Conventional Contrast-enhanced Magnetic Resonance Imaging Research Articles

Application of surgery combined with bleomycin irrigation for complex cervical-facial lymphatic malformations in children

Objective:To present experience and evaluate the safety and efficacy of surgery combined with bleomycin irrigation for the management of head and neck lymphatic malformations in children. Methods:The medical records of all patients with cervical-facial lymphatic malformations who presented to Shanghai Children's Hospital from August 2014 to December 2020 were reviewed. 97 children were divided into surgery group（81 cases） and sclerotherapy group（16 cases）. Conventional contrast-enhanced magnetic resonance imaging（MRI） and B-ultrasound examinations were performed both preoperatively and postoperatively. The surgical group received lymphangioma resection combined with bleomycin irrigation. The sclerotherapy group was treated with B-ultrasound-guided percutaneous lymphangioma aspiration and bleomycin sclerotherapy. SPSS 21.0 software was used to evaluate the clinical cure rate and postoperative complications of lesions in both groups by chi-square test. Kaplan-Meier method was used to calculate the disease-free survival rate and draw survival curve. Results:In the surgery group of 81 children, 64 cases were cured and 17 cases were effective while in the sclerosis group, 8 cases were cured and 8 cases were effective. Cox proportional risk model found that children in the surgery group had a higher cure rate and a lower risk of 5-year recurrence than those in the sclerotherapy group, with statistically significant differences（χ²=5.814, P<0.05）. The risk of recurrence in the surgery group was 35.4% of that in the sclerotherapy group（HR=0.354, P<0.05）. In regards to postoperative complications, the surgical group had no higher rate of temporal facial paralysis and other nerve injuries compared to the sclerotherapy group（χ²=1.041, P=0.308）. Conclusion:Surgery combined with bleomycin irrigation in the complex cervical-facial lymphatic malformations was confirmed to be effectively and safely. The principle of the surgery was to protect the structure and function of normal tissue while excising the lesions as much as possible. When the lesions involved the posterior two-thirds of the tongue, the floor of the mouth, parapharynx, retropharynx, or hypopharynx spaces. Radiofrequency ablation was used in the surgical excision, which made the surgery more minimally invasive, accurate and personalized.

Soft tissue sarcoma: can dynamic contrast-enhanced (DCE) MRI be used to predict the histological grade?

To determine if dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) parameters reflect histological grade of soft tissue sarcoma (STS) MATERIALS AND METHODS: The medical records of 50 patients diagnosed with pathologically confirmed STS were retrospectively reviewed. Each STS was assessed with conventional contrast-enhanced MRI and DCE-MRI using a 3.0-T MRI system. The conventional MRI characteristics of low-grade (grade 1) and high-grade (grade 2 and grade 3) tumors were analyzed. Semi-quantitative parameters, including iAUC and TTP, and quantitative parameters, including Ktrans, Kep, and Ve, were derived from DCE-MRI. The diagnostic performances and optimal thresholds of various combinations of DCE-MRI parameters for predicting histological grades of STS were investigated using receiver operator characteristic (ROC) curves. On conventional MRI, high-grade STSs were significantly larger (≥ 5cm) and more likely to show a heterogeneous signal intensity on T2WI (> 75%), peritumoral hyperintensity on T2WI, or tumor necrosis (> 50%) compared with low-grade STS. On DCE-MRI, iAUC, TTP, Ktrans, and Kep were significant predictors of STS histological grade. Ktrans had a high diagnostic value for differentiating between high-grade and low-grade STSs. The combination of iAUC, TTP, and Ktrans yielded a higher AUC value (0.841) than the other models. High-grade STSs were usually larger than low-grade STSs, had unclear boundaries, a heterogeneous signal intensity on T2-weighted image (T2WI), and extensive necrosis. On DCE-MRI, iAUC, TTP, Ktrans, and Kep could differentiate between high-grade and low-grade STSs. The combination of iAUC, TTP, and Ktrans had a high diagnostic performance for differentiating between STS histological grades.

Can diffusion weighted imaging be used as an alternative to contrast-enhanced imaging on magnetic resonance enterography for the assessment of active inflammation in Crohn disease?

The present study aimed to investigate the potential use of T2-weighted sequences with diffusion weighted imaging (DWI) in magnetic resonance (MR) enterography instead of conventional contrast-enhanced MR imaging (MRI) sequences for the evaluation of active inflammation in Crohn disease.Two-hundred thirteen intestinal segments of 43 patients, who underwent colonoscopy within 2 weeks before or after MR enterography were evaluated in this retrospective study. DWI sequences, T2-weighted sequences, and contrast-enhanced T1-weighted sequences were acquired in the MR enterography scan after cleaning of the bowel and using an oral contrast agent. First, the intestinal segments that had active inflammation in MR enterography were qualitatively evaluated in T2-weighted and contrast-enhanced T1-weighted sequences and then MR activity index (MRAI 1) and MRAI 2 were formed with and without contrast-enhanced sequences in 2 separate sessions.The correlation coefficient between contrast enhanced and DWI MR enterography scores (MRAI 1 and MRAI 2) of intestinal inflammation was 0.97 for all segments. In addition, separate correlation coefficients were calculated for terminal ileum, right colon, transverse colon, left colon, and rectum, and there was a strong correlation between the MRAI 1 and MRAI 2 scores of each segment (r = 0.86–0.97, P < .001). On the other hand, MR enterography had 88.7% sensitivity, 97.9% specificity, 95.5% positive predictive value, 94.6% negative predictive value, and 94.8% accuracy for detection of active inflammation in all intestinal segments in Crohn disease.DWI and T2-weighted sequences acquired with cleaning of the bowel can be used instead of contrast-enhanced MRI sequences for the evaluation of active inflammation in Crohn disease.

Magnetic Resonance Assessment of Peritoneal Carcinomatosis: Is There a True Benefit From Diffusion-Weighted Imaging?

PurposeTo assess the added value of diffusion weighted imaging (DWI) with intermediate (500 s/mm2) and high (1000 s/mm2) b values when combined to conventional contrast-enhanced magnetic resonance imaging (MRI) in identifying peritoneal neoplastic involvement. MethodsTwenty-four patients with peritoneal carcinomatosis from gastrointestinal or gynecological tumors were retrospectively evaluated. All patients underwent peritonectomy with hyperthermic intraoperative chemotherapy and 1.5 T MRI including DWI with 500 s/mm2 and 1000 s/mm2 b values within 1 month from surgery. Images were independently reviewed by 2 radiologists with different experience in abdominal MRI in 3 separate reading sessions, the first including conventional MR images alone (T2-weighted, T1-weighted pre- and post gadolinium injection), the second conventional MRI and DWI with a b value of 500 s/mm2 (b 500-DWI), and the third conventional MRI and DWI with a b value of 1000 s/mm2 (b 1000-DWI). Apparent diffusion coefficient maps were included in the DWI analyses. Peritoneal dissemination was assessed in 9 anatomical sites, including right and left subphrenic space, paracolic gutters, small bowel mesentery, greater omentum, gastric-bowel serosa, free peritoneal surfaces, rectosigmoid-colon mesentery, and pelvis. The presence or absence of peritoneal dissemination for each patient and for each site was scored using a 5-point confidence scale. Sensitivity, specificity, and area under the curve (AUC) for identifying per-site peritoneal implants were calculated for each reader at each reading session. Interobserver agreement was evaluated using kappa statistics. ResultsFor both readers, the sensitivity and AUC values resulting from combined interpretation of conventional MRI and DWI (both b500-DWI and b1000-DWI) were significantly higher than those of conventional MRI alone (P < 0.001). The added value of DWI was greater for the less experienced reader (sensitivity 0.55, specificity 0.73, AUC 0.64 on conventional MRI; sensitivity 0.75, specificity 0.72, AUC 0.74 on b500-DWI; sensitivity 0.87, specificity 0.72, AUC 0.80 on b1000-DWI) than for the more experienced reader (sensitivity 0.63, specificity 0.75, AUC 0.70 on conventional MRI; sensitivity 0.76, specificity 0.77, AUC 0.77 on b500-DWI; sensitivity 0.85, specificity 0.72, AUC 0.79 on b1000-DWI), although the differences between the 2 observers were not statistically significant. Interobserver agreement resulted to be fair (κ = 0.30) when dealing with conventional MRI alone. The addition of b500-DWI and b1000-DWI to conventional MRI allowed to reach a substantial agreement (κ = 0.75). ConclusionsThe combined interpretation of high b value DWI and conventional MRI provides increased sensitivity and diagnostic performance in detection of peritoneal carcinomatosis in oncologic patients.

Differentiating Primary Central Nervous System Lymphomas From Glioblastomas and Inflammatory Demyelinating Pseudotumor Using Relative Minimum Apparent Diffusion Coefficients.

Our purpose was to evaluate the diagnostic performance of diffusion-weighted imaging, the relative minimum apparent diffusion coefficient (rADCmin) in differentiating primary central nervous system lymphomas (PCNSLs) from glioblastomas (GBMs) and inflammatory demyelinating pseudotumors (IDPs). Magnetic resonance images were reviewed retrospectively in 82 patients including 39 PCNSLs, 35 GBMs, and 8 IDPs. Regions of interest were drawn around the tumor on contrast-enhanced axial images; these images were transferred onto coregistered ADC maps to obtain the ADCmin, and the normalized ADCmin ratios (rADCmin) were calculated using the formula rADCmin = ADCmin of the lesion / ADCmin of the normal white matter. The rADCmin values were compared between PCNSLs, GBMs, and IDPs using the analysis of variance test. Receiver operating characteristic curves were constructed to evaluate the diagnostic performance of rADCmin values and to determine the optimum thresholds. Simple logistic regression was analyzed to evaluate the relationship between ADCs and tumor cellularity. The rADCmin value was significantly lower in PCNSLs (0.675 ± 0.113) than GBMs (0.765 ± 0.059) and IDPs (0.834 ± 0.067) (PCNSL vs GBM, P < 0.001; PCNSL vs IDP, P < 0.001). Relative ADCmin was a significant assessor for differentiating PCNSLs from non-PCNCLs (P < 0.001). The optimal cutoff value was 0.722 (sensitivity, 74.5%; specificity, 74.1%; area under the curve, 0.803) on receiver operating characteristic analysis. A stronger negative correlation (r = -0.755, P = 0.000) was obtained between the cytoplasm and rADCmin. Relative ADCmin value is helpful in differentiating PCNSL from GBM and IDP. Thus, ADC values may provide a useful supplement to the information obtained from conventional contrast-enhanced magnetic resonance imaging and assist in future treatment planning.

Longitudinal DSC-MRI for Distinguishing Tumor Recurrence From Pseudoprogression in Patients With a High-grade Glioma.

For patients with high-grade glioma on clinical trials it is important to accurately assess time of disease progression. However, differentiation between pseudoprogression (PsP) and progressive disease (PD) is unreliable with standard magnetic resonance imaging (MRI) techniques. Dynamic susceptibility contrast perfusion MRI (DSC-MRI) can measure relative cerebral blood volume (rCBV) and may help distinguish PsP from PD. A subset of patients with high-grade glioma on a phase II clinical trial with temozolomide, paclitaxel poliglumex, and concurrent radiation were assessed. Nine patients (3 grade III, 6 grade IV), with a total of 19 enhancing lesions demonstrating progressive enhancement (≥25% increase from nadir) on postchemoradiation conventional contrast-enhanced MRI, had serial DSC-MRI. Mean leakage-corrected rCBV within enhancing lesions was computed for all postchemoradiation time points. Of the 19 progressively enhancing lesions, 10 were classified as PsP and 9 as PD by biopsy/surgery or serial enhancement patterns during interval follow-up MRI. Mean rCBV at initial progressive enhancement did not differ significantly between PsP and PD (2.35 vs. 2.17; P=0.67). However, change in rCBV at first subsequent follow-up (-0.84 vs. 0.84; P=0.001) and the overall linear trend in rCBV after initial progressive enhancement (negative vs. positive slope; P=0.04) differed significantly between PsP and PD. Longitudinal trends in rCBV may be more useful than absolute rCBV in distinguishing PsP from PD in chemoradiation-treated high-grade gliomas with DSC-MRI. Further studies of DSC-MRI in high-grade glioma as a potential technique for distinguishing PsP from PD are indicated.

Time-resolved contrast-enhanced MRA (TWIST) with gadofosveset trisodium in the classification of soft-tissue vascular anomalies in the head and neck in children following updated 2014 ISSVA classification: first report on systematic evaluation of MRI and TWIST in a cohort of 47 children

To evaluate the relative accuracy of contrast-enhanced time-resolved angiography with interleaved stochastic trajectories versus conventional contrast-enhanced magnetic resonance imaging (MRI) following International Society for the Study of Vascular Anomalies updated 2014-based classification of soft-tissue vascular anomalies in the head and neck in children. Time-resolved angiography with interleaved stochastic trajectories versus conventional contrast-enhanced MRI of children with diagnosis of soft-tissue vascular anomalies in the head and neck referred for MRI between 2008 and 2014 were retrospectively reviewed. Forty-seven children (0-18 years) were evaluated. Two paediatric neuroradiologists evaluated time-resolved MRA and conventional MRI in two different sessions (30 days apart). Blood-pool endovascular MRI contrast agent gadofosveset trisodium was used. The present cohort had the following diagnoses: infantile haemangioma (n=6), venous malformation (VM; n=23), lymphatic malformation (LM; n=16), arteriovenous malformation (AVM; n=2). Time-resolved MRA alone accurately classified 38/47 (81%) and conventional MRI 42/47 (89%), respectively. Although time-resolved MRA alone is slightly superior to conventional MRI alone for diagnosis of infantile haemangioma, conventional MRI is slightly better for diagnosis of venous and LMs. Neither time-resolved MRA nor conventional MRI was sufficient for accurate diagnosis of AVM in this cohort. Conventional MRI combined with time-resolved MRA accurately classified 44/47 cases (94%). Time-resolved MRA using gadofosveset trisodium can accurately classify soft-tissue vascular anomalies in the head and neck in children. The addition of time-resolved MRA to existing conventional MRI protocols provides haemodynamic information, assisting the diagnosis of vascular anomalies in the paediatric population at one-third of the dose of other MRI contrast agents.

93P - Assessment of Response to Neoadjuvant Chemotherapy with Diffusion Weighted Imaging at 3T

Abstract Purpose To assess radiological tumor response to neoadjuvant chemotherapy (NAC) with Diffusion weighted imaging (DWI) at 3Tesla. Materials and methods 30 patients (mean age 51.4 years) with a histopatholgical verified breast cancer (BIRADS 6) who underwent NAC were included in this prospective IRB approved study. Additionally to routine staging with dynamic contrast enhanced magnetic resonance imaging (CE-MRI) protocol a diffusion weighted sequence with the following parameters was included in the imaging protocol: single-shot, echo-planar imaging sequence with eddy current compensation, a three direction trace diffusion scheme, inversion recovery fat suppression and two b-values of 50 and 850 s/mm2 (TR/TE/TI 13700/83/220ms; FOV 340x117 mm; 40 axial slices; SI 3.5 mm (no gap); matrix 192x64 two averages; spatial resolution, 1.8x1.8x3.5 mm; bandwidth 1446 Hz/pixel; 3:19 min. Patients were examined before the beginning and after 5 or 6 cycles of NAC. In DWI manually drawn ROIs of suspicious areas were assessed for restricted diffusion and apparent diffusion coefficient (ADC) values were calculated. An ADC threshold 1.25x10-3mm2/s was defined as a marker of malignancy. Data were dichotomized and complete response (cr) and partial response (pr) were considered as response and stable disease (sd) and progressive disease (pd) were considered as non-response to NAC. The histopathological assessment of tumor response was used as the standard of reference. Results There were 23 invasive ductal cancers (IDC) and 6 invasive lobular cancers (ILC). Average tumor size was 43.4mm. In the baseline scan one IDC (3%) had an ADC value above the cut-off for malignancy and was excluded. There were 4 (14%) non-responders and 25 (86%) responders. Responders demonstrated an average increase in ADC values of 0.58x10-3mm2/s whereas non-responders failed to show a significant increase in ADC values (average increase 0.09x10-3mm2/s). The classification of DWI as responders and non-responders correlated with histopathological diagnoses of treatment response. Conclusion ADC as an adjunct to conventional CE-MRI is an additional valuable imaging biomarker for the assessment of treatment response to NAC in breast cancer patients. Disclosure All authors have declared no conflicts of interest.

A pooled analysis of diffusion‐weighted imaging in the diagnosis of hepatocellular carcinoma in chronic liver diseases

The purpose of this study was to perform a meta-analysis of all available studies of the diagnostic performance of diffusion-weighted imaging (DWI) in the detection of hepatocellular carcinoma (HCC) in patients with chronic liver disease. Databases including MEDLINE and EMBASE were searched for relevant original articles published from January 2000 to April 2012. Pooled estimation and subgroup analysis data were obtained by statistical analysis. Across the nine studies (476 patients), DWI sensitivity was 81% (95%CI: 67%-90%), and specificity was 89% (95% CI: 76%-95%). Overall, positive likelihood ratio was 7.11 (95%CI: 3.50, 14.48), negative likelihood ratio was 0.21 (95%CI: 0.12-0.37), and the diagnostic odds ratio (DOR) was 33.48 (95%CI: 16.67-67.25). The area under the curve of the summary receiver operator characteristic (ROC) was 0.92 (95% CI:0.89-0.94). In studies in which both DWI and conventional contrast-enhanced magnetic resonance imaging (CE-MRI) were performed, the comparison of DWI performance with that of conventional CE-MRI suggested no major differences against these two methods (P > 0.05). DWI combined CE-MRI had higher pooled sensitivity than DWI alone (93% vs 73%) (P < 0.05). DWI has good diagnostic performance in the detection of HCC in patients with chronic liver disease and equivalent to conventional CE-MRI. Combination of CE-MRI and DWI can improve the diagnostic accuracy of MRI. Further larger prospective studies are still needed to establish its value for detecting HCC in patients with chronic liver disease.

61O Assessment of Response to Neoadjuvant Chemotherapy with Diffusion Weighted Imaging at 3T

PurposeTo assess radiological tumor response to neoadjuvant chemotherapy (NAC) with Diffusion weighted imaging (DWI) at 3Tesla. Materials and methods30 patients (mean age 51.4 years) with a histopatholgical verified breast cancer (BIRADS 6) who underwent NAC were included in this prospective IRB approved study. Additionally to routine staging with dynamic contrast enhanced magnetic resonance imaging (CE-MRI) protocol a diffusion weighted sequence with the following parameters was included in the imaging protocol: single-shot, echo-planar imaging sequence with eddy current compensation, a three direction trace diffusion scheme, inversion recovery fat suppression and two b-values of 50 and 850 s/mm2 (TR/TE/TI 13700/83/220ms; FOV 340x117 mm; 40 axial slices; SI 3.5mm (no gap); matrix 192x64 two averages; spatial resolution, 1.8x1.8x3.5 mm; bandwidth 1446 Hz/pixel; 3:19 min. Patients were examined before the beginning and after 5 or 6 cycles of NAC. In DWI manually drawn ROIs of suspicious areas were assessed for restricted diffusion and apparent diffusion coefficient (ADC) values were calculated. An ADC threshold 1.25x10-3mm2/s was defined as a marker of malignancy. Data were dichotomized and complete response (cr) and partial response (pr) were considered as response and stable disease (sd) and progressive disease (pd) were considered as non-response to NAC. The histopathological assessment of tumor response was used as the standard of reference. ResultsThere were 23 invasive ductal cancers (IDC) and 6 invasive lobular cancers (ILC). Average tumor size was 43.4mm. In the baseline scan one IDC (3%) had an ADC value above the cut-off for malignancy and was excluded. There were 4 (14%) non-responders and 25 (86%) responders. Responders demonstrated an average increase in ADC values of 0.58x10-3mm2/s whereas non-responders failed to show a significant increase in ADC values (average increase 0.09x10-3mm2/s). The classification of DWI as responders and non-responders correlated with histopathological diagnoses of treatment response. ConclusionADC as an adjunct to conventional CE-MRI is an additional valuable imaging biomarker for the assessment of treatment response to NAC in breast cancer patients. DisclosureAll authors have declared no conflicts of interest.

Comparing the Detectability of Hepatocellular Carcinoma by C-Arm Dual-Phase Cone-Beam Computed Tomography During Hepatic Arteriography With Conventional Contrast-Enhanced Magnetic Resonance Imaging

To evaluate the sensitivity of dual-phase cone-beam computed tomography during hepatic arteriography (CBCTHA) for the detection of hepatocellular carcinoma (HCC) by comparing it with the diagnostic imaging "gold standard": contrast-enhanced magnetic resonance imaging (CE-MRI) of the liver. Eighty-eight HCC lesions (mean diameter 3.9±3.3cm) in 20 patients (13 men, mean age 61.4years [range 50 to 80]), who sequentially underwent baseline diagnostic liver CE-MRI and then underwent early arterial- and delayed portal venous-phase CBCTHA during drug eluting-bead transarterial chemoembolization, were evaluated. Dual-phase CBCTHA findings of each tumor in terms of conspicuity were compared with standard CE-MR images and classified into three grades: optimal, suboptimal, and nondiagnostic. Seventy-seven (mean diameter 4.2±3.4cm [range 0.9 to 15.9]) (93.9%) of 82 tumors were detected. Sensitivity of arterial-phase (71.9%) was lower than that of venous-phase CBCTHA (86.6%) for the detection of HCC lesions. Of the 82 tumors, 33 (40.2%) and 52 (63.4%), 26 (31.7%) and 19 (23.2%), and 23 (28%) and 11 (13.4%) nodules were classed as optimal, suboptimal, and nondiagnostic on arterial- and venous-phase CBCTHA images, respectively. Seventeen (73.9%) of the 23 tumors that were not visible on arterial phase were detected on venous phase. Six (54.5%) of the 11 tumors that were not visible on venous phase were detected on arterial phase. Dual-phase CBCTHA has sufficient image quality to detect the majority of HCC lesions compared with the imaging "gold standard": CE-MRI of the liver. Moreover, dual-phase CBCTHA is more useful and reliable than single-phasic imaging to depict HCC nodules.

Intraobserver and interobserver variability in the calculation of apparent diffusion coefficient (ADC) from diffusion-weighted magnetic resonance imaging (DW-MRI) of breast tumours

This study evaluated intraobserver and interobserver variability in the measurement of apparent diffusion coefficient (ADC) values in breast carcinomas. Twenty-eight patients with solid breast lesions >10 mm underwent conventional contrast-enhanced magnetic resonance imaging (MRI) and diffusion-weighted MRI (DW-MRI). Two observers (expert and trainee) segmented the lesion from the surrounding breast tissue on DW images with high b-value (1,000 s/mm(2)). This analysis was repeated by the expert reader after 6 months. Volumes were analysed to obtain mean, median and standard deviation (SD) of the ADC values. Interobserver and intraobserver variation was analysed using the Bland-Altman graph. All lesions were breast carcinomas, with a mean ADC value of 1.07 × 10(-3) mm(2)/s. The mean of the differences was 0.012 × 10(-3) mm(2)/s, corresponding to an intraobserver variability of 1.1% (limits of agreement: -5%/+8%). The mean interobserver difference was 0.022 × 10(-3) mm(2)/s, corresponding to an interobserver variability of 2% (limits of agreement: -9%/+14%). We found a low intraobserver and interobserver variability in calculating ADC in breast carcinomas, which supports its potential use in routine clinical practice.

Functional MRI for Radiotherapy of Gliomas

In this paper, we review the applications of functional magnetic resonance imaging (MRI) for target delineation and critical organ avoidance for brain radiotherapy. In this article we distinguish functional MRI from brain functional MRI (fMRI). Functional MRI includes magnetic resonance spectroscopic imaging (MRSI), perfusion MRI, diffusion tensor imaging (DTI) and brain fMRI. These functional MRI modalities can provide unique metabolic, pathological and physiological information that are not available in anatomic MRI and can potentially improve the treatment outcomes of brain tumors. For example, both choline (Cho) to N-acetylaspartate (NAA) and Cho to creatine (Cr) ratios from MRSI increase with increasing tumor malignancy and can be used to grade gliomas. Relative cerebral blood volume (rCBV) measurements from dynamic susceptibility contrast perfusion magnetic resonance imaging (DSC MRI) are superior to conventional contrast-enhanced MRI in predicting tumor biology and may be even superior to pathologic assessment in predicting patient clinical outcomes. Brain fMRI can help identify and avoid functionally critical areas when constructing treatment plans for brain radiotherapy. In the past, functional MRI measurements have not been routinely used in a clinical arena due to the experimental nature of these imaging modalities. As these methods become more commonly used and effective image co-registration algorithms become available, integration of functional MRI into the treatment process of brain radiotherapy now appears to be clinically feasible, at least in major medical centers.

Limitations of Conventional Contrast-enhanced MRI in Selecting Sentinel Node Biopsy Candidates among DCIS Patients

Purpose: A better predictive model for occult invasive disease in ductal carcinoma in situ (DCIS) patients is essential to guide the tailored use of sentinel node biopsies. We hypothesized that recent improvement of contrast-enhanced breast magnetic resonance imaging (MRI) could provide more accurate information on the presence of occult invasion in DCIS patients. Methods: From a prospectively maintained database, we identified 143 DCIS patients diagnosed with needle biopsies in whom MRI images were available. Results: Sixty-five patients (45.5%) were upstaged to invasive carcinoma after curative surgery. Ultrasonographic lesion size, mass-appearance on mammography, type of needle used, and the presence of suspicious microinvasive foci were associated with increased likelihood of upstaging. Among the features of MRI, only mass-appearance was significantly associated with the presence of invasive disease (p=0.002). However, up to 50% of masses in MRI cases had massappearance on mammography as well. Other morphologic and pharmacokinetic features of MRI, such as shape, margin, and patterns of enhancement and washout, did not have a significant association. Conclusion: Among various morphologic and pharmacokinetic parameters of contrast-enhanced MRI, only mass-appearance was associated with occult invasive disease. Our results show the limitations of current contrast-enhanced MRI in predicting invasive disease in patients with preoperative diagnoses of DCIS.

Distinguishing Tumefactive Demyelinating Lesions from Glioma or Central Nervous System Lymphoma: Added Value of Unenhanced CT Compared with Conventional Contrast-enhanced MR Imaging

To determine retrospectively whether unenhanced computed tomographic (CT) images of the brain have added value in distinguishing tumefactive demyelinating lesions (TDLs) from primary glioma or central nervous system (CNS) lymphoma, compared with conventional contrast material-enhanced magnetic resonance (MR) images only. This study was approved by the institutional review board, and informed consent was waived. Unenhanced CT and MR images in 15 patients with TDLs (seven women, eight men; mean age, 42 years; range, 27-57 years) and 48 patients with primary brain tumor (27 women, 21 men; mean age, 48 years; range, 19-70 years; 10 lymphomas, 38 gliomas) were retrospectively reviewed. The CT attenuation of regions that were enhanced or unenhanced at MR imaging was visually categorized into three grades, and CT attenuation values were determined quantitatively. The diagnostic accuracy of MR imaging for differentiating TDLs from tumors was compared with that of MR imaging plus CT. The following MR imaging features were found more frequently in patients with TDL than in those with brain tumor: incomplete rim enhancement, mixed T2-weighted iso- and hyperintensity of enhanced regions, absence of a mass effect, and absence of cortical involvement (all P values < .05). CT hypoattenuation of MR enhanced regions was observed in 14 (93%) of 15 patients with TDL but in only two (4%) of 48 patients with tumor. The CT attenuation of MR enhanced regions was significantly lower for patients with TDL than for those with tumor (P < .001). The diagnostic accuracy of CT plus MR imaging was significantly higher than that of MR imaging alone (97% vs 73.0%, respectively; P < .001), and the diagnostic accuracy of CT was significantly higher than that of unenhanced T1-weighted MR imaging (95% vs 63%, P < .001). Unenhanced CT plus MR imaging was more accurate for distinguishing TDLs from glioma or CNS lymphoma than contrast-enhanced MR imaging alone.

Dynamic susceptibility contrast-enhanced perfusion magnetic resonance (MR) imaging combined with contrast-enhanced MR imaging in the follow-up of immunogene-treated glioblastoma multiforme

To assess the value of the combined use of dynamic susceptibility contrast-enhanced perfusion magnetic resonance imaging (MRI) and conventional contrast-enhanced MRI for the follow-up of treatment of glioblastoma multiforme (GBM). 79 examinations were performed in six surgically and immunogene-treated patients and two surgically treated patients. Ratios of the relative cerebral blood volume (rCBV) in lesions and in the contralateral normal-appearing white matter were calculated. The regions with elevated rCBV were compared with those with contrast enhancement. Tissue specimens from surgical biopsies and autopsies were studied histopathologically. The lesion-to-normal rCBV ratios were high in the tumors prior to operation (7.3 to 18.2) as well as in the recurrent tumors (1.6 to 13.2). The volumes of the regions with elevated rCBV were similar to those with contrast enhancement in 63 of the 79 examinations. However, in 11 of 79 examinations, the regions with high rCBV were smaller than the regions with contrast enhancement ("mismatch"). In two samples from the immunogene-treated patients this was correlated with the histopathological finding of malignant tumor with numerous proliferating GBM vessels with multiple minimal lumina, sometimes thrombotized or ruptured. These vessels may have increased permeability with contrast enhancement not accompanied by increased microvascular volume. 1) Elevated rCBV on perfusion MRI corresponding to the contrast-enhancing lesion supports the diagnosis of recurrent malignant tumor. 2) A mismatch showing a volume of rCBV elevation smaller than that of contrast enhancement can be seen in particularly aggressive tumor growth and is thus not always a sign of reactive non-tumor changes. 3) The combination of perfusion MRI and conventional contrast MRI provides useful information in the follow-up of glioblastoma multiforme treatment.