Clinical utility of dynamic-enhanced MRI in salivary gland tumors: retrospective study and literature review.

PURPOSE: To improve the diagnoses of the salivary gland tumors, a dynamic-enhanced MRI (dMRI) was investigated. METHODS: We conducted a retrospective chart review of 93 cases of salivary gland tumors. The histological diagnoses were obtained from all patients using a surgical specimen and/or an open biopsy specimen. The dMRI as well as fine-needle aspiration cytology (FNAC) and intraoperative frozen section (IFS) were analyzed. This study focused on the time-intensity curve (TIC) after injection, peak time (Tpeak), washout ratio (WR) as well as the gradient of enhancement and washout profile. RESULTS: The histological diagnoses included pleomorphic adenoma (PMA) in 53 cases, the Warthin tumors (WT) in 14 cases and malignant tumors (MT) in 26 cases. Incorrect diagnosis rate of FNAC and IFS were 5.2 and 8.3%, respectively. The TIC revealed differences among the three types of tumors. Tpeak as well as WR also revealed significant differences (p < 0.001). Tpeak were lower in order of WT, MT, PMA, respectively. WR of TICs at 30, 45 and 105 s after Tpeak were higher in order of WT, MT, PMA, respectively (p < 0.001). The gradient of increment and washout in the TIC curve was also an important parameter to distinguish the three types of tumors. In MT, the rapid enhancement pattern was found in high or intermediate histological grade tumors, whereas the slow enhancement pattern was exhibited in low grade tumors. CONCLUSIONS: Our findings indicate that using Tpeak and WR, it is possible to distinguish between WT, PMA and MT. Additionally, a rapid enhancement pattern may be a potential marker for these tumors.

Ischemic White Matter Lesions Associated With Medullary Arteries: Classification of MRI Findings Based on the Anatomic Arterial Distributions.

OBJECTIVE: The purposes of this article are to describe the important role of the medullary arteries in the pathogenesis of cerebral vascular disease and to present a classification of MRI findings of ischemic white matter lesions for use in elucidating pathogenesis. CONCLUSION: From the viewpoint of the anatomy of the medullary arteries, the pattern of medullary artery-related ischemic changes and infarcts can be classified into four types: 1, ischemic leukoaraiosis; 2, infarcts involving individual medullary arteries; 3, watershed infarcts; and 4, territorial infarcts.

Phase Difference-Enhanced Magnetic Resonance (MR) Imaging (PADRE) Technique for the Detection of Age-Related Microstructural Changes in Optic Radiation: Comparison with Diffusion Tensor Imaging (DTI).

BACKGROUND The optic radiation (OR) is a white-matter bundle connecting the lateral geniculate body and the visual cortex. Phase difference-enhanced imaging (PADRE) is a new MRI technique that is able to achieve precise delineation of the OR. The aim of this study was to investigate the effect of age on the volume and signal intensity of the OR using PADRE, and to establish a volumetric reference of the OR from a healthy population, compared with diffusion tensor imaging (DTI). MATERIAL AND METHODS Thirty-nine healthy volunteers underwent MR imaging with PADRE and DTI sequences on a 3.0-T scanner. For the volumetric analysis with PADRE, the OR corresponding to the external sagittal stratum was manually traced, while an automated thresholding method was used for the DTI-based volumetric analysis of the OR. RESULTS The mean right and left OR volumes measured from the PADRE images were 1469.0±242.4 mm³ and 1372.6±310.2 mm³, respectively. Although OR volume showed no significant correlation with age, the normalized OR signal intensity showed a linear correlation with increasing age (r²=0.50-0.53; P<0.01). The OR signal intensity on PADRE and DTI-related quantitative parameters for the OR showed significant correlations (r²=0.46-0.49; P<0.01). CONCLUSIONS The PADRE technique revealed exceptional preservation of OR volume, even in later life. Moreover, PADRE was able to detect age-related changes in signal intensity of the OR and may contribute to future analyses of pathological neurodegeneration in patients with glaucoma and multiple sclerosis.

Correlation of magnetic resonance imaging optic nerve parameters to optical coherence tomography and the visual field in glaucoma.

BACKGROUND: To determine the viability of using magnetic resonance imaging measurement of optic nerve morphology as an objective analysis of glaucomatous damage. DESIGN: Retrospective study conducted at Tohoku University Hospital. PARTICIPANTS: Thirty-eight eyes of 19 patients with open-angle glaucoma. METHODS: Patients were scanned with T2-weighted and 3-T diffusion tensor magnetic resonance imaging, and parameters of the optic nerve, including fractional anisotropy, apparent diffusion coefficient and cross-sectional area, were determined. Conventional parameters of glaucomatous damage, including circumpapillary and macular retinal nerve fibre layer thickness, and mean deviation and average total deviation of the central 16 test points from the Humphrey Field Analyzer, were then compared with the magnetic resonance imaging-derived parameters. Spearman's coefficient of correlation was calculated to determine the significance of the correlation. MAIN OUTCOME MEASURE: Correlation coefficient between the magnetic resonance imaging parameters and the parameters of glaucomatous damage. RESULTS: Mean deviation was significantly correlated with all magnetic resonance imaging parameters (fractional anisotropy: r = 0.53, apparent diffusion coefficient: r = -0.44, cross-sectional area: r = 0.70). Circumpapillary retinal nerve fibre layer thickness was significantly correlated with fractional anisotropy (r = 0.60) and cross-sectional area (r = 0.47), but not apparent diffusion coefficient (r = -0.29). Central macular function and macular retinal nerve fibre layer thickness were also significantly correlated with magnetic resonance imaging parameters. CONCLUSIONS: Optic nerve magnetic resonance imaging parameters were significantly correlated to glaucomatous damage. Magnetic resonance imaging analysis of the optic nerve may, thus, have value as an objective instrument to assess glaucomatous degeneration, including the function of the macula.

Perfusion defects in non-enlarged metastatic lymph nodes using vessel wall magnetic resonance imaging: Detection performance and diagnostic value.

A perfusion defect (PD) in non-enlarged lymph nodes (LNs) of oral squamous cell carcinoma (OSCC) is the most reliable radiological criterion for the diagnosis of metastasis. However, conventional contrast-enhanced (CE) T1 weighted images using turbo spin echo (TSE) sequence is limited in detecting PD in non-enlarged LNs due to flow artifacts from cervical blood vessels. Vessel wall (VW) MR imaging with blood vessel flow suppression and high spatial resolution may provide new insights into the detection of PD. However, there are no reports in the literature on the usefulness of VW MR imaging for the diagnosis of LN metastasis. It is demonstrated that PD of non-enlarged LNs in CE VR MR imaging of OSCC patients is useful for the diagnosis of metastatic LNs. VW MR imaging was significantly more sensitive in detecting PD of non-enlarged metastatic LNs than conventional TSE imaging on visual evaluation. Furthermore, it was found that the image contrast between PD and surrounding intranodal tissue in CE VW MR images was higher than that in conventional CE TSE images. In the correlation between imaging and histopathological findings of metastatic LNs, all LNs that exhibited PD on CE VW MR images were at an advanced histopathological metastatic stage. The pathology of PD was necrotic tissue with keratinization. The results indicated that PD in CE VW imaging is useful in diagnosing non-enlarged LNs at an advanced metastasis stage. The addition of VW MR imaging to conventional MR examination achieves higher diagnostic performance for non-enlarged metastatic LNs.

Recurrence of Lymph Node Micrometastases After Radiotherapy for Head and Neck Carcinoma: A Propensity Score-matched Study.

Background: The standard irradiation dose to the elective lymph node area (ELNA) in locally patients with advanced head and neck squamous cell carcinoma (LA-HNSCC) to control lymph node micrometastases (LN-MM) has not changed since it was empirically determined in the 1950s. We investigated the optimal irradiation dose for controlling LN-MM in ELNAs. Patients and Methods: The pattern of recurrence of LA-HNSCC was retrospectively evaluated in patients who underwent concurrent chemoradiotherapy with cisplatin or radiation therapy alone. Results: In total, 162 patients were enrolled. The median observation period was 34 months. No recurrence was found in ELNAs. After propensity score matching, a cisplatin dose of ≥200 mg/m 2 yielded a significantly higher overall survival rate (p≤0.001) and locoregional control rate (p=0.034) than did a dose of <100 mg/m 2 . Conclusion: CCRT with a cisplatin dose of ≥200 mg/m 2 can reduce the irradiation dose to 40-44 Gy at 2 Gy per fraction to control LN-MM.

Comparison of different diagnostic imaging techniques for the detection of bone invasion in oral cancers.

OBJECTIVES: To evaluate the ability of different imaging modalities to accurately detect bone invasion in oral squamous cell carcinomas. PATIENTS AND METHODS: Patients with oral squamous cell carcinoma, who were scheduled for mandibulectomy or maxillectomy, underwent clinical evaluation using five preoperative imaging diagnosis methods-contrast-enhanced MRI, CT, 99mTc scintigraphy (Tc scan), FDG-PET CT (PET/CT), and panoramic radiography. The sensitivity and specificity of each modality in detecting bone invasion were calculated by comparing the findings on the images with postoperative histopathological findings. In a subgroup of patients, we further assessed the ability of MRI and CT to detect the accurate extent of bone invasion, including the height, width, and depth in patients with pathological mandibular invasion. RESULTS: Overall, 50 patients were enrolled in this study, and nine patients with pathological mandibular invasion were included in our subgroup analysis. MRI was found to be the most useful method in detecting bone invasion, showing the highest sensitivity (88.9%) and negative predictive values (92.3%). CT (87.5% specificity and 77.8% sensitivity) was more specific than MRI, though less sensitive. Combined PET/CT was more sensitive (83.3%) and less specific (71.9%) than CT. Tc scan had high sensitivity (88.9%); however, the specificity was relatively low (71.9%). CONCLUSION: MRI was the most useful method in detecting bone invasion. A negative MRI result definitively excludes bone marrow invasion. In patients with positive MRI findings, a negative CT may be useful in ruling out bone marrow invasion.

Thrombosis of a basilar perforator aneurysm associated with pontine infarction in a patient with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disease that can affect multiple organ systems. Cerebral aneurysm formation is a rare central nervous system manifestation of SLE and tends to present as subarachnoid hemorrhage. Here, we report a 34-year-old woman with SLE complicated by a thrombosed aneurysm that had arose at the origin of a perforating artery, thereby causing obstruction of the artery and subsequent development of pontine infarction. Detailed examination of thin-slice CT and magnetic resonance imaging scans led to the correct diagnosis of uncommon cause of stroke.

Unilateral chronic pulsatile headache as the single manifestation of anti-MOG antibody-associated unilateral cerebral cortical encephalitis.

Unilateral cerebral cortical encephalitis (UCCE) with myelin oligodendrocyte glycoprotein (MOG)-antibody comprises a new spectrum of disease entities generally presenting seizures. Here, we report a case of a young adult with anti-MOG antibody-associated UCCE who only presented persistent left pulsatile headache. Neurological examination revealed no deficits. Brain MRI showed a fluid-attenuated inversion recovery hyperintense lesion along the swollen left cerebral cortex. The patient was positive for anti-MOG antibodies. We diagnosed him with anti-MOG antibody-associated UCCE. Immediately after the administration of high-dose IV methylprednisolone, the headache diminished. Anti-MOG antibody-associated UCCE is a new differential diagnosis in patients with unilateral chronic pulsatile headache.

Location of the stapedius muscle with reference to the facial nerve in patients with unilateral congenital aural atresia: implication for active middle ear implants surgery.

Background: Detailed investigations of the stapedial muscle (SM) in congenital aural atresia (CAA) patients have yet to be adequately conducted.Objectives: To assess image variations in the mastoid segment of the facial nerve (FN) and SM in CAA.Materials and methods: A total of nine patients comprising of 9 ears with unilateral CAA were studied. The courses of the FN and SM were evaluated from the basic point to 1 mm intervals between the mastoid portion of FN, and measured from the mean X and Y values in each group.Results: The atresia side of FN among the Y values showed significant differences compared to the contralateral side. In terms of the SM, there were no significant differences in both the X and Y values. The stapedial muscle of the CAA patients was located medially to the FN. Conversely, the distance from the PSC to the FN revealed no significant differences with regard to the X and Y values for each group.Conclusion: The current observations revealed that the SM is located more posterior to the FN in CAA patients, and this is mainly attributed to the laterally and anteriorly displaced FN.

Clinical utility of apparent diffusion coefficient and diffusion-weighted magnetic resonance imaging for resectability assessment of head and neck tumors with skull base invasion.

BACKGROUND: The usefulness of apparent diffusion coefficient (ADC) and diffusion-weighted magnetic resonance imaging (DWI) in the detection of malignant tumors has been reported. The purpose of this study is to clarify the role of ADC and DWI for diagnosis of skull base tumors. METHODS: A total of 27 patients with head and neck tumors with skull base invasions undergoing skull base surgery were enrolled in this study. Pathological findings of dural invasion and bone invasion were compared with the diagnostic imaging. RESULTS: Advanced magnetic resonance imaging techniques revealed that ADC values in regions of pathological bone and dural invasions were significantly lower than in regions of no invasion. The area under the curve of ADC in bone invasions and dural invasions were 0.957 and 0.894, respectively. CONCLUSIONS: Our findings indicate that ADC and DWI are useful tools for the diagnosis of head and neck tumors with skull base invasion.

Phase I trial of convection-enhanced delivery of nimustine hydrochloride (ACNU) for brainstem recurrent glioma.

BACKGROUND: Treatment options for patients suffering brainstem gliomas are quite limited as surgery is not an option against intrinsic tumors at brainstem and chemotherapy generally failed to demonstrate its efficacy. Intracerebral convection-enhanced delivery (CED) is a novel approach for administering chemotherapy to patients with brain tumors. We present the results of phase I trial of CED of nimustine hydrochloride (ACNU), designed to determine the maximum tolerable concentration of ACNU, for patients with recurrent brainstem gliomas. METHODS: Sixteen patients, aged 3-81 years old, suffering from recurrent brainstem gliomas, including diffuse intrinsic pontine glioma patients as well as patients with recurrent gliomas that originated from non-brainstem sites, were enrolled in this trial between February 2011 and April 2016. The dose/concentration escalation trial included 3 dose/concentration groups (0.25, 0.5, and 0.75 mg/mL, all at 7 mL) to determine the safety and tolerability of CED of ACNU. Real-time monitoring of drug distribution was performed by mixing gadolinium-tetraazacyclododecanetetraacetic acid (Gd-DOTA) in the infusion solution. CED of ACNU was given in combination with oral or intravenous temozolomide chemotherapy. RESULTS: CED of ACNU demonstrated antitumor activity, as assessed by radiographic changes and prolonged overall survival. The recommended dosage was 0.75 mg/mL. Drug-associated toxicity was minimal. CONCLUSIONS: Intracerebral CED of ACNU under real-time monitoring of drug distribution, in combination with systemic temozolomide, was well tolerated among patients with recurrent brainstem gliomas. The safety and efficacy observed suggest the clinical benefits of this strategy against this devastating disease. Based on this phase I study, further clinical development of ACNU is warranted.

Vibrant Soundbridge implantation via a retrofacial approach in a patient with congenital aural atresia.

OBJECTIVE: A method of Vibrant Soundbridge (VSB) placement to the round window (RW) via the retrofacial approach with preoperative evaluation of the relationship between the facial nerve (FN) and RW by 3D-CT reconstruction was proposed for the treatment of congenital aural atresia (CAA) patient. METHODS: A fenestration to the mesotympanum was made mastoid portion of the FN. During the approach, part of the stapedial muscle was encountered and removed. The RW niche was identified, and the floating mass transducer was placed from an inferior approach into the RW niche. RESULTS: There were no intra-operative or post-operative surgical complications. CONCLUSION: The VSB placement to the RW via the retrofacial approach with partial removal of the stapedial muscle can be feasible alternative in CAA cases associated with an anteriorly and laterally positioned aberrant FN. Preoperative assessment using 3D CT may facilitate in assessing the feasibility of the approach and implantation of VSB.

Quantitative MRI evaluation of glaucomatous changes in the visual pathway.

BACKGROUND: The aims of this study were to investigate glaucomatous morphological changes quantitatively in the visual cortex of the brain with voxel-based morphometry (VBM), a normalizing MRI technique, and to clarify the relationship between glaucomatous damage and regional changes in the visual cortex of patients with open-angle glaucoma (OAG). METHODS: Thirty-one patients with OAG (age: 55.9 ± 10.7, male: female = 9: 22) and 20 age-matched controls (age: 54.9 ± 9.8, male: female = 10: 10) were included in this study. The cross-sectional area (CSA) of the optic nerve was manually measured with T2-weighed MRI. Images of the visual cortex were acquired with T1-weighed 3D magnetization-prepared rapid acquisition with gradient echo (MPRAGE) sequencing, and the normalized regional visual cortex volume, i.e., gray matter density (GMD), in Brodmann areas (BA) 17, 18, and 19, was calculated with a normalizing technique based on statistic parametric mapping 8 (SPM8) analysis. We compared the regional GMD of the visual cortex in the control subjects and OAG patients. Spearman's rank correlation analysis was used to determine the relationship between optic nerve CSA and GMD in BA 17, 18, and 19. RESULTS: We found that the normal and OAG patients differed significantly in optic nerve CSA (p < 0.001) and visual cortex GMD in BA 17 (p = 0.030), BA 18 (p = 0.003), and BA 19 (p = 0.005). In addition, we found a significant correlation between optic nerve CSA and visual cortex GMD in BA 19 (r = 0.33, p = 0.023), but not in BA 17 (r = 0.17, p = 0.237) or BA 18 (r = 0.24, p = 0.099). CONCLUSION: Quantitative MRI parametric evaluation of GMD can detect glaucoma-associated anatomical atrophy of the visual cortex in BA 17, 18, and 19. Furthermore, GMD in BA 19 was significantly correlated to the damage level of the optic nerve, as well as the retina, in patients with OAG. This is the first demonstration of an association between the cortex of the brain responsible for higher-order visual function and glaucoma severity. Evaluation of the visual cortex with MRI is thus a very promising potential method for objective examination in OAG.

Traumatic midline subarachnoid hemorrhage on initial computed tomography as a marker of severe diffuse axonal injury.

OBJECTIVEThe objective of this study was to test the hypothesis that midline (interhemispheric or perimesencephalic) traumatic subarachnoid hemorrhage (tSAH) on initial CT may implicate the same shearing mechanism that underlies severe diffuse axonal injury (DAI).METHODSThe authors enrolled 270 consecutive patients (mean age [± SD] 43 ± 23.3 years) with a history of head trauma who had undergone initial CT within 24 hours and brain MRI within 30 days. Six initial CT findings, including intraventricular hemorrhage (IVH) and tSAH, were used as candidate predictors of DAI. The presence of tSAH was determined at the cerebral convexities, sylvian fissures, sylvian vallecula, cerebellar folia, interhemispheric fissure, and perimesencephalic cisterns. Following MRI, patients were divided into negative and positive DAI groups, and were assigned to a DAI stage: 1) stage 0, negative DAI; 2) stage 1, DAI in lobar white matter or cerebellum; 3) stage 2, DAI involving the corpus callosum; and 4) stage 3, DAI involving the brainstem. Glasgow Outcome Scale-Extended (GOSE) scores were obtained in 232 patients.RESULTSOf 270 patients, 77 (28.5%) had DAI; tSAH and IVH were independently associated with DAI (p < 0.05). Of tSAH locations, midline tSAH was independently associated with both overall DAI and DAI stage 2 or 3 (severe DAI; p < 0.05). The midline tSAH on initial CT had sensitivity of 60.8%, specificity of 81.7%, and positive and negative predictive values of 43.7% and 89.9%, respectively, for severe DAI. When adjusted for admission Glasgow Coma Score, the midline tSAH independently predicted poor GOSE score at both hospital discharge and after 6 months.CONCLUSIONSMidline tSAH could implicate the same shearing mechanism that underlies severe DAI, for which midline tSAH on initial CT is a probable surrogate.

Canadian CT head rule and New Orleans Criteria in mild traumatic brain injury: comparison at a tertiary referral hospital in Japan.

We compared Canadian computed tomography (CT) head rule (CCHR) and New Orleans Criteria (NOC) in predicting important CT findings in patients with mild traumatic brain injury (TBI). We included 142 consecutive patients with mild TBI [Glasgow coma scale (GCS) 13-15] who showed at least one of the risk factors stated in the CCHR or the NOC. We introduced two scores: a Canadian from the CCHR and a New Orleans from the NOC. A patient's score represented a sum of the number of positive items. We examined the relationship between scores or items and the presence of important CT findings. Only the Canadian was significantly associated with important CT findings in multivariate analyses and showed higher area under the receiver operating characteristic curve (AUC) either in all 142 patients (GCS 13-15: P = 0.0130; AUC = 0.69) or in the 67 with a GCS = 15 (P = 0.0128, AUC = 0.73). Of items, ">60 years" or "≥65 years" included in either guideline was the strongest predictor of important CT finding, followed by "GCS < 15 after 2 h" included only in the CCHR. In a tertiary referral hospital in Japan, CCHR had higher performance than the NOC in predicting important CT findings.

A comparative study of the extent of cerebral microvascular injury following whole-brain irradiation versus reduced-field irradiation in long-term survivors of intracranial germ cell tumors.

BACKGROUND AND PURPOSE: Radiation-induced cerebral cavernous malformation reflects post-irradiation impairment of cerebral microcirculation. Our purpose was to determine effects of radiation field size and dose on the extent of developing cavernous malformations in long-term survivors of intracranial germ cell tumors (GCTs). METHODS: The study involved 34 patients with a history of intracranial GCTs treated with either whole-brain or reduced-field irradiation and undergoing magnetic resonance (MR) imaging with a mean follow-up of 18.5 years. The number of cavernous malformations on T2*-weighted MR images between whole-brain and reduced-field irradiation groups as well as between high- (50.2 Gy) and low-dose (24.4 Gy) fields were compared. RESULTS: A total of 235 cavernous malformation lesions were observed in 32 of 34 patients (94.1%). The mean number of lesions was 2.3 times as high in the whole-brain group as in the reduced-field group (P = 0.00296). The number of lesions in high-dose fields was significantly larger than in low-dose (P < 0.000001) or untreated fields (P < 0.001). CONCLUSION: Radiation field size and dose were positively associated with the number of cavernous malformations developed. Cavernous malformations detected on MR imaging can be used as a surrogate marker for microvascular injury following intracranial irradiation in long-term cancer survivors.

Utility of diffusion tensor imaging parameters for diagnosis of hemimegalencephaly.

BACKGROUND: Hemimegalencephaly is a rare hamartomatous entity characterised by enlargement of all or part of the cerebral hemisphere ipsilaterally with cortical dysgenesis, large lateral ventricle and white matter hypertrophy with or without advanced myelination. Although conventional magnetic resonance imaging (MRI) is useful for detecting these diagnostic features, hemimegalencephaly is not always easily distinguished from other entities, especially when hemimegalencephaly shows blurring between the grey and white matter. Diffusion tensor imaging (DTI) is a functional MRI technique commonly used to assess the integrity of white matter. The usefulness of DTI in assessing hemimegalencephaly has not been fully elucidated. In this study, we clarified the characteristics of hemimegalencephaly with regard to DTI and its parameters including fractional anisotropy and apparent diffusion coefficient. METHODS: Three patients with hemimegalencephaly underwent MRI including DTI. We first visually compared fractional anisotropy mapping and conventional MRI. Next, we quantitatively measured the fractional anisotropy and apparent diffusion coefficient values in the subcortical white matter of the hemisphere with hemimegalencephaly and corresponding normal-appearing contralateral regions and analysed the values using the Mann-Whitney U test. RESULTS: On fractional anisotropy mapping, we could clearly distinguish the junction of grey and white matter and observed thicker white matter in the hemisphere with hemimegalencephaly, which was unclear on conventional MRI. The white matter in the hemisphere with hemimegalencephaly showed significantly higher fractional anisotropy (P<0.0001) and lower apparent diffusion coefficient (P=0.0022) values than the normal contralateral side. CONCLUSION: DTI parameters showed salient hemimegalencephaly features and could be useful in its assessment.

Intraventricular hemorrhage on initial computed tomography as marker of diffuse axonal injury after traumatic brain injury.

Intraventricular hemorrhage (IVH) on initial computed tomography (CT) was reported to predict lesions of diffuse axonal injury (DAI) in the corpus callosum (CC) on subsequent magnetic resonance imaging (MRI). We aimed to examine the relationship between initial CT findings and DAI lesions detected on MRI as well as the relationship between the severity of IVH (IVH score) and severity of DAI (DAI staging). A consecutive 140 patients with traumatic brain injury (TBI) who underwent MRI within 30 days after onset were revisited. We reviewed their initial CT for the following six findings: Status of basal cistern, status of mid-line shift, epidural hematoma, IVH, subarachnoid hemorrhage, and volume of hemorrhagic mass and IVH score were assigned in each patient. Based on MRI findings, patients were divided into DAI and non-DAI groups and were assigned a DAI staging. Then, to confirm that the IVH on initial CT predicts DAI lesions on MRI, we used multi-variate analysis of the six CT findings, including IVH, and examined the relationship between IVH score and DAI staging. The IVH detected on CT was the only predictor of DAI (p=0.0139). The IVH score and DAI staging showed significant positive correlation (p<0.0003). IVH score in DAI stage 3 (with DAI involving the brain stem; p=0.0025) or stage 2 (with DAI involving CC; p=0.0042) was significantly higher than that of DAI stage 0 (no DAI lesions). In conclusion, IVH on initial CT is the only marker of DAI on subsequent MRI, specifically severe DAI (stage 2 or 3).

Conspicuity and evolution of lesions in Creutzfeldt-Jakob disease at diffusion-weighted imaging.

BACKGROUND AND PURPOSE: Diffusion-weighted imaging can disclose distinct hyperintense lesions in Creutzfeldt-Jakob disease (CJD). However, these findings and chronologic changes of CJD at diffusion-weighted imaging have not been fully investigated. Our purpose was to assess the diagnostic value of diffusion-weighted imaging in depicting CJD-related lesions and in tracking the evolution of these lesions. We also compared the sensitivity of diffusion-weighted imaging in depicting CJD-related lesions to that of fluid-attenuated inversion recovery (FLAIR) imaging. METHODS: We reviewed findings in 13 patients with a diagnosis of CJD who underwent MR imaging, including diffusion-weighted imaging. Nine patients were initially examined within 4 months of onset of symptoms (early stage), and eight were examined 4 months or later (late stage). We evaluated four items: 1) distribution of lesions at diffusion-weighted imaging, 2) conspicuity of lesions at diffusion-weighted imaging and FLAIR imaging, 3) chronologic changes in lesions at diffusion-weighted imaging, and 4) chronologic changes in lesions revealed by apparent diffusion coefficient (ADC) maps. RESULTS: Patients had striatal lesions or cerebral cortical lesions or both. The thalamus was involved in only one patient, and the globus pallidus was spared in all patients. The sensitivity of diffusion-weighted imaging in depicting lesions was superior or at least equal to that of FLAIR imaging. Hyperintense lesions at diffusion-weighted imaging changed in extent and intensity over time. Unlike infarction, lesional ADC decreased for 2 weeks or longer. CONCLUSION: The progressively hyperintense changes in the striata and cerebral cortices at diffusion-weighted imaging are considered characteristic of CJD. Diffusion-weighted imaging may be useful for the early diagnosis of CJD.