Diffusion weighted MR imaging in the differential diagnosis of haemangiomas and metastases of the liver

Background

The purpose of the study was to evaluate the value of diffusion-weighted imaging in the differential diagnosis of haemangiomas from metastases of the liver.

Patients and methods.

We analyzed 69 lesions in 38 patients (33 haemangiomas; 36 metastases) in the retrospective study. Diffusion-weighted imaging was performed using a breath-hold single-shot echo-planar spin echo sequence with three b factors (0, 500 and 1000 sec/mm²), and apparent diffusion coefficients (ADCs) were calculated. For the quantitative evaluation, signal intensity of the lesions, lesion-to-liver signal intensity ratios, ADC of the lesions, and lesion-to-liver ADC ratios were compared between the groups. The statistical significance was determined by student’s-t test.

Results

With the b factor 500 sec/mm², no statistical significance was achieved (p>0.05). With the b factor of 1000 sec/mm², both the signal intensity and lesion-to-liver signal intensity ratio of the metastases were significantly higher than those for haemangiomas (p<0.001). The cut-off value at 2.6 yielded a sensitivity of 86% and a specificity of 82% for the lesion-to-liver signal intensity ratio. The ADC, and lesion-to-liver ADC ratio of the metastases were significantly lower than those of haemangiomas (p<0.001). With cut-off value of 1.7, ADC ratio had a sensitivity of 88% and a specificity of 72% for ADC lesion/liver.

Conclusions

Diffusion-weighted imaging with high b value may help in the differential diagnosis of metastases from haemangiomas of the liver.     

Differentiation of high-grade and low-grade diffuse gliomas by intravoxel incoherent motion MR imaging

Background

Our aim was to assess the diagnostic performance of intravoxel incoherent motion (IVIM) MR imaging for differentiating high-grade gliomas (HGGs) from low-grade gliomas (LGGs).

Methods

Forty-five patients with diffuse glioma (age 50.9 ± 20.4 y; 26 males, 19 females) were assessed with IVIM imaging using 13 b-values (0–1000 s/mm²) at 3T. The perfusion fraction (f), true diffusion coefficient (D), and pseudo-diffusion coefficient (D*) were calculated by fitting the bi-exponential model. The apparent diffusion coefficient (ADC) was obtained with 2 b-values (0 and 1000 s/mm²). Relative cerebral blood volume was measured by the dynamic susceptibility contrast method. Two observers independently measured D, ADC, D*, and f, and these measurements were compared between the LGG group (n = 16) and the HGG group (n = 29).

Results

Both D (1.26 ± 0.37 mm²/s in LGG, 0.94 ± 0.19 mm²/s in HGG; P < .001) and ADC (1.28 ± 0.35 mm²/s in LGG, 1.03 ± 0.19 mm²/s in HGG; P < .01) were lower in the HGG group. D was lower than ADC in the LGG (P < .05) and HGG groups (P < .0001). D* was not different between the groups. The f-values were significantly larger in HGG (17.5 ± 6.3%) than in LGG (5.8 ± 3.8%; P < .0001) and correlated with relative cerebral blood volume (r = 0.85; P < .0001). Receiver operating characteristic analyses showed areas under curve of 0.95 with f, 0.78 with D, 0.73 with ADC, and 0.60 with D*.

Conclusion

IVIM imaging is useful in differentiating HGGs from LGGs.     

Thyroid lesions incidentally detected by 18F-FDG PET-CT — a two centre retrospective study

Background.

Incidental ¹⁸F-FDG uptake in the thyroid on PET-CT examinations represents a diagnostic challenge. The maximal standardized uptake value (SUV_max) is one possible parameter that can help in distinguishing between benign and malignant thyroid PET lesions.

Patients and methods.

We retrospectively evaluated ¹⁸F-FDG PET-CT examinations of 5,911 patients performed at two different medical centres from 2010 to 2011. If pathologically increased activity was accidentally detected in the thyroid, the SUV_max of the thyroid lesion was calculated. Patients with incidental ¹⁸F-FDG uptake in the thyroid were instructed to visit a thyroidologist, who performed further investigation including fine needle aspiration cytology (FNAC) if needed. Lesions deemed suspicious after FNAC were referred for surgery.

Results.

Incidental ¹⁸F-FDG uptake in the thyroid was found in 3.89% — in 230 out of 5,911 patients investigated on PET-CT. Malignant thyroid lesions (represented with focal thyroid uptake) were detected in 10 of 66 patients (in 15.2%). In the first medical centre the SUV_max of 36 benign lesions was 5.6 ± 2.8 compared to 15.8 ± 9.2 of 5 malignant lesions (p < 0.001). In the second centre the SUV_max of 20 benign lesions was 3.7 ± 2.2 compared to 5.1 ± 2.3 of 5 malignant lesions (p = 0.217). All 29 further investigated diffuse thyroid lesions were benign.

Conclusions.

Incidental ¹⁸F-FDG uptake in the thyroid was found in 3.89% of patients who had a PET-CT examination. Only focal thyroid uptake represented a malignant lesion in our study — in 15.2% of all focal thyroid lesions. SUV_max should only serve as one of several parameters that alert the clinician on the possibility of thyroid malignancy.     

Doppler ultrasound for diagnosis of soft tissue sarcoma: efficacy of ultrasound-based screening score

Background.

The utility of ultrasound imaging in the screening of soft-part tumours (SPTs) has been reported. We classified SPTs according to their blood flow pattern on Doppler ultrasound and re-evaluated the efficacy of this imaging modality as a screening method. Additionally, we combined Doppler ultrasound with several values to improve the diagnostic efficacy and to establish a new diagnostic tool.

Patients and methods.

This study included 189 cases of pathologically confirmed SPTs (122 cases of benign disease including SPTs and tumour-like lesions and 67 cases of malignant SPTs). Ultrasound imaging included evaluation of vascularity by colour Doppler. We established a scoring system to more effectively differentiate malignant from benign SPTs (ultrasound-based sarcoma screening [USS] score).

Results.

The mean scores in the benign and malignant groups were 1.47 ± 0.93 and 3.42 ± 1.30, respectively. Patients with malignant masses showed significantly higher USS scores than did those with benign masses (p < 1 × 10⁻¹⁰). The area under the curve was 0.88 by receiver operating characteristic (ROC) analysis. Based on the cut-off value (3 points) calculated by ROC curve analysis, the sensitivity and specificity for a diagnosis of malignant SPT was 85.1% and 86.9%, respectively.

Conclusions.

Assessment of vascularity by Doppler ultrasound alone is insufficient for differentiation between benign and malignant SPTs. Preoperative diagnosis of most SPTs is possible by combining our USS score with characteristic clinical and magnetic resonance imaging findings.     

Diagnostic Value of Elastography Using Acoustic Radiation Force Impulse Imaging and Strain Ratio for Breast Tumors

Purpose

The aim of this study was to determine whether the combination of B-mode ultrasonography (BUS), acoustic radiation force impulse (ARFI) elastography, and strain ratio (SR) provides better diagnostic performance of breast lesion differentiation than BUS alone.

Methods

ARFI elastography and SR evaluations were performed on patients with 157 breast lesions diagnosed by BUS from June to September 2013. BUS images were classified according to the Breast Imaging-Reporting and Data System. ARFI elastography was performed using Virtual Touch™ tissue imaging (VTI) and Virtual Touch™ tissue quantification (VTQ). In VTI mode, we evaluated the color-mapped patterns of the breast lesion and surrounding tissue. The lesions were classified into five categories by elasticity score. In VTQ mode, each lesion was assessed using shear wave velocity (SWV) measurements. SR was calculated from the lesion and comparable lateral fatty tissue. We compared the diagnostic performance of BUS alone and the combination of BUS, ARFI elastography, and SR evaluations.

Results

Among the 157 lesions, 40 were malignant and 117 were benign. The mean elasticity score (3.7±1.0 vs. 1.6±0.8, p<0.01), SWV (4.23±1.09 m/sec vs. 2.22±0.88 m/sec, p<0.01), and SR (5.69±1.63 vs. 2.69±1.40, p<0.01) were significantly higher for malignant lesions than benign lesions. The results for BUS combined with ARFI elastography and SR values were 97.5% sensitivity, 92.3% specificity, 93.6% accuracy, a 79.6% positive predictive value (PPV), and a 99.1% negative predictive value. The combination of the 3 radiologic examinations yielded superior specificity, accuracy, and PPV compared to BUS alone (p<0.01 for each).

Conclusion

ARFI elastography and SR evaluations showed significantly different mean values for benign and malignant lesions. Moreover, these two modalities complemented BUS and improved the diagnostic performance of breast lesion detection. Therefore, ARFI elastography and SR evaluations can be used as complementary modalities to make more accurate breast lesion diagnoses.     

Diagnostic Value of Contrast-Enhanced Ultrasound Parametric Imaging in Breast Tumors

Purpose

This study aimed to evaluate the diagnostic value of SonoLiver software for parametric imaging in breast tumors.

Methods

Contrast-enhanced ultrasound (CEUS) was performed in 216 breast lesions (113 malignant, 103 benign). The CEUS parameters were compared between benign and malignant lesions. The rise time, the time to peak, the mean transit time and dynamic vessel pattern (DVP) were analyzed using SonoLiver software.

Results

Quantitative analysis showed that the rise time was 16.52±4.15 seconds in the benign group vs. 13.86±3.36 seconds in the malignant group (p=0.007), and the time to peak was 19.86±4.87 seconds in the benign group vs. 16.52±4.85 seconds in the malignant group (p=0.009). The mean transit time was 80.55±18.65 seconds in the benign group vs. 65.16±20.28 seconds in the malignant group (p=0.006). The difference between the distribution of DVP in benign and malignant tumors was statistically significant. One hundred one malignant tumors (89.4%) performed an irregular red/yellow fill in the region of interest (ROI) and 85 benign tumors (82.5%) performed a single blue/green fill in the ROI. The sensitivity, specificity, and accuracy of parametric imaging in breast tumors were 84.1%, 85.4%, 84.7%, respectively.

Conclusion

The CEUS parametric imaging can distinguish differences between malignant and benign breast tumors as well as provide diagnostic information on breast lesions.     

Quantitative characterization of the imaging limits of diffuse low-grade oligodendrogliomas

Background

Supratentorial diffuse low-grade gliomas in adults extend beyond maximal visible MRI-defined abnormalities, and a gap exists between the imaging signal changes and the actual tumor margins. Direct quantitative comparisons between imaging and histological analyses are lacking to date. However, they are of the utmost importance if one wishes to develop realistic models for diffuse glioma growth.

Methods

In this study, we quantitatively compared the cell concentration and the edema fraction from human histological biopsy samples (BSs) performed inside and outside imaging abnormalities during serial imaging-based stereotactic biopsy of diffuse low-grade gliomas.

Results

The cell concentration was significantly higher in BSs located inside (1189 ± 378 cell/mm²) than outside (740 ± 124 cell/mm²) MRI-defined abnormalities (P = .0003). The edema fraction was significantly higher in BSs located inside (mean, 45% ± 23%) than outside (mean, 5 %± 9%) MRI-defined abnormalities (P < .0001). At borders of the MRI-defined abnormalities, 20% of the tissue surface area was occupied by edema and only 3% by tumor cells. The cycling cell concentration was significantly higher in BSs located inside (10 ± 12 cell/mm²), compared with outside (0.5 ± 0.9 cell/mm²), MRI-defined abnormalities (P = .0001).

Conclusions

We showed that the margins of T2-weighted signal changes are mainly correlated with the edema fraction. In 62.5% of patients, the cycling tumor cell fraction (defined as the ratio of the cycling tumor cell concentration to the total number of tumor cells) was higher at the limits of the MRI-defined abnormalities than closer to the center of the tumor. In the remaining patients, the cycling tumor cell fraction increased towards the center of the tumor.     

Editor's choice: Precise ex vivo histological validation of heightened cellularity and diffusion-restricted necrosis in regions of dark apparent diffusion coefficient in 7 cases of high-grade glioma

Background

Recent conflicting reports have found both brain tumor hypercellularity and necrosis in regions of restricted diffusion on MRI-derived apparent diffusion coefficient (ADC) images. This study precisely compares ADC and cell density voxel by voxel using postmortem human whole brain samples.

Methods

Patients with meningioma were evaluated to determine a normative ADC distribution within benign fluid attenuated inversion recovery (FLAIR) T2/hyperintensity surrounding tumor. This distribution was used to calculate a minimum ADC threshold to define regions of ADC-FLAIR mismatch (AFMM), where restricted diffusion presented in conjunction with T2/FLAIR hyperintensity. Contrast-enhancing voxels were excluded from this analysis. AFMM maps were generated using imaging acquired prior to death in 7 patients with high-grade glioma who eventually donated their brains upon death. Histological samples were taken from numerous regions of abnormal FLAIR and AFMM. Each sample was computationally processed to determine cell density. Custom software was then used to downsample coregistered microscopic histology to the more coarse MRI resolution. A voxel-by-voxel evaluation comparing ADC and cellularity was then performed.

Results

An ADC threshold of 0.929 × 10⁻³ mm²/s was calculated from meningioma-induced edema and was used to define AFMM. Regions of AFMM showed significantly greater cell density in 6 of 7 high-grade glioma cases compared with regions of hyperintense FLAIR alone (P < .0001). Two patients had small regions of diffusion-restricted necrosis that had significantly lower ADC than nearby hypercellularity.

Conclusions

Regions of AFMM contain hypercellularity except for regions with extremely restricted diffusion, where necrosis is present.     

Osteosarcoma subtypes: Magnetic resonance and quantitative diffusion weighted imaging criteria

Introduction

Osteosarcoma (OS) is a primary bone malignancy, characterized by spindle cells producing osteoid. The objective of this study is to describe the magnetic resonance imaging (MRI) features of different OS subtypes, record their attenuation diffusion coefficient (ADC) values and to point to the relation of their pathologic base and their corresponding ADC value.

Value of apparent diffusion coefficient measurement for discrimination of focal benign and malignant hepatic masses

The purpose of our study was to investigate the value of diffusion‐weighted magnetic resonance imaging (DW‐MRI) to discriminate benign and malignant focal lesions of the liver using parallel imaging technique. A total of 77 patients and 65 healthy controls were enrolled in the study. DW‐MRI was performed with b‐factors of 0, 500 and 1000 s/mm², and the apparent diffusion coefficients (ADC) values of the normal liver and the lesions were calculated. The mean ADC value of the focal liver lesions were as follows: simple cysts (3.16 ± 0.18 × 10^?3 mm²/s), hydatid cysts (2.58 ± 0.53 × 10^?3 mm²/s), hemangiomas (1.97 ± 0.49 × 10^?3 mm²/s), metastases (1.14 ± 0.41 × 10^?3 mm²/s) and hepatocellular carcinomas (HCC) (1.15 ± 0.36 × 10^?3 mm²/s). The mean ADC values of all the disease groups were statistically significant when compared with the mean ADC value of the normal liver (1.56 ± 0.14 × 10^?3 mm²/s), (P < 0.01). There were also statistically significant differences among the ADC values of hemangiomas and HCC metastases (P < 0.01), and simple and hydatid cysts (P < 0.008). However, there was no statistically significant difference between HCC and metastases. The present study showed that ADC measurement has the potential to differentiate benign and malignant focal hepatic lesions. We propose to add DW sequence in the MR protocol for the detection and quantitative discrimination of hepatic pathologies.     

Diffusion-weighted imaging (b value = 1500 s/mm2) is useful to decrease false-positive breast cancer cases due to fibrocystic changes

Background

We aimed to evaluate the application of apparent diffusion coefficient (ADC) values calculated from diffusion-weighted imaging (DWI) (b value = 1500 s/mm²) in the breast imaging reporting and data system (BI-RADS).

Methods

For 104 cases of breast lesions with definitive histology diagnosis (45 benign cases, 59 malignant cases) in which breast magnetic resonance imaging was performed, ADC values were compared between benign and malignant cases, between ductal carcinoma in situ (DCIS) and fibrocystic changes, and between DCIS and ductal hyperplasia (one type of fibrocystic change). Diagnostic accuracy was compared for a total of 101 images and for 34 images including only nine DCIS and 25 fibrocystic changes between BI-RADS alone (with categories 4a, 4b, and 5 defined as malignancies) and BI-RADS plus ADC.

Results

There were significant differences in mean ADC values between malignant and benign cases (p < 0.0001) and between DCIS and fibrocystic changes (p < 0.002), but not between DCIS and ductal hyperplasia. Positive predictive values were significantly greater for BI-RADS plus ADC than for BI-RADS alone in all cases (70.5% for BI-RADS alone, 81.3% for BI-RADS plus ADC) and in cases of DCIS versus fibrocystic changes (40.9% for BI-RADS alone, 64.3% for BI-RADS plus ADC), resulting in a significant improvement in diagnostic accuracy with the addition of ADC.

Conclusion

Adding ADC values calculated from DWI (b value = 1500 s/mm²) to BI-RADS is a useful way to improve differential diagnostic accuracy for malignant tumors and benign lesions, especially for DCIS versus fibrocystic changes, except in cases of ductal hyperplasia.     

Optimization of apparent diffusion coefficient measured by diffusion-weighted MRI for diagnosis of breast lesions presenting as mass and non-mass-like enhancement

The purpose of this study was to investigate the diagnostic value of the apparent diffusion coefficient (ADC), measured by diffusion-weighted magnetic resonance imaging (MRI), for the diagnosis of breast lesions presenting as mass and non-mass-like enhancement (NMLE). The breast MRI studies of 174 patients were reviewed retrospectively. A total of 188 histologically confirmed lesions were analyzed and classified into 127 mass enhancement (86 malignant and 41 benign) and 61 NMLE (42 malignant and 19 benign). The ADC values were measured using a spin-echo echo-planner-imaging (SE-EPI) sequence with b?=?1,000 s/mm². Diagnostic performance was evaluated using receiver operating characteristic (ROC) analysis. The mean ADC was 0.99?±?0.22?×?10^?3?mm²/s for invasive cancer, 1.23?±?0.33?×?10^?3?mm²/s for ductal carcinoma in situ (DCIS), and 1.52?±?0.35?×?10^?3?mm²/s for benign adenosis. The mean ADC of all NMLE lesions was 1.44?±?0.41?×?10^?3?mm²/s, which is higher than the mean ADC of all mass lesions, 1.12?±?0.33?×?10^?3?mm²/s. In the ROC analysis, the optimal cutoff ADC value for differentiating benign from malignant lesions was 1.05?×?10^?3?mm²/s for mass lesions and 1.35?×?10^?3?mm²/s for NMLE. In conclusion, ADC values can be used for the diagnosis of invasive and DCIS as well as benign tumors. The NMLE lesions tend to have higher ADC values than mass lesions; therefore, the morphological appearance of a lesion needs to be considered when using the ADC value for diagnosis.     

Diffusion-weighted images(DWI) without ADC values in assessment of small focal nodules in cirrhotic liver简

Objective： To assess if diffusion-weighted magnetic resonance （MR） imaging without apparent diffusion coefficient （ADC） values provides added diagnostic value in combination with conventional MR imaging in the detection and characterization of small nodules in cirrhotic liver. Methods： Two observers retrospectively and independently analyzed 86 nodules （_〈3 em） certified pathologically in 33 patients with liver cirrhosis, including 48 hepatocellular carcinoma （HCC） nodules, 13 high-grade dysplastic nodules （HDN）, 10 low-grade dysplastic nodules （LDNs） and 15 other benign nodules. All these focal nodules were evaluated with conventional MR images （Tl-weighted, T2-weighted and dynamic gadolinium-enhanced images） and breath-hold diffusion-weighted images （DWI） （b=500 s/mm2）. The nodules were classified by using a scale of 1-3 （1, not seen; 3, well seen） on DWI for qualitative assessment. These small nodules were characterized by two radiologists. ADC values weren＇t measured. The diagnostic performance of the combined DWI-conventional images and the conventional images alone was evaluated using receiver operating characteristic （ROC） curves. The area under the curves （Az）, sensitivity and specificity values for characterizing different small nodules were also calculated. Results： Among 48 HCC nodules, 33 （68.8%） were graded as 3 （well seen）, 6 （12.5%） were graded as 2 （partially obscured）, and 9 weren＇t seen on DWI. Among 13 HDNs, there were 3 （23.1%） and 4 （30.8%） graded as 3 and 2 respectively. Five （50%） of 10 benign nodules were partially obscured and slightly hyperintense. For 86 nodules, the average diagnostic accuracy of combined DWI-conventional images was 82.56%, which was increased significantly compared with conventional MR images with 76.17%. For HCC and HDN, the diagnostic accuracy of combined DWI-conventional images increased from 78.69% to 86.07 %. Conclusions： Diffusion-weighted MR imaging does provide added diagnostic value in the detection and characterization of HDN and HCC, and it may not be helpful for LDN and regenerative nodule （RN） in cirrhotic liver.     

Prevalence and malignancy risk of focal colorectal incidental uptake detected by 18F-FDG-PET or PET/CT: a meta-analysis

Background

The aim of the study was to meta-analyze published data about prevalence and malignancy risk of focal colorectal incidentalomas (FCIs) detected by Fluorine-18-Fluorodeoxyglucose positron emission tomography or positron emission tomography/computed tomography (¹⁸F-FDG-PET or PET/CT).

Methods

A comprehensive computer literature search of studies published through July 31^st 2012 regarding FCIs detected by ¹⁸F-FDG-PET or PET/CT was performed. Pooled prevalence of patients with FCIs and risk of malignant or premalignant FCIs after colonoscopy or histopathology verification were calculated. Furthermore, separate calculations for geographic areas were performed. Finally, average standardized uptake values (SUV) in malignant, premalignant and benign FCIs were reported.

Results

Thirty-two studies comprising 89,061 patients evaluated by ¹⁸F-FDG-PET or PET/CT were included. The pooled prevalence of FCIs detected by ¹⁸F-FDG-PET or PET/CT was 3.6% (95% confidence interval [95% CI]: 2.6–4.7%). Overall, 1,044 FCIs detected by ¹⁸F-FDG-PET or PET/CT underwent colonoscopy or histopathology evaluation. Pooled risk of malignant or premalignant lesions was 68% (95% CI: 60–75%). Risk of malignant and premalignant FCIs in Asia-Oceania was lower compared to that of Europe and America. A significant overlap in average SUV was found between malignant, premalignant and benign FCIs.

Conclusions

FCIs are observed in a not negligible number of patients who undergo ¹⁸F-FDG-PET or PET/CT studies with a high risk of malignant or premalignant lesions. SUV is not reliable as a tool to differentiate between malignant, premalignant and benign FCIs. Further investigation is warranted whenever FCIs are detected by ¹⁸F-FDG-PET or PET/CT.     

Clinical Outcome of Magnetic Resonance Imaging-Detected Additional Lesions in Breast Cancer Patients

Purpose

The aim of this study was to investigate the clinical outcome of additional breast lesions identified with breast magnetic resonance imaging (MRI) in breast cancer patients.

Methods

A total of 153 patients who underwent breast MRI between July 2006 and March 2008 were retrospectively reviewed. Thirty-three patients (21.6&) were recommended for second-look ultrasound (US) for further characterization of additional lesions detected on breast MRI and these patients constituted our study population.

Results

Assessment for lesions detected on breast MRI consisted of the following: 25 benign lesions (73.5&), two indeterminate (5.9%), and seven malignant (20.6%) in 33 patients. Second-look US identified 12 additional lesions in 34 lesions (35.3%) and these lesions were confirmed by histological examination. Of the 12 lesions found in the 11 patients, six (50.0%) including one contralateral breast cancer were malignant. The surgical plan was altered in 18.2% (six of 33) of the patients. The use of breast MRI justified a change in treatment for four patients (66.7%) and caused two patients (33.3&) to undergo unwarranted additional surgical procedures.

Conclusion

Breast MRI identified additional multifocal or contralateral cancer which was not detected initially on conventional imaging in breast cancer patients. Breast MRI has become an indispensable modality in conjunction with conventional modalities for preoperative evaluation of patients with operable breast cancer.     

Use of 18F-FDG PET/CT to locate primary malignancies in patients with hepatic cirrhosis and malignant ascites

Objective：Ascites in patients with hepatic cirrhosis is caused by cirrhosis in most cases.For most malignant ascites,the primary malignancy could be readily identified using conventional imaging methods,e.g.,computer tomography （CT） and magnetic resonance imaging （MRI）.However,in a small fraction of the patients,the primary malignancy remains occult even with these examinations.In this retrospective study,we assessed the usefulness of 18F-FDG PET/CT in patients with hepatic cirrhosis and malignant ascites of otherwise unknown origin.Methods：Twenty-eight patients with malignant ascites of unknown primary sites after CT,MRI and ultrasound during the period of five years between January 2008 and December 2012 had received 18F-FDG PET/CT.Medical records of these patients were reviewed and analyzed.Results：Elevated 18F-FDG absorption was found in 23 of 28 cases in the following sites：gastrointestinal tract （n=10,43.5％）,prostate （n=5,21.7％）,peritoneum （n=4,13.3％）,and ovary （n=4,13.3％）.Cancer was confirmed by pathology in 20 cases after open or laparoscopic surgeries.Five patients were found to have benign ascites,among which,3 were found to be false positive due to tuberculosis.SUV values were significantly higher for tumors than for benign lesions （mean values,6.95 vs.2.94; P=0.005）.Conclusions：The 18F-FDG PET/CT can be as a powerful imaging tool in identifying tissue origin in liver cirrhosis patients suspected of cancers or with cancers of unknown primary sites.     

Serial MR diffusion to predict treatment response in high-grade pediatric brain tumors: a comparison of regional and voxel-based diffusion change metrics

Background

Assessment of treatment response by measuring tumor size is known to be a late and potentially confounded response index. Serial diffusion MRI has shown potential for allowing earlier and possibly more reliable response assessment in adult patients, with limited experience in clinical settings and in pediatric brain cancer. We present a retrospective study of clinical MRI data in children with high-grade brain tumors to assess and compare the values of several diffusion change metrics to predict treatment response.

Methods

Eighteen patients (age range, 1.9–20.6 years) with high-grade brain tumors and serial diffusion MRI (pre- and posttreatment interval range, 1–16 weeks posttreatment) were identified after obtaining parental consent. The following diffusion change metrics were compared with the clinical response status assessed at 6 months: (1) regional change in absolute and normalized apparent diffusivity coefficient (ADC), (2) voxel-based fractional volume of increased (fiADC) and decreased ADC (fdADC), and (3) a new metric based on the slope of the first principal component of functional diffusion maps (fDM).

Results

Responders (n = 12) differed significantly from nonresponders (n = 6) in all 3 diffusional change metrics demonstrating higher regional ADC increase, larger fiADC, and steeper slopes (P < .05). The slope method allowed the best response prediction (P < .01, η² = 0.78) with a classification accuracy of 83% for a slope of 58° using receiver operating characteristic (ROC) analysis.

Conclusions

We demonstrate that diffusion change metrics are suitable response predictors for high-grade pediatric tumors, even in the presence of variable clinical diffusion imaging protocols.     

Incidental Breast Lesions Identified by 18F-FDG PET/CT: Which Clinical Variables Differentiate between Benign and Malignant Breast Lesions?

Purpose

The aim of our study was to evaluate the risk of malignancy and to determine which clinical variables differentiate between benign and malignant focal breast lesions found incidentally on ¹⁸F-flourodeoxyglucose positron emission tomography and computed tomography (FDG PET/CT).

Methods

From March 2005 to October 2011, 21,224 women with no history of breast cancer underwent FDG PET/CT at three university-affiliated hospitals. We retrospectively identified 214 patients with incidental focal hypermetabolic breast lesions and grouped them into benign and malignant lesion groups. Of the 214 patients, 82 patients with 91 lesions were included in this study. All lesions were confirmed histologically or were assessed by follow-up imaging for greater than 2 years. The patient age, maximum standardized uptake value (SUV_max), lesion size on ultrasonography (US), and Breast Imaging-Reporting and Data System (BI-RADS) category on US in conjunction with mammography were compared between the groups. Multivariate logistic regression analysis was used to identify independent factors associated with malignancy.

Results

The risk of malignancy was 29.7% (27/91) in breast incidentalomas detected by FDG PET/CT. The univariate analysis showed that the patient age, SUV_max, tumor size, and BI-RADS category differed significantly between the malignant and benign groups. The multivariate analysis showed that the BI-RADS category was the only significant factor differentiating benign from malignant lesions (p=0.002).

Conclusion

BIRADS category based on US in conjunction with mammography was the only useful tool to differentiate between malignant and benign lesions in breast incidentalomas on FDG PET/CT.     

Calprotectin: a novel biomarker for the diagnosis of pleural effusion

Background:

Novel non-invasive biomarkers for the precise diagnosis of malignancy in pleural effusion (PE) are needed. The aim of this study was to determine the diagnostic accuracy of calprotectin for predicting malignancy in patients with exudative PE.

Methods:

Calprotectin concentration was measured in 156 individuals diagnosed with exudative PE (67 malignant and 89 benign). Calprotectin accuracy for discriminating between malignant and benign PE was evaluated using receiver operating characteristic (ROC) curves. Univariate and multivariate logistic regression were performed to test the association between calprotectin levels and malignant PE.

Results:

Calprotectin levels were significantly lower in malignant pleural fluid (257.2 ng ml⁻¹, range: 90.7–736.4) than benign effusions (2627.1 ng ml⁻¹, range: 21–9530.1). The area under the curve was 0.963. A cutoff point of ⩽736.4 ng ml⁻¹ rendered a sensitivity of 100%, with a specificity of 83.15%, which could prove useful to delimit those patients with negative cytology tests that should be referred for more invasive diagnostic procedures. Logistic regression demonstrated a strong association between calprotectin and malignancy (adjusted OR 663.14).

Conclusion:

Calprotectin predicts malignancy in pleural fluid with high accuracy and could be a good complement to cytological methods.     

Extrinsic intestinal denervation modulates tumor development in the small intestine of ApcMin/+ mice

Background

Innervation interacts with enteric immune responses. Chronic intestinal inflammation is associated with increased risk of colorectal cancer. We aimed to study potential extrinsic neuronal modulation of intestinal tumor development in a mouse model.

Methods

Experiments were performed with male Apc^Min/+ or wild type mice (4 weeks old, body weight approximately 20 g). Subgroups with subdiaphragmatic vagotomy (apcV/wtV), sympathetic denervation of the small intestine (apcS/wtS) or sham operated controls (apcC/wtC) were investigated (n = 6-14 per group). Three months after surgical manipulation, 10 cm of terminal ileum were excised, fixed for 48 h in 4% paraformaldehyde and all tumors were counted and their area determined in mm² (mean ± standard error of the mean (SEM)). Whole mounts of the muscularis of terminal ileum and duodenum (internal positive control) were also stained for tyrosine hydroxylase to confirm successful sympathetic denervation.

Results

Tumor count in Apc^Min/+ mice was 62 ± 8 (apcC), 46 ± 11 (apcV) and 54 ± 8 (apcS) which was increased compared to wildtype controls with 4 ± 0.5 (wtC), 5 ± 0.5 (wtV) and 5 ± 0.6 (wtS; all p < 0.05). For Apc^Min/+ groups, vagotomized animals showed a trend towards decreased tumor counts compared to sham operated Apc^Min/+ controls while sympathetic denervation was similar to sham Apc^Min/+. Area covered by tumors in Apc^Min/+ mice was 55 ± 10 (apcC), 31 ± 8 (apcV) and 42 ± 8 (apcS) mm², which was generally increased compared to wildtype controls with 7 ± 0.6 (wtC), 7 ± 0.4 (wtV) and 7 ± 0.6 (wtS) mm² (all p < 0.05). In Apc^Min/+ groups, tumor area was decreased in vagotomized animals compared to sham operated controls (p < 0.05) while sympathetically denervated mice showed a minor trend to decreased tumor area compared to controls.

Conclusions

Extrinsic innervation of the small bowel is likely to modulate tumor development in Apc^Min/+ mice. Interrupted vagal innervation, but not sympathetic denervation, seems to inhibit tumor growth.