Improved Coronary Artery Visualization Using Virtual Monoenergetic Imaging from Dual-Layer Spectral Detector CT Angiography

Background: To evaluate if coronary CT angiography (CCTA) monoenergetic reconstructions, obtained with a dual-layer spectral detector computed tomography (DLCT) system, offer improved image quality compared with 120 kVp conventional images without affecting the quantitative assessment of coronary stenoses. Methods: Fifty CCTA datasets (30 men; mean age: 61.6 ± 12.3 years) acquired with a DLCT system were reconstructed using virtual monoenergetic images (VMI) from 40 to 100 keV with 10 keV increment and compared with conventional images. An analysis of objective image quality was performed, evaluating the signal- and contrast-to-noise ratio. For the subjective assessment, two readers used a 5-point Likert scoring system to evaluate sharpness, noise, demarcation of coronary plaques, vascular contrast, and an overall score. Furthermore, coronary stenoses were analyzed for each vessel to describe the diagnostic agreement between monoenergetic images and conventional images. Results: The objective image analysis showed that all reconstructions from 70 keV to 40 keV show higher SNR (from 61.33 ± 12.46 to 154.22 ± 42.91, respectively) and CNR (from 51.45 ± 11.19 to 135.63 ± 39.38, respectively) compared with conventional images (all p < 0.001). The 40 keV monoenergetic images obtained the best average score for sharpness, vascular contrast, and for the overall impression (all with p < 0.001). The detection and grading of stenoses of the coronary arteries with conventional and monoenergetic images at 70 keV and 40 keV showed an overall excellent interobserver agreement (k= 0.81 [0.72-0.91]). Conclusions: The 40 keV virtual monoenergetic images obtained with a DLCT system allow the objective and subjective image quality of coronary CT angiography to be improved.

Magnetic Resonance (MR) Cholangiopancreatography Demonstration of the Cystic Duct Entering the Right Hepatic Duct

Patient: Female, 51

Final Diagnosis: Cystic duct draining into the right hepatic biliary duct

Symptoms: Recurrent abdominal pain

Medication: —

Clinical Procedure: MR-cholangiopancreatography

Specialty: Radiology

Virtual endoscopy of the nasopharynx in the evaluation of its normal anatomy and alterations due to lymphoid hyperplasia: preliminary report

The purpose of this study was to evaluate the diagnostic usefulness of virtual endoscopy in establishing the anatomic appearance of nasopharynx, both normal and affected by lymphoid hyperplasia. Thirty-seven patients affected by chronic rhinosinusal and otomastoid pathology, all studied by rhinoscopy, were examined with multislice computed tomography (CT) and virtual endoscopy of the nasopharynx. Rhinoscopy showed a completely normal nasopharynx in 15 cases and a variable grade of lymphoid hypertrophy in 22 patients. A general agreement was observed between traditional and virtual endoscopy findings in both subgroups. The tasca of Luschka was detected in 13/15 of normal subjects and only in 3/22 patients. The Rosenmuller fossae appeared deeper in normal subjects and their symmetry could be considered an important criterion of normality. In all cases, a good evaluation of the tubaric ostium was obtained. Differentiation between hyperplasic lymphoid tissue and neoplasms is possible only in lymphoid hyperplasia characterized by median crest-like swelling with a narrow base. In most cases, differential diagnosis cannot be based only on morphological criteria of virtual endoscopy, but it should be evaluated considering the overall CT findings and clinical presentation.

Magnetic Resonance Imaging of the Anal Region: Clinical Applications

Over the past years, magnetic resonance imaging (MRI) has become a cornerstone in evaluating anal canal and adjacent tissues due to its safeness, the three-dimensional and comprehensive approach, and the high soft-tissue resolution. Several diseases arising in the anal canal can be assessed through MRI performance, including congenital conditions, benign pathologies, and malignancies. Good knowledge of the normal anatomy and MRI technical protocols is, therefore, mandatory for appropriate anal pathology evaluation. Radiologists and clinicians should be familiar with the different clinical scenarios and the anatomy of the structures involved. This pictorial review presents an overview of the diseases affecting the anal canal and the surrounding structures evaluated with dedicated MRI protocol.

Spectral CT Imaging of Prosthetic Valve Embolization after Transcatheter Aortic Valve Implantation

Transcatheter heart valve (THV) embolization is a rare complication of transcatheter aortic valve implantation (TAVI) generally caused by malpositioning, sizing inaccuracies and pacing failures. The consequences are related to the site of embolization, ranging from a silent clinical picture when the device is stably anchored in the descending aorta to potentially fatal outcomes (e.g., obstruction of flow to vital organs, aortic dissection, thrombosis, etc.). Here, we present the case of a 65-year-old severely obese woman affected by severe aortic valve stenosis who underwent TAVI complicated by embolization of the device. The patient underwent spectral CT angiography that allowed for improved image quality by means of virtual monoenergetic reconstructions, permitting optimal pre-procedural planning. She was successfully re-treated with implantation of a second prosthetic valve a few weeks later.

A Rare Variant of Hypogenetic Lung Syndrome Mimicking Scimitar Vein

Hypogenetic lung syndrome, also known as scimitar syndrome, is a rare and well-known congenital condition that includes hypoplastic right pulmonary artery and lung, right displacement of the heart, anomalous systemic arterial supply to the lung, and a characteristically curved anomalous right pulmonary vein draining into the inferior vena cava. In exceptional cases, the anomalous pulmonary vein may drain into left atrium. We here report a case of a 17-year-old girl with a rare variant of hypogenetic lung syndrome diagnosed by means of multimodality imaging and treated with percutaneous occlusion of the aortopulmonary collateral.

Separate pancreatic ducts draining into a type IV choledochal cyst: simultaneous anatomical variants in a child suffering from cholelithiasis and acute pancreatitis

The biliary tree and the pancreatic ducts originate from different buds of the primitive foregut. A plethora of anatomical variants and congenital anomalies have been described for both the biliary and the pancreatic duct systems, although they are usually asymptomatic. However, in some cases, these abnormalities can lead to serious clinical scenarios, especially when involving the biliopancreatic junction, with consequent mixing and reflux of the two different juices. To the best of our knowledge, we present the first case of pancreas divisum ducts draining into a choledochal cyst, with the lower third of the choledochus configuring a common biliopancreatic duct, in a child suffering from cholelithiasis and acute pancreatitis.

Lipomatosis of the ileocecal valve: A not to miss diagnosis when performing magnetic resonance enterography

Lipomatosis of ileocecal valve is a rare condition that can be missed using the standard protocol of Magnetic Resonance Enterography. Additional T1-weighted scans without fat saturation can be helpful when adipose lesions of the bowel are suspected.

Facial abnormalities in Nablus mask-like facial syndrome: multidetector computed tomography findings

Nablus mask-like facial syndrome (NMLFS) is a rare microdeletion syndrome characterized by a mask-like facial appearance. NMLFS has been reported in only 6 patients and has a recognizable facial appearance, along with other clinical features. The first case of NMLFS has been described by Teebi in 2000, in a 4-year-old Palestinian boy. Three years later, Salpietro et al reported a second example of NMLFS in a 21-month-old girl. The same patient recently came to our hospital to undergo a computed tomography (CT) study to evaluate the degree of development of the zygomatic-maxillary region for orthodontic treatment and orthognathic surgery. To the best of our knowledge, no reports have previously illustrated the maxillofacial CT findings of NMLFS in the radiologic data. We report the multidetector CT (MDCT) facial characteristics/abnormalities of this syndrome, emphasizing the usefulness of multiplanar reformations (MPRs) in preoperative planning.

Carotid artery assessment in dual-source photon-counting CT: impact of low-energy virtual monoenergetic imaging on image quality, vascular contrast and diagnostic assessability

PURPOSE

Preliminary dual-energy CT studies have shown that low-energy virtual monoenergetic (VMI) + reconstructions can provide superior image quality compared to standard 120 kV CTA series. The purpose of this study is to evaluate the impact of low-energy VMI reconstructions on quantitative and qualitative image quality, vascular contrast, and diagnostic assessability of the carotid artery in patients undergoing photon-counting CTA examinations.

MATERIALS AND METHODS

A total of 122 patients (67 male) who had undergone dual-source photon-counting CTA scans of the carotid artery were retrospectively analyzed in this study. Standard 120 kV CT images and low-keV VMI series from 40 to 100 keV with an interval of 15 keV were reconstructed. Quantitative analyses included the evaluation of vascular CT numbers, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). CT number measurements were performed in the common, external, and internal carotid arteries. Qualitative analyses were performed by three board-certified radiologists independently using five-point scales to evaluate image quality, vascular contrast, and diagnostic assessability of the carotid artery.

RESULTS

Mean attenuation, CNR and SNR values were highest in 40 keV VMI reconstructions (HU, 1362.32 ± 457.81; CNR, 33.19 ± 12.86; SNR, 34.37 ± 12.89) followed by 55-keV VMI reconstructions (HU, 736.94 ± 150.09; CNR, 24.49 ± 7.11; SNR, 26.25 ± 7.34); all three mean values at these keV levels were significantly higher compared with the remaining VMI series and standard 120 kV CT series (HU, 154.43 ± 23.69; CNR, 16.34 ± 5.47; SNR, 24.44 ± 7.14) (p < 0.0001). The qualitative analysis showed the highest rating scores for 55 keV VMI reconstructions followed by 40 keV and 70 keV VMI series with a significant difference compared to standard 120 kV CT images series regarding image quality, vascular contrast, and diagnostic assessability of the carotid artery (all comparisons, p < 0.01).

CONCLUSIONS

Low-keV VMI reconstructions at a level of 40-55 keV significantly improve image quality, vascular contrast, and the diagnostic assessability of the carotid artery compared with standard CT series in photon-counting CTA.

Accuracy and time efficiency of a novel deep learning algorithm for Intracranial Hemorrhage detection in CT Scans

PURPOSE

To evaluate a deep learning-based pipeline using a Dense-UNet architecture for the assessment of acute intracranial hemorrhage (ICH) on non-contrast computed tomography (NCCT) head scans after traumatic brain injury (TBI).

MATERIALS AND METHODS

This retrospective study was conducted using a prototype algorithm that evaluated 502 NCCT head scans with ICH in context of TBI. Four board-certified radiologists evaluated in consensus the CT scans to establish the standard of reference for hemorrhage presence and type of ICH. Consequently, all CT scans were independently analyzed by the algorithm and a board-certified radiologist to assess the presence and type of ICH. Additionally, the time to diagnosis was measured for both methods.

RESULTS

A total of 405/502 patients presented ICH classified in the following types: intraparenchymal (n = 172); intraventricular (n = 26); subarachnoid (n = 163); subdural (n = 178); and epidural (n = 15). The algorithm showed high diagnostic accuracy (91.24%) for the assessment of ICH with a sensitivity of 90.37% and specificity of 94.85%. To distinguish the different ICH types, the algorithm had a sensitivity of 93.47% and a specificity of 99.79%, with an accuracy of 98.54%. To detect midline shift, the algorithm had a sensitivity of 100%. In terms of processing time, the algorithm was significantly faster compared to the radiologist's time to first diagnosis (15.37 ± 1.85 vs 277 ± 14 s, p < 0.001).

CONCLUSION

A novel deep learning algorithm can provide high diagnostic accuracy for the identification and classification of ICH from unenhanced CT scans, combined with short processing times. This has the potential to assist and improve radiologists' ICH assessment in NCCT scans, especially in emergency scenarios, when time efficiency is needed.

Overview of the Large Bowel Assessment Using Magnetic Resonance Imaging: Different Techniques for Current and Emerging Clinical Applications

Radiological assessments of the small and large bowel are essential in daily clinical practice. Over plain film X-ray and ultrasound, cross-sectional techniques are considered the most comprehensive imaging modalities. In fact, computed tomography and magnetic resonance imaging take great advantage of the three-dimensional appraisal and the extensive evaluation of the abdominal cavity, allowing intestinal evaluation as well as detection of extra-intestinal findings. In this context, the chief advantage of computed tomography is the fast scan time, which is crucial for emergency cases. Nonetheless, it is undeniably impaired using ionizing radiation. As the awareness of radiation exposure is a topic of increasing importance, magnetic resonance imaging is not only becoming a mere alternative but also a primary imaging technique used in assessing intestinal diseases. Specifically, the evaluation of the large bowel through MRI can be still considered relatively uncharted territory. Although it has demonstrated superior accuracy in the assessment of some clinical entities from inflammatory bowel disease to rectal carcinoma, its role needs to be consolidated in many other conditions. Moreover, different technical methods can be applied for colonic evaluation depending on the specific disease and segment involved. This article aims to provide a thorough overview of the techniques that can be utilized in the evaluation of the large bowel and a discussion on the major findings in different colonic pathologies of primary interest.

DWI ratios: New indexes for Crohn's disease activity at magnetic resonance enterography?

BACKGROUND

The aim of the study was to provide radiologists and clinicians a rapid tool for assessment of intestinal inflammation in Crohn's disease (CD) patients through quantification of diffusion-weighted imaging (DWI) signal intensity while performing magnetic resonance enterography (MRE).

MATERIALS AND METHODS

A monocentric retrospective study was conducted between September 2018 and July 2021 on CD patients who underwent MRE. Two radiologists measured signal intensity on DWI scans at the highest b-value (800 s/mm²) within pathologic intestinal walls, lymph nodes, spleen and psoas muscle and calculated the relative ratios. Spearman, Mann-Whitney and Jonckheere-Terpstra tests were applied for estimating correlation among ratios, significant differences between the two patient groups and determining the trend in relation to endoscopic classes. Wilcoxon's and Cronbach's alpha tests were employed for comparison of DWI measurements and ratios between the two observers.

RESULTS

Fifty-nine patients were enrolled in the study. In the non-surgical group, correlation has been found among Simple Endoscopic Score for Crohn's Disease (SES-CD) classes and the different ratios: bowel/spleen (p = 0.034), bowel/psoas (p = 0.008) and bowel/lymph node (p = 0.010). Within the surgical group, positive correlation was found only between bowel/lymph node ratio and bowel/psoas ratio (p = 0.014). The J-T test demonstrated an increasing monotonic trend for bowel/psoas ratio and bowel/lymph node ratio and SES-CD classes. Inter-reader evaluation demonstrated no statistical differences for DWI measurements and high degree of concordance for the final ratios.

CONCLUSION

DWI ratios correlate with endoscopic classes in non-surgical patients and have inter-observer reproducibility.

Dual-energy CT late arterial phase iodine maps for the diagnosis of acute non-occlusive mesenteric ischemia

PURPOSE

To evaluate the diagnostic accuracy of dual-energy CT (DECT) iodine maps in comparison to conventional CT series for the assessment of non-occlusive mesenteric ischemia (NOMI).

MATERIAL AND METHODS

We evaluated data from 142 patients (72 men; 50.7%) who underwent DECT between 2018 and 2022, with surgically confirmed diagnosis of NOMI. One board-certified radiologist performed region of interest (ROI) measurements in bowel segments on late arterial (LA) and portal venous (PV) phase DECT iodine maps as well as LA conventional series, in both ischemic and non-ischemic bowel loops, using surgical reports as reference standard, and in a control group of 97 patients. Intra- and inter-reader agreement with a second board-certified radiologist was also evaluated. Receiver operating characteristic (ROC) curve analysis was performed to calculate the optimal threshold for discriminating ischemic from non-ischemic bowel segments. Subjective image rating of LA and PV iodine maps was performed.

RESULTS

DECT-based iodine concentration (IC) measurements showed significant differences in LA phase iodine maps between ischemic (median:0.72; IQR 0.52-0.91 mg/mL) and non-ischemic bowel loops (5.16; IQR 3.45-6.31 mg/ml) (P <.0001). IC quantification on LA phase revealed an AUC of 0.966 for the assessment of acute bowel ischemia, significantly higher compared to both IC quantification based on PV phase (0.951) and attenuation values evaluated on LA conventional CT series (0.828). Excellent intra-observer and strong inter-observer agreements were observed for the quantification of iodine concentration. Conversely, weak inter-observer agreement was noted for conventional HU assessments. The optimal LA phase-based IC threshold for assessing bowel ischemia was 1.34 mg/mL, yielding a sensitivity of 100% and specificity of 96.48%.

CONCLUSION

Iodine maps based on LA phase significantly improve the diagnostic accuracy for the assessment of NOMI compared to conventional CT series and PV phase iodine maps.

Congenital Infiltrating Lipomatosis of the Face: Multimodality Assessment through CT-Scan and Magnetic Resonance Imaging

Congenital infiltrating lipomatosis of the face is a rare and benign condition involving a hamartomatous proliferation of mature adipose cells. The final diagnosis derives from a combination of clinical data, histology, and imaging features and affects the treatment decision. This report describes the clinical case of a young patient suffering from facial lipomatosis with particular emphasis on radiological findings detected at CT-scan and magnetic resonance imaging.

Anomalous venoatrial connections - CT and MRI assessment

Abnormal venous atrial (VA) connections present a congenital heart disease (CHD) challenge for pediatric cardiologists. Fully anatomical evaluation is very difficult in prenatal and perinatal follow-up, but it has a profound impact on surgical correction and outcome. The echocardiogram is first-line imaging and represents the gold standard tool for simple abnormal VA connection. CT and MRI are mandatory for more complex heart disease and "nightmare cases". 3D post-processing of volumetric CT and MRI acquisition helps to clarify anatomical relationships and allows for the creation of 3D printing models that can become crucial in customizing surgical strategy. Our article describes a ten-year (2013-2022) tertiary referral CHD center of abnormal AV connections investigated with CT and MRI, illustrating most of these complex diseases with the help of volume rendering (VR) or multiplanar reconstructions (MPR). The nightmarish cases will also be addressed due to the complex cardiovascular arrangement that requires a challenging surgical solution for correction along with the post-surgical complications.

The Nutraceutical Genistein-Lycopene Combination Improves Bone Damage Induced by Glucocorticoids by Stimulating the Osteoblast Formation Process

Chronic glucocorticoid (GC) therapy is the most common cause of iatrogenic osteoporosis and represents an important risk factor for osteoporosis and bone fractures. New therapeutic approaches are required in order to treat osteoporosis and reduce the side effects related to the use of anti-osteoporotic drugs. In this context, previous studies reported the efficacy of some isoflavones and carotenoids, such as lycopene and genistein, on the reduction of the risk of fracture related to osteoporosis. The aim of this study was to investigate the effects of a combined oral treatment, consisting of genistein and lycopene, in an experimental model of glucocorticoid-induced osteoporosis (GIO). GIO was induced by subcutaneous injection of methylprednisolone (MP, 30 mg/kg) for 60 days, whereas the control group (Sham) received saline solution only. Following induction, MP animals randomly were assigned to receive alendronate, genistein, lycopene, or the association of genistein and lycopene or saline solution for additional 60 days together with MP. Femurs obtained from the Sham group were used for osteoblasts extraction; they were then incubated with dexamethasone (DEX) for 24 h to be then treated with lycopene or genistein or the association of lycopene and genistein for an additional 24 h. Treatments with lycopene and genistein restored the impaired mineralization of cells observed following DEX treatment and stimulated osteoblast differentiation by increasing the depressed expression of bALP and RUNX2 (p < 0.0001). Wnt5a, β-catenin, and Nrf-2 expression were significantly increased following genistein and lycopene treatment (p < 0.0001), thus confirming their antioxidant activity as well as their ability in stimulating osteoblast function, mostly when genistein and lycopene were used in association. The combined treatment of genistein and lycopene improved the bone damage induced by glucocorticoids and significantly restored the normal architecture of bones as well as adequate interconnectivity of bone trabeculae, thus increasing bone mineral density parameters. The obtained data demonstrated that genistein and lycopene but in particular their association might prevent GC’s adverse effects, thus stimulating bone formation and reducing bone resorption, improving bone structure and microarchitecture, through different molecular pathways, such as the Wnt/β-catenin and the Nrf-2 signaling.