Multidetector Computed Tomography Imaging Research Articles

Adrenal Vein Sampling: Tips and Tricks.

Adrenal vein sampling (AVS) is the standard method for distinguishing unilateral from bilateral sources of autonomous aldosterone production in patients with primary aldosteronism. This procedure has been performed at limited specialized centers due to its technical complexity. With recent advances in imaging technology and knowledge of adrenal vein anatomy in parallel with the development of adjunctive techniques, AVS has become easier to perform, even at nonspecialized centers. Although rare, anatomic variants of the adrenal veins can cause sampling failure or misinterpretation of the sampling results. The inferior accessory hepatic vein and the inferior emissary vein are useful anatomic landmarks for right adrenal vein cannulation, which is the most difficult and crucial step in AVS. Meticulous assessment of adrenal vein anatomy on multidetector CT images and the use of a catheter suitable for the anatomy are crucial for adrenal vein cannulation. Adjunctive techniques such as intraprocedural cortisol assay, cone-beam CT, and coaxial guidewire-catheter techniques are useful tools to confirm right adrenal vein cannulation or to troubleshoot difficult blood sampling. Interventional radiologists should be involved in interpreting the sampling results because technical factors may affect the results. In rare instances, bilateral adrenal suppression, in which aldosterone-to-cortisol ratios of both adrenal glands are lower than that of the inferior vena cava, can be encountered. Repeat sampling may be necessary in this situation. Collaboration with endocrinology and laboratory medicine services is of great importance to optimize the quality of the samples and for smooth and successful operation. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Assessment of hiatus defect size in hiatal hernia patients using computed tomography

Objectives: The aim of this study is to investigate the hiatus defect diameter by measuring on multi-detector computed tomography images in hiatal hernia patients. Methods: The multi-detector computed tomography images of 50 patients and 50 individuals in control group included in this study were investigated. The hiatus surface area (cm²), hiatus antero-posterior and transverse diameters (cm), and the thickness of both diaphragmatic crura (mm) were measured by reformatting contrast-enhanced thoraco-abdomino-pelvic computed tomography images using the region of interest method. Results: In this study, a significant difference was obtained among groups according to hiatus surface area, hiatus antero-posterior, and transverse diameter measurements, and both left and right diaphragmatic crural thickness measurements (P<0.001). In the patient group, the cut-off values were determined by using ROC analysis, and the values above these cut-off values enabled a hernia diagnosis with high sensitivity and specificity. Conclusions: Measuring the hiatus surface area on multi-detector computed tomography images could serve as a supplementary criterion for diagnosing of hiatal hernia.

External validation of the RSNA 2020 pulmonary embolism detection challenge winning deep learning algorithm

PurposeTo evaluate the diagnostic performance and generalizability of the winning DL algorithm of the RSNA 2020 PE detection challenge to a local population using CTPA data from two hospitals. Materials and MethodsConsecutive CTPA images from patients referred for suspected PE were retrospectively analysed. The winning RSNA 2020 DL algorithm was retrained on the RSNA-STR Pulmonary Embolism CT (RSPECT) dataset. The algorithm was tested in hospital A on multidetector CT (MDCT) images of 238 patients and in hospital B on spectral detector CT (SDCT) and virtual monochromatic images (VMI) of 114 patients. The output of the DL algorithm was compared with a reference standard, which included a consensus reading by at least two experienced cardiothoracic radiologists for both hospitals. Areas under the receiver operating characteristic curve (AUCs) were calculated. Sensitivity and specificity were determined using the maximum Youden index. ResultsAccording to the reference standard, PE was present in 73 patients (30.7%) in hospital A and 33 patients (29.0%) in hospital B. For the DL algorithm the AUC was 0.96 (95% CI 0.92–0.98) in hospital A, 0.89 (95% CI 0.81–0.94) for conventional reconstruction in hospital B and 0.87 (95% CI 0.80–0.93) for VMI. ConclusionThe RSNA 2020 pulmonary embolism detection on CTPA challenge winning DL algorithm, retrained on the RSPECT dataset, showed high diagnostic accuracy on MDCT images. A somewhat lower performance was observed on SDCT images, which suggest additional training on novel CT technology may improve generalizability of this DL algorithm.

Evaluation of Sacrum Measurements in Healthy Individuals and Patients with L5-S1 Spondylolisthesis

Objective: In recent studies, the relationship between sacrum morphology and orientation and spondylolisthesis has gained importance. The present study aimed to compare the morphometry of the sacrum between patients with L5-S1 spondylolisthesis and healthy subjects on multidetector computed tomography (MDCT) images. Methods: In this study, abdominopelvic MDCT images of 191 individuals (age range 20-92 years; 101 males and 90 females; 56 patients diagnosed with L5-S1 spondylolisthesis and 135 healthy individuals) were retrospectively evaluated. In this study, the sacrum parameters (Intercornual distance (ICD), sacral hiatus length (LHS), anteroposterior diameter of hiatus at the apex of sacral hiatus(APCWHSA), sacral height (SH), sacral table angle (STA), sacral table index (STI), S1 superior angle (S1A), sacral slope(SS)) evaluated morphometric and morphological in healthy individuals and patients with L5-S1 spondylolisthesis. Kolmogorov–Smirnov test was used to test the normality, which is one of the parametric test assumptions, of the data. Results: Age parameter was found statistically significant higher in the patient group (p<0.001). STA, S1A, SH, LHS and APCWHSA measurements were found to be significantly higher in the healthy group. (p<0.001, p<0.001, p=.008, p=.005, and p=.002, respectively). STI and ICD were found to be significantly higher in women in the healthy group (p=.031, p=.010), while SH parameter was found statistically significant higher in men in the healthy group (p=.007). SS was found statistically significant lower in the healthy group (p<0.001). S1A, L5-S1 spondylolisthesis was found statistically significant higher than Grade 1, Grade 2 according to the degree of slippage (p=.045). Conclusion: The results of this study showed that sacral morphology is important in the development or at least progression of spondylolisthesis.

Tracheobronchial variations in Pneumoconiosis cases: multidetector computed tomography diagnosis.

Tracheobronchial variations (TBVs) are more common than previously believed due to the increasing use of multi-detector computed tomography (MDCT). This study aimed to assess TBVs in cases of pneumoconiosis, one of the oldest occupational diseases that still poses a threat to public health. This was a descriptive study that involved reviewing chest MDCT images of 34 cases of pneumoconiosis and 34 control cases retrospectively from January 2020 to April 2022. Variations in the trachea, right main bronchus, left main bronchus, lobar and segmental branches of the cases in the patient and control groups were evaluated according to Boyden's nomenclature. The frequency of TBV was 32.4% in pneumoconiosis cases. Although the frequency of TBV was higher in the patient group than in the control group, the difference was not statistically significant (p=0.086). Furthermore, there was no significant difference in terms of TBV classification between the patient and control groups (p=0.407). Additionally, the presence of TBV did not affect the distribution of International Labour Organization categories in pneumoconiosis cases (p=0.360). Although our study provides initial insights into the occurrence of TBVs in pneumoconiosis cases, further research is needed to clarify the relationship between these variations and the disease.

Radiomics nomogram for preoperative differentiation of early-stage serous borderline ovarian tumors and serous malignant ovarian tumors.

This study aimed to construct a radiomics nomogram and validate its performance in the preoperative differentiation between early-stage (I and II) serous borderline ovarian tumors (SBOTs) and serous malignant ovarian tumors (SMOTs). Data were collected from 80 patients with early-stage SBOTs and 102 with early-stage SMOTs (training set: n = 127; validation set: n = 55). Univariate and multivariate analyses were performed to identify the independent clinicoradiological factors. A radiomics signature model was constructed using radiomics features extracted from multidetector computed tomography images of the venous phase, in which the least absolute shrinkage and selection operator regression was employed to lessen the dimensionality of the data and choose the radiomics features. A nomogram model was established by combining independent clinicoradiological factors with the radiomics signature. The performance of nomogram calibration, discrimination, and clinical usefulness was evaluated using training and validation sets. In terms of clinicoradiological characteristics, age (p = 0.001), the diameter of the solid component (p = 0.009), and human epididymis protein 4 level (p < 0.001) were identified as the independent risk factors of SMOT, for which the area under the curves (AUCs) were calculated to be 0.850 and 0.836 in the training and validation sets, respectively. Nine features were finally selected to construct the radiomics signature model, which exhibited AUCs of 0.879 and 0.826 for the training and validation sets, respectively. The nomogram model demonstrated considerable calibration and discrimination with AUCs of 0.940 and 0.909 for the training and validation sets, respectively. The nomogram model displayed more prominent clinical usefulness than the clinicoradiological and radiomics signature models according to the decision curve analysis. The nomogram model can be employed as an individualized preoperative non-invasive tool for differentiating early-stage SBOTs from SMOTs.

Visualization of anatomical structures in the fetlock region of the horse using cone beam computed tomography in comparison with conventional multidetector computed tomography.

Cone-beam computed tomography (CBCT) is regarded as a convenient and suitable alternative to conventional computed tomography. However, in the horse, the quality of obtained data sets needs to be evaluated. Therefore, the aim of this study was to compare the visibility and accessibility of clinically relevant anatomical structures displayed in CBCT and conventional multidetector computed tomography (MDCT). Twenty-nine limbs from horses euthanized for reasons unrelated to this study were used. Native and intraarticular contrast scans of the fetlock (CBCT vs. MDCT) were performed. The visibility and accessibility of selected anatomical structures were blindly scored by three independent experienced observers using a scoring system previously reported and adapted to the fetlock joint. Only minor differences between CBCT and MDCT were identified concerning the diagnostic quality of images for osseous structures. Soft tissue structures were better evaluated on MDCT images. In CBCT as well as in MDCT articular cartilage could only be visualized after intraarticular injection of contrast medium. Cone beam computed tomography of the fetlock is a useful and reliable diagnostic tool when evaluating osseous structures and delineating articular cartilage with contrast medium. However, this modality is limited for assessing soft tissues structures.

Deep learning in computed tomography super resolution using multi-modality data training.

One of the limitations in leveraging the potential of artificial intelligence in X-ray imaging is the limited availability of annotated training data. As X-ray and CT shares similar imaging physics, one could achieve cross-domain data sharing, so to generate labeled synthetic X-ray images from annotated CT volumes as digitally reconstructed radiographs (DRRs). To account for the lower resolution of CT and the CT-generated DRRs as compared to the real X-ray images, we propose the use of super-resolution (SR) techniques to enhance the CT resolution before DRRgeneration. As spatial resolution can be defined by the modulation transfer function kernel in CT physics, we propose to train a SR network using paired low-resolution (LR) and high-resolution (HR) images by varying the kernel's shape and cutoff frequency. This is different to previous deep learning-based SR techniques on RGB and medical images which focused on refining the sampling grid. Instead of generating LR images by bicubic interpolation, we aim to create realistic multi-detector CT (MDCT) like LR images from HR cone-beam CT (CBCT)scans. We propose and evaluate the use of a SR U-Net for the mapping between LR and HR CBCT image slices. We reconstructed paired LR and HR training volumes from the same CT scans with small in-plane sampling grid size of . We used the residual U-Net architecture to train two models. SRUN : trained with kernel-based LR images, and SRUN : trained with bicubic downsampled data as baseline. Both models are trained on one CBCT dataset (n = 13 391). The performance of both models was then evaluated on unseen kernel-based and interpolation-based LR CBCT images (n = 10 950), and also on MDCT images (n = 1392). Five-fold cross validation and ablation study were performed to find the optimal hyperparameters. Both SRUN and SRUN models show significant improvements (p-value 0.05) in mean absolute error (MAE), peak signal-to-noise ratio (PSNR) and structural similarity index measures (SSIMs) on unseen CBCT images. Also, the improvement percentages in MAE, PSNR, and SSIM by SRUN is larger than SRUN . For SRUN , MAE is reduced by 14%, and PSNR and SSIMs increased by 6 and 8%, respectively. To conclude, SRUN outperforms SRUN , which the former generates sharper images when tested with kernel-based LR CBCT images as well as cross-modality LR MDCTdata. Our proposed method showed better performance than the baseline interpolation approach on unseen LR CBCT. We showed that the frequency behavior of the used data is important for learning the SR features. Additionally, we showed cross-modality resolution improvements to LR MDCT images. Our approach is, therefore, a first and essential step in enabling realistic high spatial resolution CT-generated DRRs for deep learningtraining.

Comparison of the Effective Radiation Dose in the Region of the Facial Skull Between Multidetector CT, Dental Conebeam CT and Intraoperative 3D C-Arms

Study Design Experimental single-centre study of X-ray absorption using a phantom skull. Objective This experimental study aimed to compare the radiation doses of different 3D imaging devices used in maxillofacial surgery, including one Multidetector CT (MDCT), two Conebeam CT (CBCT) and four intraoperative 3D C-arms. Methods Thermoluminescent dosimeters (TLD) were used to determine the absorbed radiation in an Alderson-Rando phantom skull. The phantom skull was positioned in the before mentioned seven devices and a defined 3D facial skull image was acquired. Subsequently, the TLD’S were read out and the effective doses (ED) and the organ doses (OD) were calculated and compared. Results OD varied significantly between tissues as well as between the 3D X-ray devices. The OD of the 3D C-arms were significantly lower than those of all other devices. The OD of the CT, especially in the standard setting, was the highest. Only by special adjustments of the scan protocol regarding CMF requirements for traumatology, the MDCT could achieve almost equivalent doses as the two tested CBCT-scanners. The calculated effective doses were also lowest for the 3D C-arm devices (11.2 to 129.9 μSv). The ED of the MDCT were significant higher (284.52–844.97 μSv) than in all other devices. The ED of the CBCTs (173.7–184.9) were lower than for MDCT but still higher than those of the 3D C-arms. Conclusions Intraoperative imaging using 3D C-arm devices is an effective method to verify reduction results in maxillofacial surgery intraoperatively with significantly lower ED than postoperatively CBCT and MDCT imaging.

Spectrum of Multidetector Computed Tomography Imaging Findings in Iatrogenic Abdominopelvic Injuries: A Comprehensive Pictorial Review.

Iatrogenic injuries are unavoidable complications of surgeries and minimally invasive procedures. They are generally classified into vascular and nonvascular injuries and based on the time of injury into early and late injuries. Iatrogenic injuries, particularly vascular injuries, increase the mortality and morbidity, with prolongation of hospital-stay. Multidetector computed tomography (MDCT) is a highly sensitive, and often the first imaging modality in suspected iatrogenic injuries. This pictorial review elucidates the imaging considerations and appearances of iatrogenic injuries of the abdominopelvic organs on MDCT.

Quantitative Assessment of the Pharyngeal Recess Morphometry in Anatolian Population Using 3D Models Generated from Multidetector Computed Tomography Images

Aim: It was aimed to analyze the detailed morphometry of the pharyngeal recess (PR) using three-dimensional (3D) models reconstructed from multidetector computed tomography (MDCT) images.&#x0D; Material and Methods: This study was a retrospective analysis and performed on MDCT images of 97 patients (43 males, 54 females). 3D models of the PR were reconstructed using 3D Slicer software, enabling morphometric measurements according to established protocols. Measurements included PR depths, distances between the posterior nasal spine and torus levatorius (PNS-TL), distances between right and left TL (RTL-LTL) distances between the PNS and posterior wall of the nasopharynx (PNS-PWN), the angle (α) between the centerline of the PR and the sagittal plane. The morphologies of the PR classified into three types.&#x0D; Results: The average measurements for the parameters were as follows: PR depth - 10.42 mm, distance between PNS and TL - 10.40 mm, distance between RTL and LTL - 19.13 mm, distance between PNS and PWN - 19.92 mm, and the angle (α) - 53.65°. The prevalence of PR types was 20.62%, 47.42% and 31.96% for type 1, type 2 and type 3, respectively.&#x0D; Conclusion: Variations in reported measurements of the pharyngeal recess can be attributed to imaging techniques, patient positioning, anatomical differences, and sample sizes. The use of 3D models generated from MDCT datasets offers a high-resolution and comprehensive approach to understanding the PR's morphometry and spatial relationships, enabling accurate measurements and advancing our knowledge of this anatomical region.

Three-Dimensional (3D) Analysis of Orbital Morphometry in Healthy Anatolian Adults: Sex, Side Discrepancies, and Clinical Relevance.

Background and objective The complex structural integrity of the orbit is crucial for visual functions. Three-dimensional (3D) reconstructions from radiological images have revolutionized anatomical understanding, eliminating the limitations of two-dimensional (2D) imaging and offering intricate spatial details for complex structures. The aim of this study was to analyze the detailed morphometry of the orbit in healthy Anatolian adults, considering sex, side discrepancies, and clinical relevance using 3D models reconstructed from multidetector computed tomography (MDCT) images. Materials and methods Fifty-six (44.44%) males and 70 (55.56%) females (total: 126, mean age: 48.62) MDCT images were randomly selected and 3D skull models were reconstructed using 3D Slicer software. Measurements were conducted in millimeters (mm) for transverse and vertical diameters, circumference of the orbital opening, orbital wall lengths, as well as intraorbital and extraorbital distances. Results The method of measurements showed high reproducibility of results. The mean values for transverse and vertical diameters, circumference of the orbital opening, medial and lateral wall lengths, roof and floor lengths, and intraorbital and extraorbital distances were 40.23±2.12 mm (p<0.001), 34.94±2.16 mm (p=0.365), 44.74 ±3.02 mm (p<0.001), 46.30±2.69 mm (p<0.001), 51.26±2.91 mm (p<0.001), 49.01±3.22 mm (p<0.001), 126.10±5.71 mm (p<0.001), 19.63±2.35 mm (p=0.026), and 94.09±4.84 mm (p<0.001), respectively. Conclusion The study's high measurement reproducibility contributes significantly to the existing literature and clinical practice. These findings offer specific insights into Anatolian orbital morphometry, aiding in surgical planning, implant placement, and diagnostic assessments. The precise measurement values serve as a reliable reference for clinicians, facilitating the identification of normal and abnormal orbital anatomy and enhancing patient care. We believe this study provides valuable data for craniofacial and ophthalmological research, benefiting both clinical practice and future research endeavors in these fields.

A quantitative CBCT pipeline based on 2D antiscatter grid and grid-based scatter sampling for image-guided radiation therapy.

Quantitative accuracy is critical for expanding the role of cone beam CT (CBCT) imaging from target localization to quantitative treatment monitoring and plan adaptations in radiation therapy. Despite advances in CBCT image quality improvement methods, quantitative accuracy gap between CBCT and multi-detector CT (MDCT) remains. In this work, a physics-driven approach was investigated that combined robust scatter rejection, raw data correction and iterative image reconstruction to further improve CBCT image quality and quantitative accuracy, referred to as quantitative CBCT (qCBCT). QCBCT approach includes tungsten 2D antiscatter grid hardware, residual scatter correction with grid-based scatter sampling, image lag, and beam hardening correction for offset detector geometry linac-mounted CBCT. Images were reconstructed with iterative image reconstruction to reduce image noise. qCBCT was evaluated using a variety of phantoms to investigate the effect of object size and its composition on image quality, and image quality was benchmarked against clinical CBCT and gold standard MDCT images used for treatment planning. QCBCT provided statistically significant improvement in CT number accuracy and reduced image artifacts when compared to clinical CBCT images. When compared to gold standard MDCT, mean HU errors in qCBCT and clinical CBCT were 17±9 and 38±29 HU, respectively. Magnitude of phantom size dependent HU variations were comparable between MDCT and qCBCT images. With iterative reconstruction, contrast-to-noise ratio improved by 25% when compared to clinical CBCT protocols. Combination of novel scatter suppression techniques and other data correction methods in qCBCT provided CT number accuracy comparable to gold standard MDCT used for treatment planning. This approach may potentially improve CBCT's promise in fulfilling the tasks that demand high quantitative accuracy, such as online dose calculations and treatment response assessment, in image guided radiation therapy.

Grading Abdominal Trauma: Changes in and Implications of the Revised 2018 AAST-OIS for the Spleen, Liver, and Kidney.

According to the Centers for Disease Control and Prevention, trauma is the leading cause of fatal injuries for Americans aged 1-44 years old and the fourth leading overall cause of death. Accurate and early diagnosis, including grading of solid organ injuries after blunt abdominal trauma (BAT), is crucial to guide management and improve outcomes. The American Association for the Surgery of Trauma (AAST) Organ Injury Scale (OIS) is the most widely accepted BAT scoring system at CT both within the United States and internationally, and its uses include stratification of injury severity, thereby guiding management, and facilitation of clinical research, billing, and coding. Furthermore, this system also plays a role in the credentialing process for trauma centers in the United States. The newly revised 2018 OIS provides criteria for grading solid organ damage into three groups: imaging, operation, and pathology. The final grade is based on the highest of the three criteria. If multiple lower-grade (I or II) injuries are present in a single organ, one grade is advanced to grade III. The most substantial change in the revised 2018 AAST-OIS is incorporation of multidetector CT findings of vascular injury, including pseudoaneurysm and arteriovenous fistula. The authors outline the main revised aspects of grading organ injury using the AAST-OIS for the spleen, liver, and kidney after BAT, particularly the role of multidetector CT and alternative imaging in organ injury detection, the importance of vascular injuries in grade change, and the impact of these changes on patient management and in prediction of operative treatment success and in-hospital mortality. ©RSNA, 2023 Supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. Quiz questions for this article are available through the Online Learning Center.

Evaluation of Soft-Tissue Hematomas With Real-Time, Contrast-Enhanced Ultrasound: A Pilot Study With Preliminary Findings.

In this study, we investigated the feasibility of using contrast-enhanced ultrasound (CEUS) to detect active hemorrhage in patients presenting with soft-tissue hematomas. Adult patients with clinically suspected, actively bleeding hematomas were prospectively enrolled. Contrast-enhanced ultrasound was used to assess for contrast extravasation. Ultrasound results were compared with those of multidetector computed tomographic (MDCT) imaging, operative findings, and clinical course. Sixteen patients (9 women, 7 men; mean age, 69 [SD, 13] years) were enrolled. Thirteen patients underwent MDCT imaging during their initial visit, and for 11, CEUS and computed tomography (CT) findings were concordant. The remaining patients had a negative CEUS study that was consistent with their clinical course. In 8 patients, CT imaging showed active extravasation (6 arterial, 1 indeterminate, 1 slow venous). Contrast-enhanced ultrasound and CT findings were concordant for all cases of arterial bleeding. For 1 patient, CEUS provided superior diagnostic information by identifying a pseudoaneurysm. The 2 discrepant patient cases had a ≥3-hour delay between CT and CEUS, and in 1 patient, CEUS was limited by body habitus. The second patient had no active bleeding identified in the operating room. Compared with CT, CEUS had a sensitivity and specificity of 75% and 100%, respectively, and positive and negative predictive values were 100% and 71%, respectively. Diagnostic accuracy was 85% in this limited study. Contrast-enhanced ultrasound is a promising alternative to MDCT in select patients and may sometimes provide superior clinical information. Limiting factors are large hematoma size, unfavorable anatomic location, and body habitus.

Image Quality and Radiation Dose of Conventional and Wide-Field High-Resolution Cone-Beam Computed Tomography for Cerebral Angiography: A Phantom Study.

There has been an increase in the use of interventional neuroradiology procedures because of their non-invasiveness compared to surgeries and the improved image quality of fluoroscopy, digital subtraction angiography, and rotational angiography. Although cone-beam computed tomography (CBCT) images are inferior to multi-detector CT images in terms of low-contrast detectability and lower radiation doses, CBCT scans are frequently performed because of their accessibility. This study aimed to evaluate the image quality and radiation dose of two different high-resolution CBCTs (HR CBCT): conventional (C-HR CBCT) and wide-field HR CBCT (W-HR CBCT). The modulation transfer function (MTF), noise power spectrum (NPS), and contrast-to-noise ratio (CNR) were used to evaluate the image quality. On comparing the MTF of C-HR CBCT with a 256 × 256 matrix and that of W-HR CBCT with a 384 × 384 matrix, the MTF of W-HR CBCT with the 384 × 384 matrix was larger. A comparison of the NPS and CNR of C-HR CBCT with a 256 × 256 matrix and W-HR CBCT with a 384 × 384 matrix showed that both values were comparable. The reference air kerma values were equal for C-HR CBCT and W-HR CBCT; however, the value of the kerma area product was 1.44 times higher for W-HR CBCT compared to C-HR CBCT. The W-HR CBCT allowed for improved spatial resolution while maintaining the image noise and low-contrast detectability by changing the number of image matrices from 256 × 256 to 384 × 384. Our study revealed the image characteristics and radiation dose of W-HR CBCT. Given its advantages of low-contrast detectability and wide-area imaging with high spatial resolution, W-HR CBCT may be useful in interventional neuroradiology for acute ischemic stroke.

Multidetector CT Imaging Biomarkers as Predictors of Prognosis in Shock: Updates and Future Directions.

A severe mismatch between the supply and demand of oxygen is the common sequela of all types of shock, which present a mortality of up to 80%. Various organs play a protective role in shock and contribute to whole-body homeostasis. The ever-increasing number of multidetector CT examinations in severely ill and sometimes unstable patients leads to more frequently encountered findings leading to imminent death, together called "hypovolemic shock complex". Features on CT include dense opacification of the right heart and major systemic veins, venous layering of contrast material and blood, densely opacified parenchyma in the right hepatic lobe, decreased enhancement of the abdominal organ, a dense pulmonary artery, contrast pooling in dependent lungs, and contrast stasis in pulmonary veins. These findings are biomarkers and prognostic indicators of paramount importance which stratify risk and improve patient outcomes. In this review, we illustrate the various CT patterns in shock and review the spectrum and prognostic significance of thoraco-abdominal vascular and visceral alarming signs of impending death with the intention of increasing awareness among radiologists and radiographers to prepare for immediate resuscitation when required.

Exploring the Possibility of Measuring Vertebrae Bone Structure Metrics Using MDCT Images: An Unpaired Image-to-Image Translation Method

Bone structure metrics are vital for the evaluation of vertebral bone strength. However, the gold standard for measuring bone structure metrics, micro-Computed Tomography (micro-CT), cannot be used in vivo, which hinders the early diagnosis of fragility fractures. This paper used an unpaired image-to-image translation method to capture the mapping between clinical multidetector computed tomography (MDCT) and micro-CT images and then generated micro-CT-like images to measure bone structure metrics. MDCT and micro-CT images were scanned from 75 human lumbar spine specimens and formed training and testing sets. The generator in the model focused on learning both the structure and detailed pattern of bone trabeculae and generating micro-CT-like images, and the discriminator determined whether the generated images were micro-CT images or not. Based on similarity metrics (i.e., SSIM and FID) and bone structure metrics (i.e., bone volume fraction, trabecular separation and trabecular thickness), a set of comparisons were performed. The results show that the proposed method can perform better in terms of both similarity metrics and bone structure metrics and the improvement is statistically significant. In particular, we compared the proposed method with the paired image-to-image method and analyzed the pros and cons of the method used.

Measurement of oesophageal hiatus surface area by multiplanar reconstruction of MDCT: relationship with lower oesophageal sphincter pressure and acid reflux

To evaluate the relationship between oesophageal hiatus surface area (OHSA) and gastro-oesophageal reflux disease (GERD). Patients who underwent 24-h pH monitoring, oesophageal high-resolution manometry, and upper abdominal contrast-enhanced multidetector computed tomography (MDCT) during 2014-2021 were enrolled. Patients with a hiatus hernia (HH) on MDCT or who had a history of gastro-oesophageal surgery were excluded. Multiplanar reconstruction (MPR) of the MDCT image was used for the measurement of OHSA. Correlations of OHSA with acid exposure time (AET) and lower oesophageal sphincter (LOS) pressure of all patients were analysed. Seventy-eight patients were included in the study. OHSA was much less in the AET <4% group than in the AET >6% group (1.61±0.42 versus 2.09±0.55 cm2, p<0.001). Correlation analysis reveals that OHSA correlated positively with AET (correlation coefficient=0.47, p<0.001). Receiver operating characteristic (ROC) curve analysis reveals that OHSA can significantly distinguish patients in different groups divided by AET (area under the ROC curve [AUC]=0.76, 95% confidence interval [CI]: 0.63-0.90). OHSA was not related to LOS pressure (correlation coefficient=-0.268, p=0.051). There was no difference in OHSA between the low LOS pressure group and the normal LOS pressure group (1.84±0.61 versus 1.74±0.50 cm2, p=0.52). OHSA significantly correlated with AET but has no relationship with LOS pressure. It may be an independent risk factor of GERD.

Children’s interstitial lung disease: Multidetector computed tomography patterns and correlations between imaging and histopathology

PurposeChildhood interstitial lung disease (chILD) is an umbrella concept covering a wide range of rare lung diseases, many of which are unique to childhood. The diagnosis is based on clinical presentation, multidetector computed tomography (MDCT), genetic testing, lung-function testing, and lung biopsy. Because knowledge of the usefulness of MDCT pattern recognition in ChILD is at present limited, we examined the occurrence of MDCT patterns in children with histologically confirmed interstitial lung disease. MethodWe searched the biopsy, MDCT, and clinical information database of a single national paediatric referral hospital for 2004–2020. Data were from affected children under age 18. MDCT images we reanalysed while blinded to the identity and referral information. ResultsWe included 90 patients, of whom 63 (70 %) were male. The median age at biopsy was 1.3 years (interquartile range 0.1–16.8). Biopsy findings fell into 26 histological classes covering all nine chILD classification categories. We recognized six distinct MDCT patterns: neuroendocrine cell hyperplasia of infancy (23), organizing pneumonia (5), non-specific interstitial pneumonia (4), bronchiolitis obliterans (3), pulmonary alveolar proteinosis (2), and bronchopulmonary dysplasia (n = 2). Of the total 90, in 51 (57 %) children, none of these six MDCT patterns appeared. Of those 39 children with a recognizable MDCT pattern, in 34 (87 %), that pattern predicted their final diagnosis. ConclusionsAmong cases of chILD, we identified a specific predefined MDCT pattern in only 43 %. However, when such a recognizable pattern occurred, it was predictive of the final chILD diagnosis.