Acta radiologica open最新文献

We report a rare case of retroperitoneal pseudotumor caused by Schistosoma japonicum that was diagnosed by computed tomography (CT) guided percutaneous biopsy in a 15-year-old Filipino male. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a mass lesion, including a mesenteric artery, in the right retroperitoneal space. His mother had a history of S. japonicum infection but his initial stool examination was negative. As schistosomiasis was suspected, cone-beam CT-guided biopsy was performed to enable transcatheter therapeutic arterial embolization to be performed immediately in the event of hemorrhage. Histopathological examination revealed schistosomal eggs. Cone-beam CT-guided technique with a coaxial biopsy system is a safe and accurate diagnostic procedure for S. japonicum retroperitoneal pseudotumor.

Background: Imaging of the portal vein prior to puncture for TIPS is essential. Purpose: With this study, we examined a modified retrograde portography with regard to the reliable representation of the portal vein. Material and Methods: Prospective evaluation of 65 TIPS interventions with regard to the delimitation of the portal vein and the exact parameters of retrograde portography such as catheter diameter and contrast medium volume per injection. Results: Retrograde portographies with a large-lumen catheter (10 F) and a large contrast medium volume (40 mL) were performed in 35/63 patients with significantly better delineation of the portal vein than when using 5 F catheters with 10 mL contrast medium. Conclusion: The so-called high volume retrograde portography leads to better delimitation of the portal vein during TIPS application.

Brown tumors are uncommon manifestations of hyperparathyroidism (HPT) that without awareness are easily misdiagnosed as metastases. This short report highlights the importance of clinical context and clear communication between medical specialties when interpreting complex radiologic findings.

Background: One major challenge when inserting a tunneled, cuffed central venous catheter (CVC) for hemodialysis under fluoroscopy is to accurately place the catheter tip by assessing its position in relation to the cardiac silhouette to approximate the right atrium (RA).

Purpose: To investigate whether a weighted mean calculated from published results for two two-dimensional landmark reference distances may be useful in assessing CVC tip positions in relation to the RA.

Material and methods: Central venous catheter tip positions attained under fluoroscopic imaging during insertion using the cardiac silhouette as approximation were retrospectively related to two reference distances (carina to cranial RA border and craniocaudal RA extent), which were used to group catheter tip locations above (1), within (2), or below (3) the RA (henceforth referred to as landmark technique approximation, LTA). The LTA-derived catheter tip locations were validated by correlation with postinterventional computed tomography (CT) datasets acquired shortly after implantation (if available).

Results: Based on LTA, 45 catheter tips (10.6%) were above, 179 (42.2%) within, and 200 (47.2%) below the RA. Postinterventional CT (n = 57; 13.4%) visualized 26.3% above, 66.7% within, and 7.0% below the RA.

Conclusion: The LTA reference distances appear to lead to a rather low categorization of the CVC tips, or the tips have been placed rather low in the study population. Validation using postinterventional CT indicated an underestimation of the RA in the LTA. Patient characteristics with a higher risk of false estimation through LTA have been defined.

Radioactive seed localization is a method widely used within breast cancer treatment. This case represents a 43-year-old male patient with a foreign body in his left axilla. We used radioactive seed localization for marking the foreign body, which made the subsequent surgery possible, quick, and minimal invasive.

Background: Dual-energy contrast-enhanced mammography (DECEM) is an advanced breast imaging technique of digital mammography.

Purpose: To assess the total radiation dose received from complete DECEM using different combinations of exposure parameters for low- and high-energy images.

Materials and methods: A dedicated phantom with three different concentrations of iodine inserts was used. Each iodine insert was 10 mm in diameter and concentration of 1.0 mgI/cm³, 2.0 mgI/cm³, and 4.0 mgI/cm³. The phantom was exposed at varying kVp levels. Mean glandular dose (MGD) was estimated. Contrast to noise ratio (CNR) and figure of merit (FOM) of the iodine inserts were used to assess the image quality.

Results: The optimum CNR of the recombined images was obtained by using 28 kVp + 49 kVp tube voltage combination for 50 mm thickness, 50% fibroglandular phantom only with a 26% dose increase compared to the highest voltages (32 kVp + 49 kVp) that can be used for low energy (LE) and high energy (HE) imaging. The CNR value was increased with increasing iodine concentration (R ² > 0.99).

Conclusion: The use of as low as possible tube voltage for the LE imaging of standard 50% fibroglandular-50% adipose, 50 mm thickness breast while using the highest tube voltage for HE imaging has reduced the MGD while keeping optimum image quality.

Background: Cardiothoracic ratio (CTR) is the ratio of the diameter of the heart to the diameter of the thorax. An abnormal CTR (>0.55) is often an indicator of an underlying pathological condition. The accurate prediction of an abnormal CTR chest X-rays (CXRs) aids in the early diagnosis of clinical conditions.

Purpose: We propose a deep learning (DL)-based model for automatic CTR calculation to assist radiologists with rapid diagnosis of cardiomegaly and thus optimise the radiology flow.

Material and methods: The study population included 1012 posteroanterior CXRs from a single institution. The Attention U-Net DL architecture was used for the automatic calculation of CTR. An observer performance test was conducted to assess the radiologist's performance in diagnosing cardiomegaly with and without artificial intelligence assistance.

Results: U-Net model exhibited a sensitivity of 0.80 [95% CI: 0.75, 0.85], specificity >99%, precision of 0.99 [95% CI: 0.98, 1], and a F1 score of 0.88 [95% CI: 0.85, 0.91]. Furthermore, the sensitivity of the reviewing radiologist in identifying cardiomegaly increased from 40.50% to 88.4% when aided by the AI-generated CTR.

Conclusion: Our segmentation-based AI model demonstrated high specificity (>99%) and sensitivity (80%) for CTR calculation. The performance of the radiologist on the observer performance test improved significantly with provision of AI assistance. A DL-based segmentation model for rapid quantification of CTR can therefore have significant potential to be used in clinical workflows by reducing radiologists' burden and alerting to an abnormal enlarged heart early on.

Backgrounds: There is a lack of universally available biomarker to differentiate rheumatoid arthritis (RA) and psoriatic arthritis (PsA).

Purpose: to see if the size of the axillary lymphnodes (ALNs) and the frequency of lymphadenopathy are useful biomarker to differentiate RA and PsA.

Material and methods: Forty RA and 19 PsA patients without previous biologics usage were retrospectively included. Chest CT was assessed for the presence of lymphadenopathy and the size of the largest ALN. Frequency of lymphadenopathies was statistically compared between RA and PsA. The short axis and the long axis of the largest ALN were also compared and receiver operating characteristic (ROC) curve analysis was performed.

Results: Frequency of axillary lymphadenopathy was significantly higher in RA than in PsA (80% vs 31.6%, p < .001). Number of lymphadenopathies in each patient was also significantly higher in RA than in PsA (3.0 vs 1.2 per patient, p = .005). Sensitivity and specificity for differentiating RA from PsA by the presence of at least one axillary lymphadenopathy were 0.8 and 0.68, respectively.The short axis of the largest ALNs in RA was significantly longer than in PsA (6.5 ± 1.6 mm vs 4.7 ± 1.7 mm, p < .001). ROC curve analysis of the short axis showed AUC of 0.75 (p = .002) and the cutoff value of 5.1 mm with a sensitivity of 0.83 and specificity of 0.74, when differentiating RA and PsA.

Conclusion: Presence of ALN lymphadenopathy and the short axis of the largest ALN may have a potential utility in differentiating RA and PsA.

Lumbar spinal stenosis is one of the most commonly diagnosed pathological conditions of the spine. Patients with lumbar spinal stenosis can be symptomatic or asymptomatic. Regardless of the clinical presentation, a combination of radiological imaging modalities including magnetic resonance imaging, CT, and dynamic X-rays can be used to evaluate the severity. An often underrecognized aspect of severe lumbar spinal stenosis is its effect on nerve roots. We propose coining the term "GatorSign" to describe nerve root edema above the area of severe central canal stenosis. This radiological finding can help identify patients with severe central canal stenosis in patients who would likely be neurologically symptomatic, requiring an invasive intervention such as epidural injections or surgical decompression for relief as conservative treatments such as physical therapy and/or medications are less likely to be effective.

We report a case of a locally invasive recurrent atypical meningioma in the temporal region with late onset of meningioma lung metastasis. The patient was diagnosed in early adolescence with an atypical meningioma believed to be radiotherapy induced following treatment of a benign pilocytic astrocytoma in the hypothalamus region at 6 years of age. Even though the patient underwent several surgical and radiotherapy treatments, the intracranial meningioma kept growing and was locally invasive. The patient received experimental treatment with bevacizumab, a vascular endothelial growth factor A (VEGF-A)-inhibitor, for 4 years from age 26. Treatment was withdrawn after proven tumor growth on routine control MRI. A DOTA-TOC PET-CT-scan was performed to evaluate the DOTA-TOC somatostatin receptor number for possible SSTR (somatostatin receptor targeted therapy). In the included scan plan multiple lung metastasis were detected and later verified. Genomic tumor sequencing was performed, but no targeted treatment options were found. Instead, the patient finally, as the last treatment option, underwent 4 series of SSTR-targeted therapy (Lutetium DOTA-TOC). Unfortunately, the intracranial tumor component significantly progressed during the final stages of the treatment and the patient died less than a year after treatment was withdrawn at age 32. This case story illustrates the shortcomings of atypical/anaplastic meningioma treatment strategies at present and highlights the possibility of extracranial metastasis.