Addition Of MRI Research Articles

Addition of MRI or DRE to clinical data and risk prediction for clinically significant prostate cancer.

Addition of MRI or DRE to clinical data and risk prediction for clinically significant prostate cancer.

573 Does the addition of MRI in antenatal management of suspected PAS impact maternal surgical outcome?

573 Does the addition of MRI in antenatal management of suspected PAS impact maternal surgical outcome?

Imaging phenotypes predict overall survival in glioma more accurate than basic demographic and cell mutation profiles

BackgroundMagnetic resonance imaging (MRI), digital pathology imaging (PATH), demographics, and IDH mutation status predict overall survival (OS) in glioma. Identifying and characterizing predictive features in the different modalities may improve OS prediction accuracy. PurposeTo evaluate the OS prediction accuracy of combinations of prognostic markers in glioma patients. Materials and methodsMulti-contrast MRI, comprising T1-weighted, T1-weighted post-contrast, T2-weighted, T2 fluid-attenuated-inversion-recovery, and pathology images from glioma patients (n = 160) were retrospectively collected (1983–2008) from TCGA alongside age and sex. Phenotypic profiling of tumors was performed by quantifying the radiographic and histopathologic descriptors extracted from the delineated region-of-interest in MRI and PATH images. A Cox proportional hazard model was trained with the MRI and PATH features, IDH mutation status, and basic demographic variables (age and sex) to predict OS. The performance was evaluated in a split-train-test configuration using the concordance-index, computed between the predicted risk score and observed OS. ResultsThe average age of patients was 51.2years (women: n = 77, age-range=18–84years; men: n = 83, age-range=21–80years). The median OS of the participants was 494.5 (range,3–4752), 481 (range,7–4752), and 524.5 days (range,3–2869), respectively, in complete dataset, training, and test datasets. The addition of MRI or PATH features improved prediction of OS when compared to models based on age, sex, and mutation status alone or their combination (p < 0.001). The full multi-omics model integrated MRI, PATH, clinical, and genetic profiles and predicted the OS best (c-index= 0.87). ConclusionThe combination of imaging, genetic, and clinical profiles leads to a more accurate prognosis than the clinical and/or mutation status.

Does adding MRI and CSF-based biomarkers improve cognitive status classification based on cognitive performance questionnaires?

Cognitive status classification (e.g. dementia, cognitive impairment without dementia, and normal) based on cognitive performance questionnaires has been widely used in population-based studies, providing insight into the population dynamics of dementia. However, researchers have raised concerns about the accuracy of cognitive assessments. MRI and CSF biomarkers may provide improved classification, but the potential improvement in classification in population-based studies is relatively unknown. Data come from the Alzheimer's Disease Neuroimaging Initiative (ADNI). We examined whether the addition of MRI and CSF biomarkers improved cognitive status classification based on cognitive status questionnaires (MMSE). We estimated several multinomial logistic regression models with different combinations of MMSE and CSF/MRI biomarkers. Based on these models, we also predicted prevalence of each cognitive status category using a model with MMSE only and a model with MMSE + MRI + CSF measures and compared them to diagnosed prevalence. Our analysis showed a slight improvement in variance explained (pseudo-R2) between the model with MMSE only and the model including MMSE and MRI/CSF biomarkers; the pseudo-R2 increased from .401 to .445. Additionally, in evaluating differences in predicted prevalence for each cognitive status, we found a small improvement in the predicted prevalence of cognitively normal individuals between the MMSE only model and the model with MMSE and CSF/MRI biomarkers (3.1% improvement). We found no improvement in the correct prediction of dementia prevalence. MRI and CSF biomarkers, while important for understanding dementia pathology in clinical research, were not found to substantially improve cognitive status classification based on cognitive status performance, which may limit adoption in population-based surveys due to costs, training, and invasiveness associated with their collection.

In Reply: Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on the Evaluation and Treatment of Patients With Thoracolumbar Spine Trauma: Radiological Evaluation.

To the Editor: We would like to thank the editor for giving us the opportunity to reply to the letter and comments by Dr Aly.1 Radiological evaluation of thoracolumbar fractures is important for fracture classification and deciding the treatment plan. However, there is no consensus on the imaging protocol followed for the evaluation of these fractures. The primary objective of our systematic review was to determine whether the use of MRI to determine ligamentous integrity, in addition to x-rays and computerized tomography (CT), predicted the need for surgical intervention.2 Two of 2278 studies met the inclusion criteria. Winklhofer et al,3 in their retrospective study of 100 patients with thoracolumbar fractures, found that the Arbeitsgemeinschaft fur Osteosynthesefragen classification changed in 31% and the thoracolumbar injury classification and severity classification changed in 33% of patients after MRI review. With the addition of MRI, the Thoracolumbar Injury Classification and Severity score changed from <5 (indication for conservative treatment) to ≥5 (indication for surgery) in 24% of patients.3 Pizones et al4 conducted a prospective study of 30 patients and found that MRI changed the diagnosis in 40% of patients, fracture classification in 24% of fractures, and treatment plan in 16% of patients. However, both these studies provided only level III evidence and included a heterogeneous patient population. Aly et al,5 in their retrospective review of 244 patients with thoracolumbar fractures, included patients with intact neurological status only and diagnosed posterior ligamentous complex (PLC) injury by ≥2 CT findings (instead of one) and black stripe on MRI (instead of high-signal intensity). They used a more robust methodology compared with the previous 2 studies and found that MRI changed the fracture classification by 10% and Thoracolumbar AOSpine Injury Score (TLAOSIS)–based treatment by 20%. They explained the lower rate of fracture reclassification (10% vs 30% reported previously) by differences in sample size, patient population, and CT/MRI criteria for PLC injury. They also provided detailed fracture reclassification rates after MRI for each fracture subtype and TLAOSIS category which may help guide when to get an MRI in patients with thoracolumbar fracture with no neurological deficit. The study by Aly et al1 is commendable because it adds to the current literature on the topic and also addresses some of the drawbacks of the previous studies. However, there are certain limitations of this study such as retrospective, single-institution design, and lack of external validation. We believe that prospective multicenter studies are required to establish these findings. In addition, radiological studies that focus on the characteristics of PLC injury to differentiate between self-healing injuries and injuries that require surgery would be valuable.

Preoperative MRI for Evaluation of Extent of Disease in IDC Compared to ILC

ObjectivesThe purpose of this study was to assess the incremental value of preoperative breast MRI over mammography and US in depicting the accurate extent of disease in invasive duct carcinoma (IDC) compared to invasive lobular carcinoma (ILC). Patients and MethodsRetrospective analysis of pre-operative mammography, US and MRI was performed in 239 patients with either IDC (n = 193) or ILC (n = 46). Images were evaluated for solitary, multifocal or multi centric disease and compared for concordance with postsurgical pathology. Discordance was documented as either overestimation or underestimation. Two tailed paired T and Fischer's exact tests were used for analysis. ResultsMultifocality was present on pathology in 35% and 61% of patients with IDC and ILC (P < .05) and multicentricity in 23% and 41% respectively (P = .84). In ILC, MRI demonstrated better concordance with pathology compared to mammography and US (89%, 44%, 49% for multifocality [P < .05] and 80.5%, 63%, 71% for multicentricity [P = .3]). For IDC, concordance with pathology for all modalities was similar (65%-76%). Among discordant cases, underestimation was significantly more common for mammography and US, while MRI more frequently overestimated disease extent. MRI very rarely overestimated multifocal disease in ILC (2%). ConclusionMRI demonstrates an 80% to 90% concordance rate with pathology for ILC, superior to mammography and US. The addition of MRI in IDC patients may decrease underestimation of disease extent and potentially contribute to a reduction in post-operative residual disease.

Radiographs and MRI of the Cervical Spine in Juvenile Idiopathic Arthritis: A Cross-Sectional Retrospective Study.

Background: Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease among children. In some patients, cervical spine arthritis remains a serious and chronic manifestation of JIA. The aim of this study was to assess the frequency of cervical spine lesions on radiographs and MRI in JIA patients with clinical signs of cervical spine involvement and to verify if with the addition of MRI, the use of radiographs could be abandoned. Methods: This retrospective study evaluated consecutive 34 children (25 girls; aged 6–18 years, median 15.5 years) with JIA and with clinical involvement of cervical spine. In each patient, both radiographs and MRI of the cervical spine were performed. Imaging findings were correlated with clinical and laboratory data. Results: The cervical spine was affected in 35% of patients. The most frequent lesions were subaxial subluxations (SAS; 24%), apophyseal joint ankylosis (9%), and C1/C2 joint lesions (9%). Anterior atlanto-axial subluxation (AAS) was diagnosed only by radiography, and most of the SAS were seen on radiography, whereas only a few on MRI. Reversely, C1/C2 soft tissue involvement were seen on MRI only. Cervical spine involvement was associated with raised ESR (p = 0.012) and CRP (p = 0.014). Conclusions: The cervical spine lesions are still frequent complication of JIA affecting up to 35% of JIA patients. Most of them develop serious complications, such as AAS and ankylosis. Despite advantages of MRI in terms of the imaging of the atlanto-axial region radiography shows superiority in diagnosis of AAS and SAS.

How Often MRI Would Change the Fracture Classification or Decision-making in Thoracolumbar Fractures Compared to CT Alone?

Introduction: This study aimed at analyzing the frequency and predictor of the change in classification of TLFs after performing MRI compared with CT alone.&#x0D; Methodology: This retrospective review included 235 consecutive patients with acute TLFs (T1-L5) who presented at a single level-1 trauma center between 2014 and 2021 and underwent both CT and MRI. Patients with translation injury, neurologic deficit, or osteoporotic fracture were excluded. Three reviewers independently classified all fractures according to AOSpine and Thoracolumbar Injury classification (TLISS) by CT and then MRI. A fourth reviewer only looked at the MRI images. Posterior ligamentous complex Injury was diagnosed on CT and MRI by two positive CT findings and black stripe discontinuity. Mc-Nemar test was used to evaluate the difference in the proportions of AO type A and B.&#x0D; Result: The AO classification by CT was type A in 181 patients (77%) and type B in 54 patients (23%). The addition of MRI after CT changed AO classification in 25/235 patients (10.6%, P &lt; 0.0001) due to an 8.5% (20/235) upgrade from type A to type B and 2.1% (5/235) downgrade from type B to type A. When PLC injury in CT was defined by one positive CT finding and in MRI by high signal intensity, it significantly increased the rate of fracture reclassification by MRI compared to default analysis (22% and 33% vs 11%, respectively; P &lt; 0.0001). The best predictor of upgrade from type A to type B and downgrade from type B to type A was a single positive CT finding, and the presence of only two CT signs as opposed to three signs, respectively (reclassification rate 26% vs 4.6%, P &lt; 0.0001 and 17% vs 0%, P = 0.03, respectively). Thoracic and thoracolumbar fractures showed a significantly higher reclassification rate than low lumbar (20% and 10% vs 0%, respectively, P = 0.07).&#x0D; Conclusion: Using appropriate CT/MRI criteria of PLC injury, the rate of fracture reclassification by MRI can be as low as 10%. The use of alternative CT/MRI criteria or inaccurate image interpretation could significantly increase the rate of fracture reclassification up to 20–30%. The rate of change of fracture classification by MRI could be predicted by the number of positive CT findings on CT or fracture level.

Magnetic resonance with diffusion-weighted imaging improves assessment of focal liver lesions in patients with potentially resectable pancreatic cancer on CT.

To investigate added value of MRI to preoperative staging MDCT for evaluation of focal liver lesions (FLLs) in potentially resectable pancreatic ductal adenocarcinomas (PDACs). In patients with potentially resectable PDACs after staging MDCT (n=167), characteristics of FLLs were scored as benign, indeterminate or metastases on an MDCT set and combined MDCT and MRI set by two readers, independently. Size of hepatic lesions was measured and detection rate of hepatic metastasis unsuspected by MDCT and diagnostic yield of MRI for FLLs were assessed. Reader-averaged figure-of-merit (FOM) of the combined set was significantly higher than that of MDCT alone (0.94 vs. 0.86, p=.028). In the negative-on-CT group, the diagnostic yield of MRI was 1.5-2.3% (2/133 and 3/133 for readers 1 and 2, respectively). In the indeterminate-on-CT group, MRI yield was 10.5-13.6% (2/19 and 3/22) and in patients with suspicious-metastasis-on-CT, 8.3-26.7% (1/12 and 4/15). All lesions with false-positive and false-negative CT findings were ≤1 cm. In potentially resectable PDACs, addition of MRI with DWI can provide significantly better diagnostic performance in characterization of focal liver lesions, especially for small-sized (≤ 1 cm) MDCT-indeterminate or suspicious metastasis lesions, aiding in determination of appropriate operation candidates. • Addition of MRI provides better diagnostic performance in characterization of liver lesions. • Combined interpretation of MRI and MDCT provided less frequent indeterminate liver lesions. • Diagnostic yield of MRI was high in CT-indeterminate or suspicious metastatic lesions. • Operation candidates can be determined with greater confidence in potentially resectable PDACs.

Screening with magnetic resonance imaging, mammography and ultrasound in women at average and intermediate risk of breast cancer

BackgroundThe addition of MRI to mammography and ultrasound for breast cancer screening has been shown to improve screening sensitivity for high risk women, but there is little data to date for women at average or intermediate risk.MethodsTwo thousand nine hundred and ninety-five women, aged 40 to 65 years with no previous history of breast cancer were enrolled in a screening program, which consisted of two rounds of MRI, ultrasound and mammography, one year apart. Three hundred and fifty-six women had a CHEK2 mutation, 370 women had a first-degree relative with breast cancer (and no CHEK2 mutation) and 2269 women had neither risk factor. Subjects were followed for breast cancer for three years from the second screening examination.ResultsTwenty-seven invasive epithelial cancers, one angiosarcoma and six cases of DCIS were identified over the four-year period. Of the 27 invasive cancers, 20 were screen-detected, 2 were interval cancers, and five cancers were identified in the second or third follow-up year (i.e., after the end of the screening period). For invasive cancer, the sensitivity of MRI was 86%, the sensitivity of ultrasound was 59% and the sensitivity of mammography was 50%. The number of biopsies incurred by MRI (n = 156) was greater than the number incurred by mammography (n = 35) or ultrasound (n = 57). Of the 19 invasive cancers detected by MRI, 17 (89%) were also detected by ultrasound or mammography.ConclusionsIn terms of sensitivity, MRI is slightly better than the combination of mammography and ultrasound for screening of women at average or intermediate risk of breast cancer. However, because of additional costs incurred by MRI screening, and the small gain in sensitivity, MRI screening is probably not warranted outside of high-risk populations.

Parsing the Utility of CT and MRI in the Subaxial Cervical Spine Injury Classification (SLIC) System: Is CT SLIC Enough?

The aim of our blinded retrospective study was to evaluate the diagnostic performance of the Subaxial Cervical Spine Injury Classification (SLIC) System in predicting the need for surgical intervention after subaxial cervical spine injury; SLIC scores were determined using CT alone or both CT and MRI. Patients were included if they had injuries that were subaxial (C3-C7), if they had undergone CT and MRI within 48 hours of admission, if they were either treated surgically or had sufficient clinical documentation describing nonsurgical management (halo device or hard collar), and if the SLIC neurologic score could be determined from a documented neurologic examination. Two hundred two consecutive patients (139 surgical patients and 63 nonsurgical control subjects) from January 2010 through December 2013 met all criteria and were included in the study. Additionally, 40 patients were randomly selected from this group for the purpose of determining interrater agreement. Initially, readers gave a SLIC score (< 4 for nonsurgical, 4 = indeterminate, > 4 for surgical) based on neurologic status and CT only. After waiting 4 weeks to minimize recall bias, the readers repeated scoring with the addition of MRI. Diagnostic performance values-that is, sensitivity, specificity, AUC under the ROC curve, and interrater agreement (Cohen kappa)-for both trials were determined. Using a SLIC score of 4 as the cutoff value for surgical intervention, we found that SLIC scoring based on CT and MRI had a sensitivity of 94.6%, specificity of 71.0%, and AUC of 0.87 with a kappa value of 0.28. SLIC scoring based on CT alone had a sensitivity of 86.2%, specificity of 77.3%, and AUC of 0.88 with a kappa value of 0.52. SLIC scoring based on CT alone performs similarly to SLIC scoring based on CT and MRI but with improved interobserver agreement. Although MRI is useful for surgical planning, these results indicate that MRI may have limited added value in the initial triage of patients with subaxial cervical spine injury for conservative versus surgical management.

Assessment of Clinical Complete Response After Chemoradiation for Rectal Cancer with Digital Rectal Examination, Endoscopy, and MRI: Selection for Organ-Saving Treatment.

BackgroundThe response to chemoradiotherapy (CRT) for rectal cancer can be assessed by clinical examination, consisting of digital rectal examination (DRE) and endoscopy, and by MRI. A high accuracy is required to select complete response (CR) for organ-preserving treatment. The aim of this study was to evaluate the value of clinical examination (endoscopy with or without biopsy and DRE), T2W-MRI, and diffusion-weighted MRI (DWI) for the detection of CR after CRT.MethodsThis prospective cohort study in a university hospital recruited 50 patients who underwent clinical assessment (DRE, endoscopy with or without biopsy), T2W-MRI, and DWI at 6–8 weeks after CRT. Confidence levels were used to score the likelihood of CR. The reference standard was histopathology or recurrence-free interval of >12 months in cases of wait-and-see approaches. Diagnostic performance was calculated by area under the receiver operator characteristics curve, with corresponding sensitivities and specificities. Strategies were assessed and compared by use of likelihood ratios.ResultsSeventeen (34 %) of 50 patients had a CR. Areas under the curve were 0.88 (0.78–1.00) for clinical assessment and 0.79 (0.66–0.92) for T2W-MRI and DWI. Combining the modalities led to a posttest probability for predicting a CR of 98 %. Conversely, when all modalities indicated residual tumor, 15 % of patients still experienced CR.ConclusionsClinical assessment after CRT is the single most accurate modality for identification of CR after CRT. Addition of MRI with DWI further improves the diagnostic performance, and the combination can be recommended as the optimal strategy for a safe and accurate selection of CR after CRT.

SU‐E‐J‐07: A Functional MR Protocol for the Pancreatic Tumor Delineation

Purpose:Pancreatic cancer is one of the cancers with the poorest survival prognosis. At the time of diagnosis most of pancreatic cancers are unresectable and those patients can be treated by radiotherapy. Radiotherapy for pancreatic cancer is limited due to uncertainties in CT‐based delineations. MRI provides an excellent soft tissue contrast. Here, an MR protocol is developed to improve delineations for radiotherapy treatment of pancreatic cancer. In a later stage this protocol can also be used for on‐line visualization of the pancreas during MRI guided treatments.Methods:Nine pancreatic cancer patients were included. The MR protocol included T2 weighted(T2w), T1 weighted(T1w), diffusion weighted(DWI) and dynamic contrast enhanced(DCE) techniques. The tumor was delineated on T2w and T1w MRI by an experienced radiation oncologist. Healthy pancreas or pancreatitis (assigned by the oncologist based on T2w) areas were also delineated. Apparent diffusion coefficient(ADC), and area under the curve(AUC)/time to peak(TTP) maps were obtained from DWI and DCE scans, respectively.Results:A clear demarcation of tumor area was visible on b800 DWI images in 5 patients. ADC maps of those patients characterized tumor as an area with restricted water diffusion. Tumor delineations based on solely DCE were possible in 7 patients. In 6 of those patients AUC maps demonstrated tumor heterogeneity: a hypointense area with a hyperintense ring. TTP values clearly discriminated the tumor and the healthy pancreas but could not distinguish tumor and the pancreatitis accurately.Conclusion:MR imaging results in a more pronounced tumor contrast than contrast enhanced CT. The addition of quantitative, functional MRI provides valuable, additional information to the radiation oncologist on the spatial tumor extent by discriminating tumor from the healthy pancreas(TTP, DWI) and characterizing the tumor(ADC). Our findings indicate that tumor delineation in pancreatic cancer can greatly benefit from the addition of MRI and especially functional MR techniques.

The effect on detection rate of second cancers after the addition of MRI to conventional screening mammography in patients with a history of breast cancer.

10572 Background: Mammography is currently used in the surveillance of breast cancer survivors, who are at increased risk of developing ipsilateral and contralateral breast cancers regardless of age at diagnosis or time since diagnosis. Several prospective studies have shown the utility of breast MRI in other high risk populations; however, little data exists on the use of MRI for surveillance of breast cancer survivors. We aimed to compare the outcome of surveillance breast MRI vs. mammography in this population. Methods: We identified women &lt;65 with non-metastatic breast cancer or DCIS with at least one MRI performed at our center &gt;11 months after initial diagnosis, along with a mammogram done within 6 months of the MRI. We compared the outcome of MRI and mammography in terms of biopsies performed as well as in detection of new cancers. Results: Of 512 consecutive charts reviewed, 204 patients met inclusion criteria, 105 (51.4%) of whom were African-American. The average number of MRIs per patient was 2.3 (range 2-7), with a total of 474 MRIs performed between 2005 and 2011. MRI resulted in BIRADS scores of 1 or 2 in 73.5% of studies vs. 84.4% for mammography. There were 19 biopsies performed due to MRI findings alone, 7 done due to mammographic findings alone, and 6 biopsies done based on abnormalities seen on both MRI and mammography. There were 7 malignancies identified based on an abnormal MRI, 3 seen on both MRI and mammography, and none identified via mammography alone. The malignancies identified via MRI alone included 1 patient with DCIS, 5 with stage I disease, and 1 with isolated lung metastases. Of the 10 recurrences detected, 5 (50%) were in African Americans. Two patients developed interval cancers within 6 months of normal screening MRI and mammography. Sensitivity and specificity for MRI were 83.3% (95% CI 0.51-0.97) and 92.2% (95% CI 0.87-0.95), vs. 25% (95% CI 0.05-0.57) and 94.8% (95% CI 0.90-0.97) for mammography. Positive and negative predictive values were 40% and 98.9% for MRI vs. 25% and 95.2% for mammography. Conclusions: Gadolinium-enhanced breast MRI is a useful surveillance modality in breast cancer survivors &lt; age 65. Prospective studies are needed in this population.

Klatskin Tumors and the Accuracy of the Bismuth-Corlette Classification

The Bismuth-Corlette (BC) classification is the current preoperative standard to assess hilar cholangiocarcinomas (HC). The aim of this study is to evaluate the accuracy, sensitivity, and prognostic value of the BC classification. Data of patients undergoing resection for HC were analyzed. Endoscopic retrograde cholangiography and standard computed tomography were undertaken in all cases. Additional 3D-CT-reconstructions, magnetic resonance imaging, and percutaneous transhepatic cholangiography were obtained in selected patients. A systematic review and meta-analysis of the literature was performed. Ninety patients underwent resection of the hilar bile duct confluence, with right or left hemihepatectomy in 68 instances. The overall accuracy of the BC classification was 48 per cent. Rates of BC under- and over-estimation were 29 per cent and 23 per cent, respectively. The addition of MRI, 3D-CT-reconstructions, or percutaneous transhepatic cholangiography improved the accuracy to 49 per cent (P = 1.0), 53 per cent (P = 0.074), and 64 per cent (P < 0.001), respectively. Lowest sensitivity rates were for BC Type IIIA/IIIB tumors. Meta-analysis of published BC data corresponding to 540 patients did not reach significance. The BC classification has low accuracy and no prognostic value in cases of HC undergoing resection.

Expertise Does Not Mitigate Significant Intra- and Inter-Observer Variations in Contouring of Prostate and Associated Dosimetric Outcomes

Phenomenon of intra- and inter-observer variations (IOV) in delineation of prostate is well known and poorly understood. 7,980 articles recovered through Google search engine give controversial assessment of IOV magnitude and clinical importance, with some authors reporting major impact on the dose distribution. Proposed remedies included use of formalized contouring protocols and atlases, addition of MRI, assistance of diagnostic radiologists, and computer contouring algorithm; all- empiric, none - focused on root cause of IOV.

Non-operative treatment after neoadjuvant chemoradiotherapy for rectal cancer

The past decade has seen pronounced changes in the treatment of locally advanced rectal cancer. Historically, the standard of care involved surgery followed by adjuvant radiotherapy or chemoradiotherapy. More recently, the emergence of neo-adjuvant chemoradiotherapy has fundamentally changed the management of patients with locally advanced disease. In clinical trials, pathological complete responses of up to 25% have raised the question as to whether surgery can be avoided in a select cohort of patients. A trial of omission of surgery for selected patients with complete response after preoperative chemoradiotherapy has shown favourable long-term results. In this article, we outline emerging factors for achieving pathological complete response, non-operative strategies to date, methods for prediction of response to chemoradiotherapy, and future directions with the addition of MRI as a radiological guide to complete response.

未破裂脳動静脈奇形 未破裂脳動静脈奇形に対するｒａｄｉｏｓｕｒｇｅｒｙの適応決定に関する諸問題

We discuss several issues in considering indication of radiosurgery for unruptured cerebral arteriovenous malformations. The risk of hemorrhage until obliteration was reduced by 54% compared to that before radiosurgery. Hemorrhage risk was further reduced after obliteration, but a small risk of hemorrhage (12% of that before radiosurgery) remained, although the outcome of these patients was favorable. The risk of radiation-induced complications could be reduced with addition of MRI or CT in treatment planning. Further safety can be achieved by integrating tractography into treatment planning. The surgical resection of the nidus becomes easier after radiosurgery. The frequency of radiosurgery-induced malignancy may be comparable to that of surgical mortality. Patients generally tend to select less-invasive treatment. Nevertheless, long-term complications must be considered in treating patients with unruptured cerebral arteriovenous malformations.

Die „EVA”-Studie: Evaluierung der Leistungsfähigkeit diagnostischer Verfahren (Mammographie, Sonographie, MRT) zur sekundären und tertiären Prävention des familiären Mammakarzinoms - Zwischenergebnisse nach der ersten Hälfte der Förderungsperiode

To investigate the respective diagnostic accuracies of the different breast imaging modalities, i. e., mammography (Mx), high-frequency breast ultrasound (US), and dynamic contrast-enhanced breast (MRI) regarding the early diagnosis of familial (hereditary) breast cancer. A prospective, non-randomized controlled clinical multi-center trial is performed at 4 academic tertiary care centers in Germany (Ulm, Munchen/Grosshadern, Munster and Bonn) for a total period of 4 years, sponsored by the German Cancer Aid. The protocol consists of semiannual clinical visits and breast ultrasound, and annual bilateral two-view Mx, US and MRI. Imaging studies were first analyzed independently, then Mx was read in conjunction with US, followed by Mx combined with MRI, and finally, all three imaging modalities were read in synopsis. We present the concept and first results of this trial. So far, 748 screening rounds are available for analysis in 613 women. A total of 12 breast cancers have been identified, with 11/12 cases in the pTis or pT1/N0 stage. The mean size of detected invasive cancers was 7 mm. A total of 19 benign lesions were biopsied due to false-positive imaging diagnoses. The breast cancer detection rates were: Mx: 5/12 (42 %), US 3/12 (25 %), MRI 10/12 (83 %), and the positive predictive values: Mx 5/17 (29 %), US 3/15 (30 %), and MRI 10/23 (43 %). The preliminary data suggest that early diagnosis of familial breast cancer is feasible by intensified surveillance, in particular with the addition of MRI.

Clinical significance of 3D reconstruction of arteriovenous malformation using digital subtraction angiography and its modification with CT information in stereotactic radiosurgery

Purpose A three-dimensional (3D) reconstruction method of arteriovenous malformation (AVM) nidus from digital subtraction angiography (DSA) in combination with CT and/or MRI was developed, and its usefulness was evaluated in this study. Methods and materials The contour of the AVM nidus was delineated on two orthogonal projected DSA images. First, the volume and center of the AVM nidus were calculated in a classic DSA plan using three maximal lengths of the nidus in three perpendicular directions, assuming that the nidus had a prolate ellipsoid shape. Second, in the 3D-DSA plan, the contours of the AVM nidus on the two orthogonal projected DSA images were segmented to be compatible with the slice thickness of the CT image. Assuming that each segment of the nidus has an ellipsoid pillar shape, the volume and center of each segment were calculated. The volume and 3D shape of the nidus were calculated by 3D reconstruction in the 3D-DSA plan. Third, in the CT-DSA plan, the contour based on the segmented DSA was superimposed on the corresponding transaxial CT image slice by slice. The cylindrical shape of the nidus in the transaxial image was modified using the enhanced CT images in the CT-DSA plan. These three planning methods were compared using dose–volume statistics from real patients' data. Eighteen patients with intracranial AVMs in different brain locations who had been treated by radiosurgery were the subjects of this study. To examine the visibility (validity) of the nidus on the CT image, the “nidus” was delineated on an enhanced CT image without DSA superposition in the CT plan and compared with the CT-DSA plan. Results The variance in the distance between coordinates determined by the CT plan and those determined by the classic DSA plan was significantly larger than the variance in the CT-DSA plan ( p < 0.0001 for lateral, AP, and craniocaudal directions). The difference in the variance was not reduced by the addition of MRI ( p < 0.0001 for each direction). The mean volume ± SD of the nidus calculated was 5.9 ± 8.0 cm 3 in the classic DSA plan, 4.0 ± 5.6 cm 3 in the 3D-DSA plan, and 3.6 ± 5.2 cm 3 in the CT-DSA plan. The 3D-DSA plan significantly reduced the mean nidus volume 31.8% ± 12.7% from the classic DSA plan ( p = 0.0054). The CT-DSA plan further significantly reduced the volume 9.8% ± 8.8% from the 3D-DSA plan ( p = 0.0021). The mean overlapping volume of the nidus between the CT plan and CT-DSA plan was 2.6 ± 4.3 cm 3 (range 0.17–18.9), corresponding to 63.7% ± 19.2% (range 11.4–85.3%) of the volume in the CT-DSA plan. Conclusion The superposition of the segmented DSA information on CT was shown to be an important tool to determine the precise shape of the nidus and is suggested to be useful to reduce partial occlusion of the AVM or radiation complications in radiosurgery.