Assessment of the intramural segment of interarterial anomalous coronary arteries originating from the opposite sinus of Valsalva on CT angiography

Background Of the coronary anomaly variants, an anomalous coronary artery originating from the opposite sinus (AAOCA) with an interarterial course poses the highest the risk of sudden cardiac death. Assessment of high risk anatomical characteristics can be done with Computed Tomography Angiography (CTA). High risk features are a slit-like ostium, acute angle take-off, proximal narrowing and an intramural course. For an intramural course no clear-cut CT parameters exist. Purpose To deduct new CTA criteria to identify an intramural course as well as the length of the intramural segment based on peroperative findings. Material and methods Twenty patients were included that received unroofing surgery of the right or left AAOCA between 2010 and 2019. All patients had a pre-operative CTA (0.5–1mm slice-thickness) performed. The presence of the intramural segment was measured peroperatively by the surgeon and used as indicator for CTA evaluation. Using multiplanar reconstructions, CTA images were rotated perpendicular to the horizontal plane of the aortic valve annulus and AAOCA to assess the distance between the aortic and AAOCA lumen and the shape of the AAOCA. This was done at every 2mm for the length of the intramural course as described by the surgeon (Figure 1). Results Analysis of 20 patients (40% male, AAORCA n=17, age at diagnosis AAOCA 45.6±10.5 years), showed a mean intramural length of 11.5±2.4mm at surgery. The median distance between the aortic and AAOCA lumen was 0.76mm (IQR 0.72–0.97mm) for the intramural segment. At the distal end of the intramural part (indicated by no. 5 in Figure 1), the mean distance was 1.20mm±0.27mm. The median ratio between the antero-posterior and transverse diameter of the AAOCA lumen at the distal end of the intramural part was 0.94 (IQR 0.88–0.99). Along the intramural part (Figure 1, no. 1–4) this ratio was 0.56mm±0.11mm, indicating a more flattened ostial shape along the course of the vessel. Conclusions Results indicate that an aortic to AAOCA lumen distance of ≤0.76mm on CTA is suggestive of an intramural course. A distance between the aorta and AAOCA of ≥1.2mm combined with an antero-posterior to transverse diameter ratio of 0.94 of the AAOCA indicates that the intramural trajectory has ended. FUNDunding Acknowledgement Type of funding sources: None.

Optimization of cone beam computed tomography for the assessment of alterations of the maxillary sinuses

Objective: To test the standard protocols of a CBCT unit in order to find lower-dose alternatives with diagnostically acceptable image quality for the maxillary sinuses visualization. Study design: An observational study was performed. Two dry skulls were used to simulate four conditions of the maxillary sinuses: normality, mucous retention pseudocyst, membrane thickening and bone graft. Cone beam computed tomography scans were obtained with an i-CAT classic unit using different acquisition protocols and a box of polystyrene to simulate soft tissue attenuation. All the protocols were established by the manufacturer, combining different energy parameters, fields of view and voxel sizes. Multiplanar reconstructions were presented to three Oral Radiologists through blind and randomized distribution. The specialists judged general image quality, sharpness, contrast, and the presence of noise and artifacts based on a 4-points scale. Results: Protocols with higher energy parameters had significant association with higher scores for general quality, sharpness and contrast (p<0.05). Protocols with intermediate level of radiation dose had also significant association with good and excellent image quality; for the presence of noise and artifacts the images were rated acceptable. Conclusion: i-CAT default protocols with lower dose of radiation were able to deliver acceptable image quality for the visualization of the maxillary sinuses.

Ligaments of the scapho-trapezial-trapezoidal joint: MR anatomy in asymptomatic and symptomatic individuals

Purpose To evaluate the MRI anatomy of the scapho-trapezial-trapezoidal (STT) ligament complex in asymptomatic and symptomatic individuals. Material and methods In this retrospective study, STT ligament complex of 42 (male 69%, median age 37.5 years) asymptomatic (n = 25) and symptomatic (n = 17) (defined as pain described over the STT joint) individuals was examined using a high-resolution 3D proton density-weighted isovoxel sequence (MR arthrogram) with multiplanar reconstructions. Two musculoskeletal radiologists independently assessed visibility, signal intensity (SI), morphology, and thickness of the radiopalmar scapho-trapezial ligament (rpSTL), palmar scapho-capitate capsular ligament (pSCL), palmar STT capsule (pSTTC), and dorsal STT capsule (dSTTC). Results Interreader agreement ranged from fair to good and intraclass correlations were good. The rpSTL was almost always visible (85.7%/80.1%; reader 1/reader 2). The pSCL and dSTTC were visible in all cases. The pSTTC was visible in only 52.4%/42.9%. Mean thickness of the rpSTL, pSCL, pSTTC, and dSTTC was 1.4 ± 0.5 mm/1.3 ± 0.5 mm, 2.8 ± 0.7 mm/2.7 ± 0.6 mm, 0.5 ± 0.5 mm/0.4 ± 0.4 mm, and 0.5 ± 0.3 mm/0.3 ± 0.3 mm. Both readers rated SI of the rpSTL significantly more often as increased in the symptomatic group (increased SI in asymptomatic group: 20%/15%; symptomatic group: 56%/50%) (p-values < 0.005). For all other ligaments, no significant difference was observed for SI between symptomatic and asymptomatic group (p-values ranging between 0.188 and 0.890). For all other ligaments, no significant differences were observed regarding ligament visibility, morphology, and thickness (p-values ranging between 0.274 and 1.000). Conclusion The anatomy of the STT ligament complex can consistently be visualized on high-resolution 3D MRI. Increased signal intensity of rpSTL is significantly more frequent in patients with radial-sided wrist pain.

A Case of Incidentally Detected Bladder Lipoma and a Review of the Literature

Background: Lipomas are benign fatty tumors made of fat tissue. Bladder lipomas are extremely rare. For this reason, it is necessary to be aware of the imaging features when incidentally detected in imaging. Case Report: In the abdominal computed tomography (CT) performed as part of the follow-up examination of a 43-year-old patient, who had undergone surgery for adrenal adenoma five years earlier, a 14x9x8 mm smoothly marginated, ovoid-shaped, hypodense mass lesion with a homogeneous internal structure was detected in the anterior bladder wall. The pre-contrast density of the lesion was measured as -105 HU. The magnetic resonance imaging performed one year after the CT examination revealed a 14x9x8 intramural mass in the bladder wall, showing protrusion toward the lumen. The group was observed to be markedly hypointense on fat-suppressed T1 and T2-weighted images and considered consistent with a bladder lipoma. Discussion: Bladder lipomas are benign lesions that can vary in clinical presentations but usually cause hematuria. The differential diagnosis of bladder lipomas includes other mesenchymal rare benign tumors that can arise from the urinary bladder submucosal layer, including leiomyoma, hemangioma, plasmacytoma, fibroma, and neurofibroma, in imaging bladder lipomas present as homogeneous lesions containing macroscopic fat. Only the liposarcoma and pelvic lipomatosis could also show similar features. The less differentiated liposarcomas tend to present more heterogeneous enhancement, irregular-shaped margins, and infiltrative behavior. Also, appropriate multiplanar reconstructions may allow the radiologist to determine it is an extravesical pelvic lipomatosis. Conclusion: Using CT and MRI, these lesions rich in adipose tissue can be distinguished from other lesions, and their diagnosis can be made to a great extent. However, a histopathological examination is required for a definitive diagnosis.

Simulation of superselective catheterization for cerebrovascular lesions using a virtual injection software

Background This report addresses the feasibility of virtual injection software based on contrast-enhanced cone-beam CTs (CBCTs) in the context of cerebrovascular lesion embolization. Intracranial arteriovenous malformation (AVM), dural arteriovenous fistula (AVF) and mycotic aneurysm embolization cases with CBCTs performed between 2013 and 2020 were retrospectively reviewed. Cerebrovascular lesions were reviewed by 2 neurointerventionalists using a dedicated virtual injection software (EmboASSIST, GE Healthcare; Chicago, IL). Points of Interest (POIs) surrounding the vascular lesions were first identified. The software then automatically displayed POI-associated vascular traces from vessel roots to selected POIs. Vascular segments and reason for POI identification were recorded. Using 2D multiplanar reconstructions from CBCTs, the accuracy of vascular traces was assessed. Clinical utility metrics were recorded on a 3-point Likert scale from 1 (no benefit) to 3 (very beneficial). Results Nine cases (7 AVM, 1 AVF, 1 mycotic aneurysm) were reviewed, with 26 POIs selected. Three POIs were in 2nd order segments, 8 POIs in 3rd order segments and 15 POIs in 4th order segments of their respective arteries. The reviewers rated all 26 POI traces – involving a total of 90 vascular segments – as accurate. The average utility score across the 8 questions were 2.7 and 2.8 respectively from each reviewer, acknowledging the software’s potential benefit in cerebrovascular embolization procedural planning. Conclusion The operators considered CBCT-based virtual injection software clinically useful and accurate in guiding and planning cerebrovascular lesion embolization in this retrospective review. Future prospective studies in larger cohorts are warranted for validation of this modality.

3D MRI of the Knee

Three-dimensional (3D) magnetic resonance imaging (MRI) of the knee is widely used in musculoskeletal (MSK) imaging. Currently, 3D sequences are most commonly used for morphological imaging. Isotropic 3D MRI provides higher out-of-plane resolution than standard two-dimensional (2D) MRI, leading to reduced partial volume averaging artifacts and allowing for multiplanar reconstructions in any plane with any thickness from a single high-resolution isotropic acquisition. Specifically, isotropic 3D fast spin-echo imaging, with options for tissue weighting similar to those used in multiplanar 2D FSE imaging, is of particular interest to MSK radiologists. New applications for 3D spatially encoded sequences are also increasingly available for clinical use. These applications offer advantages over standard 2D techniques for metal artifact reduction, quantitative cartilage imaging, nerve imaging, and bone shape analysis. Emerging fast imaging techniques can be used to overcome the long acquisition times that have limited the adoption of 3D imaging in clinical protocols.

How Great is Greater Tuberosity? – A Analysis by CT Multiplanar Reconstruction

Objective: This study was designed to explore the precise size of the greater tuberosity of humerus in Chinese population.Methods: The radiologic study was performed on 66 CTs of shoulder from the hospital’s CT scan database of out-patient department from December 2018 to February 2020. This study designed a method to measure the size of the greater tuberosity (GT). The width, height and thickness of the greater tuberosity were measured on CT image multiplanar reconstructions (MPR), which was independently conducted by two observers.Results: 66 intact shoulders CT scans were analyzed, including 26 women and 40 men with a mean age of 36.79 ± 9.17 years, with 41 right and 25 left shoulders. There were no significant differences in GT width, GT height, GT thickness and PH thickness between two observers. The ICC for the GT width measurements taken by CT was 0.872. The ICC for the GT height was 0.810. The ICC for the GT thickness was 0.777. The ICC for the PH thickness was 0.971. For male cases, the total PH thickness was 51.06±2.30 (45.70-55.20) mm for female cases, the total PH thickness was 45.79±2.57 (41.40-51.25) mm. Gender have a significant impact on the results, man had a larger GT than woman.Conclusions: The method was an applicable way the measure the size of greater tuberosity, it showed good reliability. The size of GT in male cases was larger than female. These data provides important information for further research and clinical practice.

Additional criterion for assessing the risk of gastric variceal bleeding according to multispiral computed tomography

Aim. To establish the parameters of gastric varices which determine a high risk of gastric bleeding according to the results of multispiral computed tomography.Material and methods. The results of studies of 39 patients with liver cirrhosis and gastric varices were retrospectively studied. Nine of them had signs of previous bleeding on endoscopic examination or the corresponding data in the medical history. In 3 patients gastric bleeding occurred 30-47 days after multispiral computed tomography.Results. According to the results of multispiral computed tomography with multiplanar reconstructions gastric bleeding was detected in 12 patients with protrusion of submucosal varicose veins into the gastric lumen by 5 mm or more with a vein diameter >7 mm.Conclusion. The results of multispiral computed tomography, complemented by the hydro-computed tomography technique, provide important additional information on predicting the development of gastric bleeding in the selection of patients for preventive minimally invasive interventions on the veins of the stomach.

The relationship of global sagittal malalignment to fatty infiltration in the aging spine

Purpose To investigate associations between muscle size, fat infiltration (FI), and global sagittal alignment in patients with adult spinal deformity (ASD). Methods Retrospective cohort study was conducted on a single-institution database of ASD patients with preoperative radiographs and CTs. Following multiplanar reconstructions of CTs, images in the plane of each vertebra were generated. The posterior vertebral musculature (PVM) was contoured on axial images at three vertebral levels (T2, T10, L3). FI was calculated by comparing Hounsfield units within muscles to the normative values of fat. Correlation analyses were conducted between demographics, alignment, and muscle characteristics. Results 107 patients underwent preoperative spine CT (58yo, 79%F, BMI 27 kg/m2). Muscle data were available for 49 pts at T2, 39 pts at T10, and 81 pts at L3. Mean FI was T2 = 33% ± 18, T10 = 28% ± 19, L3_Erector = 39% ± 19, and L3_Psoas = 19% ± 9. FI correlated across levels (T2 vs. T10 r = 0.698; T10 vs L3_Erector r = 0.506; L3_Erector vs Psoas r = 0.419) and with demographics; older pts had greater fat percentages (r = 0.31–0.45) and BMIs (r = 0.24–0.51). Increased FI at T2, T10, and L3 was associated with increased pelvic retroversion (PT: r = 0.25–0.43), global deformity (TPA: r = 0.27–0.45), and anterior malalignment (SVA: r = 0.23–0.41). The degree of FI in the PVM increased with the severity of SRS-Schwab PT and SVA modifiers. Conclusion In ASD patients, global sagittal malalignment is related to FI of the PVM throughout the lumbar and thoracic spine, as identified through CT. Future research should investigate how FI relates to ASD pathogenesis.