Variability induced by the MR imager in dynamic contrast-enhanced imaging of the prostate.

PURPOSE: To evaluate the variability induced by the imager in discriminating high-grade (Gleason≥7) prostate cancers (HGC) using dynamic contrast-enhanced MRI. MATERIAL AND METHODS: We retrospectively selected 3T MRIs with temporal resolution<10 seconds and comprising T1 mapping from a prospective radiologic-pathologic database of patients treated by prostatectomy. Ktrans, Kep, Ve and Vp were calculated for each lesion seen on MRI using the Weinmann arterial input function (AIF) and three patient-specific AIFs measured in the right and left iliac arteries in pixels in the center of the lumen (psAIF-ST) or manually selected by two independent readers (psAIF-R1 and psAIF-R2). RESULTS: A total of 43 patients (mean age, 63.6±4.9 [SD]; range: 48-72 years) with 100 lesions on MRI (55 HGC) were selected. MRIs were performed on imager A (22 patients, 49 lesions) or B (21 patients, 51 lesions) from two different manufacturers. Using the Weinmann AIF, Kep (P=0.005), Ve (P=0.04) and Vp (P=0.01) significantly discriminated HCG. After adjusting on tissue classes, the imager significantly influenced the values of Kep (P=0.049) and Ve (P=0.007). Using patient-specific AIFs, Vp with psAIF-ST (P=0.008) and psAIF-R2 (P=0.04), and Kep with psAIF-R1 (P=0.03) significantly discriminated HGC. After adjusting on tissue classes, types of patient-specific AIF and side of measurement, the imager significantly influenced the values of Ktrans (P=0.0002), Ve (P=0.0072) and Vp (P=0.0003). For all AIFs, the diagnostic value of pharmacokinetic parameters remained unchanged after adjustment on the imager, with stable odds ratios. CONCLUSION: The imager induced variability in the absolute values of pharmacokinetic parameters but did not change their diagnostic performance.

Selection of an early biomarker for vascular normalization using dynamic contrast-enhanced ultrasonography to predict outcomes of metastatic patients treated with bevacizumab.

BACKGROUND: Dynamic contrast-enhanced ultrasonography (DCE-US) has been used for evaluation of tumor response to antiangiogenic treatments. The objective of this study was to assess the link between DCE-US data obtained during the first week of treatment and subsequent tumor progression. PATIENTS AND METHODS: Patients treated with antiangiogenic therapies were included in a multicentric prospective study from 2007 to 2010. DCE-US examinations were available at baseline and at day 7. For each examination, a 3 min perfusion curve was recorded just after injection of a contrast agent. Each perfusion curve was modeled with seven parameters. We analyzed the correlation between criteria measured up to day 7 on freedom from progression (FFP). The impact was assessed globally, according to tumor localization and to type of treatment. RESULTS: The median follow-up was 20 months. The mean transit time (MTT) evaluated at day 7 was the only criterion significantly associated with FFP (P = 0.002). The cut-off point maximizing the difference between FFP curves was 12 s. Patients with at least a 12 s MTT had a better FFP. The results according to tumor type were significantly heterogeneous: the impact of MTT on FFP was more marked for breast cancer (P = 0.004) and for colon cancer (P = 0.025) than for other tumor types. Similarly, the differences in FFP according to MTT at day 7 were marked (P = 0.004) in patients receiving bevacizumab. CONCLUSION: The MTT evaluated with DCE-US at day 7 is significantly correlated to FFP of patients treated with bevacizumab. This criterion might be linked to vascular normalization. AFSSAPS NO: 2007-A00399-44.

'Peripheric' pancreatic cysts: performance of CT scan, MRI and endoscopy according to final pathological examination.

OBJECTIVE: To assess the accuracy of pre-operative staging in patients with peripheral pancreatic cystic neoplasms (pPCNs). METHODS: From 2005 to 2011, 148 patients underwent a pancreatectomy for pPCNs. The pre-operative examination methods of computed tomography (CT), magnetic resonance imaging (MRI), endoscopic ultrasonography (EUS) were compared for their ability to predict the suggested diagnosis accurately, and the definitive diagnosis was affirmed by pathological examination. RESULTS: A mural nodule was detected in 34 patients (23%): only 1 patient (3%) had an invasive pPCN at the final histological examination. A biopsy was performed in 79 patients (53%) during EUS: in 55 patients (70%), the biopsy could not conclude a diagnosis; the biopsy provided the correct and wrong diagnosis in 19 patients (24%) and 5 patients (6%), respectively. A correct diagnosis was affirmed by CT, EUS and pancreatic MRI in 60 (41%), 103 (74%) and 80 (86%) patients (when comparing EUS and MRI; P = 0.03), respectively. The positive predictive values (PPVs) of CT, EUS and MRI were 70%, 75% and 87%, respectively. CONCLUSIONS: Pancreatic MRI appears to be the most appropriate examination to diagnose pPCNs accurately. EUS alone had a poor PPV. Mural nodules in a PCN should not be considered an indisputable sign of pPCN invasiveness.

Aggressive angiomyxoma with diffusion-weighted magnetic resonance imaging and dynamic contrast enhancement: a case report and review of the literature.

INTRODUCTION: Aggressive angiomyxoma (AA) is a rare benign soft tissue tumour usually affecting the pelvis and perineum of young women. Magnetic resonance imaging (MRI) is crucial in the management of AA patients for its diagnostic contribution and for the preoperative assessment of the actual tumour extension. Given the current development of less aggressive therapeutics associated with a higher risk of recurrence, close follow-up with MRI is fundamental after treatment. In this context, diffusion-weighted (DW) imaging has already shown high efficacy in the detection of early small relapses in prostate or rectal cancer. CASE REPORT: We report here a case of pelvic AA in a 51-year-old woman examined with dynamic contrast enhancement and DW-MRI, including apparent diffusion coefficient mapping and calculation. CONCLUSION: To our knowledge, this is the first description of DW-MRI in AA reported in the literature. Here, knowledge about imaging features of AA will be reviewed and expanded.

Two-stage hepatectomy: who will not jump over the second hurdle?

BACKGROUND: Two-stage hepatectomy uses compensatory liver regeneration after a first noncurative hepatectomy to enable a second curative resection in patients with bilobar colorectal liver metastasis (CLM). OBJECTIVE: To determine the predictive factors of failure of two-stage hepatectomy. METHOD: Between 2000 and 2010, 48 patients with irresectable CLM were eligible for two-stage hepatectomy. The planned strategy was a) cleaning of the left hepatic lobe (first hepatectomy), b) right portal vein embolisation and c) right hepatectomy (second hepatectomy). Six patients had occult CLM (n = 5) or extra-hepatic disease (n = 1), which was discovered during the first hepatectomy. Thus, 42 patients completed the first hepatectomy and underwent portal vein embolisation in order to receive the second hepatectomy. Eight patients did not undergo a second hepatectomy due to disease progression. RESULTS: Upon univariate analysis, two factors were identified that precluded patients from having the second hepatectomy: the combined resection of a primary tumour during the first hepatectomy (p = 0.01) and administration of chemotherapy between the two hepatectomies (p = 0.03). An independent association with impairment to perform the two-stage strategy was demonstrated by multivariate analysis for only the combined resection of the primary colorectal cancer during the first hepatectomy (p = 0.04). CONCLUSION: Due to the small number of patients and the absence of equivalent conclusions in other studies, we cannot recommend performance of an isolated colorectal resection prior to chemotherapy. However, resection of an asymptomatic primary tumour before chemotherapy should not be considered as an outdated procedure.

Is neoadjuvant chemotherapy prior to radio-chemotherapy beneficial in T4 anal carcinoma?

BACKGROUND: This study retrospectively describes the outcome of a series of 38 patients (pts) with T4 anal carcinoma exclusively treated by radio and chemotherapy. PATIENTS AND METHODS: From 1992 to 2007, 38 pts with UST4-N0-2-M0 anal carcinoma were treated with exclusive radiotherapy and chemotherapy. All patients received external beam radiotherapy (EBRT) (median dose 45 Gy) with a concomitant chemotherapy (5-fluorouracil-cisplatin). Eleven patients received neo-adjuvant chemotherapy (5-fluorouracil-cisplatin). After 2-8 weeks, a 15-20 Gy boost was delivered either with EBRT (20 pts) or interstitial (192)Ir brachytherapy (18 pts). Mean follow-up was 66 months. RESULTS: After chemoradiation therapy (CRT), 13 pts (34%) had a complete response, 23 pts (60%) a response >50% (2 pts were not evaluated). The 5-year-disease-free survival was 79.2 ± 6.5%, and the 5-year overall survival was 83.9 ± 6%. Eight patients developed tumor progression (mean delay 8.8 months), six of them requiring a salvage surgery with definitive colostomy for local relapse. Late severe complication requiring colostomy was observed in 2 pts. The 5-year-colostomy-free survival was 78 ± 6.9%. Patients who received primary chemotherapy had a statistically significant better 5-year colostomy-free survival (100% vs. 38 ± 16.4%, P = 0.0006). CONCLUSION: T4 anal carcinoma can be treated with a curative intent using a sphincter-sparing approach of CRT, and neo-adjuvant chemotherapy should be considered prior to radiotherapy.

Pancreatic endocrine tumor with neoplastic venous thrombus and bilobar liver metastasis. A case report.

We report the case of an asymptomatic 56-year-old woman with a metastatic pancreatic endocrine tumor, fortuitously discovered by abdominal imaging. A CT-scan showed a large mass in the pancreatic tail invading the spleen and stomach; in addition, there was neoplastic thrombus within the spleno-mesentericoportal venous confluence and bilobar liver metastases. Surgical resection was performed in two stages. The first procedure was an extended left pancreatectomy with venous thrombectomy and "clearance" of the left hepatic lobe. During the interval, embolization of the right portal vein was carried out. Right hepatectomy and radiofrequency destruction of residual metastases was then performed. On the basis of completeness of the resection and the histopathological data, the patient did not undergo any adjuvant therapy, in accordance with French guidelines. At 1 year of follow-up, there was no evidence of recurrence.

[Comparison of 64 MDCT coronary CTA and coronary angiography in the detection of coronary artery stenosis in low risk patients with stable angina and acute coronary syndrome]. / Comparaison du scanner 64-détecteurs et de la coronarographie dans la détection des sténoses coronariennes chez des patients porteurs d'angor stable et de syndrome coronaire aigu à bas risques.

PURPOSE: To determine the accuracy of 64 MDCT coronary CTA (CCTA) compared to coronary angiography in low risk patients with stable angina and acute coronary syndrome and determine the number of significant coronary artery stenoses ( 50%) in these patients. Materials and methods. Fifty-five patients underwent CCTA using a 32 MDCT unit with z flying focus allowing the acquisition of 64 slices of 0.6 mm thickness as well as coronary angiography (gold standard). Nine patients were excluded due to prior coronary artery bypass surgery (n=4), insufficient breath hold (n=3), calcium scoring>1000 (n=1) and delay between both examinations over 4 months (n=1). Forty-six patients: 27 males and 19 females were included. CCTA results were compared to coronary angiography per segment and artery with threshold detection of stenoses 50%. The degree of correlation between both examinations was performed using a regression analysis with a Pearson correlation coefficient<0.05 considered significant. RESULTS: The overall accuracy of CCTA was 90%; limitations related to the presence of calcifications, motion artifacts or insufficient vessel opacification. The correlation for all analyzed segments was 96.4%. Thirty-eight of 50 significant stenoses seen on coronary angiography were correctly detected on CCTA. Sensitivity, specificity, PPVC and NPV for detection of stenoses 50% were 76%, 98.3%, 80.3% and 97.7% respectively. Evaluation per segment had a NPV of 96.8% (interventricular and diagonal segments) to 100% (main trunk). CONCLUSION: Our results for specificity and NPV are similar to reports from the literature. This suggests that CCTA in this clinical setting may replace coronary angiography.

Non-invasive coronary angiography for patients with acute atypical chest pain discharged after negative screening including maximal negative treadmill stress test. A prospective study.

UNLABELLED: Among patients admitted in the emergency department for acute atypical chest pain those with an acute coronary syndrome (ACS) who are mistakenly discharged home have high mortality. A recent retrospective study has demonstrated that multislice computed tomography (MSCT) coronary angiography could improve triage of these patients. We aimed to prospectively confirm these data on patients with a negative screening including maximal treadmill stress. PATIENTS: 30 patients discharged from the emergency department after negative screening for an ACS were included. All patients underwent MSCT angiography of the coronary artery. Patients with coronary atheroma on MSCT had an invasive coronary angiography to confirm these findings. RESULTS: Seven patients (23%) had obstructive coronary artery disease on MSCT. Invasive coronary angiography (ICA) confirmed the diagnosis in all patients. CONCLUSION: In patients with no previously known coronary artery disease admitted to the emergency department with atypical acute chest pain and discharged after negative screening, including maximal treadmill stress test, MSCT coronary angiography is useful for the diagnosis of obstructive coronary artery disease.

Diffusion-weighted magnetic resonance imaging with apparent diffusion coefficient (ADC) determination in normal and pathological fetal kidneys.

OBJECTIVES: To assess the use of diffusion-weighted magnetic resonance imaging (DW-MRI) in the evaluation of the fetal kidney and to estimate age-dependent changes in the apparent diffusion coefficient (ADC) of normal and pathological fetal kidneys. METHODS: DW-MRI was performed on a 1.5-T machine at 23-38 gestational weeks in 51 pregnant women in whom the fetal kidneys were normal and in 10 whose fetuses had renal pathology (three with suspected nephropathy, three with renal tract dilatation, one with unilateral renal venous thrombosis, and three with twin-twin transfusion syndrome (TTTS)). The ADC was measured in an approximately 1-cm2 region of interest within the renal parenchyma. RESULTS: ADC values in normal renal parenchyma ranged from 1.1 to 1.8 10(-3) mm2 s-1. There was no significant age-dependent change in the ADC of normal kidneys. In cases of nephropathy, the ADC value was not always pathological but an ADC map could show abnormal findings. In cases of dilatation, the ADC value was difficult to determine when the dilatation was huge. In cases of TTTS, the ADC of the donor twin was higher than that of the recipient twin and the difference seemed to be related to the severity of the syndrome. CONCLUSION: Evaluation of the ADC for fetal kidneys is feasible. Fetal measurement of the ADC value and ADC maps may be useful tools with which to explore the fetal kidney when used in conjunction with current methods. DW-MR images, ADC value and ADC map seem to be useful in cases of suspected nephropathy (hyperechoic kidneys), dilated kidney and vascular pathology (renal venous thrombosis, TTTS).