Acta radiologica最新文献

Background: Organ preservation strategies have been widely implemented for rectal cancer (RC) patients with a good response after neoadjuvant chemoradiation (nCRT). However, to accurately select eligible patients remains one of the key diagnostic challenges.

Purpose: To identify eligible candidates for organ preservation after nCRT in RC, by identifying luminal response and lymph node metastases, based on T2W-MRI signal intensities.

Material and methods: A total of 171 RC patients underwent MRI before and after nCRT. The primary tumor (pre-nCRT-MRI) and tumor remnant (post-nCRT-MRI) were manually delineated. Ten signal intensity features were extracted and delta features were calculated by subtraction. Histopathological evaluation classified patients as lymph node negative (ypN0) or positive (ypN+), and as good responders (GR) or partial/poor responders (PR). Five models were constructed based on the timing of imaging.

Results: 42/170 (25%) patients had ypN+, and 72/152 (47%) patients were considered GR. Univariate analysis showed 13/40 signal intensity features were significantly different between luminal response groups and 4/40 between nodal response groups. In multivariate analysis, the Baseline + Restaging-model yielded the best results for both luminal and nodal response with AUCs in the test set of 0.81 (95% CI=0.67-0.95) and 0.74 (95% CI=0.59-0.90), respectively. To identify PR, the Delta-model yielded an AUC of 0.72 (95% CI=0.56-0.89) and the Delta + Restaging-model an AUC of 0.81 (95% CI=0.67-0.95), both were not able to differentiate nodal response. The models including solely baseline or restaging features were not predictive.

Conclusion: T2W-MRI signal intensities of the primary rectal tumor are related to the luminal and nodal response after nCRT and hold promise to identify patients eligible for organ preservation.

Background: Distinguishing radiation necrosis (RN) from recurrent tumor (RT) in patients with gliomas treated with radiation therapy presents an important clinical dilemma.

Purpose: To evaluate the diagnostic performance of multiparametric magnetic resonance imaging (MRI) techniques in distinguishing RN from RT in patients with histologically confirmed glioma treated previously with radiotherapy and chemotherapy or without chemotherapy using a combination of dynamic susceptibility-weighted contrast-enhanced (DSC) perfusion MRI, diffusion tensor imaging (DTI), and MR spectroscopy (MRS).

Material and methods: Patients with glioma who developed a new enhancing mass after standard treatment were retrospectively evaluated. Conventional MRI, DTI, DSC, and MRS were performed. The region of interest (ROI) was manually drawn in the enhancing lesions, peri-lesional white matter edema, and the contralateral normal-appearing white matter. Apparent diffusion coefficient (ADC), fractional anisotropy (FA), relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF), N-acetylaspartate (NAA), choline (Cho), creatine (Cr), NAA/Cr, Cho/NAA, and Cho/Cr were calculated. Two-tailed t-test and receiver operating characteristic (ROC) curve analysis were performed.

Results: In total, 34 patients with RT and 25 with RN met our inclusion criteria. FA, rCBF, rCBV, Cho/NAA, Cho/Cr were statistically significant between the two groups (P < 0.05). The sensitivity and specificity of FA, rCBF, rCBV, Cho/NAA, and Cho/Cr in the diagnosis of RT were 70.6%, 97.1%, 91.2%, 91.2%, and 82.4% and 64%, 100%, 100%, 96%, and 72% respectively.

Conclusion: DTI, DSC, and MRS are of great value in the differential diagnosis of RN and RT of glioma. The diagnostic performance of DSC is better than DTI and MRS.

Background: Little is known of the influence of scanner field strength on quantitative diffusivity variables, especially kurtosis in healthy ovaries.

Purpose: To evaluate the influence of scanner field strength on quantitative diffusion variables in pelvic MRI of the ovaries.

Material and methods: This prospective, single-centre study consisted of repeated 1.5-T and 3-T examinations in 30 female volunteers (mean age=27.9 years, age range=20.3-45.2 years) from July 2017 to September 2019. Multi b-value DWI 0, 50, 100, 800, 1500, 2000 s/mm² was acquired over three timepoints during the menstrual cycle. Ovaries were segmented at b = 1500 s/mm². Median apparent diffusion coefficient (ADC) and advanced kurtosis parameters D_app and K_app were calculated. Statistical analysis was performed with the variations of diffusivity variables being compared between 1.5-T and 3-T MRI using a Mann-Whitney rank-sum test.

Results: Median ADC and D_app (µm²/ms) did not statistically differ. Median ADC were 1.509 (range=1.371-1.610), 1.619 (range=1.463-1.747), and 1.511 (range=1.423-1.639) at 1.5 T; 1.542 (range=1.428-1.682), 1.658 (range=1.510-1.806), and 1.572 (range=1.455-1.709) at 3 T (P = 0.14, 0.19, and 0.07), whereas median D_app were 2.024 (range=1.913-2.152), 2.192 (range=2.010-2.327), and 2.045 (range=1.958-2.170) at 1.5 T; 2.013 (range=1.952-2.188), 2.179 (range=2.018-2.327), and 2.082 (range=1.959-2.194) at 3 T (P = 0.77, 0.99, and 0.34) for timepoints 1, 2, and 3, respectively. Statistical comparison of K_app revealed significant differences for all timepoints: 0.629 (range=0.595-0.652), 0.604 (range=0.574-0.651), and 0.622 (range=0.581-0.664) at 1.5 T; 0.601 (range=0.563-0.626), 0.567 (range=0.526-0.633), and 0.599 (range=0.541-0.650) at 3 T (P < 0.001, 0.005, and 0.03).

Conclusion: Diffusivity mapping in the ovaries provides similar absolute median diffusion values, but statistically significant differences in absolute kurtosis values between 1.5 T and 3 T.

Background: Axial computed tomography (CT) cross-sections offer an accessible model for assessing diverse pathologies associated with hyperostosis frontalis interna (HFI) based on the Hershkovitz classification.

Purpose: To delineate the CT characteristics of HFI, emphasizing a radiological description using the Hershkovitz classification. It investigated whether the Hershkovitz classification can be predicted using density, a variable unexplored in the literature. HFI thickness and the presence of concurrent hyperostosis beyond the frontal bone (HBFB) were evaluated across varying degrees of the Hershkovitz classification.

Material and methods: This retrospective study evaluated characteristics of HFI on CT. Each case was assigned a Hershkovitz classification. Density and thickness of the HFI along with the presence of concurrent HBFB were evaluated and correlated with the Hershkovitz classification.

Results: Axial CT of 77 patients with HFI was evaluated. Patient characteristics including sex were uncorrelated with CT measurements (P > 0.25) and Hershkovitz classification (P > 0.06). Increasing HFI thickness was associated with a higher Hershkovitz classification (odds ratio [OR] = 1.863, 95% confidence interval [CI] = 1.452-2.389; P < 0.001), and increasing density of HFI was associated with a lower Hershkovitz classification (OR = 0.995, 95% CI = 0.992-0.998; P = 0.002). Higher Hershkovitz classification was also found to be associated with the presence of concurrent HBFB (OR = 31.694, 95% CI = 6.483-154.938; P < 0.001).

Conclusion: In our cohort, Hershkovitz classification on axial CT correlated with increased HFI thickness, presence of HBFB, and lower HFI density.

Background: The capsuloligamentous complex injury of the first metatarsophalangeal joint (MTPJ) is a common cause of turf toe.

Purpose: To investigate whether high-resolution 3 T magnetic resonance imaging (MRI) could demonstrate all the normal anatomic structures and the MR features of the capsuloligamentous complex injury of the first MTPJ, and to evaluate the diagnostic performance of MRI in the diagnosis of the capsuloligamentous complex injuries of the first MTPJ.

Material and methods: A total of 115 feet were included in this study, including 48 feet from 24 healthy volunteers and 67 feet from 67 patients with the capsuloligamentous complex of the first MTPJ injuries. All feet had MRI examination. The MRI features of the capsuloligamentous complex of the first MTPJ of the volunteers and patients were analyzed. Diagnostic sensitivity, specificity, and accuracy of MRI were calculated using the surgery as the standard of reference. The inter-observer agreement was assessed using kappa analysis.

Results: The central portion of the plantar plate and ligament injury manifested as discontinuity, with an indistinct appearance with hyperintense signal within the involved structures. The sensitivities, specificities, and diagnostic accuracy value of MRI for diagnosing most structures of the capsuloligamentous complex injuries of the first MTPJ were 67%-100%, 93%-100%, and 0.82-0.99, respectively, and overall good to perfect inter-observer agreements (kappa=0.63-0.95).

Conclusion: High-resolution MRI allows adequate visualization of normal anatomic structures of the first MTPJ. The best visualized structure is sesamoid phalangeal ligament and the most frequent injury is complete tear of the medial sesamoid phalangeal ligament.

Background: Radiomics analysis is widely used to assess tumor prognosis.

Purpose: To explore the value of computed tomography (CT) radiomics nomogram in predicting disease-free survival (DFS) of patients with colorectal cancer (CRC) after operation.

Material and methods: A total of 522 CRC patients from three centers were retrospectively included. Radiomics features were extracted from CT images, and the least absolute shrinkage and selection operator Cox regression algorithm was employed to select radiomics features. Clinical risk factors associated with DFS were selected through univariate and multivariate Cox regression analysis to build the clinical model. A predictive nomogram was developed by amalgamating pertinent clinical risk factors and radiomics features. The predictive performance of the nomogram was evaluated using the C-index, calibration curve, and decision curve. DFS probabilities were estimated using the Kaplan-Meier method.

Results: Integrating the retained eight radiomics features and three clinical risk factors (pathological N stage, microsatellite instability, perineural invasion), a nomogram was constructed. The C-index for the nomogram were 0.819 (95% CI=0.794-0.844), 0.782 (95% CI=0.740-0.824), 0.786 (95% CI=0.753-0.819), and 0.803 (95% CI=0.765-0.841) in the training set, internal validation set, external validation set 1, and external validation set 2, respectively. The calibration curves demonstrated a favorable congruence between the predicted and observed values as depicted by the nomogram. The decision curve analysis underscored that the nomogram yielded a heightened clinical net benefit.

Conclusion: The constructed radiomics nomogram, amalgamating the radiomics features and clinical risk factors, exhibited commendable performance in the individualized prediction of postoperative DFS in CRC patients.

Background: Gadolinium-iodine mixed contrast agents can significantly improve the visualization of the fallopian tubes in magnetic resonance hysterosalpingography (MR-HSG). However, the mixing ratio of gadolinium-iodine contrast agents has not yet been standardized.

Purpose: To explore the optimal mixing ratio of gadolinium-iodine contrast agents suitable for MR-HSG.

Material and methods: A total of 16 mixing ratios of gadolinium and saline mixtures (Gd-NS), gadolinium and iopromide mixtures (Gd-I370), and gadolinium and iodixanol mixtures (Gd-I320) were formulated for an in vitro study. These mixed contrast agents were scanned on 1.5 T and 3.0 T using T1 contrast enhancement sequences. For qualitative assessment, contrast agent imaging quality was graded on a subjective 3-point scale (good, moderate, and poor). For the quantitative evaluation, differences in the signal intensity (SI) of the three contrast agents, as well as the SI variations between 1.5 T and 3.0 T, were compared.

Results: Gd-I370 and Gd-I320 exhibited the highest SI and good image at a 1:300 ratio on 1.5 T and a 1:200 ratio on 3.0 T. The difference in the SI among the three contrast agents was not statistically significant at 1.5 T (P > 0.05). At 3.0 T, the comparison between the SIs of Gd-I370 and Gd-I320 was not statistically significant (P > 0.05). The SIs of contrast agents on 3.0 T were higher than those on 1.5 T (P < 0.05).

Conclusion: A gadolinium-iodine contrast agent with a 1:300 mixing ratio may be more suitable for 1.5 T MR-HSG, while a 1:200 mixing ratio may be more suitable for 3.0 T MR-HSG. Additionally, the contrast agent SI is higher on 3.0 T than on 1.5 T.

Background: Cerebral infarction is one of the most common diseases. Diffusion tensor imaging (DTI) has been used to evaluate for crossed cerebellar diaschisis (CCD) to observe the expression of repulsive guidance molecule a (RGMa), the axonal regeneration as well as the effect on neural functional recovery in the middle cerebral artery occlusion (MCAO) rat model.

Purpose: To certify the expression pattern of RGMa in cerebral infarction and the mechanism of CCD to provide a new target for clinical therapy.

Material and methods: Building the MCAO rat model, every 16 rats were randomly divided into one of six groups. The brain was scanned over the time points above and the rats were sacrificed for immunohistochemistry staining and reverse transcription polymerase chain reaction (RT-PCR) to assay the RGMa expression.

Results: The apparent diffusion coefficient (ADC) and fractional anisotropy (FA) value of MCAO rats declined and peaked at 12 h. The contralateral cerebellum had a lower parameter than the other side. The expression of RGMa kept climbing and achieved the maximum at 48 h (P < 0.05). The value of the protein in the cerebellum was higher (P < 0.05) compared with controls, especially the right cerebellum. The expression of RGMa was negative compared to the parameter of magnetic resonance imaging (MRI) and the axonal regeneration.

Conclusion: The MRI and pathology parameters after MACO had significant differences compared to the controls, as well as the bilateral cerebellum, which provided evidence of CCD. RGMa was related to the axonal regeneration in the injured brain.

Background: Hip joint (HJ) pain, which may be caused by lumbar disease, is a common complaint.

Purpose: To investigate the prevalence and specific correlations between various HJ diseases and lumbar spine magnetic resonance imaging (MRI) findings in patients with HJ pain.

Material and methods: Patients with the chief complaint of HJ pain who had both HJ MRI and lumbar MRI were retrospectively included. According to the existence of HJ disease, patients were divided into the following groups: non-HJ disease; osteoarthritis (OA); femoroacetabular impingement (FAI); ischiofemoral impingement (IFI); greater trochanter pain syndrome (GTPS); and other diseases. The prevalence of major lumbar MRI findings was compared. Correlations between HJ disease and major lumbar MR findings were explored.

Results: A total of 585 patients were included, of which 566 (96.8%) had major findings on lumbar MRI. The HJ disease group was more likely to be female and had more spondylolisthesis, while the non-HJ disease group had more low back or leg pain. The OA group was older and correlated with lumbar spinal stenosis (contingency coefficient = 0.164) and spondylolisthesis (contingency coefficient = 0.095). The FAI group was younger, had more male patients, and correlated with lumbosacral transitional vertebrae (contingency coefficient = 0.122). The IFI group was older, had more female patients, and correlated with facet joint osteoarthritis (contingency coefficient = 0.168). The GTPS group was older, had more female patients, and correlated with spondylolisthesis (contingency coefficient = 0.097).

Conclusion: Major lumbar MRI findings were frequently observed in patients with hip pain, even in patients without HJ disease. Specific lumbar MRI finding correlated with different HJ disease.

Background: Preoperative identification of T-box pituitary transcription factor 19 (TPIT) lineage silent adenomas in non-functioning pituitary adenomas (NFPAs) is important.

Purpose: To compare the clinical, laboratory, and radiological features of the three cell lineages of adenomas in NFPAs and evaluate the diagnostic efficacy of multiple microcysts and clivus invasion on magnetic resonance imaging (MRI) for TPIT lineage adenomas in NFPAs.

Material and methods: A total of 405 patients with NFPA were retrospectively enrolled, including steroidogenic factor 1 (SF-1) lineage adenomas (n = 204), TPIT lineage adenomas (n = 111), and pituitary transcription factor 1 (PIT-1) lineage adenomas (n = 90). The clinical, laboratory, and radiological features of the three lineages adenomas were compared. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of multiple microcysts, clivus invasion, and their combination were calculated to diagnose TPIT lineage adenomas in NFPAs.

Results: Among the three lineages of NFPAs, patients with SF-1 lineage were older than those with TPIT and PIT-1 lineages (P < 0.001). TPIT lineage adenomas were most common in women (P < 0.001) and had the highest tumor volume (P < 0.001), and incidence of clivus invasion (P < 0.001). The multiple microcysts and clivus invasion in the diagnosis of TPIT lineage adenomas in NFPAs had high specificity (88.44% vs. 98.64%) and accuracy (77.28%).

Conclusion: The MRI findings of multiple microcysts and clivus invasion can help diagnose TPIT lineage adenomas in NFPAs with high specificity.