Demyelinating Lesions.

Background Few studies have evaluated the accumulation of 18 F-fluorodeoxyglucose (FDG), 11 C-methionine (MET), and other positron emission tomography (PET) tracers in patients with demyelinating disease. Purpose This study aimed to investigate the accumulation of FDG-PET/computed tomography (CT) and MET-PET/CT in demyelinating lesions. Material and Methods A retrospective search of the patient database in our hospital identified five patients with demyelinating disease in whom PET studies performed in the past 10 years revealed accumulation of FDG or MET. The clinical diagnoses were multiple sclerosis ( n =1), myelitis ( n =1), limbic encephalitis ( n =1), chronic inflammatory demyelinating polyneuropathy (CIDP; n =1), and acute demyelinating encephalomyelitis (ADEM; n =1). Two patients received FDG-PET/CT alone and three patients received both FDG-PET/CT and MET-PET/CT on the same day. Images were visually and conjointly reviewed by two radiologists. In semiquantitative evaluation, the maximum standardized uptake value (SUV max ) of the lesion was measured. The lesion-to-normal brain uptake ratio (L/N ratio) was calculated. Results FDG and/or MET accumulated to a part of the lesions seen on MRI. SUV max on FDG-PET/CT ranged from 3.8 to 10.3, and L/N ratio on MET-PET/CT ranged from 16.6 to 2.4. Conclusion It has been established that neoplastic and demyelinating lesions can be differentiated on the basis of FDG or MET uptake. However, as accumulation of FDG and MET can also occur in demyelinating lesions; knowledge of this possibility is of clinical importance.

PET findings in lymphomatosis and gliomatosis of the brain: a comparison of C-11 methionine PET/CT and F-18 FDG PET/CT.

BACKGROUND: Positron emission tomography (PET) findings for gliomatosis and lymphomatosis have been rarely reported. PURPOSE: To compare PET/computed tomography (CT) findings using 11C-methionine (MET) from PET/CT findings using 18F-fluorodeoxy glucose (FDG) for patients with lymphomatosis or gliomatosis of the brain. MATERIAL AND METHODS: Participants comprised all 10 patients with lymphomatosis or gliomatosis of the brain treated at our institution in the past 12 years. Underlying pathologies comprised intravascular lymphoma (n = 1), lymphomatosis (n = 3), and gliomatosis (n = 6). All cases were pathologically diagnosed. In seven patients, both MET-PET/CT and FDG-PET/CT were performed simultaneously in a single study. In three patients, only FDG-PET/CT was performed. The degree of tracer accumulation to the lesion was evaluated qualitatively. Quantitatively, the ratio of maximum standard uptake value (SUVmax) in tumor to that in normal tissue (T/N ratio) was measured and compared between FDG and MET. RESULTS: Qualitatively, MET accumulated to part of the lesion in six of seven patients and almost all of the lesion in one in seven patients. FDG accumulated to part of the lesion in three of ten patients and almost all of the lesion in one of ten patients. No FDG accumulation was seen in the lesion in six patients. Quantitatively, mean ± SD T/N ratio was significantly higher with MET (2.11 ± 0.63) than with FDG (1.18 ± 0.84; P < 0.05, Wilcoxon signed-rank test). CONCLUSION: In lymphomatosis and gliomatosis, FDG accumulates in only part of the lesion. FDG is thus less suitable than MET for depicting these lesions.

Comparison of Time-of-Flight-Magnetic Resonance Angiography From Silent Scan Magnetic Resonance Angiography in Depiction of Arteriovenous Malformation of the Brain.

OBJECTIVE: Silent magnetic resonance angiography (MRA) was compared with time-of-flight (TOF)-MRA in imaging of arteriovenous malformations (AVMs) of the brain. METHODS: Thirty-five consecutive patients with AVMs of the brain were included. Quantitative analyses were performed by measuring both signal-to-noise ratio and contrast-to-noise ratio of the nidus. Qualitative analysis (scores 1-4) was performed by evaluating depictions of feeding arteries and draining veins independently by 2 reviewers. RESULTS: Both signal-to-noise ratio and contrast-to-noise ratio in TOF-MRA were significantly higher than those in silent MRA. For both feeders and drainers, scores were significantly higher in silent MRA than in TOF-MRA for both reviewers. Interrater agreement was higher in silent MRA than in TOF-MRA. CONCLUSIONS: Silent MRA visualized feeders and drainers in AVMs significantly better than did TOF-MRA. Interrater agreement was also better in silent MRA.

11C-Methionine Positron Emission Tomography/Computed Tomography Versus 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Evaluation of Residual or Recurrent World Health Organization Grades II and III Meningioma After Treatment.

OBJECTIVE: The aim of this study was to determine the assessment of positron emission tomography-computed tomography using C-methionine (MET PET/CT) for World Health Organization (WHO) grades II and III meningiomas; MET PET/CT was compared with PET/CT using F-fluorodeoxy glucose (FDG PET/CT). METHODS: This study was performed in 17 cases with residual and/or recurrent WHO grades II and III meningiomas. Two neuroradiologists reviewed both PET/CT scans. For agreement, the κ coefficient was measured. Difference in tumor-to-normal brain uptake ratios (T/N ratios) between 2 PET/CT scans was analyzed. Correlation between the maximum tumor size and T/N ratio in PET/CT was studied. RESULTS: For agreement by both reviewers, the κ coefficient was 0.51 (P < 0.05). The T/N ratio was significantly higher for MET PET/CT (3.24 ± 1.36) than for FDG PET/CT (0.93 ± 0.44) (P < 0.01). C-methionine ratio significantly correlated with tumor size (y = 8.1x + 16.3, n = 22, P < 0.05), but FDG ratio did not CONCLUSIONS: C-methionine PET/CT has superior potential for imaging of WHO grades II and III meningiomas with residual or recurrent tumors compared with FDG PET/CT.

[Indication for Radiotherapy for Breast Cancer Metastasis to the Skull Base Accompanied by Cranial Nerve Palsies].

Distant metastasis to the skull base region frequently manifests various cranial nerve symptoms and reduces patients' quality of life(QOL). We report a 62-year-old woman with skull base metastasis of breast cancer, whose condition clinically improved following palliative radiotherapy. The patient presented to our hospital with hoarseness. CT screening revealed a tumor in the right breast, axial lymph node swelling, and osteoblastic change at multiple sites. A core needle biopsy of the breast tumor revealed invasive lobular carcinoma. She also had nausea, anorexia, vertigo, lower left angle of the mouth, apraxia of lid closing, and dysphagia owing to several cranial nerve palsies. MRI T1- and T2-weighted images showed a diffuse low-signal intensity of the skull base region, and the patient was diagnosed as having breast cancer with symptomatic skull base metastases. Her cranial nerve symptoms improved after 1 week of palliative irradiation to the skull base. We conclude that, even among terminal-stage patients, palliative radiotherapy to the skull base region is an effective treatment option to improve patients' QOL.

Comparison of Rates of Growth between Unruptured and Ruptured Aneurysms Using Magnetic Resonance Angiography.

BACKGROUND AND PURPOSE: Growth is a key risk factor for rupture of unruptured cerebral aneurysms. There are few reports of investigations into the actual growth of ruptured intracranial aneurysms. The aim of the present study was to ascertain the risk of rupture of aneurysms based on the growth of unruptured and ruptured aneurysms. METHODS: Changes in size on magnetic resonance angiography (MRA) were examined in 50 patients with ruptured cerebral aneurysms. Images obtained before and after subarachnoid hemorrhage were used. Moreover, changes in aneurysm size were retrospectively examined in 73 patients with 100 unruptured cerebral aneurysms that were followed serially with MRA that was performed using a 1.5-T or 3-T system. The size of the aneurysm was determined by measuring the maximum diameter on maximum intensity projection MRA images. Based on these data, the annual growth rates (mm growth/year) of unruptured and ruptured aneurysms were calculated and compared. RESULTS: The median annual growth rate of ruptured aneurysms was significantly greater than that of unruptured aneurysms (.69 versus .077 mm/year, P < .01). The annual growth rates of ruptured aneurysms showed a negative correlation between the duration from initial MRA to the time of rupture. CONCLUSION: A high annual growth rate is a key risk factor for aneurysm rupture. This finding provides strong evidence for the treatment of unruptured cerebral aneurysms.

Accumulation of 11C-methionine in the normal pituitary gland on 11C-methionine PET.

Background For pituitary tumors, positron emission tomography (PET) with 11C-methonine (MET) has been reported as feasible to facilitate diagnosis. MET is well-known to accumulate in the normal pituitary glands, but almost no studies have examined the degree of MET accumulation in the normal pituitary gland. Purpose To investigate accumulation of MET in normal pituitary gland on PET/CT. Material and Methods Among patients who underwent PET/CT using MET over the past 7 years, 77 patients who fulfilled our criteria for normal pituitary glands were retrospectively selected. Maximum standardized uptake value (SUVmax) for the pituitary gland was measured. Results SUVmax of MET in the pituitary gland was in the range of 0.9-6.6 (mean ± standard deviation = 2.60 ± 1.04). A negative correlation between SUVmax and patient age (y = -0.032 × + 4.29, n = 77, r = 0.55) was found by linear regression analysis. SUVmax of the pituitary gland did not differ significantly between women and men. Conclusion MET shows strong accumulation in normal pituitary gland. PET/CT would thus be feasible to differentiate between normal and abnormal pituitary glands.

PET/CT findings for tumors in the base of the skull: comparison of 18 F-FDG with 11 C-methionine.

BACKGROUND: Positron emission tomography/computed tomography (PET/CT) using 18 F-fluorodeoxyglucose (FDG) has been used to characterize various malignancies. There are few reports regarding the use of 11 C-methionine (MET)-PET/CT to characterize tumors in the skull base. PURPOSE: To compare MET-PET/CT with FDG-PET/CT in cases of tumors of the skull base. MATERIAL AND METHODS: Both MET-PET/CT and FDG-PET/CT were performed in 27 patients with tumors of the skull base. In all cases, pathology was determined by surgery or biopsy. The images were visually and independently reviewed by two reviewers. For qualitative analysis, the inter-rater agreement between two reviewers was measured. For semi-quantitative evaluation, the tumor-to-normal brain uptake ratios (T/N ratios) were calculated by dividing the maximum of standardized uptake value (SUVmax) for the tumor by the SUVmax of the normal contra-lateral cerebellar hemisphere. Difference in T/N ratios between FDG-PET/CT and MET-PET/CT was analyzed for statistical significance. RESULTS: On qualitative evaluation, the inter-rater agreement of MET-PET/CT was superior than that of FDG-PET/CT. MET uptake was interpreted as positive in every tumor by both reviewers. MET-PET/CT had a significantly higher T/N ratio than FDG-PET/CT (2.96 ± 1.25 vs. 1.02 ± 0.54, respectively; P < 0.001). CONCLUSION: MET-PET/CT showed superior inter-rater agreement and had higher uptake for tumors at the skull base than FDG-PET/CT. The present study suggests that MET-PET/CT has superior potential for imaging of tumors of the skull base.

Differentiation of Brain Tumor Recurrence from Post-Radiotherapy Necrosis with 11C-Methionine PET: Visual Assessment versus Quantitative Assessment.

PURPOSE: The aim of this multi-center study was to assess the diagnostic capability of visual assessment in L-methyl-11C-methionine positron emission tomography (MET-PET) for differentiating a recurrent brain tumor from radiation-induced necrosis after radiotherapy, and to compare it to the accuracy of quantitative analysis. METHODS: A total of 73 brain lesions (glioma: 31, brain metastasis: 42) in 70 patients who underwent MET-PET were included in this study. Visual analysis was performed by comparison of MET uptake in the brain lesion with MET uptake in one of four regions (around the lesion, contralateral frontal lobe, contralateral area, and contralateral cerebellar cortex). The concordance rate and logistic regression analysis were used to evaluate the diagnostic ability of visual assessment. Receiver-operating characteristic curve analysis was used to compare visual assessment with quantitative assessment based on the lesion-to-normal (L/N) ratio of MET uptake. RESULTS: Interobserver and intraobserver κ-values were highest at 0.657 and 0.714, respectively, when assessing MET uptake in the lesion compared to that in the contralateral cerebellar cortex. Logistic regression analysis showed that assessing MET uptake in the contralateral cerebellar cortex with brain metastasis was significantly related to the final result. The highest area under the receiver-operating characteristic curve (AUC) with visual assessment for brain metastasis was 0.85, showing no statistically significant difference with L/Nmax of the contralateral brain (AUC = 0.89) or with L/Nmean of the contralateral cerebellar cortex (AUC = 0.89), which were the areas that were the highest in the quantitative assessment. For evaluation of gliomas, no specific candidate was confirmed among the four areas used in visual assessment, and no significant difference was seen between visual assessment and quantitative assessment. CONCLUSION: The visual assessment showed no significant difference from quantitative assessment of MET-PET with a relevant cut-off value for the differentiation of recurrent brain tumors from radiation-induced necrosis.

T2-weighted IDEAL fast spin echo imaging of the brachial plexus: comparison with STIR.

BACKGROUND: Short TI inversion-recovery (STIR) imaging is widely used, but its signal-to-noise-ratio (SNR) is relatively low. Iterative decomposition of water and fat with echo asymmetric and least-squares estimation (IDEAL) imaging has demonstrated promising results in several areas. PURPOSE: To compare T2-weighted fast spin-echo IDEAL (T2W IDEAL-FSE) with STIR to determine which sequence is superior to image the brachial plexus. MATERIAL AND METHODS: The brachial plexus was imaged in 18 patients and six volunteers. The patients' diseases comprised of: suspected chronic inflammatory demyelinating polyneuropathy (CIDP), brachial plexus palsy of unknown origin, and suspected amyotrophic lateral sclerosis. Frontal partial MIP images were acquired. Image quality was qualitatively and independently scored by two radiologists on a three-point grading scale for noise, visibility of the nerve roots, and overall image quality. Inter-observer agreement of the rating by two readers was assessed. The SNR and contrast-to-noise-ratio (CNR) were quantitatively calculated, and differences between T2W IDEAL-FSE and STIR were compared. RESULTS: Qualitatively, each score for T2W IDEAL-FSE was significantly higher (P < 0.01) than that for STIR. Quantitatively, both SNR and CNR for T2W IDEAL-FSE (45.3 ± 12.6 and 27.1 ± 12.1, respectively) were significantly higher (P < 0.001) than those for STIR (17.4 ± 6.1 and 8.2 ± 4.7, respectively). CONCLUSION: T2W IDEAL-FSE could be used to replace STIR for visualization of the brachial plexus.

Correlation between severity of carotid stenosis and vascular reserve measured by acetazolamide brain perfusion single photon emission computed tomography.

Few studies have investigated the relationship between the degree of stenosis of the internal carotid artery (ICA) and cerebrovascular reserve (CVR). This study examined that relationship. A total of 56 ICAs in 43 patients were included. Computed tomography scan or magnetic resonance imaging showed no evidence of infarction in any of these patients. Both iodine-123-N-isopropyl-p-iodoamphetamine ((123)IMP)-single photon emission computed tomography (SPECT) in the resting state and (123)IMP-SPECT with acetazolamide (ACZ) enhancement were performed. Quantitated cerebral blood flow (CBF) images were acquired with the (123)IMP autoradiography technique. The mean CBF without ACZ administration (resting CBF) and CVR in the middle cerebral artery territory were calculated using stereotactic extraction estimation (SEE) analysis software. The degree of stenosis in the origin of the ICA was calculated from intra-arterial digital subtraction angiography. Resting CBF was not correlated with the degree of ICA stenosis; however, nonlinear regression analysis (second-order equation) showed a moderate correlation between CVR and the degree of ICA stenosis. In 72% of the cases with a CVR <30%, ICA stenosis was >74%. Using the SEE method, CVR was moderately correlated with the degree of ICA stenosis. Our findings indicate that evaluating CVR by ACZ-enhanced (123)IMP-SPECT in patients with ICA stenosis is of clinical value.

Low Alberta stroke program early computed tomography score within 3 hours of onset predicts subsequent symptomatic intracranial hemorrhage in patients treated with 0.6 mg/kg Alteplase.

BACKGROUND: The significance of early ischemic changes (EICs) on computed tomography (CT) in selecting candidates for thrombolysis remains controversial. The Alberta Stroke Program Early CT Score (ASPECTS) provides a semiquantitative scale that scores EICs within the middle cerebral artery territory using a 10-point grading system. We examined whether ASPECTS can predict the response to intravenous thrombolysis within 3 hours of stroke onset and incidence of secondary hemorrhage. METHODS: Data from the Japan Alteplase Clinical Trial (J-ACT), in which 103 patients were included, were evaluated to assess the efficacy and safety of 0.6 mg/kg alteplase within 3 hours. All CT hardcopies were reevaluated retrospectively using the ASPECTS system. Multivariate logistic regression analysis was undertaken to determine whether an effect of ASPECTS existed on a defined favorable outcome as 0 or 1 on the modified Rankin Scale at 3 months, and symptomatic intracranial hemorrhage (sICH) within 36 hours. RESULTS: The median ASPECTS value was 10 (range 3 to 10), and 56.3% revealed no evidence of EICs. ASPECTS had no effect on the patients' outcome, although a higher age and National Institutes of Health Stroke Scale score were negatively associated with a favorable outcome. On the other hand, lower ASPECTS was significantly associated with sICH (odds ratio [OR] 2.224; 95% confidence interval [CI] 1.227-4.032; P = .0084) and systolic blood pressure (OR 1.090; 95% CI 1.007-1.180; P = .0323) and the pre-ictal use of antiplatelet medications (OR 15.551; 95% CI 1.144-211.374; P = .0393). CONCLUSIONS: In J-ACT, patients with low ASPECTS values have an increased risk of thrombolysis-related sICH.

Evaluation of postoperative status after clipping surgery in patients with cerebral aneurysm on 3-dimensional-CT angiography with elimination of clips.

BACKGROUND AND PURPOSE: the use of 3-dimensional computed tomography angiography (3D-CTA) for clipped aneurysms is limited. Usefulness of 3D-CTA with elimination of bone and clips was evaluated in patients with clipped cerebral aneurysms. METHODS: forty-three clipped cerebral aneurysms were included. As review of digital subtraction angiography after surgery is the current gold standard, the presence or absence of remnant necks on 3D-CTA with elimination of bone and clips was compared with that on conventional CTA, using receiver operating characteristic analysis (5, definitely absent; 1, definitely present). RESULTS: in the ROC analysis, the Az (.949) in CTA with clip elimination significantly (P < .05) differed from that (.751) of conventional 3D-CTA. If a score of 1 or 2 is considered to represent positive detection of remnant necks, then the sensitivity of 3D-CTA with clip elimination and of conventional 3D-CTA is 73% and 36%, respectively. If a score of 5 or 4 is considered to represent negative detection of remnant necks, then the specificity of 3D-CTA with clip elimination and of conventional 3D-CTA is 88% and 78%, respectively. CONCLUSIONS: 3D-CTA with elimination of bone and clips can improve the accuracy of detection of remnant necks after clipping surgery for cerebral aneurysms.

Three-dimensional bone-free computed tomographic angiography of aneurysms near the skull base using a new bone-removal application.

PURPOSE: Bone elimination is needed for computed tomography angiography (CTA) because bone structures obscure aneurysms located at the skull base. The purpose of our study was to evaluate the efficacy of three-dimensional (3D)-CTA using an application for bone elimination. MATERIALS AND METHODS: A total of 27 patients with 32 angiographically confirmed aneurysms near the skull base were investigated. The 3D maximum intensity projection (MIP) images were initially obtained using the application. Further postprocessing was performed to obtain the MIP and volume-rendered (VR) images. The quality of the initial MIP images by the application was analyzed. Visualization of aneurysms after further processing was also reviewed. RESULTS: The initial MIP images by the application showed almost bone-free images in 23 of the 27 patients. In 8 patients, the image of the internal carotid artery (ICA) was segmentally removed in the initial MIP images by the application. Further postprocessing was able to recover all loss of the ICA image in these eight patients. For visualizing aneurysms and their necks, VR images with the application were significantly superior to VR images without the application. CONCLUSION: The application for bone elimination allows fast, selective elimination of bony structures and can improve the interpretation of aneurysms near the skull base.

Reduced perfusion reserve in Leukoaraiosis demonstrated using acetazolamide challenge 123I-IMP SPECT.

OBJECTIVE: We examined the relationship between the perfusion reserve as measured by acetazolamide (ACZ)-challenge N-isopropyl-I-123-p-iodoamphetamine (IMP)-single-photon emission computed tomography (SPECT) and the degree of leukoaraiosis (LA) as estimated using magnetic resonance imaging. METHODS: In 51 patients receiving IMP-SPECT with the resting state and ACZ challenge, the unaffected cerebral hemispheres were included in the present study. Mean cerebral blood flow (CBF) in the resting state and ACZ reactivity were acquired. Absolute CBF value and ACZ reactivity were compared among patients with LA grades 0, 1, and 2. The relationship between mean age and LA grade was also assessed. RESULTS: No significant difference in the absolute CBF value in the resting state was observed among the 3 LA groups. Although vasoreactivity in LA grade 0 did not differ from that in grade 1, vasoreactivity in LA grade 2 was significantly lower (P < 0.05) than that in grades 0 or 1. CONCLUSIONS: The perfusion reserve is impaired in advanced LA.

Visualization of anterior disc displacement in temporomandibular disorders on contrast-enhanced magnetic resonance imaging: comparison with T2-weighted, proton density-weighted, and precontrast T1-weighted imaging.

OBJECTIVE: To compare postcontrast T1-weighted imaging (T1WI+) with precontrast T1-weighted (T1WI-), T2-weighted (T2WI), and proton density-weighted imaging (ProWI) in depiction of the anterior disc displacement (ADD) in temporomandibular disorders (TMDs). STUDY DESIGN: A total of 120 joints with TMD were included in this study. Qualitatively, Receiver operating characteristic analysis was performed. Quantitatively, the ratio of the intensity in the retrodiscal tissue to intensity in the disc (intensity ratio) was measured. RESULTS: One reader achieved superior performance in visualization of ADD with T1WI+ than with the other sequences. The other reader showed superiority with T1WI+ rather than T2WI or T1WI-. The intensity ratio on T1WI+ was significantly higher than the intensity ratio on other sequences. On T1WI,+ the intensity ratio in the joints with ADD was significantly higher than that in the joints without ADD. CONCLUSION: Postcontrast T1-weighted imaging can improve the visualization of ADD in TMDs.