Multiparametric analysis for pharynx SCC

Purpose : To predict local control / failure by a multiparametric approach using magnetic resonance (MR)-derived tumor morphological and functional parameters in pharynx squamous cell carcinoma (SCC) patients. Materials and Methods : Twenty-eight patients with oropharyngeal and hypopharyngeal SCCs were included in this study. Quantitative morphological parameters and intratumoral characteristics on T2-weighted images, tumor blood flow from pseudo-continuous arterial spin labeling, and tumor diffusion parameters of three diffusion models from multi-b-value diffusion-weighted imaging as well as patients’ characteristics were analyzed. The patients were divided into local control / failure groups. Univariate and multiparametric analysis were performed for the patient group division. Results : The value of morphological parameter of ‘sphericity’ and intratumoral characteristic of ‘homogeneity’ was revealed respectively significant for the prediction of the local control status in univariate analysis. Higher diagnostic performance was obtained with the sensitivity of 0.8, specificity of 0.75, positive predictive value of 0.89, negative predictive value of 0.6 and accuracy of 0.79 by multiparametric diagnostic model compared to results in the univariate analysis. Conclusion : A multiparametric analysis with MR-derived quantitative parameters may be useful to predict local control in pharynx SCC patients

Five-point Likert scaling on MRI predicts clinically significant prostate carcinoma

Background: To clarify the relationship between the probability of prostate cancer scaled using a 5-point Likert system and the biological characteristics of corresponding tumor foci. Methods: The present study involved 44 patients undergoing 3.0-Tesla multiparametric MRI before laparoscopic radical prostatectomy. Tracing based on pathological and MRI findings was performed. The relationship between the probability of cancer scaled using the 5-point Likert system and the biological characteristics of corresponding tumor foci was evaluated. Results: A total of 102 tumor foci were identified histologically from the 44 specimens. Of the 102 tumors, 55 were assigned a score based on MRI findings (score 1: n = 3; score 2: n = 3; score 3: n = 16; score 4: n = 11 score 5: n = 22), while 47 were not pointed out on MRI. The tracing study revealed that the proportion of >0.5 cm3 tumors increased according to the upgrade of Likert scores (score 1 or 2: 33 %; score 3: 68.8 %; score 4 or 5: 90.9 %, χ2 test, p 7 also increased from scale 2 to scale 5 (scale 2: 0 %; scale 3: 56.3 %; scale 4: 72.7 %; 5: 90.9 %, χ2 test, p = 0.0001). On using score 3 or higher as the threshold of cancer detection on MRI, the detection rate markedly improved if the tumor volume exceeded 0.5 cm3 (<0.2 cm3: 10.3 %; 0.2-0.5 cm3: 25 %; 0.5-1.0 cm3: 66.7 %; 1.0 < cm3: 92.1 %). Conclusions: Each Likert scale favobably reflected the corresponding tumor’s volume and Gleason score. Our observations show that “score 3 or higher” could be a useful threshold to predict clinically significant carcinoma when considering treatment options

Prospective study on the mismatch concept in acute stroke patients within the first 24 h after symptom onset - 1000Plus study

<p>Abstract</p> <p>Background</p> <p>The mismatch between diffusion weighted imaging (DWI) lesion and perfusion imaging (PI) deficit volumes has been used as a surrogate of ischemic penumbra. This pathophysiology-orientated patient selection criterion for acute stroke treatment may have the potential to replace a fixed time window. Two recent trials - DEFUSE and EPITHET - investigated the mismatch concept in a multicenter prospective approach. Both studies randomized highly selected patients (n = 74/n = 100) and therefore confirmation in a large consecutive cohort is desirable. We here present a single-center approach with a 3T MR tomograph next door to the stroke unit, serving as a bridge from the ER to the stroke unit to screen all TIA and stroke patients. Our primary hypothesis is that the prognostic value of the mismatch concept is depending on the vessel status. Primary endpoint of the study is infarct growth determined by imaging, secondary endpoints are neurological deficit on day 5-7 and functional outcome after 3 months.</p> <p>Methods and design</p> <p>1000Plus is a prospective, single centre observational study with 1200 patients to be recruited. All patients admitted to the ER with the clinical diagnosis of an acute cerebrovascular event within 24 hours after symptom onset are screened. Examinations are performed on day 1, 2 and 5-7 with neurological examination including National Institute of Health Stroke Scale (NIHSS) scoring and stroke MRI including T2*, DWI, TOF-MRA, FLAIR and PI. PI is conducted as dynamic susceptibility-enhanced contrast imaging with a fixed dosage of 5 ml 1 M Gadobutrol. For post-processing of PI, mean transit time (MTT) parametric images are determined by deconvolution of the arterial input function (AIF) which is automatically identified. Lesion volumes and mismatch are measured and calculated by using the perfusion mismatch analyzer (PMA) software from ASIST-Japan. Primary endpoint is the change of infarct size between baseline examination and day 5-7 follow up.</p> <p>Discussions</p> <p>The aim of this study is to describe the incidence of mismatch and the predictive value of PI for final lesion size and functional outcome depending on delay of imaging and vascular recanalization. It is crucial to standardize PI for future randomized clinical trials as for individual therapeutic decisions and we expect to contribute to this challenging task.</p> <p>Trial Registration</p> <p>clinicaltrials.gov NCT00715533</p

Residual tumour detection in post-treatment granulation tissue by using advanced diffusion models in head and neck squamous cell carcinoma patients

Purpose: To evaluate the detectability of the residual tumour in post-treatment granulation tissue using parameters obtained with an advanced diffusion model in patients with head and neck squamous cell carcinoma (HNSCC) treated by chemoradiation therapy. Materials and methods: We retrospectively evaluated 23 patients with HNSCC after the full course of chemoradiation therapy. The diffusion-weighted image (DWI) acquisition used single-shot spin-echo echo-planar imaging with 11 b-values (0-1000). We calculated 10 DWI parameters using a mono-exponential model, a bi-exponential model, a stretched exponential model (SEM), a diffusion kurtosis imaging (DKI) model and a statistical diffusion model (SDM) in the region of interest (ROI) placed on the post-treatment granulation tissue. The presence of residual tumour was determined by histological findings or clinical follow-up. Results: Among the 23 patients, seven patients were revealed to have residual tumour. The univariate analysis revealed significant differences in six parameters between the patients with and without residual tumour. From the receiver operating characteristic curve analysis, the highest area under curve was detected in the center of the Gaussian distribution of diffusion coefficient (Ds) obtained by the SDM. The multivariate analysis revealed that the Ds and diffusion heterogeneity (α) obtained by the SEM were predictors for the presence of residual tumour. Conclusion: DWI parameters obtained by advanced fitting models will be one of the diagnostic tools for the detection of residual tumour

Susceptibility-Weighted Magnetic Resonance Imaging Detects Impaired Cerebral Hemodynamics in the Superior Sagittal Sinus Thrombosis : Case Report

An 11-year-old female receiving treatment for acute lymphoblastic leukemia presented with superior sagittal sinus (SSS) thrombosis. T1-weighted, T2-weighted, and fluid-attenuated inversion recovery magnetic resonance (MR) imaging, and MR venography showed that the SSS was totally occluded by thrombus. Susceptibility-weighted MR imaging showed hypointense thrombus in the SSS and markedly dilated cortical veins over the bilateral cerebral hemispheres. Two days later, her symptoms had slightly resolved. Iodine-123 N-isopropyl-p-iodoamphetamine single photon emission computed tomography showed marked decrease of cerebral blood flow in the bilateral frontal lobes, indicating that venous congestion had disturbed the cerebral hemodynamics. MR venography showed that the SSS was still mostly occluded, but susceptibility-weighted imaging showed that the dilation of the cortical veins was less marked, suggesting that collateral venous routes had gradually developed. The finding of dilated cortical veins had almost disappeared at 28 days after the onset. Susceptibility-weighted imaging can be used as a non-invasive method to monitor the severity of venous congestion caused by cerebral venous sinus thrombosis

MRA for radiosurgery of AVM

Purpose: To investigate the discrepancy between the arteriovenous malformations (AVMs) seen on magnetic resonance angiography (MRA), and seen on stereotactic digital subtracted angiography (DSA). Materials and Methods: The target volume on stereotactic DSA (VDSA) and the target volume on MRA (VMRA) were separately delineated in 28 intracranial AVMs. The coordinates of the center and the outer edges of VDSA and VMRA were calculated and used for the analyses. Results: The standard deviations (mean value) of the displacement of centers of VMRA from VDSA were 2.67mm (-1.82 mm) in the left-right direction, 3.23 mm (-0.08 mm) in the anterior-posterior direction, and 2.16 mm (0.91 mm) in the cranio-caudal direction. VMRA covered less than 80% of VDSA in any dimensions in 9 cases (32%), although no significant difference was seen in the target volume between each method with a mean value of 11.9 cc for VDSA and 12.3 cc for VMRA (p=0.948). Conclusion: The shift of centers between each modality is not negligible. Considering no significant difference between VDSA and VMRA, but inadequate coverage of the VDSA by VMRA, it is reasonable to consider that the target on MRA might include the feeding artery and draining vein, and possibly miss a portion of the nidus

Three-dimensional Pseudo-continuous Arterial Spin-labeling Using Turbo-spin Echo with Pseudo-steady State Readout : A Comparison with Other Major Readout Methods

We evaluated 3D pseudo-continuous arterial spin labeling (pCASL) using turbo spin echo with a pseudo-steady-state (PSS) readout in comparison with the other major readout methods of 3D spiral and 2D echo-planar imaging (EPI). 3D-PSS produced cerebral blood flow (CBF) values well correlated to those of the 3D spiral readout. By visual evaluation, the image quality of 3D-PSS pCASL was superior to that of 2D-EPI. The 3D-PSS technique was suggested useful as pCASL readout

Development of three-dimensional MR neurography using an optimized combination of compressed sensing and parallel imaging

Purpose: To assess the cervical magnetic resonance neurography (MRN) imaging quality obtained with compressed sensing and sensitivity-encoding (compressed SENSE; CS-SENSE) technique in comparison to that obtained with the conventional parallel imaging (i.e., SENSE) technique. Materials and methods: Five healthy volunteers underwent a three-dimensional (3D) turbo spin-echo (TSE)-based cervical MRN examination using a 3.0 Tesla MR-unit. All MRN acquisitions were performed with CS-SENSE and conventional SENSE. We used four acceleration factors (4, 8, 16 and 32) in CS-SENSE. The image quality in MRN was evaluated by assessing the degree of cervical nerve depiction using the contrast ratio (CR) and contrast-noise ratio (CNR) between the cervical nerve and the background signal intensity and a visual scoring system (1: poor, 2: moderate, 3: good). In all of the CR, CNR and visual score, we calculated the ratio of the CS-SENSE-based MRN to that from SENSE-based MRN plus the 95% confidence intervals (CIs) of these ratios. Results: In the multiple comparison of MRN images with the control of conventional SENSE-based MRN, both the quantitative CR values and the visual score for the CS-SENSE factors of 16 and 32 were significantly lower, whereas the CS-SENSE factors of 4 and 8 showed a non-significant difference. In addition, the quantitative CNR values obtained with the CS-SENSE factors of 4 and 8 were significantly higher than that obtained with the conventional SENSE-based MRN while the CS-SENSE factor of 32 was significantly lower, in contrast, the CS SENSE factors of 16 showed a non-significant difference. For CS-SENSE factors of 4 and 8, all ratios of the CS SENSE-based MRN values for CR, CNR and visual scores to those from SENSE-based MRN were above 0.95. Conclusion: CS-SENSE-based MRN can accomplish fast scanning with sufficient image quality when using a high acceleration factor