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In this paper, a fully automatic computer-aided detection (CAD) method is proposed for the detection of prostate cancer. The CAD method consists of multiple sequential steps in order to detect locations that are suspicious for prostate cancer. In the initial stage, a voxel classification is performed using a Hessian-based blob detection algorithm at multiple scales on an apparent diffusion coefficient map. Next, a parametricmulti-object segmentationmethod is applied and the resulting segmentation is used as a mask to restrict the candidate detection to the prostate. The remaining candidates are characterized by performing histogram analysis on multiparametricMRimages. The resulting feature set is summarized into amalignancy likelihood by a supervised classifier in a two-stage classification approach. The detection performance for prostate cancer was tested on a screening population of 200 consecutive patients and evaluated using the free response operating characteristic methodology. The results show that the CAD method obtained sensitivities of 0.41, 0.65 and 0.74 at false positive (FP) levels of 1, 3 and 5 per patient, respectively. In conclusion, this study showed that it is feasible to automatically detect prostate cancer at a FP rate lower than systematic biopsy. The CAD method may assist the radiologist to detect prostate cancer locations and could potentially guide biopsy towards the most aggressive part of the tumour. [ABSTRACT FROM AUTHOR]

Purpose: Computer aided diagnosis (CAD) of lymph node metastases may help reduce reading time and improve interpretation of the large amount of image data in a 3-D pelvic MRI exam. The purpose of this study was to develop an algorithm for automated segmentation of pelvic lymph nodes from a single seed point, as part of a CAD system for the classification of normal vs metastatic lymph nodes, and to evaluate its performance compared to other algorithms. Methods: The authors' database consisted of pelvic MR images of 146 consecutive patients, acquired between January 2008 and April 2010. Each dataset included four different MR sequences, acquired after infusion of a lymph node specific contrast medium based on ultrasmall superparamagnetic particles of iron oxide. All data sets were analyzed by two expert readers who, reading in consensus, annotated and manually segmented the lymph nodes. The authors compared four segmentation algorithms: confidence connected region growing (CCRG), extended CCRG (ECC), graph cut segmentation (GCS), and a segmentation method based on a parametric shape and appearance model (PSAM). The methods were ranked based on spatial overlap with the manual segmentations, and based on diagnostic accuracy in a CAD system, with the experts' annotations as reference standard. Results: A total of 2347 manually annotated lymph nodes were included in the analysis, of which 566 contained a metastasis. The mean spatial overlap (Dice similarity coefficient) was: 0.35 (CCRG), 0.57 (ECC), 0.44 (GCS), and 0.46 (PSAM). When combined with the classification system, the area under the ROC curve was: 0.805 (CCRG), 0.890 (ECC), 0.807 (GCS), 0.891 (PSAM), and 0.935 (manual segmentation). Conclusions: We identified two segmentation methods, ECC and PSAM, that achieve a high diagnostic accuracy when used in conjunction with a CAD system for classification of normal vs metastatic lymph nodes. The manual segmentations still achieve the highest diagnostic accuracy. [ABSTRACT FROM AUTHOR]

Systemic chemotherapy is effective in only a subset of patients with metastasized colorectal cancer. Therefore, early selection of patients who are most likely to benefit from chemotherapy is desirable. Response to treatment may be determined by the delivery of the drug to the tumor, retention of the drug in the tumor and by the amount of intracellular uptake, metabolic activation and catabolism, as well as other factors. The first aim of this study was to investigate the predictive value of DCE-MRI with the contrast agent Gd-DTPA for tumor response to first-line chemotherapy in patients with liver metastases of colorectal cancer. The second aim was to investigate the predictive value of 5-fluorouracil (FU) uptake, retention and catabolism as measured by localized 19F MRS for tumor response to FU therapy. Since FU uptake, retention and metabolism may depend on tumor vascularization, the relationship between 19F MRS and the DCE-MRI parameters kep, Ktrans and ve was also examined (). In this study, 37 patients were included. The kinetic parameters of DCE-MRI, kep, Ktrans and ve, before start of treatment did not predict tumor response after 2 months, suggesting that the delivery of chemotherapy by tumor vasculature is not a major factor determining response in first-line treatment. No evident correlations between 19F MRS parameters and tumor response were found. This suggests that in liver metastases that are not selected on the basis of their tumor diameter, FU uptake and catabolism are not limiting factors for response. The transfer constant Ktrans, as measured by DCE-MRI before start of treatment, was negatively correlated with FU half-life in the liver metastases, which suggests that, in metastases with a larger tumor blood flow or permeability surface area product, FU is rapidly washed out from the tumor. Copyright © 2006 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine which morphological features of low-intensity lesions in the peripheral zone of the prostate are predictable of prostate cancer on pre-biopsy T2-weighted integrated endorectal phased-array MR images. The MR examinations were performed in 69 consecutive patients with elevated level of prostate-specific antigen (>4 ng/ml) and/or a positive digital rectal examination before transperineal 12-site biopsy. Two radiologists evaluated presence of lesions, their morphological features, and possibility of malignancy in divided into four sections of the peripheral zone. Imaging analysis findings were compared with biopsy results. Discriminative features were selected by stepwise logistic regression. Descriptive statistics and receiver operating characteristics (ROC) curves were also calculated. Sixty-eight benign lesions and 23 malignant lesions were found. Wedge shape and diffuse extensions without mass effect were significantly associated with benignity ( P=0.0105 and 0.002, respectively). Lesion size was significantly associated with malignancy ( P=0.0001). For evaluating probability of malignancy for lesions, regression model showed a comparable accuracy with the total impression for the readers in ROC analysis (Az 0.9095 vs 0.9266, respectively). Wedge shape, diffuse extension without mass effect, and size are the morphological features of low-intensity lesions in the peripheral zone on pre-biopsy T2-weighted MR images that give the best prediction of malignancy. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the effectiveness of radioiodine therapy as an alternative for surgery in elderly patients with a large, compressive goiter using objective methods for measuring thyroid volume and tracheal compression.Design: Prospective study.Setting: University hospital in the Netherlands.Patients: 19 patients (mean age +/- SD, 66 +/- 14 years) with a large, compressive multinodular goiter who had a high operative risk or refused to have thyroid surgery.Intervention: A single intravenous dose of 131I at 2.6 +/- 1.0 GBq (70 +/- 28 mCi) (3.7 MBq or 100 microCi/g of thyroid tissue), followed by daily administration of L-thyroxine in doses that did not suppress thyroid-stimulating hormone.Measurements: Clinical evaluation and measurements of thyroid volume, maximal tracheal deviation, and the smallest cross-sectional area of the tracheal lumen with magnetic resonance imaging before and 1 year after 131I treatment.Results: No exacerbation of compressive symptoms after 131I therapy was observed. Thyroid volume was 269 +/- 153 mL before treatment and 154 +/- 73 mL 1 year after treatment (P < 0.001). Thyroid volume was reduced 40% +/- 15% (range, 19% to 68%). Maximal tracheal deviation (1.9 +/- 0.8 cm before and 1.5 +/- 0.7 cm 1 year after therapy) had decreased by 20% +/- 20% (range, -4% to 73%; P < 0.001), and the smallest cross-sectional area of tracheal lumen (0.78 +/- 0.38 cm2 before and 1.04 +/- 0.48 cm2 1 year after therapy) had increased by 36% +/- 38% (range, -3% to 125%; P < 0.001). Clinical signs and symptoms improved in 8 of 12 patients with dyspnea and inspiratory stridor and in both patients with compression of the superior vena cava.Conclusions: Therapy with 131I is an effective alternative to surgery for elderly patients with a large, compressive multinodular goiter. [ABSTRACT FROM AUTHOR]

A 67-year-old man was treated with maintenance intravesical BCG for superficial bladder cancer. As a culture-proven complication of this therapy, he developed general malaise, high fever, granulomatous hepatitis and a mycotic aneurysm in his left knee. All complications were treated successfully with antituberculous therapy. No vascular surgery was necessary. This case report again stresses the necessity to recognise complications of BCG treatment and to start adequate therapy as soon as possible.Copyright © 2003 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

A malignant fibrous histiocytoma of the mediastinum was successfully treated by surgery and radiotherapy. Magnetic resonance imaging was able to show the site of invasion, the two different components of the tumour, and the blood supply. [ABSTRACT FROM PUBLISHER]

Pilot study evaluating the diagnostic value of magnetic resonance lymphography (MRL) compared with conventional imaging techniques in the preoperative staging of the clinically (palpable) negative neck (cN0) in squamous cell carcinoma of the oral cavity (SCCOC). Patients with SCCOC without clinical evidence of lymph node metastasis and scheduled for surgery underwent MRL in combination with ultrasound with or without fine needle aspiration cytology and multi-detector computer tomography. MRL images were interpreted by 2 independent radiologists. All patients were planned for resection of the primary tumor and a selective neck dissection of levels I-III. Histopathologic results were evaluated as the gold standard and compared with preoperative findings. One of nine evaluated patients had a metastatic node on histopathologic analysis. In all but 1 patient, MRL showed possible metastatic spread in at least 1 node. On a node-to-node basis, negative predictive value (NPV) and sensitivity reached 100% for 1.5- en 3Tesla (T) MRL, specificity reached 92% at 1.5T and 93% at 3T MRL, and positive predictive value (PPV) was 8% at 1.5T MRL, for both radiologists. PPV at 3T MRL was 10% and 9%, for radiologists I and II, respectively. This pilot study shows that MRL has a high NPV based on a node-to-node analysis. However, its PPV was only 10%, and therefore its use as a single imaging technique in the preoperative staging of the cN0 neck in SCCOC seems to be limited. Further studies are needed to confirm these data., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

The development of targeted therapies is a major breakthrough in the treatment of cancer. By evoking necrosis and cavitation, evaluation based on tumour size alone, as is done in the RECIST criteria, is no longer an adequate method. New molecular and functional imaging techniques are developed. This review focuses on the use of new imaging modalities for the evaluation of treatment response of pathway based targeted therapies. First, the basic principles of functional and molecular imaging modalities are briefly discussed. Thereafter, their clinical application in targeted therapies is correlated to the underlying biological mechanism. In this way, the best method for response evaluation for a new agent can be identified.

Aim: To compare the diagnostic accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) in the diagnosis of lymph node metastases in prostate cancer., Methods: After a comprehensive literature search, studies were included that allowed construction of contingency tables for detection of lymph node metastases using CT or MRI. In addition, a summary receiver-operating characteristic (ROC) analysis was performed., Results: A total of 24 studies were included. For CT, pooled sensitivity was 0.42 (0.26-0.56 95% CI) and pooled specificity was 0.82 (0.8-0.83 95% CI). For MRI, the pooled sensitivity was 0.39 (0.22-0.56 95% CI) and pooled specificity was 0.82 (0.79-0.83 95% CI). The differences in performance of CT and MRI were not statistically significant., Conclusion: CT and MRI demonstrate an equally poor performance in the detection of lymph node metastases from prostate cancer. Reliance on either CT or MRI will misrepresent the patient's true status regarding nodal metastases, and thus misdirect the therapeutic strategies offered to the patient.

Aims: Invasive lobular carcinoma of the breast (ILC) is known to be substantially underestimated by mammography, which makes correct planning of treatment difficult. MRI has been proposed as a valuable adjunct to mammography. The purpose of the current study is to evaluate its value, compare it to mammography and assess the possible causes of over- and underestimation of lesion size on MRI., Method: The mammograms and MRI scans of 67 consecutive patients with ILC were retrieved and re-evaluated. Size measurements were correlated to the sizes extracted from the pathology report., Results: MRI measurements correlated better to pathologic size (r=0.85) than mammographic measurements (r=0.27). Underestimation of tumour size was more common on mammography (p<0.001); overestimation occurred with equal frequency (p=0.69). Overestimation on MRI, caused by non-malignant findings, was attributed to enhancing lobular carcinoma in situ., Conclusion: MRI is a more accurate modality for determining tumour size in patients with ILC than mammography. The typical underestimation of lesion size by mammography can be prevented with the aid of MRI, without increasing the risk of lesion overestimation.

Systemic chemotherapy is effective in only a subset of patients with metastasized colorectal cancer. Therefore, early selection of patients who are most likely to benefit from chemotherapy is desirable. Response to treatment may be determined by the delivery of the drug to the tumor, retention of the drug in the tumor and by the amount of intracellular uptake, metabolic activation and catabolism, as well as other factors. The first aim of this study was to investigate the predictive value of DCE-MRI with the contrast agent Gd-DTPA for tumor response to first-line chemotherapy in patients with liver metastases of colorectal cancer. The second aim was to investigate the predictive value of 5-fluorouracil (FU) uptake, retention and catabolism as measured by localized (19)F MRS for tumor response to FU therapy. Since FU uptake, retention and metabolism may depend on tumor vascularization, the relationship between (19)F MRS and the DCE-MRI parameters k(ep), K(trans) and v(e) was also examined (1). In this study, 37 patients were included. The kinetic parameters of DCE-MRI, k(ep), K(trans) and v(e), before start of treatment did not predict tumor response after 2 months, suggesting that the delivery of chemotherapy by tumor vasculature is not a major factor determining response in first-line treatment. No evident correlations between (19)F MRS parameters and tumor response were found. This suggests that in liver metastases that are not selected on the basis of their tumor diameter, FU uptake and catabolism are not limiting factors for response. The transfer constant K(trans), as measured by DCE-MRI before start of treatment, was negatively correlated with FU half-life in the liver metastases, which suggests that, in metastases with a larger tumor blood flow or permeability surface area product, FU is rapidly washed out from the tumor., (c 2006 John Wiley & Sons, Ltd.)

Objectives: To determine whether the failure of chemotherapy in patients with regionally metastatic or unresectable transitional cell carcinoma (TCC) of the bladder can be predicted early in the course of chemotherapy with magnetic resonance (MR) imaging., Methods: In this prospective study, 36 patients with regionally metastatic or unresectable TCC of the urinary bladder underwent MR imaging before and after two, four, and six cycles of chemotherapy with Methotrexate, Vinblastine, Adriamycin (doxorubicin) and Cisplatin (MVAC). The response after two cycles of MVAC was evaluated by using conventional tumour size parameters with unenhanced MR imaging and with changes in the time to the start of tumour or lymph node enhanced at fast dynamic contrast-enhanced MR imaging. The results obtained with these techniques were compared with the findings at histopathology in cystectomy or transurethral resection specimens that were obtained after chemotherapy. Duration of survival was defined as the time from the start of chemotherapy until disease-specific death. Kaplan-Meier curves were drawn to determine the difference in prognosis between responders and nonresponders., Results: After two cycles of chemotherapy, the accuracy, sensitivity, and specificity in distinguishing responders from nonresponders with conventional MR imaging were 69%, 81%, and 50%, respectively. With the fast dynamic contrast-enhanced technique, accuracy, sensitivity, and specificity were 92%, 91%, and 93% respectively. The median bladder cancer specific survival was 28 months for all patients studied. Responders to chemotherapy at fast dynamic contrast-enhanced MR had better median disease-specific survival than nonresponders (42 months vs. 12 months [p<0.0001])., Conclusion: We can predict whether a patient will respond to chemotherapy after two cycles of chemotherapy with fast dynamic contrast-enhanced MR imaging.

The aim of the study was to evaluate mammography in detecting and staging of invasive lobular carcinoma (ILC) in order to assess the performance and impact of observer variability. Forty-two cases of ILC were retrospectively evaluated twice by two breast radiologists. Mammographic performance as well as intra- and interobserver variations was evaluated. Thirty-five percent to 37% of the cases were understaged. The largest differences between radiologists were found in the breast imaging reporting and data system (BIRADS) classification and staging performance. These results can have serious influence on patient management.

Background: Although breast cancer screening is recommended to start at a younger age for women with a hereditary risk of breast cancer, the sensitivity of mammography for these women is reduced. We compared magnetic resonance imaging (MRI) with mammography to determine which is more sensitive and whether MRI could play a role in the early detection of breast cancer for these women., Methods: We constructed a retrospective cohort of all breast MRI and mammography surveillance reports made in our department from November 1994 to February 2001. All of the 179 women in the cohort had received biannual palpation in addition to annual imaging by MRI, mammography, or both. The 258 MRI images and the 262 mammograms were classified with the use of the BI-RADS (i.e., Breast Imaging Reporting and Data System) scoring system, which has five categories to indicate the level of suspicion of a lesion. Receiver operator characteristic curves were generated for MRI and mammography, and the area under each curve (AUC) was assessed for the entire cohort of 179 women and for a subset of 75 women who had received both an MRI and a mammographic examination within a 4-month period. All statistical tests were two-sided., Results: In the cohort of 179 women, we detected 13 breast cancers. Seven cancers were not revealed by mammography, but all were detected by MRI. For the entire cohort, the AUC for mammography was 0.74 (95% confidence interval [CI] = 0.68 to 0.79), and the AUC for MRI was 0.99 (95% CI = 0.98 to 1.0). For the subset of women who had both examinations, the AUC for mammography was 0.70 (95% CI = 0.60 to 0.80), and the AUC for MRI was 0.98 (95% CI = 0.95 to 1.0)., Conclusion: MRI was more accurate than mammography in annual breast cancer surveillance of women with a hereditary risk of breast cancer. Larger prospective studies to examine the role of MRI in screening programs are justified.

Purpose: To determine the appropriate use of magnetic resonance (MR) imaging for preoperative staging of prostate cancer., Materials and Methods: Literature review was performed by using the principles of evidence-based medicine and medical technology assessment. A decision analytic model was used to compare (a) the strategy that radical prostatectomy is performed on the basis of clinical staging with (b) the strategy that extracapsular disease detected at MR imaging contraindicates radical prostatectomy in patients who were considered surgical candidates on the basis of clinical staging., Results: After review of the literature, expert panel opinion did not recommend MR staging. No studies in which therapeutic efficacy was addressed were found. The decision analytic model indicated that the strategy including MR staging decreased costs (MR imaging, $10,568; radical prostatectomy, $11,669) and resulted in almost equal life expectancy (MR imaging, 12.59 years; radical prostatectomy, 12.60 years) and quality-adjusted life-years ([QALYs] MR imaging, 12.53; radical prostatectomy, 12.52). Results of sensitivity analyses demonstrated that the MR strategy was both more effective and less costly if the prior probability of extracapsular disease was at least 39% when considering QALY and 50% when considering unadjusted life expectancy., Conclusion: It is not yet conclusively determined whether preoperative MR staging is appropriate, but results of decision analysis suggest that MR staging is cost-effective for men with moderate or high prior probability of extracapsular disease.