Journal of the Belgian Society of Radiology最新文献

Teaching Point: Retropharyngeal hematoma appearing under rivaroxaban is uncommon but should be suspected in cases of dysphagia, dysphonia or breathing difficulties.

Background: Solitary fibrous tumors (SFTs) are rare and can be misdiagnosed because of their various radiological appearances.

Purpose: To clarify the characteristic MRI findings of SFTs by analyzing their radiological-pathological correlation.

Material and methods: Nine consecutive patients with SFT who underwent magnetic resonance imaging (MRI) prior to surgery were analyzed. Eight patients underwent contrast-enhanced MRI, and three underwent dynamic MRI. Radiological-pathological correlation analysis, co-occurrence matrix, run-length matrix, and histogram analysis were performed to assess the relationship between pathological findings T1- and T2-weighted images (T1-WI and T2-WI).

Results: All nine lesions ranged in size from 20 to 36 mm. Seven lesions were located in the superior portion of the retrobulbar space found outside of the muscle cone, and two lesions in the inferior portion were located within it. No significant correlation was observed between the amount of collagenous tissue and the qualitative evaluation of the signal on T1-WI and T2-WI. Kurtosis on T2-WI was significantly correlated with the amount of collagenous tissue (ρ = -0.97, p < 0.0001) and endothelial cells (ρ = -0.49, p = 0.0479).

Conclusion: Kurtosis in the histogram analysis on T2WI showed a strong correlation with the amount of collagenous tissue.

Hemorrhage in the basal ganglia resulting to lenticulostriate artery aneurysm rupture is extremely rare. This distal micro-aneurysm of the perforating lenticulostriate arteries is called Charcot-Bouchard aneurysm. We wish to report a case of an hematoma in the basal ganglia due to a Charcot-Bouchard aneurysm demonstrated by Computed Tomography Angiograpy (CTA) and Magnetic Resonance Angiography (MRA) and confirmed by selective catheter angiography.

Teaching point: Charcot-Bouchard aneurysm is a very rare distal micro-aneurysm of the perforating lenticulostriate arteries. Young patients who experience basal ganglia hemorrhage should have contrast-enhanced CT, especially if they don't have arterial hypertension and if subarachnoid hemorrhage is associated.

An 82-year-old male was transferred for an abdominal CT scan for chronic cutaneous fistulation at the level of the right abdominal wall. Previous CT and ultrasound imaging described recurrent collections in the right abdominal wall, requiring CT guided abscess drainage. The abdominal CT scan revealed an abscess in between the internal oblique and transversus abdominis muscle layers of the right flank, with significant fat stranding and loss of the intermuscular fat planes ( Figure 1 ). Inside this abscess, we notice a spontaneous hyperdense nodular lesion (Hounsfield Units 130), which doesn't enhance after contrast injection ( Figure 1 arrow). Looking back at the previous CT scans we discern the presence of this hyperdense lesion, which tends to migrate over time over a small distance along the abdominal wall ( Figure 2 A-D arrow). We can trace this back on the numerous previous scans, with different local tissue reactions over time. The first performed CT 8 years prior reveals a perforated calculous cholecystitis, containing multiple cholecystolithiases with the same density as our previously mentioned hyperdense lesion ( Figure 3 arrow). Thus, raising the suspicion of a biliary origin of this corpus alienum.

Teaching point: Spilled gallstones during laparoscopy may lead to late abscess.

Purpose: To evaluate the correlation of maximum standardized uptake values (SUV_max) of ¹⁸F-Fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) with the apparent diffusion coefficient (ADC) of diffusion weighted imaging (DWI) in musculoskeletal malignancies.

Methods: Institutional ethics committee approved this retrospective study. Twenty-seven patients (mean age: 44.85 ± 24.07; 17 men and 10 women) with a total of 29 musculoskeletal tumors underwent both FDG-PET/CT and DWI between January 2017 and March 2020. Region-of-interest (ROI)-based maximal standardized uptake values (SUV_max) of the tumors were measured on FDG-PET/CT images. Two radiologists measured lesions' mean and minimum apparent diffusion coefficient (ADC_mean and ADC_min) using five distinct ROIs on DWI images. Pearson correlation analysis was used to assess the correlation between SUV_max and ADC values.

Results: There were 18 soft tissue tumors (62.1%) and 11 bone tumors (37.9%) with a mean maximum diameter of 9.4 ± 6.2 cm. The mean SUV_max, ADC_mean and ADC_min of the whole lesions were 12.93 ± 9.63, 0.85 ± 0.28 × 10^-3mm²/s and 0.61 ± 0.27 × 10^-3mm²/s, respectively. SUV_max had a weak correlation with tumor maximum diameter (r = 0.378, p = 0.043), whereas ADC_mean and ADC_min had none. There was strong inverse correlation between SUV_max and both ADC_mean (r = -0.616, p < 0.001) and ADC_min (r = -0.638, p < 0.001).

Conclusion: In musculoskeletal tumors, quantitative markers of FDG uptake and diffusion restriction strongly correlate.

Teaching point: Clival chordoma is a rare find in children, presenting as a locally destructive, T2 hyperintense, and strongly enhancing mass.

Unilateral cervical facet joint dislocation (UCFJD) is the most frequently missed cervical spine injury on plain radiographs. If left untreated, UCFJD can progress to bilateral cervical facet joint dislocation. Given the complexity of cervical facet joint dislocations, radiologists rely on metaphorical signs to identify them on radiographs. The "Bow-tie" and "laminar space" signs represent UCFJD on plain radiographs. The "reversed hamburger", "naked facet" and "headphones" signs represent cervical facet joint dislocations on axial cross-sectional imaging. Illustrating these signs in an engaging manner facilitates pattern-based recognition, which can benefit trainees and radiologists. Moreover, pattern-based recognition can be applied to machine learning.

Purpose: To investigate the role of low-dose chest computed tomography (CT) imaging in the triage of patients suspected of coronavirus disease 2019 (COVID-19) in an emergency setting.

Materials and methods: Data from 610 patients admitted to our emergency unit from March 20, 2020, until April 11, 2020, with suspicion of COVID-19 were collected. Diagnostic values of low-dose chest CT for COVID-19 were calculated using consecutive reverse-transcription polymerase chain reaction (RT-PCR) tests and bronchoalveolar lavage (BAL) as reference. Comparative analysis of the 199 COVID-19 positive versus 411 COVID-19 negative patients was done with identification of risk factors and predictors of worse outcome.

Results: Sensitivity and specificity of low-dose CT for the diagnosis of COVID-19 respectively ranged from 75% (150/199) to 88% (175/199) and 94% (386/411) to 99% (386/389), depending on the inclusion of inconclusive results. On multivariate analysis, a higher body mass index (BMI), fever, and dyspnea on admission were risk factors for COVID-19 (all p-values < 0.05). The mortality rate was 12.6% (25/199). Higher age and high levels of C-reactive protein (CRP) and D-dimers were predictors of worse outcome (all p-values < 0.05).

Conclusion: Low-dose chest CT has a high specificity and a moderate to high sensitivity in symptomatic patients with suspicion of COVID-19 and could be used as an effective tool in setting of triage in high-prevalence areas.

Teaching point: A giant soleus tug lesion is a benign pseudo-tumoral excrescence at the attachment of the soleus muscle at the posterior upper third of the tibia.

Teaching Point: The imaging clues to differentiate idiopathic tumoral calcinosis from other calcified soft tissue lesions include: pseudotumoral appearance with mass effect, bone erosion with intra-osseous protrusion of calcification, lobulated morphology, and peri-articular location on the extensor side.