Evaluation of the extracranial "multifocal arcuate sign," a novel MRI finding for the diagnosis of giant cell arteritis, on STIR and contrast-enhanced T1-weighted images.

BACKGROUND: While early diagnosis of giant cell arteritis (GCA) based on clinical criteria and contrast-enhanced MRI findings can lead to early treatment and prevention of blindness and cerebrovascular accidents, previously reported diagnostic methods which utilize contrast-enhanced whole head images are cumbersome. Diagnostic delay is common as patients may not be aware of initial symptoms and their significance. To improve current diagnostic capabilities, new MRI-based diagnostic criteria need to be established. This study aimed to evaluate the "multifocal arcuate sign" on short tau inversion recovery (STIR) and contrast-enhanced T1-weighted (CE-T1W) images as a novel extracranial finding for the diagnosis of GCA. METHODS: A total of 17 consecutive patients (including five with GCA) who underwent CE-T1W and whole-brain axial STIR imaging simultaneously between June 2010 and April 2020 were enrolled. We retrospectively reviewed their MR images. The "multifocal arcuate sign" was defined as "multiple distant arcuate areas with high signal intensity in extracranial soft tissues such as subcutaneous fat, muscles, and tendons." Extracranial abnormal high-signal-intensity areas were classified as "None," when no lesions were detected; "Monofocal," when lesions were detected only in one place; and "Multifocal," when lesions were detected in multiple places. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of "Multifocal" areas were calculated using cross tabulation. Fisher's exact test was used to compare "Multifocal" areas in five patients with GCA and those with other diseases. In addition, mean Cohen's kappa and Fleiss' kappa statistics were used to compare inter-reader agreement. RESULTS: The sensitivity, specificity, PPV, and NPV of the "multifocal arcuate sign" in patients with GCA were 60%, 92-100%, 75-100%, and 85-86%, respectively. Significantly more patients with GCA had "Multifocal" areas compared to those with other diseases (Fisher's exact test, p = 0.008-0.027). Mean Cohen's kappa and Fleiss' kappa for inter-reader agreement with respect to the five GCA patients were 0.52 and 0.49, respectively, for both STIR and CE-T1W sequences. CONCLUSIONS: The new radiologic finding of "multifocal arcuate sign" on STIR and CE-T1W images may be used as a radiologic criterion for the diagnosis of GCA, which can make plain MRI a promising diagnostic modality.

Clinical and image features: large-vessel vasculitis after granulocyte colony stimulating factor administration.

BACKGROUND: Granulocyte colony stimulating factor (G-CSF) is known to cause vasculitis, mainly in the small vessels. Several cases of large-vessel vasculitis (LVV) caused by G-CSF have recently been reported in the literature; we retrospectively suspect that some cases of LVV in our institution were associated with administration of G-CSF. PURPOSE: To evaluate the clinical and radiological findings in our cases and to compare them with those in previous reports. MATERIAL AND METHODS: We retrospectively evaluated clinical and radiological findings in four cases of LVV that occurred after administration of G-CSF in our institution. We also reviewed papers on G-CSF-related LVV and compared their findings to ours. RESULTS: G-CSF-related LVV occurred in patients aged > 50 years and more frequently in women. Most patients developed vasculitis within 15 days after the last administration. While 14/16 patients were symptomatic, the remaining two patients were asymptomatic and diagnosed incidentally. In all cases, laboratory inflammatory markers increased, but there were no autoantibodies that clearly indicated other autoimmune vasculitis. Computed tomography revealed elevated soft tissue density around the affected vessels. CONCLUSION: LVV is among the potential adverse events of G-CSF administration. We should keep this outcome in mind when we interpret medical images of patients with previous G-CSF treatment history even if they are asymptomatic.

Correlation between hypoxic area in primary brain tumors and WHO grade: differentiation from malignancy using 18F-fluoromisonidazole positron emission tomography.

Background 18F-fluoromisonidazole positron emission tomography (FMISO-PET) has been used for identification of hypoxic areas in tumors, and since hypoxia causes hypoxia-inducible factor-1 and enhancement of tumor growth, identifying the hypoxic area in the tumor tissue is important. Purpose To evaluate the usefulness of FMISO-PET in the grading of primary brain tumors. Material and Methods FMISO-PET was performed preoperatively on 41 consecutive patients with pathologically confirmed brain tumor. A neuroradiologist retrospectively measured both maximum standardized uptake value (SUVmax) and mean SUV (SUVmean) in the tumor and normal cerebellar parenchyma. Maximum tumor/normal control ratio (T/Nmax) and mean tumor/normal control ratio (T/Nmean) were calculated and analyzed. Results There was a positive correlation between World Health Organization (WHO) grade and both T/Nmax and T/Nmean (r = 0.731 and 0.713, respectively). When all cases were divided into benign (WHO grade II) and malignant groups (III and IV), there were significant differences between the two groups in both T/Nmax and T/Nmean ( P < 0.001). If the cutoff value was defined as T/Nmax = 1.25 and T/Nmean = 1.23, T/Nmax had a sensitivity of 90.0% and a specificity of 90.9% while T/Nmean had a sensitivity of 93.3% and a specificity of 90.9% in differentiating the benign group from the malignant group. Conclusion Both T/Nmax and T/Nmean in FMISO-PET have a positive correlation with primary brain tumor grading, making FMISO-PET useful in diagnosing the malignancy of primary brain tumors.

Relationship between Standard Uptake Values of Positron Emission Tomography/Computed Tomography and Salivary Metabolites in Oral Cancer: A Pilot Study.

18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) is usually used for staging or evaluation of treatment response rather than for cancer screening. However, 18F-FDG PET/CT has also been used in Japan for cancer screening in people with no cancer symptoms, and accumulating evidence supports this application of 18F-FDG PET/CT. Previously, we have observed a correlation between the saliva and tumor metabolomic profiles in patients with oral cancer. Hence, if salivary metabolites demonstrate a significant correlation with PET parameters such as the maximum standardized uptake value (SUVmax), they may have the potential to be used as a screening tool before PET/CT to identify patients with high SUVmax. Hence, in this study, we aimed to explore the relationship between salivary metabolites and SUVmax of 18F-FDG PET/CT using previously collected data. 18F-FDG PET/CT was performed for staging 26 patients with oral cancer. The collected data were integrated and analyzed along with quantified salivary hydrophilic metabolites obtained from the same patients with oral cancer and controls (n = 44). In total, 11 metabolites showed significant correlations with SUVmax in the delayed phases. A multiple logistic regression model of the two metabolites showed the ability to discriminate between patients with oral cancer and controls, with an area under the receiver operating characteristic curve of 0.738 (p = 0.001). This study uniquely confirmed a relationship between salivary metabolites and SUVmax of PET/CT in patients with oral cancer; salivary metabolites were significantly correlated with SUVmax. These salivary metabolites can be used as a screening tool before PET/CT to identify patients with high SUVmax, i.e., to detect the presence of oral cancer.

Radiological imaging features of glioblastoma with oligodendroglioma component: a comparison with conventional glioblastoma.

BACKGROUND: Glioblastoma with oligodendroglioma component (GBMO) is a subtype of conventional glioblastoma (cGBM), which is categorized as WHO grade IV. GBMO can be histopathologically distinguished from cGBM and the prognosis of GBMO is better than that of cGBM. However, no systematic review of GBMO imaging findings has been published to date. PURPOSE: To clarify the radiological imaging features of GBMO compared with those of cGBM. MATERIAL AND METHODS: The participants were 15 patients with GBMO and 32 patients with cGBM as a control group, all of whom were histopathologically diagnosed. A radiologist retrospectively reviewed the imaging findings of both computed tomography (CT) and magnetic resonance imaging (MRI) for density, signal intensity, contrast medium enhancement (CE), cortical swelling, and cortical swelling without CE. We statistically analyzed the imaging findings by Chi-squared test. RESULTS: Cortical swelling without CE in GBMO was significantly greater than that in cGBM (P = 0.004). Non-CE and heterogeneous solid enhancement were observed significantly more often in GBMO (P = 0.004). No other findings were significant. CONCLUSION: There was significant difference in the findings of the CE, which exhibited solid heterogeneous enhancement in GBMO. Cortical swelling without CE can be considered significantly characteristic of GBMO.

The Efficacy of Color-Mapped Diffusion-Weighted Images Combined With CT in the Diagnosis and Treatment of Cholesteatoma Using Transcanal Endoscopic Ear Surgery.

OBJECTIVE: To assess the efficacy of a color-mapped diffusion-weighted image combined with a computed tomography scan (CMDWI-CT) in preoperatively evaluating the anatomical location of cholesteatomas and determining whether a patient is indicated for transcanal endoscopic ear surgery (TEES) to reduce intraoperative switching to microscopic ear surgery (MES). STUDY DESIGN: Prospective case study. SETTING: A single university hospital. PATIENTS: Fifty-five patients scheduled for middle ear cholesteatoma surgery. INTERVENTION: The CMDWI-CT is produced in a multistep process. A color-mapped fusion image (CMFI) is created by performing MR cisternography on a 1-mm thin-slice nonecho planar diffusion-weighted imaging (non-EPI DWI) and then by performing color mapping on the resulting image to enhance cholesteatoma visualization. False positives are reduced by taking a T1-weighted image (T1WI), whereas false negatives are further reduced by preoperative endoscopic examination. As cholesteatomas are difficult to locate on a CMFI in the temporal bone region, we stripped out the MR cisternography data from the CMFI and then fused the CMFI to the initial computer tomography (CT) scan to create a CMDWI-CT. This CMDWI-CT better clarifies the cholesteatoma position within temporal bone. MAIN OUTCOME MEASURE(S): CMDWI-CT preoperative findings were compared with intraoperative findings. The positive predictive value and negative predictive value were also evaluated depending on the cholesteatoma location. RESULTS: CMDWI-CT facilitated accurate detection of the cholesteatoma anatomical location in the temporal bone region which was reflected in positive predictive and negative predictive values of over 90% for all areas of the middle ear. CONCLUSION: CMDWI-CT is a reliable diagnostic modality for evaluating the anatomical location of cholesteatomas that seem as high-signal regions on a CMFI and for determining whether TEES is indicated for treatment in such patients.

The efficacy of color mapped fusion images in the diagnosis and treatment of cholesteatoma using transcanal endoscopic ear surgery.

OBJECTIVE: To assess the efficacy of color mapped fusion images (CMFIs) in preoperatively evaluating the anatomic location of cholesteatomas and determining whether a patient is indicated for transcanal endoscopic ear surgery. STUDY DESIGN: Prospective case study. SETTING: A single university hospital. PATIENTS: Ninety-two patients scheduled for middle ear cholesteatoma surgery. INTERVENTION: Imaging analysis was first performed using echo planar diffusion-weighted imaging (EPI) for the first patient group with mixed results. Imaging analysis was then performed using 1-mm thin-slice non-EPI combined with magnetic resonance cisternography in a second group. The resulting image was then processed using color mapping to create a CMFI that enhanced cholesteatoma visualization. A second non-EPI was also performed on the third group, incorporating a T1-weighted image (T1WI) to reduce false-positives. MAIN OUTCOME MEASURE(S): Preoperative findings from EPI, non-EPI/CMFIs, and non-EPI/T1WI-enhanced CMFIs were compared with intraoperative findings. The positive predictive value and negative predictive value were also evaluated for each group. RESULTS: Both the positive predictive value and negative predictive value obtained from the CMFIs were high in all areas of the middle ear, and CMFI facilitated accurate detection of the anatomic location of cholesteatomas of 3 mm or larger. The incidence of false-positives was further reduced in the final 18 patients by performing T1WI to distinguish between cholesteatomas and cholesterin granulomas. CONCLUSION: CMFI combined with T1WI is a reliable diagnostic modality for evaluating the anatomic location of cholesteatomas 3 mm or larger and determining whether transcanal endoscopic ear surgery is indicated for treatment in such cases.

Detectability and anatomical correlation of middle ear cholesteatoma using fused thin slice non-echo planar imaging diffusion-weighted image and magnetic resonance cisternography (FTS-nEPID).

Cholesteatomas show high intensity in diffusion-weighted imaging (DWI). We performed fused thin slice non-echo planar imaging (EPI) DWI and magnetic resonance cisternography (FTS-nEPID) for cholesteatoma patients to increase the detectability of FTS-nEPID for cholesteatoma. The subjects are 77 consecutive patients who underwent FTS-nEPID as a preoperative study (mean age: 53.3±21.8, 47 men and 30 women). Otorhinolaryngologists performed the operations. We anatomically classified the middle ear into four portions. A radiologist evaluated the images for cholesteatoma and assessed the anatomical invasive range in four portions using only FTS-nEPID. We classified large cholesteatomas that invaded more than three portions and small ones that invaded less than two portions based on the results obtained from surgery, and calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). For all cholesteatomas with an existing diagnosis, the sensitivity, specificity, PPV, and NPV were 71%, 70%, 94%, and 27%, respectively. In anatomical evaluation, the sensitivity, specificity, PPV, and NPV were 49%, 85%, 77%, and 64%, respectively. For large cholesteatomas with an existing diagnosis, the sensitivity was 86%. In anatomical evaluation, the sensitivity, specificity, PPV, and NPV were 51%, 57%, 88%, and 18%, respectively. For small cholesteatomas with an existing diagnosis, the sensitivity, specificity, PPV, and NPV were 59%, 78%, 92%, and 30%, respectively. In anatomical evaluation, the sensitivity, specificity, PPV, and NPV were 40%, 85%, 60%, and 71%, respectively. FTS-nEPID may be useful for diagnosing cholesteatomas. Further research is needed for anatomical evaluation because there were many false-negative results.

Brain stem and cerebellar atrophy in chronic progressive neuro-Behçet's disease.

PURPOSE: Chronic progressive neuro-Behçet's disease (CPNBD) resembles multiple sclerosis (MS) on patient background and image findings, and therefore is difficult to diagnose. The purpose is to identify the characteristic magnetic resonance imaging (MRI) findings of CPNBD and to clarify the differences between the MRI findings of CPNBD and those of MS. MATERIALS AND METHODS: The subjects consist of a CPNBD group (n=4; 1 male and 3 females; mean age, 51 y.o.), a MS group (n=19; 3 males and 16 females; mean age, 45 y.o.) and a normal control group (n=23; 10 males and 13 females; mean age, 45 y.o.). Brain stem atrophy, cerebellar atrophy, and leukoencephalopathy were retrospectively evaluated in each subjects. In middle sagittal brain MR images, the prepontine distance was measured as an indirect index of brain stem and cerebellar atrophy and the pontine and mesencephalic distance was measured as a direct index of brain stem atrophy. These indexes were statistically analyzed. RESULTS: Brain stem atrophy, cerebellar atrophy, and leukoencephalopathy were seen in all CPNBD cases. Prepontine distance was significantly different between the CPNBD group and the MS group (p<0.05), and between the CPNBD group and the normal control group (p<0.001). Pontine and mesencephalic distance were significantly different between the CPNBD group and the MS group (p<0.001, p<0.01 respectively), and between the CPNBD group and the normal control group (p<0.001). CONCLUSIONS: Chronic progressive neuro-Behçet's disease should be considered in patients with brain stem and cerebellar atrophy in addition to leukoencephalopathy similar to that seen in multiple sclerosis.

Delineation of malignant glioma by turbo spin echo multislice motion-sensitized driven-equilibrium (TSE-MSDE) with gadolinium-based contrast media: a case report.

T1-weighted images by turbo spin echo multislice motion-sensitized driven-equilibrium with gadolinium-based contrast media clearly delineated the brainstem invasion of a malignant glioma in an 80-year-old woman compared with other magnetic resonance imaging sequences.

Inverse-direction scanning improves the image quality of whole carotid CT angiography with 64-MDCT.

PURPOSE: The purpose of this prospective study was to clarify whether reducing the incidence of perivenous artifacts through craniocaudal scanning improves the quality of 64-multidetecter computed tomography (MDCT) angiography images of the whole carotid artery. METHODS: Forty patients underwent MDCT angiography in the caudocranial (n=20) or craniocaudal (n=20) direction in 2007. All patients were injected with 75 ml of contrast media followed by a 35-ml saline chaser bolus at 4.0 ml/s in the right antecubital vein. Maximum intensity projection (MIP) images were scored according to image quality on a scale of 1-5. Bilateral arterial and venous attenuation was measured on 10 separated slices. We compared the mean image quality score of the two groups (i.e. those scanned caudocranially and those scanned craniocaudally). We analyzed the correlation between vascular attenuation and mean image quality. RESULTS: Compared with the caudocranial group, the craniocaudal group had higher image quality scores (median, 3.70 vs. 3.40; 95% CI, 3.50-3.96 vs. 3.06-3.60; p<0.05), higher arterial attenuation (median, 550 HU vs. 489 HU; range, 270-686 vs. 302-574; p<0.05), and lower maximum venous attenuation (median, 436 vs. 1452 HU; range, 250-617 vs. 377-2044; p<0.01). Multiple regression analysis revealed that the most significant correlation factor with image quality was minimum arterial attenuation (R2=0.42, p<0.001) measured near the brachiocephalic artery. In the caudocranial group only, there was a negative correlation between right brachiocephalic venous attenuation and minimum arterial attenuation. CONCLUSIONS: Compared with conventional caudocranial scanning, craniocaudal scanning improves the image quality of 64-MDCT angiography images of the whole carotid artery.