Differentiation and diagnosis of benign and malignant testicular lesions using 18F-FDG PET/CT

ObjectivesThe purpose of this study was to evaluate the differential diagnostic value of ¹⁸F-fluorodeoxy glucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) for benign and malignant testicular lesions.MethodsThe PET/CT scans of 53 patients with testicular lesions confirmed by biopsy or surgical pathology were retrospectively analyzed. There were 32 cases of malignant tumors and 21 cases of benign lesions. Differences in the maximum standardized uptake value (SUVmax) measurements and the SUVmax lesion/background ratios between benign and malignant lesions were analyzed. The diagnostic value of this PET/CT modality for the differential diagnosis of benign versus malignant testicular lesions was calculated.ResultsThe differences in the SUVmax measurements and the SUVmax lesion/background ratios between benign and malignant lesions were statistically significant (SUVmax: Z = −4.295, p = 0.000; SUVmax lesion/background ratio: Z = −5.219, p = 0.000); specifically, both of these indicators were higher in malignant lesions compared to benign lesions. An SUVmax of 3.75 was the optimal cutoff value to differentiate between benign and malignant testicular lesions. The diagnostic sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of this PET/CT modality in the differential diagnosis of benign versus malignant testicular lesions were 90.6%, 80.9%, 86.8%, 87.9%, and 85.0%, respectively.Conclusions¹⁸F-FDG PET/CT can accurately identify benign and malignant testicular lesions.     

Time to enhancement derived from ultrafast breast MRI as a novel parameter to discriminate benign from malignant breast lesions

ObjectivesTo investigate time to enhancement (TTE) as novel dynamic parameter for lesion classification in breast magnetic resonance imaging (MRI).MethodsIn this retrospective study, 157 women with 195 enhancing abnormalities (99 malignant and 96 benign) were included. All patients underwent a bi-temporal MRI protocol that included ultrafast time-resolved angiography with stochastic trajectory (TWIST) acquisitions (1.0 × 0.9 × 2.5 mm, temporal resolution 4.32 s), during the inflow of contrast agent. TTE derived from TWIST series and relative enhancement versus time curve type derived from volumetric interpolated breath-hold examination (VIBE) series were assessed and combined with basic morphological information to differentiate benign from malignant lesions. Receiver operating characteristic analysis and kappa statistics were applied.ResultsTTE had a significantly better discriminative ability than curve type (p < 0.001 and p = 0.026 for reader 1 and 2, respectively). Including morphology, sensitivity of TWIST and VIBE assessment was equivalent (p = 0.549 and p = 0.344, respectively). Specificity and diagnostic accuracy were significantly higher for TWIST than for VIBE assessment (p < 0.001). Inter-reader agreement in differentiating malignant from benign lesions was almost perfect for TWIST evaluation (κ = 0.86) and substantial for conventional assessment (κ = 0.75).ConclusionsTTE derived from ultrafast TWIST acquisitions is a valuable parameter that allows robust differentiation between malignant and benign breast lesions with high accuracy.     

Magnetic resonance diffusion tensor imaging of the testis: Preliminary observations

IntroductionTo evaluate the feasibility of testis diffusion tensor imaging (DTI), to determine normative apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values and to assess the efficacy of DTI in characterizing testicular pathology.Materials and methodsFifty-six men underwent MRI of the scrotum, including DTI. Parametric and non-parametric statistical tests were used to compare the ADC and FA between the cranial, middle and lower thirds of normal testis and between the bilateral testicular thirds. Comparison between the ADC and FA of normal testis, malignant and benign testicular lesions was performed.ResultsNo significant differences of the ADC and FA in normal testis between the cranial, middle and lower thirds and between the bilateral testicular thirds were found. ADC was significantly lower in malignancies compared to normal testis (P = 0.006) and benign testicular lesions (P = 0.006). FA was significantly higher both in malignancies (P = 0.001) and benign lesions (P < 0.001) compared to normal testis. FA in malignancies did not differ from FA in benign lesions (P = 0.221)ConclusionsThis study shows the feasibility of testis DTI. Both ADC and FA significantly differ between testicular lesions and normal testis, although FA did not show an incremental diagnostic value compared to ADC in lesion differentiation.     

Simultaneous whole-body 18F-FDG PET-MRI in primary staging of breast cancer: A pilot study

PurposeAccurate initial staging in breast carcinoma is important for treatment planning and for establishing the likely prognosis. The purpose of this study was to assess the utility of whole body simultaneous ¹⁸F-FDG PET-MRI in initial staging of breast carcinoma.Methods36 patients with histologically confirmed invasive ductal carcinoma underwent simultaneous whole body ¹⁸F-FDG PET-MRI on integrated 3 T PET-MR scanner (Siemens Biograph mMR) for primary staging. Primary lesion, nodes and metastases were evaluated on PET, MRI and PET-MRI for lesion count and diagnostic confidence (DC). Kappa co relation analysis was done to assess agreement between the satellite, nodal and metastatic lesions detected by PET and MRI. Histopathology, clinical/imaging follow-up served as the reference standard.Results36 patients with 37 histopathologically proven index breast cancer were retrospectively studied. Of 36 patients, 25 patients underwent surgery and 11 patients received systemic therapy. All index cancers were seen on PET and MR. Fused PET-MRI showed highest diagnostic confidence score of 5 as compared to PET (median 4; range 3–5) and MRI (median 4; range 4–5) alone. 2/36 (5.5%) patients were detected to have unsuspected contralateral synchronous cancer. 47 satellite lesions were detected on DCE MRI of which 23 were FDG avid with multifocality and multicentricity in 21 (58%) patients. Kappa co relation analysis revealed fair agreement for satellite lesion detection by the two modalities (κ = 0.303; P = 0.003).The study showed a sensitivity of 60% and 93.3% on PET and MRI respectively for detection of axillary lymph nodes with a specificity of 91% for both and a false negative rate of 6.7% on MRI and 40% on PET. Kappa co relation analysis between PET and MRI for all the lymph nodes detected revealed fair agreement by the two modalities (κ = 0.337; P = 0.000). Combined PET-MRI increased diagnostic confidence for nodal involvement (median DC 5, range 4–5; P < 0.05).Distant metastases were found in 8/36 (22%) patients at the time of diagnosis with a total of 91 metastatic lesions on PET (DC ≥ 4) and 105 on MRI (DC ≥ 4), the difference being statistically significant (P = 0.001) while Kappa co relation analysis showed significant agreement between the two modalities (κ = 0.667; P = 0.000). Overall PET-MRI led to a change in management in 12 (33.3%) patients.ConclusionIn this pilot study, simultaneous ¹⁸F-FDG PET-MR, has been found to be useful in whole-body initial staging of breast cancer patients.     

Image quality of ct angiography using model-based iterative reconstruction in infants with congenital heart disease: Comparison with filtered back projection and hybrid iterative reconstruction

PurposeTo compare the image quality, rate of coronary artery visualization and diagnostic accuracy of 256-slice multi-detector computed tomography angiography (CTA) with prospective electrocardiographic (ECG) triggering at a tube voltage of 80 kVp between 3 reconstruction algorithms (filtered back projection (FBP), hybrid iterative reconstruction (iDose⁴) and iterative model reconstruction (IMR)) in infants with congenital heart disease (CHD).MethodsFifty-one infants with CHD who underwent cardiac CTA in our institution between December 2014 and March 2015 were included. The effective radiation doses were calculated. Imaging data were reconstructed using the FBP, iDose⁴ and IMR algorithms. Parameters of objective image quality (noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR)); subjective image quality (overall image quality, image noise and margin sharpness); coronary artery visibility; and diagnostic accuracy for the three algorithms were measured and compared.ResultsThe mean effective radiation dose was 0.61 ± 0.32 mSv. Compared to FBP and iDose⁴, IMR yielded significantly lower noise (P < 0.01), higher SNR and CNR values (P < 0.01), and a greater subjective image quality score (P < 0.01). The total number of coronary segments visualized was significantly higher for both iDose⁴ and IMR than for FBP (P = 0.002 and P = 0.025, respectively), but there was no significant difference in this parameter between iDose⁴ and IMR (P = 0.397). There was no significant difference in the diagnostic accuracy between the FBP, iDose⁴ and IMR algorithms (χ² = 0.343, P = 0.842).ConclusionsFor infants with CHD undergoing cardiac CTA, the IMR reconstruction algorithm provided significantly increased objective and subjective image quality compared with the FBP and iDose⁴ algorithms. However, IMR did not improve the diagnostic accuracy or coronary artery visualization compared with iDose⁴.     

Improved cancer detection in automated breast ultrasound by radiologists using Computer Aided Detection

ObjectiveTo investigate the effect of dedicated Computer Aided Detection (CAD) software for automated breast ultrasound (ABUS) on the performance of radiologists screening for breast cancer.Methods90 ABUS views of 90 patients were randomly selected from a multi-institutional archive of cases collected between 2010 and 2013. This dataset included normal cases (n = 40) with >1 year of follow up, benign (n = 30) lesions that were either biopsied or remained stable, and malignant lesions (n = 20). Six readers evaluated all cases with and without CAD in two sessions. CAD-software included conventional CAD-marks and an intelligent minimum intensity projection of the breast tissue. Readers reported using a likelihood-of-malignancy scale from 0 to 100. Alternative free-response ROC analysis was used to measure the performance.ResultsWithout CAD, the average area-under-the-curve (AUC) of the readers was 0.77 and significantly improved with CAD to 0.84 (p = 0.001). Sensitivity of all readers improved (range 5.2–10.6%) by using CAD but specificity decreased in four out of six readers (range 1.4–5.7%). No significant difference was observed in the AUC between experienced radiologists and residents both with and without CAD.ConclusionsDedicated CAD-software for ABUS has the potential to improve the cancer detection rates of radiologists screening for breast cancer.     

Dual-modal computer-assisted evaluation of axillary lymph node metastasis in breast cancer patients on both real-time elastography and B-mode ultrasound

PurposeTo propose a computer-assisted method for quantifying the hardness of an axillary lymph node on real-time elastography (RTE) and its morphology on B-mode ultrasound; and to combine the dual-modal features for differentiation of metastatic and benign axillary lymph nodes in breast cancer patients.Materials and methodsA total of 161 axillary lymph nodes (benign, n = 69; metastatic, n = 92) from 158 patients with breast cancer were examined with both B-mode ultrasound and RTE. With computer assistance, five morphological features describing the hilum, size, shape, and echogenic uniformity of a lymph node were extracted from B-mode, and three hardness features were extracted from RTE. Single-modal and dual-modal features were used to classify benign and metastatic nodes with two computerized classification approaches, i.e., a scoring approach and a support vector machine (SVM) approach. The computerized approaches were also compared with a visual evaluation approach.ResultsAll features exhibited significant differences between benign and metastatic nodes (p < 0.001), with the highest area under the receiver operating characteristic curve (AUC) of 0.803 and the highest accuracy (ACC) of 75.2% for a single feature. The SVM on dual-modal features achieved the largest AUC (0.895) and ACC (85.7%) among all methods, exceeding the scoring (AUC = 0.881; ACC = 83.6%) and the visual evaluation methods (AUC = 0.830; ACC = 84.5%). With the leave-one-out cross validation, the SVM on dual-modal features still obtained an ACC as high as 84.5%.ConclusionDual-modal features can be extracted from RTE and B-mode ultrasound with computer assistance, which are valuable for discrimination between benign and metastatic lymph nodes. The SVM on dual-modal features outperforms the scoring and visual evaluation methods, as well as all methods using single-modal features. The computer-assisted dual-modal evaluation of lymph nodes could be potentially used in daily clinical practice for assessing axillary metastasis in breast cancer patients.     

Transplant renal artery stenosis: Evaluation with contrast-enhanced ultrasound

ObjectiveTo assess the efficacy of contrast-enhanced ultrasound (CEUS) in depicting transplant renal artery stenosis (TRAS).Materials and methodsSeventy-eight patients (56 men and 22 women; aged 36 ± 12.2 years) who were suspected of TRAS due to either Doppler ultrasound (DUS) abnormalities or difficult control of blood pressure and/or persistent deterioration of renal function were enrolled to perform CEUS. The reference standard for the TRAS diagnoses was computed tomography angiography (CTA). The diagnostic performance of DUS and CEUS parameters was assessed by the area under the receiver operating characteristic curve (AUC).ResultsTRAS was diagnosed in 32 out of 78 cases by CTA. The AUC, accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of CEUS in predicting TRAS were 0.92, 92.3%, 87.5%, 95.7%, 93.3%, and 91.7%, respectively. CEUS rectified 13 (28.3%) false-positive cases on DUS, which were confirmed by CTA. Compared to DUS parameters, CEUS showed the highest AUC, statistically significant differences of AUC were found (P = 0.006–0.039), except for that of the PSV ratio in the main transplant renal artery to that in interlobar artery (PSV-ratio) (AUC: 0.92 versus 0.86, P = 0.422). However, CEUS showed a significantly higher specificity (95.7% versus 76.1%, P = 0.008) and the same sensitivity compared to PSV-ratio.ConclusionsCEUS is superior to DUS in depicting TRAS. Moreover, our results suggest that CEUS might potentially be used as a noninvasive tool to spare many patients from unnecessary CTA.     

Pancreatic adenocarcinoma: A simple CT score for predicting margin-positive resection in patients with resectable disease

BackgroundNegative-margin status is a prognostic indicator for long-term survival following curative intent resection for pancreatic adenocarcinoma. Patients at increased risk for positive-margin resections may benefit from neoadjuvant chemotherapy prior to resection.MethodsWe retrospectively analyzed preoperative computed-tomography (CT) scans in 108 consecutive patients that underwent curative intent resection for a resectable pancreatic ductal adenocarcinoma from 2009 to 2016 in two academic hospitals. Two radiologists independently staged the tumor, including tumor location, size, and tumor-to-superior mesenteric/portal vein (SMV/PV) contact. Uni and multivariate analysis were performed to identify independent predictors of an R1 resection.ResultsTwenty-nine patients had an R1 resection (26.9%). Tumor size, location, and presence of tumor-to-SMV/PV contact were significantly associated with an R1 resection. In multivariate analysis, the independent parameters associated with resection status were: tumor size (R² = 9.7), and tumor location (neck R² = 6.6; pancreaticoduodenal interface R² = 4.4; uncinate process R² = 4.1), but not tumor-to-SMV/PV contact (R² = 0.1, p = 0.7). A simple CT score was built based on tumor size and location. Patients with an R0 resectability score ≥3, i.e. patients with tumor size ≥30 mm (except when tumor location is at the pancreatico-duodenal interface) or patients with tumor size ≥20 mm AND tumor located in the uncinate process or neck, were at high-risk of an R1 resection (AUC, 0.82; sensitivity, 79%; specificity, 76%). This score also showed good diagnostic performances for predicting an R1 resection involving the medial resection margin only (AUC, 0.85).ConclusionsA simple score based on tumor location and size can accurately predict patients at high-risk of an R1 resection.     

Impact of fibroglandular tissue and background parenchymal enhancement on diffusion weighted imaging of breast lesions

PurposeTo evaluate the influence of the amount of fibroglandular breast tissue (FGT) and background-parenchymal enhancement (BPE) on lesion detection, quantitative analysis of normal breast tissue and of breast lesions on DWI.Materials and methodsIRB approved this retrospective study on focal findings at contrast-enhanced (CE) breast MR and DWI performed during July–December 2011. Patients with cysts, previous irradiation, silicone implants and current chemotherapy were excluded. DWI with fat suppression was acquired before dynamic acquisition (b factors: 0.1000 s/mm²) using 1.5 and 3 T scanners. Using correlation with dynamic and T2 images, ROIs were drawn free-hand within the borders of any visible lesion and in contralateral normal breast. Fisher's exact test to evaluate visibility and Wilcoxon-rank-sum test for comparison of ADC values were used. The amount of FGT and BPE was visually assessed by concurrent MRI. Analysis was stratified by menopausal status.Results25/127 (20%) lesions were excluded for technical reasons. 65/102 (64%) lesions were visible on DWI (median diameter: 1.85 cm). Mass lesions (M) were more visible (43/60 = 72%) than non-mass enhancement (NME) (22/42 = 52%) and malignant lesions were more visible (55/72 = 76%) than benign (10/30 = 33%). BPE and FGT did not influence visibility of M (p = 0.35 and p = 0.57 respectively) as well as of NME (p = 0.54 and p = 0.10). BPE and FGT did not influence visibility of malignant (p = 0.96 and p = 1.0) and benign lesions (p = 1.0 and p = 0.10). Results were confirmed adjusting for menopausal status. The ADC value of normal breast tissue was not influenced by BPE, while it was lower in predominantly fatty breasts compared to dense ones (p = 0.002).ConclusionsFGT affects the quantitative evaluation of ADC in normal breast tissue whereas BPE does not. Furthermore, both BPE and FGT do not influence visibility of benign or malignant findings, including both mass lesions and non-mass enhancement, on DWI.     

Apparent diffusion coefficient in the analysis of prostate cancer: determination of optimal b-value pair to differentiate normal from malignant tissue

PurposeDetermining optimal b-value pair for differentiation between normal and prostate cancer (PCa) tissues.MethodsForty-three patients with diagnosis or PCa symptoms were included. Apparent diffusion coefficient (ADC) was estimated using minimum and maximum b-values of 0, 50, 100, 150, 200, 500 s/mm2 and 500, 800, 1100, 1400, 1700 and 2000s/mm2, respectively. Diagnostic performances were evaluated when Area-under-the-curve (AUC) > 95%.Results15 of the 35 b-values pair surpassed this AUC threshold. The pair (50, 2000 s/mm2) provided the highest AUC (96%) with ADC cutoff 0.89 × 10–³ mm²/s, sensitivity 95.5%, specificity 93.2% and accuracy 94.4%.ConclusionsThe best b-value pair was b = 50, 2000 s/mm2.     

Intra-individual comparison of CAIPIRINHA VIBE technique with conventional VIBE sequences in contrast-enhanced MRI of focal liver lesions

PurposeTo evaluate the impact of controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) volume interpolated breath-hold examination (VIBE) magnetic resonance imaging (MRI) technique on image quality, reader confidence, and inter-observer agreement for the assessment of focal liver lesions in comparison with the standard VIBE approach.Material and methodsIn this IRB-approved intra-individual comparison study, abdominal arterial and portal-venous contrast-enhanced MRI studies were retrospectively analyzed in 38 patients with malignant liver lesions. Each patient underwent both CAIPIRINHA and conventional VIBE 3 T MRI within 3 months, showing stable disease. Images were evaluated using 5-point rating scales by two blinded radiologists with more than 20 and 5 years of experience in MRI, respectively. Readers scored dignity of liver lesions and assessed which liver segments were affected by malignancy (ranging from 1 = definitely benign/not affected to 5 = definitely malignant/affected by malignancy). Readers also rated overall image quality, sharpness of intrahepatic veins, and diagnostic confidence (ranging from 1 = poor to 5 = excellent).ResultsReviewers achieved a higher inter-observer reliability using CAIPIRINHA when they reported which liver segments were affected by malignancy compared to traditional VIBE series (κ = 0.62 and 0.54, respectively, p < 0.05). Similarly, CAIPIRINHA showed a slightly higher inter-rater agreement for the dignity of focal liver lesions versus the standard VIBE images (κ = 0.50 and 0.49, respectively, p < 0.05). CAIPIRINHA series also scored higher in comparison to standard VIBE sequences (mean scores: image quality, 4.2 and 3.5; sharpness of intrahepatic vessels, 3.8 and 3.2, respectively, p < 0.05) for both reviewers and allowed for higher subjective diagnostic confidence (ratings, 3.8 and 3.2, respectively, p < 0.05).ConclusionCompared to the standard VIBE approach, CAIPIRINHA VIBE technique provides improved image quality and sharpness of intrahepatic veins, as well as higher diagnostic confidence. Additionally, this technique allows for higher inter-observer agreement when reporting focal liver lesions for both dignity and allocation.     

Value of diffusion tensor imaging in differentiating malignant from benign parotid gland tumors

PurposeTo evaluate whether diffusion tensor imaging (DTI) can be used to differentiate malignant parotid gland tumors from the benign ones.Materials and methodsThe study population comprised 59 parotid gland tumors (24 Warthin’s tumors, 19 pleomorphic adenomas, seven other benign tumors, and nine malignant tumors). Single-shot echo-planar DTI was performed with motion-probing gradients along 30 noncollinear directions (b = 1000 s/mm²) at 3.0 T. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values for benign and malignant tumors were compared using the Mann–Whitney U test. Receiver-operating characteristic (ROC) curve analysis was performed to assess the ability of the ADC and FA values to differentiate malignant tumors from the benign ones.ResultsADC values showed no significant difference between malignant (0.93 ± 0.21 × 10⁻³ mm²/s) and benign tumors (1.19 ± 0.50 × 10⁻³ mm²/s) (p = 0.225). FA values of malignant tumors were significantly higher than those of benign tumors (0.26 ± 0.06 vs. 0.17 ± 0.05, p < 0.001). The area under the ROC curve of FA was significantly greater than that under the curve of ADC (0.884 vs. 0.628, p = 0.010).ConclusionsDTI, particularly FA, can help differentiate malignant parotid gland tumors from the benign ones.     

Prospectively ECG-triggered high-pitch coronary CT angiography at 70 kVp with 30 mL contrast agent: An intraindividual comparison with sequential scanning at 120 kVp with 60 mL contrast agent

PurposeTo investigate image quality, radiation dose, and diagnostic efficiency of prospectively ECG-triggered high-pitch coronary CT angiography (CCTA) at 70 kVp with 30 mL contrast agent intra-individually compared with routine CCTA protocol.Materials and methodsOne hundred and thirty eight patients with suspected coronary artery disease, body mass index (BMI) ≤ 25 kg/m² and heart rate (HR) ≤ 70 beats per minute (bpm) underwent prospectively ECG-triggered high-pitch CCTA at 70 kVp and 30 mL contrast agent (protocol A) and prospectively ECG-triggered sequential scanning at 120 kVp and 60 mL contrast medium (protocol B). Objective and subjective image quality, radiation doses, and diagnostic accuracy were evaluated and compared between the two protocols.ResultsHigher CT attenuation, higher noise, lower signal-to-noise ratios (SNRs) and lower contrast-to-noise ratios (CNRs) were found in protocol A than in protocol B (P < 0.001). However, image quality of protocol A were diagnostic. In patients with BMI < 23 kg/m² or HR < 60 bpm, subjective image quality scores of some coronary arteries in protocol A were not significantly different from protocol B (P > 0.05). Effective dose in protocol A has reduced by 96.7% compared with protocol B (P < 0.001). No significant differences were found for diagnostic accuracy between the two protocols on a per-segment (P = 0.513), per-vessel (P = 0.317) and per-patient (P = 0.125) basis.ConclusionsProspectively ECG-triggered high-pitch CCTA at 70 kVp with 30 mL contrast agent can reduce radiation dose but maintain image quality and high diagnostic accuracy in a selected, non-obese population.     

Photodynamic diagnostic ureterorenoscopy: A valuable tool in the detection of upper urinary tract tumour

BackgroundPhotodynamic diagnosis increases the detection rate and hence decreases recurrence rates of urothelial cancer (UC) of the bladder. This technique has been implemented in the upper urinary tract and like in the bladder, has shown to increase the detection rate of urothelial lesions.ObjectivesTo determine the sensitivity, specificity, and detection rates for photodynamic diagnostic flexible ureterorenoscopy (PDD-FURS) and white light ureterorenoscopy (WL-FURS).Design between 2009 and 2013, PDD-FURS was performed within 106 Upper urinary tract (UUT) Units (Mean age—72.6 ± 9.5). Indications for the procedure included abnormal upper urinary tract on imaging, normal flexible cystoscopy with abnormal urine cytology, endoscopic treatment and follow-up of UUT UC. Oral 5-aminolevulinic acid was used as the photosensitizer administered 3-4 h pre-operatively.Results48 lesions were detected, of which 95.8% (46/48) where visualised by PDD-FURS compared to 47.9% (23/48) shown by WL-FURS (P < 0.0001). PDD-FURS detected significantly more carcinoma in situ (CIS) or dysplasia lesions than WL-FURS (93.75% (15/16) vs. 18.75% (3/16), respectively, (P = 0.0006)). Furthermore, PDD-FURS detected significantly more UC lesions than WL-FURS (96.9% (31/32) vs. 62.5% (20/32) (P = 0.007)).PDD-FURS was more sensitive (95.8; range: 85.7–99.5) than WL-FURS (53.5; range: 37.7–68.8) in detecting UUT-UC (P < 0.0001). There was no difference (P = 0.716) in the specificity between PDD-FURS (96.6; range: 88.1–99.6) and WL-FURS (95.2; range: 86.7–99).ConclusionsOur results PDD-FURS with oral 5-ALA as photosensitizer suggest higher sensitivity and detection rate of urothelial tumours than WL-FURS, with a good safety profile. In our series, PDD-FURS enhanced the visualisation of flat lesions, such as CIS and dysplasia that otherwise would have been missed.     

Role of semi–quantitative dynamic contrast–enhanced MR imaging in characterization and grading of prostate cancer

ObjectiveThe study retrospectively assessed the diagnostic value of semi-quantitative dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) in characterization and grading of prostate cancer, with correlation to histopathological analysis.Materials and methods161 consecutive patients with prostate cancer underwent DCE MRI. 430 lesions, including 200 cancers with Gleason grade (GG) of 6 (n = 25), 7 (n = 112) and 8 or higher (n = 63); 80 benign hyperplasia; and 150 healthy tissues were assessed using a histology–MRI correlation. Time–intensity curve types between two radiologists and kinetic parameters (C_peak, time to peak, wash-in and wash-out) were compared in the different tissue types and GGs. Receiver operating characteristic curve analysis was performed to assess for each parameter to differentiate cancer from benign hyperplasia or healthy tissue, and GG 8 or higher from GG 6 or 7.ResultsType 2 was the prevalent assigned curve type. Inter-radiologist agreement for the curve types was excellent. Cancer and GG 8 or higher significantly showed a higher C_peak and faster wash-in compared to healthy tissue and GG 6. Only wash-in significantly differentiated cancer from healthy tissue, and GG 8 or higher from GG 6, having an area under the curve (AUC) of 0.755 and 0.815 respectively. Wash-in for the combined parameters revealed AUCs of 0.791 and 0.839 in two (C_peak) parameters, and AUCs of 0.862 and 0.891 in three (C_peak and wash-out) parameters.ConclusionSemi-quantitative parameters can differentiate cancer from benign hyperplasia and healthy tissue. Wash-in is the most accurate differentiation parameter of cancer foci and GG 8 or higher.     

Diagnostic performance of diffusion-weighted MR imaging in differentiation of diabetic osteoarthropathy and osteomyelitis in diabetic foot

PurposeTo study the diagnostic performance of diffusion weighted MR imaging in differentiation of diabetic osteoarthropathy and osteomyelitis in diabetic foot.Patients and methodsThis prospective study was carried out on 41 patients with diabetic foot, 22 males and 19 females with mean age of 51 years. They underwent diffusion-weighted MR imaging of the foot. The apparent diffusion coefficient (ADC) values of the bony lesions were calculated by two reviewers and correlated with the surgical findings or biopsy. The kappa statistic (k) was used to estimate the proportion of inter-observer agreement of two reviewers.ResultsThe mean ADC of acute diabetic osteoarthropathy was 1.27 ± 0.19 × 10⁻³ mm²/s for reviewer 1 and 1.26 ± 0.21 × 10⁻³ mm²/s for reviewer 2. The mean ADC value in diabetic osteomyelitis was 0.86 ± 0.11 × 10⁻³ mm²/s for reviewer 1 and 0.85 ± 0.12 × 10⁻³ mm²/s for reviewer 2. There was excellent inter-observer agreement of ADC value of bony lesions in diabetic foot by both reviewers (K = 0.93). There was statistically significant difference in the ADC values of both groups (P = 0.001). The cut-off point of ADC value of both reviewers used in differentiating acute diabetic osteoarthropathy and osteomyelitis were 0.98 × 10⁻³ mm²/s and 1.04 × 10⁻³ mm²/s with an accuracy of 94% and 93% and area under the curve of 0.94 and 0.93 respectively.ConclusionWe conclude that the ADC value is a non-invasive imaging parameter that can help in differentiation of diabetic osteoarthropathy from osteomyelitis with excellent inter-observer agreement.     

Material density iodine images in dual-energy CT: Detection and characterization of hypervascular liver lesions compared to magnetic resonance imaging

PurposeTo determine the diagnostic potential of Material Density (MD) iodine images in dual-energy CT (DECT) for the detection and characterization of hypervascular liver lesions compared to monenergetic 65 keV images, using MRI as the standard.Materials and methodsThe study complied with HIPAA guidelines and was approved by the institutional review board. Fifty-two patients (36 men, 16 women; age range, 29–87 years) with 236 hypervascular liver lesions (benign, n = 31; malignant, n = 205; mean diameter, 29.4 mm; range: 6–90.6 mm) were included. All of them underwent both contrast-enhanced single-source DECT and contrast-enhanced abdominal MRI within three months. Late arterial phase CT imaging was performed with dual energies of 140 and 80 kVp. Protocol A showed monoenergetic 65 keV images, and protocol B presented MD-iodine images. Three radiologists qualitatively evaluated randomized images, and lesion detection, characterization, and reader confidence were recorded. Liver-to-lesion ratio (LLR) and contrast-to-noise ratio (CNR) were assessed on protocol A, protocol B, and MRI. Paired t-tests were used to compare LLR, CNR, and the number of detected lesions.ResultsLLR was significantly increased in protocol B (2.8 ± 2.33) compared to protocol A (0.77 ± 0.55) and MRI (0.61 ± 0.66). CNR was significantly higher in protocol B (0.08 ± 0.04) compared to protocol A (0.01 ± 0.01) and MRI (0.01 ± 0.01). All three observers correctly identified more liver lesions using protocol B vs protocol A: 83.13% vs 63.64%, 84.57% vs 68.09%, and 79.37% vs 65.52%. There was no significant difference between the three observers in classification of a lesion as benign or malignant. However, higher diagnostic confidence was reported more frequently by the experienced radiologist when using protocol B vs protocol A (84.6% vs 75%).ConclusionMD-iodine images in DECT help to increase the conspicuity and detection of hypervascular liver lesions.     

CT and MRI findings of type I and type II epithelial ovarian cancer

ObjectiveTo assess whether types I and II epithelial ovarian cancer (EOC) differ in CT and MRI imaging features.MethodsFor this retrospective study, we enrolled 65 patients with 68 ovarian lesions that have been pathologically proven to be EOC. Of these patients, 38 cases underwent MR examinations only, 15 cases underwent CT examinations only, and 12 cases completed both examinations. The clinical information [age, CA-125, menopausal status, and Ki-67] and imaging findings were compared between two types of EOCs. The diagnostic performance of image findings were assessed by receiver-operating characteristic curve(ROC) analysis. The association between EOC type and imaging features was assessed by multivariate logistic regression analysis. The random forest approach was used to build a classifier in differential diagnosis between two types of EOCs.ResultsOf the 68 EOC lesions, 24 lesions were categorized as types I and other 44 lesions as type II based on the immunohistochemical results, respectively. Patients in type I EOCs were more likely to involve menopausal women and showed lower CA-125 and Ki-67 values (Ki–67 < 30%) than patients in type II EOCs. The imaging characteristics of type II EOCs frequently demonstrated a solid or predominantly solid mass (38.6% vs. 12.5%, P < 0.05), smaller lesions (diameter <6 cm; 27.3% vs. 4.2%, P < 0.05), absence of mural nodules (65.9% vs. 25.9%, P = 0.001), and mild enhancement (84.1% vs. 54.2%, P < 0.05) compared to type I EOCs. Combination of tumor size, morphology, mural nodule, enhancement degrees (AUC = 0.808) has a higher specificity (87.50%) and positive predictive value (90.0%) than any single image finding alone in differential diagnosis between two types of EOCs. The multivariate logistic regression analysis showed that enhancement degrees(OR 0.200, P < 0.05),mural nodule(OR 0.158, P < 0.05) significantly influence EOC classification. Random forests model identified both as the most important discriminating variables. The diagnostic accuracy of the classifier was 73.53%.ConclusionsDifferences in imaging characteristics existed between two types of EOCs. Combination of several image findings improved the preoperative diagnostic performance, which is helpful for the clinical treatment and prognosis evaluation.     

Correlations between the iodine concentrations from dual energy computed tomography and molecular markers Ki-67 and HIF-1α in rectal cancer: A preliminary study

PurposeTo investigate whether dual energy computed tomography (CT) with iodine quantification is correlated with molecular markers Ki-67and hypoxia-inducible factor 1α (HIF-1α)in rectal cancer (RC).Materials and methodsEighty patients (43 males and 37 females) diagnosed with rectal cancer got pelvic contrast-enhanced CT scan with dual energy computed tomography before any anticancer treatment. Analyse the normalized iodine concentration (NIC) values and CT values at each energy level (40–140 keV) from the virtual monochromatic image of the primary lesions. The postoperative specimens of all 80 patients underwent Ki-67 and HIF-1α immunohistochemistry staining. By SPSS17.0 software package, we analyzed the correlations of NIC values and CT values at each energy level (40–140 keV) with Ki-67 and HIF-1α expression. The receiver operating characteristic (ROC) curves of these dual energy computed tomography parameters were calculated and the diagnostic value were assessed.ResultsThere was a weak positive correlation between NIC values and carcinoembryonic antigen level (r = 0.246, P = 0.028) in RC. Both the value and the level of Ki-67 expression were correlated positively with the NIC values (r = 0.344, P = 0.002 and r = 0.248, P = 0.026). HIF-1α expression was correlated positively with the NIC values of the RC (r = 0.598, P < 0.001). The best threshold values of NIC values in diagnosing the expression of HIF-1α was 0.5839. The sensitivity, 78%; specificity, 87%; PPV, 86%; NPV,79%;accuracy, 83%.ConclusionThe NIC values on dual energy computed tomography may be used as a measurement of hypoxia in RC and determining the ability of tumor invasion noninvasively.