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Aim: To evaluate the change in signal intensity (SI) and volume (V) from multiparametric magnetic resonance imaging (MRI) for assessing the response of locally advanced rectal cancer (LARC) to chemoradiotherapy (CRT). Materials and methods: Eight‐two LARC patients who underwent pre‐ and post‐CRT T2‐weighted (T2W), apparent diffusion coefficient (ADC), and contrast‐enhanced T1‐weighted (ceT1W) MRI were retrospectively analyzed. The change of volume (%△V) and relative SI ratio (%△SIR) from each sequence were determined. All LARCs were confirmed pathologically and classified as tumor regression grade (TRG) ‐0, 1, 2,or 3. Descriptive statistics and receiver operating characteristic (ROC) analysis, with calculation of area under the curve (AUC), were used to compare the diagnostic performances. Results: Sixteen patients had TRG‐0, 15 had TRG‐1, 35 had TRG‐2, and 16 had TRG‐3. Except for ADC‐%△SIR, the remaining %△V and %△SIR values on MR sequences had significant differences among the four groups. The %△V and %△SIR (alone or together) did not distinguish TRG‐1 from TRG‐2, nor TRG‐2 from TRG‐3; however, differences between other TRGs were identified by %△V and %△SIR. The combined use of ADC‐%△V and T2W‐%△SIR provided the best diagnostic performance in distinguishing of TRG‐0 from TRG‐2 (AUC: 0.954) and from TRG‐3 (AUC: 1.000). Conclusions: Preoperative MRI of LARC patients after CRT has high diagnostic value for determination TRG, and may therefore improve the selection of patients most suitable for surgery. [ABSTRACT FROM AUTHOR]

This study aims to emphasise the importance of imaging in the diagnosis and treatment decision‐making in Zinner syndrome and provide a classification for seminal vesicle cysts. The data of six patients with Zinner syndrome in a single institution were collected. All patients underwent a contrast‐enhanced computed tomography (CT) exam. Among these patients, five patients also underwent an magnetic resonance imaging (MRI). These results were combined with the review of available literature to classify the seminal vesicle cysts. Among these patients, two patients had urinary urgency and frequency, while four patients had no urinary symptoms. No reproductive‐system symptoms were revealed. The imaging revealed left‐sided involvement in two patients and right‐sided involvement in four patients. The associated features included ipsilateral renal agenesis, seminal vesicle cyst or agenesis, and ejaculatory duct obstruction. Either an ipsilateral ureterocele or an ipsilateral small testis was noted. The seminal vesicle cysts demonstrated varying attenuation or intensity in the imaging. Imaging (CT and especially MRI) can be critical in the noninvasive diagnosis of Zinner syndrome and in allowing aberrant anatomy to be displayed for possible surgery. The proposed seminal vesicle cyst imaging classification could potentially contribute to clinical decision‐making. [ABSTRACT FROM AUTHOR]

Background: MRI of patients with locally advanced rectal cancer (LARC) can predict the pathological complete response (pCR) to preoperative chemoradiation therapy (CRT). Our purpose was to use MRI results to evaluate the diagnostic value of combined changes in signal intensity (SI) and volume (V) of patients with LARC for predicting pCR to CRT., Methods: This retrospective study on 100 patients with LARC analyzed clinical and imaging data that were collected from March, 2018, to March, 2020. Before and after CRT, T2-weighted (T2W), apparent diffusion coefficient (ADC), and contrast-enhanced T1-weighted (ceT1W) data were analyzed. Percent changes of V (%#916;V) and relative SI ratio (%#916;SIR) on different sequences were calculated. After CRT, patients had pathological confirmation as pCR or non-pCR. Data were analyzed using nonparametric tests and receiver operating characteristic (ROC) analysis., Results: There were 34 pCR and 66 non-pCR patients. Except for ADC-%#916;SIR, the combined parameters and single parameters had a greater decrease in the pCR group. The combination of ADC-%#916;V and T2W-%#916;SIR had the greatest diagnostic value (AUC=0.85,cutoff=0.23%) and the combination of ADC-%ΔV% and #916;SIR had the best accuracy (89%, cutoff=44.11%). Except for T2W-%#916;V and T2W-%#916;SIR, the different sequences had moderate differences in diagnostic performance. The diagnostic performance of combined parameters or single parameters on ADC and T2W was significantly better than those on ceT1W (p#916;60;0.01)., Conclusion: All sequences except ADC-%#916;SIR provided reliable predictions of pCR, although ceT1W data had limited usefulness.

Background and Purpose: Radiation exposure in the CT diagnostic imaging process is a conspicuous concern in pediatric patients. This study aimed to evaluate whether 60-keV virtual monoenergetic images of the pediatric cranium in dual-layer CT can reduce the radiation dose while maintaining image quality compared with conventional images., Materials and Methods: One hundred six unenhanced pediatric head scans acquired by dual-layer CT were retrospectively assessed. The patients were assigned to 2 groups of 53 and scanned with 250 and 180 mAs, respectively. Dose-length product values were retrieved, and noise, SNR, and contrast-to-noise ratio were calculated for each case. Two radiologists blinded to the reconstruction technique used evaluated image quality on a 5-point Likert scale. Statistical assessment was performed with ANOVA and the Wilcoxon test, adjusted for multiple comparisons., Results: Mean dose-length product values were 717.47 (SD, 41.52) mGy×cm and 520.74 (SD, 42) mGy×cm for the 250- and 180-mAs groups, respectively. Irrespective of the radiation dose, noise was significantly lower, SNR and contrast-to-noise ratio were significantly higher, and subjective analysis revealed significant superiority of 60-keV virtual monoenergetic images compared with conventional images (all P  < .001). SNR, contrast-to-noise ratio, and subjective evaluation in 60-keV virtual monoenergetic images were not significantly different between the 2 scan groups ( P  > .05). Radiation dose parameters were significantly lower in the 180-mAs group compared with the 250-mAs group ( P < .001)., Conclusions: Dual-layer CT 60-keV virtual monoenergetic images allowed a radiation dose reduction of 28% without image-quality loss in pediatric cranial CT., (© 2023 by American Journal of Neuroradiology.)

Patients with spontaneous isolated superior mesenteric artery (SMA) dissection (SISMAD) usually present with acute or chronic abdominal pain and are admitted to the emergency or digestive diseases department to undergo auxiliary examinations, typically abdominal plain CT or contrast-enhanced CT (CECT). Plain CT is the most crucial examination in emergency radiology. An enlarged SMA diameter and perivascular fat stranding (PFS) on plain CT, though non-specific, may be the only indications for SISMAD. These results may be easily overlooked and the diagnosis of SISMAD may be missed. However, PFS around the SMA on CT may be the only indicator of the possible presence of SISMAD, particularly during the early stage when there are no massive changes in the vascular wall. The present study aimed to determine whether PFS surrounding the SMA on CT may help with the diagnosis of SISMAD by indicating the requirement for further examination. The data of 161 consecutive patients with SMA dissection who underwent abdominal CECT or underwent SMA CT angiography (CTA) after abdominal plain CT between February 2015 and February 2018 were retrospectively reviewed. SMA diameter, classification, PFS, complications, comorbidities and treatments were analyzed. The results demonstrated that SISMAD with PFS was significantly associated with admission type (emergency), clinical manifestations (abdominal pain), diagnostic modality and dissection subtype. On plain CT, PFS surrounding the SMA may be a marker for SISMAD, particularly in the emergency setting, and indicates the requirement for CTA examination., (Copyright © 2020, Spandidos Publications.)