Prediction of the treatment outcome using intravoxel incoherent motion and diffusional kurtosis imaging in nasal or sinonasal squamous cell carcinoma patients.

OBJECTIVES: To evaluate the diagnostic value of intravoxel incoherent motion (IVIM) and diffusional kurtosis imaging (DKI) parameters in nasal or sinonasal squamous cell carcinoma (SCC) patients to determine local control/failure. METHODS: Twenty-eight patients were evaluated. MR acquisition used single-shot spin-echo EPI with 12 b-values. Quantitative parameters (mean value, 25th, 50th and 75th percentiles) of IVIM (perfusion fraction f, pseudo-diffusion coefficient D*, and true-diffusion coefficient D), DKI (kurtosis value K, kurtosis corrected diffusion coefficient Dk) and apparent diffusion coefficient (ADC) were calculated. Parameter values at both the pretreatment and early-treatment period, and the percentage change between these two periods were obtained. RESULTS: Multivariate logistic regression analysis: the percentage changes of D (mean, 25th, 50th, 75th), K (mean, 50th, 75th), Dk (mean, 25th, 50th), and ADC (mean, 25th, 50th) were predictors of local control. ROC curve analysis: the parameter with the highest accuracy = the percentage change of D value with the histogram 25th percentile (0.93 diagnostic accuracy). Multivariate Cox regression analyses: the percentage changes of D (mean, 25th, 50th), K (mean, 50th, 75th), Dk (mean, 25th, 50th) and ADC (mean, 25th, 50th) are predictors. CONCLUSIONS: IVIM and DKI parameters, especially the D-value's histogram 25th percentile, are useful for predicting local control. KEY POINTS: • Noninvasive assessment of treatment outcome in SCC patients was achieved using IVIM/DKI. • Several IVIM and DKI parameters can predict the local control. • Especially, the D-value's histogram 25th percentile has high diagnostic accuracy.

Measurement of tumor blood flow in head and neck squamous cell carcinoma by pseudo-continuous arterial spin labeling: comparison with dynamic contrast-enhanced MRI.

PURPOSE: To investigate the feasibility of tumor blood flow (TBF) measurement in head and neck squamous cell carcinoma (HNSCC) using pseudo-continuous arterial spin labeling (pCASL) in a comparison with dynamic contrast-enhanced (DCE) perfusion. MATERIALS AND METHODS: We prospectively scanned 18 patients with HNSCC using 3T magnetic resonance imaging (MRI) with both pCASL and DCE perfusion. Quantitative TBF value in the whole-tumor region of interest (ROI), and regional TBF in the ROIs of the central and peripheral areas in the tumor were respectively measured. Relative TBF value in the whole-tumor ROI was also calculated. We determined the correlation and agreement between each measured TBF by pCASL and DCE perfusion using Pearson's correlation coefficients, intraclass correlation coefficients (ICC), and Bland-Altman analysis. RESULTS: In the whole-tumor ROIs, significant correlation was observed between the absolute TBF values (r = 0.72, P < 0.01), with an ICC of 0.72; moreover, higher correlation was observed in the relative TBF (r = 0.79). The correlation was higher in the peripheral ROI (r = 0.70) than the central ROI (r = 0.65), with an ICC of 0.62 and 0.54, respectively. Bland-Altman plots revealed the underestimation of TBF by pCASL in central ROIs. CONCLUSION: TBF measurement by pCASL was feasible in patients with HNSCC.

Measurement of tumor blood flow in head and neck squamous cell carcinoma by pseudo-continuous arterial spin labeling: comparison with dynamic contrast-enhanced MRI.

PURPOSE: To investigate the feasibility of tumor blood flow (TBF) measurement in head and neck squamous cell carcinoma (HNSCC) using pseudo-continuous arterial spin labeling (pCASL) in a comparison with dynamic contrast-enhanced (DCE) perfusion. MATERIALS AND METHODS: We prospectively scanned 18 patients with HNSCC using 3T magnetic resonance imaging (MRI) with both pCASL and DCE perfusion. Quantitative TBF value in the whole-tumor region of interest (ROI), and regional TBF in the ROIs of the central and peripheral areas in the tumor were respectively measured. Relative TBF value in the whole-tumor ROI was also calculated. We determined the correlation and agreement between each measured TBF by pCASL and DCE perfusion using Pearson's correlation coefficients, intraclass correlation coefficients (ICC), and Bland-Altman analysis. RESULTS: In the whole-tumor ROIs, significant correlation was observed between the absolute TBF values (r = 0.72, P < 0.01), with an ICC of 0.72; moreover, higher correlation was observed in the relative TBF (r = 0.79). The correlation was higher in the peripheral ROI (r = 0.70) than the central ROI (r = 0.65), with an ICC of 0.62 and 0.54, respectively. Bland-Altman plots revealed the underestimation of TBF by pCASL in central ROIs. CONCLUSION: TBF measurement by pCASL was feasible in patients with HNSCC. J. Magn. Reson. Imaging 2015;41:1-1. © 2014 Wiley Periodicals, Inc.

Arterial spin labeling to determine tumor viability in head and neck cancer before and after treatment.

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

Prediction of the attachment site of sinonasal inverted papillomas by preoperative imaging.

OBJECTIVE: Accurate preoperative identification of the attachment site is the key to the successful surgical management of sinonasal inverted papillomas (IPs). This study investigated the value of preoperative imaging to identify the attachment sites of IPs. METHODS: We analyzed I 0 consecutive patients with pathologically proven IPs. Two radiologists predicted the attachment sites of IPs from computed tomography (CT), 3.0 Tesla magnetic resonance imaging (3.0T MRI), 1.5T MRI, and CT plus 3.0T MRI. The actual tumor attachment sites were confirmed via pathological examination of specimens and compared with the predicted sites. RESULTS: Computed tomography showed the highest sensitivity (P < .0001), although both MRI formats showed greater specificity (P < .0001). The sensitivity of MRI plus CT was equal to that of CT and better than that of MRI (P < .0001), whereas its specificity was better than that of CT (P < .0001) and comparable to that of MRI. Prediction using 3.0T MRI appeared slightly superior to that using 1.5T MRI in terms of sensitivity and specificity, although the differences were not significant. CONCLUSION: Computed tomography and MRI had different features for prediction of sinonasal IP attachment sites. Preoperative CT plus MRI provided more useful information than CT or MRI alone.

Detection of brain metastases by 3-dimensional magnetic resonance imaging at 3 T: comparison between T1-weighted volume isotropic turbo spin echo acquisition and 3-dimensional T1-weighted fluid-attenuated inversion recovery imaging.

OBJECTIVE: This study aimed to compare the diagnostic performance in the detection of brain metastases between contrast-enhanced T1-weighted volume isotropic turbo spin echo acquisition (T1-VISTA) and 3-dimensional T1-weighted fluid-attenuated inversion recovery (3D-T1-FLAIR) imaging at 3 T. METHODS: Two neuroradiologists selected 129 true (metastases) and 70 false (vessels and artifacts) lesions on the contrast-enhanced T1-VISTA and 3D-T1-FLAIR images of 14 cancer patients with hyperintense brain lesions. Four blinded neuroradiologists distinguished between the true and false lesions, using a 5-point confidence rating scale. The receiver operating characteristic analysis was performed to compare the diagnostic performance. Contrast-to-noise ratio of the true lesions was also compared between the 2 sequences by using paired t tests. RESULTS: For lesions less than 3 mm, the area under curve and sensitivity achieved by T1-VISTA imaging were significantly greater than 3D-T1-FLAIR imaging. The contrast-to-noise ratio was also significantly greater with T1-VISTA imaging. CONCLUSIONS: The contrast-enhanced T1-VISTA imaging is better suited than 3D-T1-FLAIR imaging, for detection of small metastases.

Hyperintense putaminal rim at 1.5 T: prevalence in normal subjects and distinguishing features from multiple system atrophy.

BACKGROUND: Hyperintense putaminal rim (HPR) is an important magnetic resonance imaging (MRI) sign for multiple system atrophy (MSA). Recent studies have suggested that it can also be observed in normal subjects at 3 T. Whether it can be observed in normal subjects at 1.5 T is not known. This study aimed to determine whether HPR could be observed in normal subjects at 1.5 T; and if so, to establish its prevalence, the MRI characteristics, and the features which distinguish from HPR in MSA patients. METHODS: Axial T2-weighted images of 130 normal subjects were evaluated for the prevalence of HPR, its age and gender distribution, laterality, maximum dimension, association with hypointensity of nearby putamen, and presence of discontinuity. To distinguish from that observed in MSA, axial T2-weighted images of 6 MSA patients with predominant parkinsonism (MSA-P) and 15 MSA patients with predominant cerebellar symptoms (MSA-C) were also evaluated. The characteristics of HPR were compared between these patients and age-matched normal subjects. The mean diffusivity (MD) values of putamen were also compared. Fisher's exact test, t-test, and one way analysis of variance were used to determine significance at corrected p < 0.05. RESULTS: HPR was observed in 38.5% of normal subjects. Age and gender predilection and laterality were not observed. In most cases, it occupied the full length or anterior half of the lateral margin of putamen, and was continuous throughout its length. Maximum transverse dimension was 2 mm. There was no association with hypointensity of nearby putamen. However, in MSA-P, HPR was located predominantly at the posterolateral aspect of putamen, and associated with putaminal atrophy. Discontinuity of HPR was more frequently observed in MSA-P. On visual analysis, the characteristics of HPR were similar between MSA-C patients and normal subjects. Patients with MSA of either type had significantly higher MD values of putamen than normal subjects. CONCLUSIONS: HPR can be observed in 38.5% of normal subjects at 1.5 T. Thin linear hyperintensity without discontinuity, occupying the full length or anterior half of the lateral margin of the putamen, is suggestive of "normal." In doubtful cases, measurement of the MD values of nearby putamen may be valuable.

Non-invasive measurement of oxygen saturation in the spinal vein using SWI: quantitative evaluation under conditions of physiological and caffeine load.

Susceptibility-weighted imaging (SWI) has been used for quantitative and non-invasive measurement of blood oxygen saturation in the brain. In this study, we used SWI for quantitative measurement of oxygen saturation in the spinal vein to look for physiological- or caffeine-induced changes in venous oxygenation. SWI measurements were obtained for 5 healthy volunteers using 1.5-T MR units, under 1) 3 kinds of physiological load (breath holding, Bh; hyperventilation, Hv; and inspiration of highly concentrated oxygen, Ox) and 2) caffeine load. Oxygen saturation in the anterior spinal vein (ASV) was calculated. We evaluated changes in oxygen saturation induced by physiological load. We also evaluated the time-course of oxygen saturation after caffeine intake. For the physiological load measurements, the average oxygen saturation for the 5 subjects was significantly lower in Hv (0.75) and significantly higher in Bh (0.84) when compared with control (0.80). There was no significant difference between Ox (0.81) and control. Oxygen saturation gradually decreased after caffeine intake. The average values of oxygen saturation were 0.79 (0 min), 0.76 (20 min), 0.74 (40 min), and 0.73 (60 min), respectively. We demonstrated a significant difference in oxygen saturation at 40 and 60 min after caffeine intake when compared with 0 min. In conclusion, we demonstrated the feasibility of using SWI for non-invasive measurement of oxygen saturation in the spinal vein. We showed changes in oxygen saturation under physiological as well as caffeine load and suggest that this method is a useful tool for the clinical evaluation of spinal cord oxygenation.

Susceptibility-weighted imaging of cerebral fat embolism.

Cerebral fat embolism (CFE) causes microinfarcts, vasogenic edema, and petechiae in the brain. Conventional magnetic resonance imaging has been reported to effectively visualize microinfarcts and vasogenic edema in CFE, but not petechiae. We report 3 cases of CFE in which susceptibility-weighted imaging distinctly demonstrated multiple minute hypointense foci in the brain, which were interpreted as petechiae, susceptibility-weighted imaging is a useful adjunct to conventional magnetic resonance imaging for the evaluation of CFE.

Diagnostic value of tumor blood flow and its histogram analysis obtained with pCASL to differentiate sinonasal malignant lymphoma from squamous cell carcinoma.

OBJECTIVES: To investigate the diagnostic value of tumor blood flow (TBF) obtained with pseudo-continuous arterial spin labeling (pCASL) for the differentiation of squamous cell carcinoma (SCC) and malignant lymphoma (ML) in the nasal or sinonasal cavity. METHODS: Thirty-three patients with SCC and 6 patients with ML in the nasal or sinonasal cavity were retrospectively analyzed. Quantitative TBF values were obtained using whole-tumor region of interest (ROI) from pCASL data. The histogram analysis of TBF values within the tumor ROI was also performed by calculating the coefficient of variation (CV), kurtosis, and skewness. The mean TBF value, histogram CV, kurtosis and skewness of the patients with SCC were compared with those of the ML patients. The diagnostic accuracy to differentiate SCC from ML was also calculated by receiver operating characteristic (ROC) curve analysis. In addition, multiple logistic regression models were also performed to determine their independent predictive value, and diagnostic accuracy with the combined use of these parameters. RESULTS: Between the SCC and ML groups, significant differences were observed in mean TBF, CV, and kurtosis, but not in skewness. In ROC curve analysis, the diagnostic accuracy values for the differentiation of SCC from ML in mean TBF, CV, and kurtosis were all 0.87, respectively. Multiple logistic regression models revealed TBF and CV were respectively independent predictive value. With the combination of these parameters, the diagnostic accuracy was elevated to 0.97. CONCLUSIONS: The TBF value and its histogram analysis obtained with pCASL can help differentiate SCC and ML.

Intravoxel incoherent motion diffusion-weighted imaging in head and neck squamous cell carcinoma: assessment of perfusion-related parameters compared to dynamic contrast-enhanced MRI.

PURPOSE: To investigate the correlation between perfusion-related parameters obtained with intravoxel incoherent motion (IVIM) and classical perfusion parameters obtained with dynamic contrast-enhanced (DCE) magnetic resonance imaging in patients with head and neck squamous cell carcinoma (HNSCC), and to compare direct and asymptotic fitting, the pixel-by-pixel approach, and a region of interest (ROI)-based approach respectively for IVIM parameter calculation. MATERIALS AND METHODS: Seventeen patients with HNSCC were included in this retrospective study. All magnetic resonance (MR) scanning was performed using a 3T MR unit. Acquisition of IVIM was performed using single-shot spin-echo echo-planar imaging with three orthogonal gradients with 12 b-values (0, 10, 20, 30, 50, 80, 100, 200, 400, 800, 1000, and 2000). Perfusion-related parameters of perfusion fraction 'f' and the pseudo-diffusion coefficient 'D*' were calculated from IVIM data by using least square fitting with the two fitting methods of direct and asymptotic fitting, respectively. DCE perfusion was performed in a total of 64 dynamic phases with a 3.2-s phase interval. The two-compartment exchange model was used for the quantification of tumor blood volume (TBV) and tumor blood flow (TBF). Each tumor was delineated with a polygonal ROI for the calculation of f, f∙D* performed using both the pixel-by-pixel approach and the ROI-based approach. In the pixel-by-pixel approach, after fitting each pixel to obtain f, f∙D* maps, the mean value in the delineated ROI on these maps was calculated. In the ROI-based approach, the mean value of signal intensity was calculated within the ROI for each b-value in IVIM images, and then fitting was performed using these values. Correlations between f in a total of four combinations (direct or asymptotic fitting and pixel-by-pixel or ROI-based approach) and TBV were respectively analyzed using Pearson's correlation coefficients. Correlations between f∙D* and TBF were also similarly analyzed. RESULTS: In all combinations of f and TBV, f∙D* and TBF, there was a significant correlation. In the comparison of f and TBV, a moderate correlation was observed only between f obtained by direct fitting with the pixel-by-pixel approach, whereas a good correlation was observed in the comparisons using the other three combinations. In the comparison of f∙D* and TBF, a good correlation was observed only with f∙D* obtained by asymptotic fitting with the ROI-based approach. In contrast, moderate correlations were observed in the comparisons using the other three combinations. CONCLUSION: IVIM was found to be feasible for the analysis of perfusion-related parameters in patients with HNSCC. Especially, the combination of asymptotic fitting with the ROI-based approach was better correlated with DCE perfusion.

Isolated posterior fossa involvement in posterior reversible encephalopathy syndrome.

Posterior reversible encephalopathy syndrome (PRES) is characterized by reversible vasogenic edema affecting the subcortical white matter of bilateral occipital and parietal lobes. We describe a case of isolated posterior fossa involvement of PRES which occurred during remission induction chemotherapy for T-cell acute lymphoblastic leukemia. Both the brainstem and cerebellum were extensively involved, but the supratentorial structures were completely spared. The follow-up magnetic resonance images revealed reversibility of most lesions. The knowledge of atypical radiological features of PRES is essential for prompt diagnosis.

Compound heterozygosity for two novel mutations in a severe factor XI deficiency.

We identified two novel mutations in an asymptomatic 25-year-old Japanese patient with severe factor XI deficiency. Direct sequencing analysis of PCR products from his factor XI gene revealed a G to T transversion in exon 12, resulting in the nonsense mutation (Glu447Stop) and a G insertion in five consecutive guanine nucleotides ((501)Trp(TGG)-(502)Gly(GGG)) in exon 13 that is expected to lead to the substitution of the last 105 amino acids ((503)Tyr-(607)Val) with 32 abnormal amino acid residues ((503)Val-(534)Thr) followed by stop codon. We also demonstrated that two mutations are associated with the separate alleles in this patient, indicating compound heterozygosity for these mutations. Both mutations lead to the disruption of the catalytic domain structure of the FXI molecule and thus are responsible for his deficiency of factor XI.