Diagnostic value of cone beam computed tomography (CBCT) in occult scaphoid and wrist fractures

ObjectiveEvaluate the diagnostic value of cone beam computed tomography (CBCT) for scaphoid and wrist fractures that are missed on standard radiographs.Materials and methodsBetween September 2014 and October 2015, we prospectively enrolled 49 patients with a clinically suspected scaphoid fracture following an acute injury but had normal radiographs. Each patients underwent radiographs, CBCT and (magnetic resonance imaging) MRI within 7 days of the initial injury event. Both exam were evaluated independently by two radiologists.ResultsFor scaphoid cortical fractures CBCT sensitivity is 100% (95% CI: 75%–100%), specificity 97% (95% CI: 83%–100%). CBCT diagnosed all 24 corticals wrist fractures, corresponding to a sensitivity of 100% (95% CI: 83%–100%), specificity of 95% (95% CI: 75%–100%). Kappa agreement rate between the two radiologists was K = 0.95 (95% CI: 0.85–1) for scaphoid fractures and K = 0.87 (95% CI: 0.73–1) for wrist fractures.ConclusionsCBCT is superior to radiographs for diagnosing occult cortical fractures. Because of its low radiation dose, we believe that CBCT can be used in current practice as a replacement or supplement to radiographs to detect these fractures and optimize the cost-effectiveness ratio by limiting the number of needless immobilizations.     

A meta-analysis of the value of fluorodeoxyglucose-PET/PET-CT in the evaluation of fever of unknown origin

Background and purposeThe diagnosis of patients with fever of unknown origin (FUO) remains a challenging medical problem for internal medicine. A reliable estimate of the diagnostic performance of FDG-PET and FDG-PET/CT in the assessment of FUO unidentified by conventional workup has never been systematically assessed, and present systematic review was aimed at this issue.MethodsA systematic search for relevant studies was performed of the PubMed, Embase, and Cochrane databases. Methodological quality of each study was assessed. Sensitivity, specificity and area under the curve (AUC) were meta-analyzed. Subgroup analyses were performed if results of individual studies were heterogeneous.ResultsThe inclusion criteria were met by nine studies. Overall, the studies had good methodological quality. Pooled sensitivity and specificity of FDG-PET for the detection of FUO were 0.826 (95% CI; 0.729–0.899) and 0.578 (95% CI; 0.488–0.665), respectively, and the AUC was 0.810. Heterogeneity among the results of FDG PET studies was present (QSE = 12.40, I² = 67.7%; QSp = 35.98, I² = 88.9%). Pooled sensitivity and specificity of FDG-PET/CT were 0.982 (95% CI; 0.936–0.998) and 0.859 (95% CI; 0.750–0.934), respectively, and the AUC was 0.947. We did not find any statistical differences in the AUC and Q* index between FDG-PET and FDG-PET/CT (Z = 0.566, p > 0.05).ConclusionsAlthough the FDG-PET studies that we examined were heterogeneous, FDG-PET appears to be a sensitive and promising diagnostic tool for the detection of the causes of FUO. FDG-PET/CT should be considered among the first diagnostic tools for patients with FUO in whom conventional diagnostics have been unsuccessful.     

Imaging modalities in the diagnosis of pancreatic adenocarcinoma: A systematic review and meta-analysis of sensitivity,specificity and diagnostic accuracy

BackgroundPancreatic cancer, primarily pancreatic ductal adenocarcinoma (PDAC), accounts for 2.4% of cancer diagnoses and 5.8% of cancer death annually. Early diagnoses can improve 5-year survival in PDAC. The aim of this systematic review was to determine the sensitivity, specificity and diagnostic accuracy values for MRI, CT, PET&PET/CT, EUS and transabdominal ultrasound (TAUS) in the diagnosis of PDAC.MethodsA systematic review was undertaken to identify studies reporting sensitivity, specificity and/or diagnostic accuracy for the diagnosis of PDAC with MRI, CT, PET, EUS or TAUS. Proportional meta-analysis was performed for each modality.ResultsA total of 5399 patients, 3567 with PDAC, from 52 studies were included. The sensitivity, specificity and diagnostic accuracy were 93% (95% CI = 88–96), 89% (95% CI = 82–94) and 90% (95% CI = 86–94) for MRI; 90% (95% CI = 87–93), 87% (95% CI = 79–93) and 89% (95% CI = 85–93) for CT; 89% (95% CI = 85–93), 70% (95% CI = 54–84) and 84% (95% CI = 79–89) for PET; 91% (95% CI = 87–94), 86% (95% CI = 81–91) and 89% (95% CI = 87–92) for EUS; and 88% (95% CI = 86–90), 94% (95% CI = 87–98) and 91% (95% C = 87–93) for TAUS.ConclusionThis review concludes all modalities, except for PET, are equivalent within 95% confidence intervals for the diagnosis of PDAC.     

CT-based radiomics signature for differentiating Borrmann type IV gastric cancer from primary gastric lymphoma

PurposeTo evaluate the value of CT-based radiomics signature for differentiating Borrmann type IV gastric cancer (GC) from primary gastric lymphoma (PGL).Materials and methods40 patients with Borrmann type IV GC and 30 patients with PGL were retrospectively recruited. 485 radiomics features were extracted and selected from the portal venous CT images to build a radiomics signature. Subjective CT findings, including gastric wall peristalsis, perigastric fat infiltration, lymphadenopathy below the renal hila and enhancement pattern, were assessed to construct a subjective findings model. The radiomics signature, subjective CT findings, age and gender were integrated into a combined model by multivariate analysis. The diagnostic performance of these three models was assessed with receiver operating characteristics curves (ROC) and were compared using DeLong test.ResultsThe subjective findings model, the radiomics signature and the combined model showed a diagnostic accuracy of 81.43% (AUC [area under the curve], 0.806; 95% CI [confidence interval]: 0.696–0.917; sensitivity, 63.33%; specificity, 95.00%), 84.29% (AUC, 0.886 [95% CI: 0.809–0.963]; sensitivity, 86.67%; specificity, 82.50%), 87.14% (AUC, 0.903 [95%CI: 0.831–0.975]; sensitivity, 70.00%; specificity, 100%), respectively. There were no significant differences in AUC among these three models (P = 0.051–0.422).ConclusionRadiomics analysis has the potential to accurately differentiate Borrmann type IV GC from PGL.     

Dual-energy CT virtual non-calcium technique for detection of bone marrow edema in patients with vertebral fractures: A prospective feasibility study on a single- source volume CT scanner

ObjectivesDual-energy computed tomography (DECT) is a recent development for detecting bone marrow edema (BME) in patients with vertebral compression fractures. The aim of this pilot study was to determine the reliability of single-source DECT in detecting vertebral BME using magnetic resonance imaging (MRI) as standard of reference.Materials and methodsNine patients with radiographic thoracic or lumbar vertebral compression fractures underwent both, DECT on a 320-row single-source scanner and 1.5 T MRI. Virtual non-calcium (VNC) images were reconstructed from the DECT volume datasets. Three blinded readers independently scored images for the presence of BME. Only vertebrae with loss of height in radiography (target vertebrae) were included in the analysis. A vertebra was counted as positive if two readers agreed on the presence of BME. Cohen’s kappa was calculated for interrater comparison. Intervertebral ratios of target and the reference vertebra were compared for CT attenuation and MR signal intensity in a reference vertebra using Spearman correlation. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated.ResultsFourteen target vertebrae with a radiographic height loss were identified; eight of them showed BME on MRI, while DECT identified BME in 7 instances. There were no false positive virtual non-calcium images, resulting in a sensitivity of 0.88 (0.75–1.0 among all readers) and specificity of 1.0 (0.81–1.0). Interrater agreement was inferior for DECT (κ = 0.63–0.89) compared to MRI (κ = 0.9–1.0). Intervertebral ratio in VNC images strongly correlated with short-tau inversion recovery (r = 0.87) and inversely with T1 (-0.89). SNR (0.2 +/− 0.2 in VNC and 16.7 +/− 7.3 in STIR) and CNR (0.2 +/− 0.3 and 7.1 +/− 6.3) values were inferior in VNC.ConclusionsDetecting BME with single-source DECT is feasible and allows detection of vertebral compression fractures with reasonably high sensitivity and specificity. However, image quality of VNC reconstructions has to be improved to achieve better interrater agreement. Nonetheless, DECT might accelerate the diagnostic work-flow in patients with vertebral compression fractures in the future and reduce the number of additional MRI examinations.     

Magnetic resonance imaging for detection of parametrial invasion in cervical cancer: An updated systematic review and meta-analysis of the literature between 2012 and 2016

Objective

To review the diagnostic performance of MRI for detection of parametrial invasion (PMI) in cervical cancer patients.

Methods

MEDLINE and EMBASE databases were searched for studies providing diagnostic performance of MRI for detecting PMI in patients with cervical cancer. Studies published between 2012 and 2016 using surgico-pathological results as reference standard were included. Study quality was evaluated using QUADAS-2. Sensitivity and specificity of all studies were calculated. Results were pooled and plotted in a hierarchical summary receiver operating characteristic plot. Meta-regression and subgroup analyses were performed.

Results

Fourteen studies (1,028 patients) were included. Study quality was generally moderate. Pooled sensitivity was 0.76 (95% CI 0.67–0.84) and specificity was 0.94 (95% CI 0.91–0.95). The possibility of heterogeneity was considered low: Cochran’s Q-test (p?=?0.471), Tau² (0.240), Higgins I² (0%). With meta-regression analysis, magnet strength, use of DWI, and antispasmodic drugs were significant factors affecting heterogeneity (p?<?0.01). Subgroup analysis for studies solely using radical hysterectomy as reference standard yielded pooled sensitivity and specificity of 0.73 (95% CI 0.60–0.83) and 0.93 (95% CI 0.90–0.95), respectively.

Conclusions

MRI shows good performance for detection of PMI in cervical cancer. Using 3-T scanners and DWI may improve diagnostic performance.

Key Points

? MRI shows good performance for detection of parametrial invasion in cervical cancer. ? Subgroup of studies using only radical hysterectomy showed consistent results. ? Using 3-Tesla scanners and diffusion-weighted imaging may improve diagnostic performance.

     

Evaluation of noninvasive diagnostic criteria for hepatocellular carcinoma on pretransplant MRI (2010): correlation between MR imaging features and histological features on liver specimen

PurposeTo validate the 2010 diagnostic criteria from the American Association for the Study of Liver Diseases (AASLD) for hepatocellular carcinoma (HCC) on MRI using the surgical liver specimen as a gold standard.Patients and methodsA total of 21 liver transplant recipients were retrospectively included. Each underwent surgery because of HCC between January 2007 and January 2008. Pre-transplant MRI was performed on a 1.5 Tesla MR unit. The T1W and T2W signal and kinetic contrast enhancement were correlated for each lesion with the surgical specimen. Lesion diameters between MRI and specimen were compared (Spearman). A multivariate model was created (R statistics software package) to predict the presence and grade of tumor differentiation (WHO, Edmonson Steiner).ResultsA total of 71 nodules were detected at histology, including 54 HCC (mean size: 25.3 mm) compared to 68 on MRI. There was moderate agreement (r = 0.58, P < 0.001) between the maximum lesion diameters measured on MRI and at histology. Wash-out on MRI provided an accuracy of 75 % for the detection of HCC (sensitivity = 75 %, specificity = 76 %). Adding T2W hyperintensity to the AASLD criteria increased the sensitivity of MRI from 70.3 % to 77.7 % for the diagnosis of HCC and from 67.6 % to 79 % for nodules less than 20 mm in diameter, without affecting specificity. On multivariate analysis, wash out as a single variable was significantly associated with a diagnosis of HCC (P < 0.01, odds ratio 12.0, CI 95 % [2.6–55.5]). T1W hyperintensity (P = 0.04, odds ratio 5.4) and loss of signal on opposed-phase images (P = 0.02, odds ratio 9.2) were predictive of good differentiation.ConclusionOn MRI, the AASLD criteria or presence of wash out within a liver nodule in patients with underlying chronic hepatocellular disease are suggestive of tumoral transformation. The addition of T2W hyperintensity to the AASLD criteria increases the detection of HCC, especially nodules smaller than 20 mm.     

Evaluating the ability to detect pancreatic lesions using a special ultrasonography examination focusing on the pancreas

PurposeThe ability to detect pancreatic cysts was compared between special ultrasonography (US) examination focusing on the pancreas (special pancreatic US) and routine upper abdominal ultrasonography to objectively assess the ability of the former to detect cysts.Subjects and methodsOf 3704 patients who underwent special pancreatic US at our hospital, 186 underwent routine upper abdominal US within six months, had pancreatic cysts, and underwent magnetic resonance imaging (MRI). In these patients, 447 cysts measuring ≥5 mm were detected via MRI, which was used as the gold standard. The ability and sensitivity of the US modalities to detect each cyst was determined.ResultsThe sensitivity of special pancreatic US was 92.2% (95% confidence interval [CI], 89.7% − 94.7%) and that of routine upper abdominal US was 70.2% (95% CI, 66.0% − 74.5%). McNemar test (Stata Version 13.1) revealed a significant difference in the cyst (≥5 mm) detection sensitivity between the two modalities (p < 0.001). An analysis stratified by patients similarly revealed a significant difference between the two modalities (p < 0.001). The cyst detection sensitivity was also analyzed in various parts of the pancreas. The sensitivity of special pancreatic US was 88.7% for the uncinate process and inferior head, 97.5% for the head, 97.1% for the body, 89.0% for the body-tail, and 66.7% for the tail, whereas that of routine upper abdominal US was 74.2% for the uncinate process, 69.5% for the head, 81.0% for the body, 67.0% for the body-tail, and 26.7% for the tail. The McNemar test revealed significant differences in the sensitivity of the two modalities for all pancreatic parts (p < 0.001 − 0.016).ConclusionCompared with routine upper abdominal US, special pancreatic US had higher sensitivity in detecting pancreatic cysts.     

Diffusion MRI for rectal cancer staging: ADC measurements before and after ultrasonographic gel lumen distension

ObjectivesTo compare Apparent Diffusion Coefficient (ADC) measurements in rectal neoplastic lesions before and after lumen distension obtained with sonography transmission gel.MethodsFrom January 2014 to July 2016, 25 patients (average age 63.7, range 41–85, 18 males) were studied for pre-treatment rectal cancer staging using a 1.5 T MRI. Diffusion MRI was obtained using echo-planar imaging with b = 800 value; all patients were studied acquiring diffusion sequences with and without rectal lumen distension obtained using sonography transmission gel. In both diffusion sequences, two blinded readers calculated border ADC values and small ADC values, drawing regions of interest respectively along tumour borders and far from tumour borders. Mean ADC values among readers − for each type of ADC measurement − were compared using Wilcoxon matched pairs signed rank test. Correlation was assessed using Pearson analysis.ResultsBorder ADC mean value for diffusion MR sequences without endorectal contrast was 1.122 mm²/sec, with 95% Confidence Interval (CI) = 1.02–1.22; using gel lumen distension, higher border ADC mean value of 1.269 mm²/s (95% CI = 1.16–1.38) was obtained. Wilcoxon matched pairs signed rank test revealed statistical difference (p < 0.01); a strong Pearson correlation was reported, with r value of 0.69. Small-ADC mean value was 1.038 mm²/s (95% CI = 0.91–1.16) for diffusion sequences acquired without endorectal distension and 1.127 mm²/s (95% CI = 0.98–1.27) for diffusion sequences obtained after endorectal gel lumen distension. Wilcoxon analysis did not show statistical difference (p = 0.13). A very strong positive correlation was observed, with r value of 0.81.ConclusionsADC measurements are slightly higher using endorectal sonographic transmission gel; ROI should be traced far from tumour borders, to minimize gel filled-pixel along the interface between lumen and lesion. Further studies are needed to investigate better reliability of ADC in rectal cancer MRI using sonographic gel intraluminal distension.     

The diagnostic accuracy of neck ultrasound, 4D-Computed tomographyand sestamibi imaging in parathyroid carcinoma

IntroductionOur aim was to investigate the accuracy of available imaging modalities for parathyroid carcinoma (PC) in our institution and to identify which imaging modality, or combination thereof, is optimal in preoperative determination of precise tumor location.MethodsAll operated PC patients in our institution between 2000 and 2015 that had at least one of the following in-house preoperative scans: neck ultrasonography (US), neck 4D-Computed Tomography (4DCT) and 99mTc Sestamibi SPECT/CT (MIBI). Sensitivity, specificity and accuracy of PC tumor localization were assessed individually and in combination.Results20 patients fulfilled the inclusion criteria and were analysed. There were 18 US, 18 CT and 9 MIBI scans. The sensitivity and accuracy for tumor localisation of US was 80% (CI 56–94%) and 73% respectively, of 4DCT was 79% (CI 58–93%) and 82%, and of MIBI was 81% (CI 54–96%) and 78%. The sensitivity and accuracy of the combination of CT and MIBI was 94% (CI 73–100%) and 95% and for the combination of US, CT and MIBI was 100% (CI 72–100%) and 100% respectively. The wash-out of the PC lesions, expressed as a percentage change in Hounsfield Units from the arterial phase to early delayed phase was −9.29% and to the late delayed phase was −16.88% (n = 11).ConclusionsThe sensitivity of solitary preoperative imaging of PC patients, whether by US, CT or MIBI, is approximately 80%. Combinations of CT with MIBI and US increase the sensitivity to 95% or better. Combined preoperative imaging of patients with clinical possibility of PC is therefore recommended.     

Magnetic resonance imaging of the prostate at 1.5 versus 3.0 T: A prospective comparison study of image quality

ObjectivesThis study prospectively evaluates objective image quality (IQ), subjective IQ, and PI-RADS scoring of prostate MRI at 3.0 T (3T) and 1.5 T (1.5T) within the same patients.MethodsSixty-three consecutive patients (64 ± 9 years) were prospectively included in this non-inferiority trial, powered at 80% to demonstrate a ≤10% difference in signal-to-noise (SNR) and contrast-to-noise ratio (CNR) of T2-weighted and diffusion-weighted imaging (T2WI, DWI) at 1.5 T compared to 3 T. Secondary endpoints were analysis of subjective IQ and PI-RADS v2 scoring.ResultsAll patients received multi-parametric prostate MRI on a 3 T (T2WI, DWI, DCE) and bi-parametric MRI (T2WI, DWI) on a 1.5 T scanner using body coils, respectively. SNR and CNR of T2WI were similar at 1.5 T and 3 T (p = 0.7–1), but of DWI significantly lower at 1.5 T (p < 0.01). Subjective IQ was significantly better at 3 T for both, T2WI and DWI (p < 0.01). PI-RADS scores were comparable for both field strengths (p = 0.05–1). Inter-reader agreement was excellent for subjective IQ assessment and PI-RADS scoring (k = 0.9–1).ConclusionProstate MRI at 1.5 T can reveal comparable objective image quality in T2WI, but is inferior to 3 T in DWI and subjective IQ. However, similar PI-RADS scoring and thus diagnostic performance seems feasible independent of the field strength even without an endorectal coil.     

Direct comparison of PI-RADS version 2 and version 1 regarding interreader agreement and diagnostic accuracy for the detection of clinically significant prostate cancer

Purposeto simultaneously evaluate interreader agreement and diagnostic accuracy in the of PI-RADS v2 and compare it to v1.MethodsA total of 67 patients (median age 65.3 y, range 51.2–78.2 y; PSA 6.8 μg/L, 0.2–33 μg/L) undergoing MRI of the prostate and subsequent transperineal template biopsy within ≤6 months from MRI were included. Four readers from two institutions evaluated the likelihood of prostate cancer using PI-RADS v1 and v2 in two separate reading sessions ≥3 months apart. Interreader agreement was assessed for each pulse-sequence and for total PI-RADS scores using the intraclass correlation coefficient (ICC). Differences were considered significant for non-overlapping 95%-confidence intervals. Diagnostic accuracy was assessed with the area under the receiver operating characteristic curve (A_Z). A p-value <0.05 was considered statistically significant.ResultsInterreader agreement for DCE-scores was good in v2 (ICC₂ = 0.70; 95% CI: 0.66–0.74) and slightly lower in v1 (ICC₁ = 0.64, 0.59–0.69). Agreement for DWI scores (ICC₁ = 0.77, ICC₂ = 0.76) as well as final PI-RADS scores per quadrant were nearly identical (ICC₁ = ICC₂ = 0.71). Diagnostic accuracy showed no significant differences (p = 0.09–0.93) between v1 and v2 in any of the readers (range: A_Z = 0.78–0.88).ConclusionPI-RADS scores show similar interreader agreement in v2 and v1 at comparable diagnostic performance. The simplification of the DCE interpretation in v2 might slightly improve agreement while not negatively affecting diagnostic performance.     

Comparison of screening CEDM and MRI for women at increased risk for breast cancer: A pilot study

ObjectivesContrast enhanced digital mammography (CEDM) is a new breast imaging technology increasingly used in the diagnostic setting but its utility in the pure screening setting has not been reported. The goal of this pilot study is to prospectively compare screening CEDM to breast MRI in women with an increased risk for breast cancer.MethodsIn this IRB-approved HIPAA-compliant study, 318 women at increased breast cancer risk were consented (December 2012–May 2015) to undergo CEDM in addition to their scheduled MRI. CEDM was performed within 30 days of screening MRI. CEDM was interpreted blinded to MRI. The reference standard was defined as a combination of pathology and 2-year imaging follow-up.ResultsData from 307/318 patients were evaluable. Three cancers (two invasive cancers, one ductal carcinoma in situ) were detected at first round screening: MRI detected all three and CEDM detected the two invasive cancers. None of the three cancers was seen on the low energy mammograms which are comparable to conventional mammography. At 2 year imaging follow up, there were 5 additional screen detected cancers and no palpable cancers. The positive predictive value 3 (PPV₃) for CEDM was 15% (2/13, 95% CI: 2–45%) and 14% for MRI (3/21, 95% CI: 3–36%). The specificity of CEDM and MRI were 94.7% and 94.1% respectively.ConclusionsBoth CEDM and MRI detected additional cancers not seen on conventional mammography, primarily invasive cancers. Our pilot data suggest that CEDM could be valuable as a supplemental imaging exam for women at increased risk for breast cancer who do not meet the criteria for MRI or for whom access to MRI is limited. Validation in larger multi institutional trials is warranted.     

Diagnostic value of Transient Elastography (Fibroscan) in the evaluation of liver fibrosis in chronic viral hepatitis C: Comparison to liver biopsy

Purpose

To assess the Transient Elastography diagnostic and staging role in liver fibrosis in chronic hepatitis C in comparison to hepatic biopsy.

Comprehensive physical fitness and high blood pressure in children and adolescents: A national cross-sectional survey in China

ObjectivesTo assess the association between comprehensive physical fitness and high blood pressure (HBP) among Chinese children and adolescents.DesignNational cross-sectional surveys.Methods214,301 school students’ data aged 7−18 years was extracted in 2014. Six components of physical fitness (forced vital capacity, standing long jump, sit-and-reach, body muscle strength, 50 m dash and endurance running) were measured, standardized and aggregated as a summary physical fitness indicator (PFI). HBP, systolic HBP (SHBP) and diastolic HBP (DHBP) were defined according to sex-, age- and height-specific references in China.ResultsThe prevalence of HBP, SHBP and DHBP was 8.6%, 4.7% and 5.7%, respectively, and PFI was −0.9 in Chinese children and adolescents. A significant negative association between the PFI and HBP was observed with adjusted prevalence of HBP (10.8% (95% CI: 10.4–11.2) to 7.6% (95% CI: 7.3–8.0), P_trend < 0.001), SHBP (5.7% (95% CI: 5.4–6.1) to 4.4% (95% CI: 4.1–4.6), P_trend < 0.001), and DHBP (7.6% (95% CI: 7.2–7.9) to 4.6% (95% CI: 4.3–4.9), P_trend < 0.001) and their ORs (HBP: 0.87(95% CI: 0.82–0.93) to 0.68(95% CI: 0.64–0.73), P_trend < 0.001; SHBP: 0.86(95% CI: 0.79–0.94) to 0.75(95% CI:0.69–0.82), P_trend < 0.001; DHBP: 0.85(95% CI: 0.79–0.92) to 0.59(95% CI: 0.54–0.64), P_trend < 0.001) declined with the increase in PFI. Stratified nutritional status exhibited a similar negative association between PFI and HBP, SHBP and DHBP in children with normal weight, overnutrition, and undernutrition. Stand long jump, body muscle strength, 50 m dash, and endurance running, had a negative association with HBP, SHBP and DHBP, but forced vital capacity had a positive such association. Sit-and-reach and HBP are not significantly associated.ConclusionsPhysical fitness was negatively correlated to the increased HBP in children and adolescents. Comprehensive policies and measures to enhance children and adolescents’ physical fitness are urgently needed through the promotion of physical activity, healthy dietary patterns, and strategies of educational guidelines to reduce schoolwork, which will in turn reduce the cardiovascular burdens in the future.     

Computed tomography versus digital subtraction angiography for the diagnosis of obscure gastrointestinal bleeding

PurposeThe diagnostic yield of computed tomography angiography (CTA) compared to digital subtraction angiography (DSA) for major obscure gastrointestinal bleeding (OGIB) is not known. Aim of the study was to prospectively evaluate the diagnostic yield of CTA versus DSA for the diagnosis of major OGIB.Material and methodsThe institutional review board approved the study and informed consent was obtained from each patient. Patients with major OGIB were prospectively enrolled to undergo both CTA and DSA. Two blinded radiologists each reviewed the CTA and DSA images retrospectively and independently. Contrast material extravasation into the gastrointestinal lumen was considered diagnostic for active bleeding. Primary end point of the study was the diagnostic yield, defined as the frequency a technique identified an active bleeding or a potential bleeding lesion. The diagnostic yield of CTA and DSA were compared by McNemar's test.Results24 consecutive patients (11 men; median age 64 years) were included. CTA and DSA identified an active bleeding or a potential bleeding lesion in 92% (22 of 24 patients; 95% CI 72%–99%) and 29% (7 of 24 patients; 95% CI 12%–49%) of patients, respectively (p < 0.001). CTA and DSA identified an active bleeding in 42% (10 of 24; 95% CI 22%–63%) and 21% (5 of 24; 95% CI 7%–42%) of patients, respectively (p = 0.06).ConclusionDue to the lower invasiveness and higher diagnostic yield CTA should be favored over DSA for the diagnosis of major OGIB.     

Utility of diffusion-weighted MRI in the diagnosis of bladder carcinoma

BackgroundThe purposes of our study were to investigate the feasibility of diffusion-weighted imaging in the detection of malignant bladder tumors, with comparison to the high-resolution thin-section fast spin-echo (FSE) T2-weighted MRI, and also to compare the apparent diffusion coefficient (ADC) values of the bladder tumors with the surrounding structures.Material and MethodsFifty-three consecutive patients consisting of 44 males and 9 females who presented with a bladder mass were prospectively enrolled in this study. Mean age was 62.53±12.03 (age range, 33–86 years). These patients were evaluated by high-resolution thin-section FSE T2-weighted and diffusion-weighted MRI for the detection of bladder masses. Following MRI, within 2 weeks, all patients were subjected to either surgery or cystoscopic biopsy, and the obtained histopathological proofs were used as the reference standard. Furthermore, ADC values of the bladder tumors, urine, the normal bladder wall, the central and peripheral zones of the prostate, the seminal vesicule, and the uterus outer myometrium were also calculated. ADC values of the bladder carcinomas and the related surrounding structures were compared as to whether a statistically significant difference was present or not.ResultsIn a total of 47 patients, consisting of 39 males and 8 females, bladder carcinomas were clearly shown as having conspicuous high and intermediate signal intensity masses, relative to the surrounding structures on diffusion-weighted and T2-weighted images, respectively. An 89% sensitivity and a 100% positive predictive value were obtained for both FSE T2-weighted and diffusion-weighted MRI in the diagnosis of bladder carcinoma. Mean ADC values and standard deviations of the bladder tumors and the surrounding structures were as follows: bladder carcinomas (n= 47): 1.28±0.31, normal bladder wall (n= 47): 1.98±0.41, urine (n= 47): 3.12±0.24, seminal vesicle (n= 39): 1.82±0.33, peripheral zone of prostate (n= 39): 1.80±0.29, central zone of prostate (n= 39): 1.55±0.33, and uterus outer myometrium (n= 8): 1.53±0.19. It can be clearly seen that the mean ADC values of the bladder carcinomas were significantly lower than the surrounding structures (P< .05).Conclus?onHigh-resolution thin-section FSE T2 and diffusion-weighted MRI show high diagnostic performance and are comparable in the detection of bladder tumors. Diffusion-weighted MRI provides high quality images of the malignant bladder tumors against a suppressed background signal. Diffusion-weighted MRI using ADC measurements may be useful in the evaluation of tumor invasion to the adjacent organs.     

Pulmonary MRI at 3T: Non-enhanced pulmonary magnetic resonance Imaging Characterization Quotients for differentiation of infectious and malignant lesions

ObjectiveTo investigate 3T pulmonary magnetic resonance imaging (MRI) for characterization of solid pulmonary lesions in immunocompromised patients and to differentiate infectious from malignant lesions.Materials and methodsThirty-eight pulmonary lesions in 29 patients were evaluated. Seventeen patients were immunocompromised (11 infections and 6 lymphomas) and 12 served as controls (4 bacterial pneumonias, 8 solid tumors). Ten of the 15 infections were acute. Signal intensities (SI) were measured in the lesion, chest wall muscle, and subcutaneous fat. Scaled SIs as Non-enhanced Imaging Characterization Quotients ((SI_Lesion − SI_Muscle)/(SI_Fat − SI_Muscle)*100) were calculated from the T2-weighted images using the mean SI (T2-NICQ_mean) or the 90th percentile of SI (T2-NICQ_90th) of the lesion. Simple quotients were calculated by dividing the SI of the lesion by the SI of chest wall muscle (e.g. T1-Q_mean: SI_Lesion/SI_Muscle).ResultsInfectious pulmonary lesions showed a higher T2-NICQ_mean (40.1 [14.6–56.0] vs. 20.9 [2.4–30.1], p < 0.05) and T2-NICQ_90th (74.3 [43.8–91.6] vs. 38.5 [15.8–48.1], p < 0.01) than malignant lesions. T1-Q_mean was higher in malignant lesions (0.85 [0.68–0.94] vs. 0.93 [0.87–1.09], p < 0.05). Considering infections only, T2-NICQ_90th was lower when anti-infectious treatment was administered >24 h prior to MRI (81.8 [71.8–97.6] vs. 41.4 [26.6–51.1], p < 0.01). Using Youden’s index (YI), the optimal cutoff to differentiate infectious from malignant lesions was 43.1 for T2-NICQ_mean (YI = 0.42, 0.47 sensitivity, 0.95 specificity) and 55.5 for T2-NICQ_90th (YI = 0.61, 0.71 sensitivity, 0.91 specificity). Combining T2-NICQ_90th and T1-Q_mean increased diagnostic performance (YI = 0.72, 0.77 sensitivity, 0.95 specificity).ConclusionConsidering each quotient alone, T2-NICQ_90th showed the best diagnostic performance and could allow differentiation of acute infectious from malignant pulmonary lesions with high specificity. Combining T2-NICQ_90th with T1-Q_mean increased overall performance, especially regarding sensitivity.     

The quantitative diagnostic capability of routine MR imaging and diffusion-weighted imaging in osteoporosis patients

ObjectivesTo determine the quantitative diagnostic capability of magnetic resonance imaging (MRI), compared to dual-energy X-ray absorptiometry (DEXA), for osteoporosis.Materials and MethodsEight male volunteers and eight patients underwent both DEXA and MRI. Results were obtained from each subject's L2 to L4, for a total of 48 lumbar vertebrae. Based on their bone mineral density (BMD) acquired from DEXA, the vertebrae were classified as follows: normal (n= 28), osteopenic (n= 0), and osteoporotic (n= 20). All MR examinations were performed on a 1.5-T scanner to obtain T₁-weighted imaging (T1WI), fat-suppression T₂-weighted imaging (FS-T2WI), and diffusion-weighted imaging (DWI). These quantitative MR parameters were determined: T1WI and FS-T2WI signal-to-noise ratios and DWI apparent diffusion coefficient values. To determine the diagnostic capability of MRI as an osteoporosis indicator, MR parameters were assessed statistically.ResultsAll MR parameters significantly correlated with BMD (T1WI: r=?0.64, FS-T2WI: r=?0.36, DWI: r=?0.29), with significant differences among normal and osteoporotic vertebrae (P< .05). By receiver operating characteristic analysis, the area under the curve of T1WI was significantly higher than others (P< .05). When adapted as feasible threshold values, sensitivity, specificity, and accuracy of T1WI were 95.0% (19/20), 92.9% (26/28), and 93.8% (45/48), respectively.ConclusionRoutine MRI, in particular T1WI, had a potential for the assessment of osteoporosis.     

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.