Perfusion-weighted Sequences Research Articles

Ventricle contact is associated with lower survival and increased peritumoral perfusion in glioblastoma.

The purpose of this study was to prospectively investigate outcome and differences in peritumoral MRI characteristics of glioblastomas (GBMs) that were in contact with the ventricles (ventricle-contacting tumors) and those that were not (noncontacting tumors). GBMs are heterogeneous tumors with variable survival. Lower survival is suggested for patients with ventricle-contacting tumors than for those with noncontacting tumors. This might be supported by aggressive peritumoral MRI features. However, differences in MRI characteristics of the peritumoral environment between ventricle-contacting and noncontacting GBMs have not yet been investigated. Patients with newly diagnosed GBM underwent preoperative MRI with contrast-enhanced T1-weighted, FLAIR, diffusion-weighted, and perfusion-weighted sequences. Tumors were categorized into ventricle-contacting or noncontacting based on contrast enhancement. Survival analysis was performed using log-rank for univariate analysis and Cox regression for multivariate analysis. Normalized perfusion (relative cerebral blood volume [rCBV]) and diffusion (apparent diffusion coefficient [ADC]) values were calculated in 2 regions: the peritumoral nonenhancing FLAIR region overlapping the subventricular zone and the remaining peritumoral nonenhancing FLAIR region. Overall survival was significantly lower for patients with contacting tumors than for those with noncontacting tumors (434 vs 747 days, p < 0.001). Progression-free survival showed a comparable trend (260 vs 375 days, p = 0.094). Multivariate analysis confirmed a survival difference for both overall survival (HR 3.930, 95% CI 1.740-8.875, p = 0.001) and progression-free survival (HR 2.506, 95% CI 1.254-5.007, p = 0.009). Peritumoral perfusion was higher in contacting than in noncontacting tumors for both FLAIR regions (p = 0.04). There was no difference in peritumoral ADC values between the 2 groups. Patients with ventricle-contacting tumors had poorer outcomes than patients with noncontacting tumors. This disadvantage of ventricle contact might be explained by higher peritumoral perfusion leading to more aggressive behavior.

Assessment of solid components of borderline ovarian tumor and stage I carcinoma: added value of combined diffusion- and perfusion-weighted magnetic resonance imaging.

BackgroundWe sought to determine the value of combining diffusion-weighted (DW) and perfusion-weighted (PW) sequences with a conventional magnetic resonance (MR) sequence to assess solid components of borderline ovarian tumors (BOTs) and stage I carcinomas.MethodsConventional, DW, and PW sequences in the tumor imaging studies of 70 patients (BOTs, n=38; stage I carcinomas, n=32) who underwent surgery with pathologic correlation were assessed. Two independent radiologists calculated the parameters apparent diffusion coefficient (ADC), Ktrans (vessel permeability), and Ve (cell density) for the solid components. The distribution on conventional MR sequence and mean, standard deviation, and 95% confidence interval of each DW and PW parameter were calculated. The inter-observer agreement among the two radiologists was assessed. Area under the receiver operating characteristic curve (AUC) and multivariate logistic regression were performed to compare the effectiveness of DW and PW sequences for average values and to characterize the diagnostic performance of combined DW and PW sequences.ResultsThere were excellent agreements for DW and PW parameters between radiologists. The distributions of ADC, Ktrans, and Ve values were significantly different between BOTs and stage I carcinomas, yielding AUCs of 0.58 and 0.68, 0.78 and 0.82, and 0.70 and 0.72, respectively, with ADC yielding the lowest diagnostic performance. The AUCs of the DW, PW, and combined PW and DW sequences were 0.71±0.05, 0.80±0.05, and 0.85±0.05, respectively.ConclusionCombining PW and DW sequences to a conventional sequence potentially improves the diagnostic accuracy in the differentiation of BOTs and stage I carcinomas.

Use of computed tomography perfusion for acute stroke in routine clinical practice: Complex scenarios, mimics, and artifacts.

Background Computed tomography perfusion is becoming widely accepted and used in acute stroke treatment. Computed tomography perfusion provides pathophysiological information needed in the acute decision making. Moreover, computed tomography perfusion shows excellent correlation with diffusion-weighted imaging and perfusion-weighted sequences to evaluate core and penumbra volumes. Multimodal computed tomography perfusion has practical advantages over magnetic resonance imaging, including availability, accessibility, and speed. Nevertheless, it bears some limitations, as the limited accuracy for small ischemic lesions or brainstem ischemia. Interpretation of the computed tomography perfusion maps can sometimes be difficult. The stroke neurologist faces complex or atypical cases of cerebral ischemia and stroke mimics, and needs to decide whether the "lesions" on computed tomography perfusion are real or artifact. Aims The purpose of this review is, based on clinical cases from a comprehensive stroke center, to describe the added value that computed tomography perfusion can provide to the stroke physician in the acute phase before a treatment decision is made.

MP17-10 EVALUATION OF PI-RADS CLASSIFICATION IN PREDICTION OF TUMOUR AGGRESSIVENESS – COMPARISON TO RADICAL PROSTATECTOMY SPECIMEN

You have accessJournal of UrologyImaging/Radiology: Uroradiology III1 Apr 2015MP17-10 EVALUATION OF PI-RADS CLASSIFICATION IN PREDICTION OF TUMOUR AGGRESSIVENESS – COMPARISON TO RADICAL PROSTATECTOMY SPECIMEN Angelika Borkowetz, Ivan Platzek, Marieta Toma, Stefan Zastrow, Michael Froehner, Rainer Koch, and Manfred Wirth Angelika BorkowetzAngelika Borkowetz More articles by this author , Ivan PlatzekIvan Platzek More articles by this author , Marieta TomaMarieta Toma More articles by this author , Stefan ZastrowStefan Zastrow More articles by this author , Michael FroehnerMichael Froehner More articles by this author , Rainer KochRainer Koch More articles by this author , and Manfred WirthManfred Wirth More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.852AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The Prostate Imaging and Reporting Data System (PI-RADS) is told to represent a decision-making support for targeted biopsy of tumour-suspicious lesions in multiparametric MRI (mpMRI) of the prostate. We examined the applicability of this classification by direct comparison of mpMRI and radical prostatectomy specimen (PrS). METHODS We enrolled 65 patients who underwent radical prostatectomy. In all patients, PCa was proven by the combination of transperineal MRI/ultrasound-fusion prostate biopsy and a systematic transrectal 12-core-biopsy previously. All patients were examined by 3Tesla mpMRI (T2-, diffusion (DWI, ADC)- and perfusion-weighted sequences) evaluated according to the criteria of the European Society of Urogenital Radiology. Tumour-suspicious lesions were classified according to the PI-RADS classification. MpMRI and whole-mount PrS were compared by a uro-radiologist and a uro-pathologist directly. The correlation of PI-RADS and Gleason Score (GS) was evaluated. RESULTS 112 lesions were detected in mpMRI (PI-RADS≤3: 59% (n=66); PI-RADS≥4 41% (n=46)). In PrS, 206 cancer foci were proven (GS=6: 26% (n=54); GS≥7: 74% (n=152)). PCa was detected in 89 (80%) lesions in mpMRI (GS=6: 13% (n=12), GS≥7: 87% (n=77)). The tumour detection rate in lesions classified as PI-RADS≥4 was 91% (42/46) and in those classified as PI-RADS≤3 it was 73% (48/66), (p=0.015). In detail, the detection rate was 66% (GS=6: 6%; GS≥7: 59%) in lesions with PI-RADS2 (n=17), 76% (GS=6: 18%; GS≥7: 57%) in those with PI-RADS3 (n=49), 87% (GS=6: 4%; GS≥7: 83%) in those with PI-RADS4 (n=30) and 100% (100% GS≥7) in those with PI-RADS5 (n=16). The area under the curve (AUC) for detection of tumours with GS≥7 was 0.646 (95% CI; 0.455-0.746). Cancer foci with visualization in mpMRI (n=89) were greater than those without detection in mpMRI (n=117) (mean 25 mm vs. 10 mm; p<0.001). CONCLUSIONS PI-RADS represents an applicable classification of tumour-suspicious lesions in mpMRI. PI-RADS≥4 is associated with a high detection rate of tumours with GS≥7. But due to a high portion of tumours with GS≥7, biopsy of lesions classified as PI-RADS3 should be considered furthermore. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e179-e180 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Angelika Borkowetz More articles by this author Ivan Platzek More articles by this author Marieta Toma More articles by this author Stefan Zastrow More articles by this author Michael Froehner More articles by this author Rainer Koch More articles by this author Manfred Wirth More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Lymph Node Staging

Cancers of the head and neck (HNC) include cancers of the larynx, nasal passages/nose, oral cavity, pharynx, salivary glands, buccal regions, and thyroid. In these cancers, lymph node staging and localization of pathological lymph nodes are necessary to decide on either (neo) adjuvant or surgical therapy and are a major factor for the prognosis in HNC patients. Cervical node metastases have different incidence, and their presence is associated with a decrease in global survival to roughly half and with higher recurrence rates. The node metastases can be categorized in the following 2 groups: overt (clinical) or nonovert (occult). The latter can be subcategorized as metastases detectable by traditional methods (eg, staining) or "submicroscopic" metastases, only evident with immunohistochemical or molecular analysis. Compared with clinical invasive and laboratory examinations, which may have complications and are expensive, radiology plays an important role in lymph node staging. Mainly, the overt node metastases are the field of radiological imaging, and second, the detection of nonovert metastases is important and holds promise for the future because many patients of those initially classified as cN0 have, in fact, occult metastatic disease (pN1). Vice versa, radiological imaging has to avoid false-positive results that can lead to an elective or radical neck dissection, which are associated with increased morbidity and mortality and thus overshadow the improvement in survival. Radiological imaging plays a role not only as an initial staging of N+ but also in the case of N0 due to the continuing controversy for the treatment of N0 patients. A close observation of the patient may reveal a positive node in the follow-up. The imaging modalities used for the node staging in HNC patients include ultrasound, contrast-enhanced computed tomography, contrast-enhanced magnetic resonance imaging (MRI), and positron emission tomography scans. None of the above-mentioned methods reaches a 100% sensitivity or specificity, and the accuracy of the exact number of metastases or levels involved has not been studied; thus, neck dissection with subsequent pathological examination remains the gold standard for node staging. Among the described cross-sectional imaging modalities, MRI presents a lot of advantages mainly due to the increased soft tissue contrast and the ability to obtain tissue characteristics in different sequences, including diffusion- and perfusion-weighted sequences and proton spectroscopy imaging. The lack of the radiation burden makes MRI suitable for a close follow-up of the patient, and the imaging with the use of new intravenous contrast material (such as ultrasmall iron oxide particles) seems superior to the conventional. In this article, we will focus on the lymph node MRI staging in HNC patients and the MR anatomy of the nodes, the necessary diagnostic workup, and the advantages of the method over computed tomography. The possibilities of the new imaging sequences and the treatment implications will be addressed as well.