Atrial dimension reference values in healthy participants using the biplane/monoplane method for clinical and research use.

AIM: To provide reference values of the dimensions of the left and right atrium (RA) obtained using the biplane and monoplane methods, respectively, on two- and four-chamber views, which represent the standard projections acquired in clinical practice, and correlation with body surface area (BSA), age, and gender. MATERIALS AND METHODS: Healthy volunteers, M:F = 1:1, including five participants per gender and age decile from 20 to 70 years, who underwent cardiovascular magnetic resonance imaging (CMR) were enrolled prospectively. Normal atrial reference values were calculated for male and female subpopulations and stratified by age. Atrial areas and volumes were assessed both as absolute values and indexed to BSA. Differences among genders and correlation with age were assessed. Intra- and interobserver reproducibility were assessed in a subpopulation. RESULTS: Fifty participants (mean age 43.3 ± 14 years, 25 men) were evaluated. Image analysis took <1 minute for each subject (mean time 30 ± 5 seconds). Intra- and interobserver reproducibility were excellent (ICC >0.85 for all datasets). RA areas were significantly higher in males (p=0.0001). The left atrial (LA) surface did not show significant differences among genders. Atrial areas normalised to BSA did not show significant gender differences. Both right and left absolute atrial volumes turned out to be significantly higher in males (p=0.0001 and p=0.0047, respectively), and normalised to BSA remained significantly different only for the RA (p=0.0006). Neither atrial volume nor areas showed significant correlation with age. CONCLUSIONS: The monoplane method is a fast and reproducible technique to assess atrial dimensions. Absolute atrial dimensions show significant variations among genders. Gender-specific reference ranges for atrial dimensions are recommended.

T2-weighted, apparent diffusion coefficient and 18F-FDG PET histogram analysis of rectal cancer after preoperative chemoradiotherapy.

BACKGROUND: The aim of our study was to investigate the correlation among T2-weighted (T2w) images, apparent diffusion coefficient (ADC) maps, 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) images, histogram analysis and the pathological response in locally advanced rectal cancer (LARC) after preoperative chemoradiotherapy (pCRT). METHODS: Patients with LARC were prospectively enrolled between February 2015 and August 2018 and underwent PET/magnetic resonance imaging (MRI). MRI included T2w and diffusion-weighted imaging (DWI)-sequences. ADC maps and PET images were matched to the T2w images. Voxel-based standardized uptake values (SUVs,) ADC and T2w-signal-intensity values were collected from the volumes of interest (VOIs) and mean, skewness and kurtosis were calculated. Spearman's correlation coefficient was applied to evaluate the correlation among the variables and tumor regression grade (TRG), T stage, N stage and fibrosis. RESULTS: Twenty-two patients with biopsy-proven LARC in the low or mid rectum were enrolled [17 males, mean age was 69 years (range 49-85 years)]. Seven patients experienced complete regression (TRG1). A significant positive correlation was found between SUV mean values (ρ = 0.480; p = 0.037) and TRG. No other significant correlations were found. CONCLUSIONS: Histogram analysis of SUV values is a predictor of TRG in LARC.

Radiomics: a new tool to differentiate adrenocortical adenoma from carcinoma.

BACKGROUND: The main challenge in the management of indeterminate incidentally discovered adrenal tumours is to differentiate benign from malignant lesions. In the absence of clear signs of invasion or metastases, imaging techniques do not always precisely define the nature of the mass. The present pilot study aimed to determine whether radiomics may predict malignancy in adrenocortical tumours. METHODS: CT images in unenhanced, arterial, and venous phases from 19 patients who had undergone resection of adrenocortical tumours and a cohort who had undergone surveillance for at least 5 years for incidentalomas were reviewed. A volume of interest was drawn for each lesion using dedicated software, and, for each phase, first-order (histogram) and second-order (grey-level colour matrix and run-length matrix) radiological features were extracted. Data were revised by an unsupervised machine learning approach using the K-means clustering technique. RESULTS: Of operated patients, nine had non-functional adenoma and 10 carcinoma. There were 11 patients in the surveillance group. Two first-order features in unenhanced CT and one in arterial CT, and 14 second-order parameters in unenhanced and venous CT and 10 second-order features in arterial CT, were able to differentiate adrenocortical carcinoma from adenoma (P < 0.050). After excluding two malignant outliers, the unsupervised machine learning approach correctly predicted malignancy in seven of eight adrenocortical carcinomas in all phases. CONCLUSION: Radiomics with CT texture analysis was able to discriminate malignant from benign adrenocortical tumours, even by an unsupervised machine learning approach, in nearly all patients.

Lung visualisation on PET/MRI: implementing a protocol with a short echo-time and low flip-angle volumetric interpolated breath-hold examination sequence.

AIM: To assess the diagnostic performance in detecting lung lesions of a short echo-time (TE) and low flip-angle (FA) volumetric interpolated breath-hold examination (VIBE) sequence included in the integrated positron-emission tomography (PET)/magnetic resonance imaging (MRI) protocol. METHOD AND MATERIALS: Thirty-seven oncological patients who underwent computed tomography (CT) and PET/MRI, including both a dedicated short TE, low FA VIBE (modified VIBE) and a standard VIBE of the lung, were enrolled. Modified VIBE images were reviewed retrospectively and independently by three raters, to detect pulmonary nodules, parenchymal consolidation, and bands. Three other groups examined standard VIBE, PET, and CT images. MRI and PET findings were compared to CT using Krippendorff's alpha using patient-based and a lesion-based analysis. Krippendorff's alpha was calculated to assess the interobserver agreement among the three raters of the modified VIBE. RESULTS: In the patient-based analysis (positivity ≥1 lesion), the comparison of modified VIBE with CT showed an alpha of 0.54 for nodules <6 mm (versus 0.41 for standard VIBE and 0.09 for PET) and an alpha of 0.88 for nodules ≥6 mm (versus 0.74 for standard VIBE and 0.42 for PET). On a lesion-based analysis (presence/absence of each lesion), modified VIBE compared to CT showed an alpha of0.58 for nodules <6 mm (versus 0.44 for standard VIBE and 0.09 for PET) and an alpha of 0.90 for nodules ≥6 mm (versus 0.79 for standard VIBE and 0.50 for PET). The alpha value for the interobserver agreement was 0.90 for nodules <6 mm, 0.91 for nodules ≥6 mm, 1.00 for consolidations, and 0.95 for bands in the patient-based analysis and 0.89, 0.93, 1.00, and 0.95 in the lesion-based analysis. CONCLUSIONS: Modified VIBE proved to be reproducible, showed better accuracy than standard VIBE and PET, and very good concordance with CT in assessing lung nodules ≥6 mm, whereas the agreement was less satisfactory for smaller nodules.

Diffusion-weighted whole-body MRI for evaluation of early response in multiple myeloma.

AIM: To evaluate the modifications of the apparent diffusion coefficient (ADC) in myelomatous lesions before and after induction treatment and the correlation with patient response to therapy according to International Myeloma Working Group (IMWG) criteria. MATERIALS AND METHODS: A homogeneous group of 18 patients with a diagnosis of symptomatic multiple myeloma who underwent whole-body MRI with diffusion-weighted imaging (DWI-MRI) before and after bortezomib-based induction chemotherapy were evaluated prospectively. Quantitative analysis of ADC maps of myelomatous lesions was performed with the following pattern types: focal pattern, diffuse pattern (moderate and severe), and "salt and pepper" pattern. Lesions were evaluated by quantitative image analysis including measurement of the mean ADC in three measurements. Imaging results were compared to laboratory results as the clinical reference standard. RESULTS: A statistically significant increase in ADC values were found in the lesions of patients that responded to treatment. Interestingly, focal lesions showed a strongly significant increase in ADC values in responders, whereas no significant variation in ADC value in non-focal lesions (diffuse pattern and "salt and peppers" pattern) between responders and non-responders group was demonstrated. CONCLUSIONS: DWI-MRI could provide additional quantitative information useful in monitoring early therapy response according to ADC changes of focal lesions.

Is under diagnosis of celiac disease compounded by mismanagement in the primary care setting?. A survey in the Italian Province of Brescia.

AIM: Celiac disease is under diagnosed in the primary care setting, mainly because of lack of awareness on the heterogenic manifestation of the disease. Furthermore, patients diagnosed at open access endoscopy may be mismanaged with incomplete dietary information. The aim of this paper was to evaluate prevalence and incidence in 1996 and 1997 for celiac disease in the Italian Province of Brescia and to obtain information on the extent of underdiagnosis and mismanagement. METHODS: The authors assessed the under diagnosis of celiac disease by relating the number of patients on gluten-free diet at 31 December 1997 (prevalent cases) to the expected number of patients in a population of 1,055,499 assuming 1/200 disease prevalence. Post-diagnosis management was assessed by questionnaire for all incident cases in the hospital practice and in the primary care setting. RESULTS: Five hundred and ninety-four prevalent cases were identified compared with an estimated disease prevalence of 5,000 cases, a figure corresponding to 8/9 under diagnosis. One hundred and thirty-five incident cases during 1996-1997 have been identified. Overall 80% of incident cases were symptomatic, but 40% only with the classical symptoms of malabsorption. Forty-three of the 135 incident cases did not receive appropriate dietary education following diagnosis, a figure corresponding to 1:3 mismanagement, and all of them were diagnosed in the primary care setting at open access endoscopy. CONCLUSIONS: Our study indicates that under diagnosis of celiac disease in the primary care setting is compounded by disease mismanagement, a finding suggesting the need for increasing awareness not only on the heterogenicity of clinical manifestation but also on the appropriate dietary management of celiac disease.