Acta radiologica open最新文献

Background: Although intraoperative magnetic resonance imaging (iMRI) is well established in neurosurgery, its role in musculoskeletal oncology remains unclear.

Purpose: To assess the feasibility and safety of iMRI in bone and soft tissue tumor surgery, focusing on giant cell tumor of bone (GCTB) after denosumab.

Material and methods: Fourteen patients (12 GCTB, 1 undifferentiated pleomorphic sarcoma [UPS], 1 chondroblastoma) underwent tumor resection with intraoperative 0.4 T MRI between 2017 and 2024. Outcomes included residual tumor detection, recurrence, and safety.

Results: iMRI identified residual tumor in 7 of 12 GCTB patients (58.3%), all histologically confirmed. At a median follow-up of 42 months, recurrence occurred in one GCTB case (8.3%). iMRI guided complete resection in a femoral head chondroblastoma, enabling full functional recovery. Soft tissue assessment was limited in the UPS case. No iMRI-related complications occurred.

Conclusion: iMRI is a feasible and safe adjunct in bone tumor surgery, enhancing detection of residual tumor and supporting joint-preserving procedures, particularly in GCTB after denosumab.

Fetal magnetic resonance imaging (MRI) has become a valuable noninvasive method for evaluating congenital anomalies of the fetus and can serve as an important adjunct to the prenatal ultrasound, particularly where the ultrasound is unable to exclude or detect fetal abnormalities. This pictorial review will describe the utilization of three-dimensional fast imaging employing steady-state acquisition (3D-FIESTA) in various clinical entities, specifically at 3T, and how to generate clinically valuable information.

Extrapulmonary tuberculosis represents 15-20% of all tuberculosis infections and can involve nearly any organ, earning tuberculosis a reputation as one of the great mimickers in medicine. Imaging plays a critical role in diagnosing extrapulmonary tuberculosis, which presents with a wide range of manifestations. We present a pictorial essay comprising cases from Asia, where tuberculosis remains endemic, illustrating the imaging characteristics of extrapulmonary tuberculosis with a focus on thoracoabdominal pathology. Differential diagnoses that exhibit similar imaging findings are also discussed. We aim to raise awareness among radiologists about the importance of considering extrapulmonary tuberculosis for accurate diagnosis and timely management.

Background: Magnetic resonance imaging (MRI) enables the non-invasive assessment of myocardial tissue properties through the T1, T2, and T2* relaxation mapping. Establishing population-specific normal reference values enhances diagnostic accuracy.

Purpose: To study the effect of sex and age on the T1, T2, and T2* relaxation time constants in a healthy Finnish population.

Methods: We recruited 47 healthy volunteers aged 18-60 years from Eastern Finland from 2023 to 2024 and categorised them by sex and age (18-30 years, 31-41 years, and 42-60 years). The participants underwent a comprehensive screening process to eliminate the possibility of cardiac disease. MRI scans were conducted on 40 participants at 1.5 T. The T1, T2, and T2* relaxation time constants were calculated for basal, mid-ventricular, and apical short-axis slices.

Results: The T1 and T2 relaxation time constants were higher in females than males (T1: 1040 ± 29 vs 1020 ± 17 ms, p < .01; T2: 51 ± 4 vs 48 ± 3 ms, p < .001). The 95% normal T1 range was 981-1098 ms for females and 985-1054 ms for males. The normal T2 range was 44-58 ms for females and 43-53 ms for males. No sex differences were found in the T2* relaxation times. The septal T2* across the whole population was 36 ± 7 ms (95% normal limit: 22-49 ms).

Conclusion: This study established age-independent and sex-specific reference values for the native myocardial T1, T2, and T2* relaxation time constants at 1.5 T. Females had higher T1 and T2 values than males, and age did not affect these values.

Background: Computed tomography (CT)-guided transthoracic biopsy is essential for diagnosing pulmonary lesions but exposes patients to considerable radiation from repeated image acquisitions. With the growing emphasis on radiation safety, applying validated low-dose CT protocols to interventional procedures has become a key clinical priority.

Purpose: To assess the feasibility, safety, diagnostic yield, and radiation dose of low-dose computed tomography-guided transthoracic biopsies using an 80 kVp protocol compared with standard 120 kVp protocols.

Methods: A retrospective review was performed on 183 consecutive computed tomography-guided transthoracic biopsies of lung nodules or masses, including 143 procedures with the standard 120 kVp protocol and 40 procedures with a low-dose 80 kVp protocol at 30 mAs. Procedural characteristics, image quality, histopathological adequacy, radiation exposure, and complications were analyzed. Both subjective and objective image quality assessments, including signal-to-noise and contrast-to-noise ratios, and cellular analyses of specimens were compared.

Results: The low-dose protocol reduced mean effective radiation dose from 5.89 ± 2.88 millisieverts to 0.19 ± 0.06 millisieverts, a 96.8% reduction. Biopsy specimen adequacy was 85% in the low-dose group versus 79% in the standard-dose group. Complication rates were comparable, 45% versus 43.4%. Subjective image quality was lower in the low-dose group, but objective signal-to-noise and contrast-to-noise ratios remained sufficient for accurate diagnosis.

Conclusion: Computed tomography-guided transthoracic biopsies with an 80 kVp and 30 mAs protocol significantly reduce radiation exposure without compromising diagnostic yield or safety. This low-dose approach is a viable alternative to conventional protocols and can be adopted in routine interventional radiology practice.

Radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) located in the caudate lobe is technically challenging because of the tumor's deep location and proximity to major vascular structures. A 71-year-old woman with a 2-cm HCC in segment I underwent conventional transcatheter arterial chemoembolization (TACE) via the femoral artery. Immediate RFA was not feasible because CT arterial portography revealed no safe puncture route due to surrounding vasculature. On the following day, angiography using a left transradial approach was performed with the patient in the prone position, enabling identification of a safe dorsal puncture path. After creation of an artificial pneumothorax, percutaneous CT-guided RFA was successfully completed without complications. Prone transradial angiography can facilitate safe RFA for hepatic tumors in anatomically challenging locations such as the caudate lobe. This approach may broaden treatment options when conventional supine access is not possible.

Background: Although plain chest x-rays (CXRs) have become standard examinations in many countries, they vary greatly and are recognized as potentially inappropriate imaging procedures.

Purpose: To enhance the safety, quality, effectiveness, and efficiency of healthcare services, by providing knowledge of the temporal and geographical variations in the use of CXRs.

Materials and methods: Outpatient and inpatient data for CXRs was collected for Norway for the years 2013-2022. Data included patients' age and sex, NCRP code, examination name, modality, hospital/imaging centre, and whether they were in- or outpatients.

Results: On average 648,005 CXRs were performed per year in Norway. This amounts to 123 CXRs per 1000 persons per year (2022). 92% of the examinations were performed at public hospitals, and 39% were outpatient examinations. There was a 17% reduction in CXRs from 2013 to 2022. More male than female patients (54%) got a CXR, especially for the age years 60-79. Geographical variations with a factor of 3.7 and 4.7 were observed for inpatient and outpatient examinations, respectively. The differences between catchment areas decreased from 2013 to 2022.

Conclusions: This is the first study of the number of CXRs from a whole nation for as long as 10 years. It documents substantial geographical variations in number of examinations and a temporal reduction in the total number of examinations. Information of the temporal and geographical variations is crucial for addressing the issue of appropriate imaging and to increase the safety, quality, effectiveness, and efficiency of the healthcare services.

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis. Mixed ECD-Langerhans cell histiocytosis (LCH) is uncommon, with fewer than 200 cases reported. Diagnosis is challenging and relies on clinical, radiological, and histopathological correlation. We present the case of a 61-year-old man with night sweats, weight loss, and recently diagnosed type 2 diabetes. Imaging revealed cystic lung lesions, perirenal infiltration, and circumferential aortic wall thickening. FDG PET-CT demonstrated multifocal hypermetabolism involving lymph nodes, perirenal soft tissues, and the aortic wall, but no bone involvement. These lesions were shown to progress on subsequent imaging. A lymph node and perirenal biopsies confirmed a mixed form of ECD-LCH with BRAFV600 E mutation and associated chronic myelomonocytic leukemia. The patient was started on targeted therapy with cobimetinib, a MEK inhibitor. Mixed ECD-LCH is a rare entity that typically demonstrates more frequent and widespread organ involvement, particularly affecting the lungs. Its clinical and radiological presentation can have features of both disorders, such as bone, lung, kidney, and vascular involvement. The diagnosis is challenging and requires biopsy with histopathology and genetic testing to be confirmed. Treatment is generally targeted therapy guided by the driver mutations that are identified. We present a rare case of mixed ECD-LCH with thoraco-abdominal and pulmonary involvement. Comprehensive diagnostic workup including histopathology and molecular profiling is crucial for accurate diagnosis and initiation of targeted therapy.

Metaplastic breast cancer (MBC) is a rare and heterogeneous malignancy characterized by the presence of both epithelial and mesenchymal elements. Among its variants, MBC with osteoclastic giant cells is extremely uncommon and presents diagnostic challenges because of its diverse histopathological and imaging features. We report the imaging features of a patient with pathologically proven MBC with osteoclastic giant cells as follows: a high-density mass with microcalcification was revealed on mammography; and a microlobulated, mixed cystic and solid mass with posterior acoustic enhancement was revealed on ultrasound. MRI revealed a round mass with circumscribed margins, rim enhancement and high T1-weighted signal intensity due to internal haemorrhage, heterogeneous T2-weighted high-signal intensity and initial fast enhancement and rapid washout kinetics that was classified as BI-RADS 5. Left mastectomy was performed, and the final diagnosis was consistent with that of MBC.

Background: Transjugular intrahepatic portosystemic shunt (TIPS) is effective for portal decompression, but its effect on splenic congestion is not proven. Platelet changes and spleen size following TIPS are controversially reported while the exact volume of the spleen has rarely been investigated.

Purpose: To analyze the effect of TIPS placement on portosystemic gradient (PSG), platelet count (PLT), and exact spleen volume (SV) using contrast-enhanced computed tomography (CT).

Methods: For study inclusion, successful TIPS placements in adult patients with liver cirrhosis and portal hypertension who received CT within 3 months prior and 12 months after TIPS-placement were reviewed (12/2013-09/2021). Exclusion criteria were additional liver/portal interventions, TIPS-dysfunction, progressive portal/liver vein occlusion and hepatic malperfusion or progressive portosystemic collaterals, and active bleeding on CT. Additionally, patients with splenic/hematological disorders, hemodialysis, and clinical apparent infections/multi-organ-failure/death were excluded. PSG and PLT were recorded. Exact SV were segmented on pre-/post-TIPS-CT. Data were compared before and after TIPS placement. Mean ± standard deviation and significance level (p) were given.

Results: Overall, data of 18 TIPS procedures were available for comparison. PSG reduction following TIPS placement was significant (pre: 18 ± 7 mmHg, post: 5 ± 2 mmHg; p < .001). SV tended to decrease (pre: 832 ± 412 cm³, post: 772 ± 345 cm³; p = .112) and PLT did not change (pre: 130 ± 64Tsd/µL, post: 116 ± 61Tsd/µL; p = .160).

Conclusion: When exact SV is assessed and confounders are excluded using CT, neither a significant SV reduction nor a PLT-increase are detected following TIPS. Patients without PLT increase and SV reduction after TIPS might benefit from additional interventions (e.g., splenic artery embolization).