Journal of Clinical Imaging Science最新文献

Objectives: The objectives of the study are to identify usefulness of chest radiography (CXR) and computed tomography (CT) for the assessment of optimal Impella positioning compared to echocardiography.

Material and methods: In this retrospective study, records of 500 patients were reviewed, 95 subjects met the inclusion criteria. The distance from the carina, top of the aortic arch, and in case of CT, from the aortic valve plane to the Impella inlet port was measured. Subjects were stratified into two groups based on echocardiography: Those that did require repositioning and those that did not.

Results: CT revealed greater distance from the carina to the aortic valve plane in patients requiring Impella repositioning compared to those which did not (81.6 ± 15.9 mm vs. 67 ± 13.2 mm, P = 0.019). The distance from the aortic valve plane to the Impella inlet was shorter in repositioned cases on CT (22.3 ± 28.6 mm vs. 35.8 ± 13.3 mm, P = 0.045). The expected location of the aortic valve plane was 6.8 ± 1.3 cm from the carina among CT cases, representing a useful measurement for evaluation on CXR. Significant predictors of aortic valve plane to carina distance on CT were found to be aortic arch to Impella outlet on CXR (P < 0.0001) and carina to Impella outlet on CXR (P < 0.0001).

Conclusions: CT imaging correctly identified patients that required repositioning on echocardiography. Key CT measurements serve as crucial indicators for repositioning and there is notable agreement on measurements across CXR and CT as well as CT and echocardiography in identification of Impella high or low positioning. In addition, there is evidence of significant predictors of CT measurements from CXR.

Objectives: Computed tomography (CT)-guided biopsy is often used to increase the safety and accuracy of biopsies for disease diagnosis. However, CT-guided biopsy is associated with metal artifacts from the biopsy needle and increased patient and operator exposure due to frequent CT fluoroscopy. Therefore, we thought it possible to solve this problem by setting the CT fluoroscopy conditions to a higher tube voltage and a lower tube current-time product (high-tube voltage conditions) than recommended. As a preliminary study, metal artifacts, low-contrast detectability, patient and operator's exposure, and visual changes in high-tube voltage conditions were assessed using phantoms and compared with recommended conditions.

Material and methods: On an interventional radiology CT system, the phantom was scanned under recommended conditions (120 kV, 30 mAs) and high-tube voltage conditions (135 kV, 30-5 mAs). The metal artifacts and low-contrast detectability of each condition were analyzed and compared using the acquired images. In addition, the phantom surface dose assuming patient exposure and the air dose assuming the operator's standing position were measured and compared. Furthermore, visual assessment was performed by six radiological technologists.

Results: Low-contrast detectability was slightly reduced, metal artifacts were significantly lower under high-tube voltage conditions, and patient and operator exposure were lower than the recommended conditions. Furthermore, the findings of the visual assessment were largely consistent with those of the physical assessment.

Conclusion: High-tube voltage conditions in CT fluoroscopy during CT-guided biopsy may be useful in reducing metallic artifacts and patient and operator radiation exposure.

Head and neck cancer is the seventh most common cancer globally, with over 300 thousand deaths annually. Magnetic resonance imaging (MRI) of head and neck tumors is a well-known method for its evaluation, although malignant and benign imaging tumors often overlap. Permeability is an advanced method performed by MRI that assist in the diagnosis and evaluation of the neoplasm treatments, having a well-established role in some cases, such as salivary gland tumors, and promising in others, such as squamous cell carcinoma and lymph node evaluation. This pictorial review aims to demonstrate the diverse applications of magnetic resonance permeability imaging in head and neck tumors, highlighting its role in differentiating benign from malignant lesions, such as parotid gland tumors, assessing head and neck squamous cell carcinoma, and evaluating lymph node involvement. By correlating these advanced imaging findings with conventional magnetic resonance techniques, this review aims to enhance radiologists' understanding of the method and its clinical utility in improving diagnostic and treatment planning.

Objectives: This study evaluated the efficacy of dual-layer spectral detector computed tomography (DLCT) for detecting early ischemic changes (EICs) in patients with acute ischemic stroke (AIS), focusing on electron density (ED) and effective atomic number (effective Z) imaging.

Material and methods: This retrospective study included 15 patients (mean age: 76.5 ± 9.8 years) with AIS who underwent non-contrast computed tomography (CT) with DLCT and magnetic resonance imaging (MRI) on the same day. Quantitative analysis was performed to compare conventional CT, ED, and effective Z values between the infarcted and contralateral brain regions. Qualitative assessment was conducted by two radiologists using the modified Alberta Stroke Program Early CT Score methodology. Receiver operating characteristic curve analysis was performed to evaluate diagnostic performance, and kappa statistics were used to assess interobserver agreement.

Results: Significant differences were observed in the conventional CT and ED values (P < 0.01) but not in effective Z values (P = 0.46) between the infarcted and contralateral regions. ED imaging demonstrated superior diagnostic accuracy (area under curve [AUC] = 0.90) compared with conventional 120-kVp CT (AUC = 0.85) and effective Z imaging (AUC = 0.62). Furthermore, interobserver agreement (kappa = 0.71) was better for ED imaging than for conventional 120-kVp CT (kappa = 0.65). Qualitative analysis revealed that ED images showed better agreement with MRI findings and higher interobserver consistency than conventional 120-kVp images.

Conclusion: Compared with conventional CT, DLCT with ED imaging significantly enhanced detection of EICs in AIS.

This review discusses the evaluation of renal cell carcinoma (RCC) subtypes using computed tomography (CT) and magnetic resonance imaging (MRI). RCC is a malignancy with different histopathological subtypes, constituting approximately 90% of adult kidney tumors. It has been reported that these subtypes show significant differences in terms of clinical behavior, treatment response, and prognosis. In the study, CT and MRI findings of subtypes such as clear cell RCC (ccRCC), papillary RCC (pRCC), chromophobe RCC (chRCC), medullary RCC (mRCC), collecting duct RCC (cdRCC), and multiloculated cystic RCC (mcRCC) were compared. It was stated that CT is the first-choice imaging method in the staging and surgical planning of RCC and provides detailed information about the tumor size, vascularity, and metastatic spread. On the other hand, it has been emphasized that MRI allows better characterization of RCC subtypes with its soft-tissue resolution and contrast agent usage advantage. The study draws attention to the different imaging features of each subtype and details the role of these findings in the clinical decision-making process. It has been stated that ccRCC exhibits intense contrast enhancement and rapid washout pattern in the corticomedullary phase on CT and appears hyperintense on T2A and hypointense on T1 weighted imaging (T1A) on MRI. It has been stated that pRCC has hypovascular features, has lower contrast enhancement, and has homogeneous borders. It has been stated that chRCC has a less vascular structure and exhibits moderate contrast enhancement in the corticomedullary phase. It has been reported that mRCC has invasive features and is usually diagnosed at an advanced stage while cdRCC has a very aggressive clinical course. It has been stated that mcRCC contains distinct cystic areas between the septa, has a well-circumscribed structure, and generally has a low malignancy potential. As a result, it has been stated that detailed evaluation of CT and MRI findings of RCC subtypes plays a critical role in the diagnosis, treatment, and prognosis of these subtypes. It has been emphasized that the findings presented in this study will contribute to the development of more targeted treatment approaches in RCC management.

Congenital portosystemic shunt (CPSS) is a rare vascular anomaly in which portal vein blood flows into the systemic circulation without passing through the liver. They occur in approximately 1 in 30,000-50,000 live births. We present an 11-year-old patient with an extrahepatic CPSS managed with long-term follow-up. The initial clinical presentation showed no significant abnormalities. Subsequent assessments revealed slightly elevated ammonia (NH₃) and total bile acids (TBAs). Two times angiography at the ages of 2 and 11 years confirmed a shunt between the portal vein and left renal vein, with a gradual shift in blood flow dominance from the celiac artery-splenic vein system to the superior mesenteric artery-superior mesenteric vein system as the patient aged. Due to the risk of complications, transcatheter shunt embolization was performed, utilizing 12 coils to achieve complete shunt embolization. Post-embolization, NH3, and TBA levels normalized, and the patient remained asymptomatic. This case highlights the importance of timing in CPSS intervention, particularly with shifting hemodynamics and underscores the need for further studies on optimal intervention timing in pediatric CPSS.

Objectives: This study aimed to investigate the accuracy of myocardial extracellular volume (ECV) quantification using a prototype photon-counting detector (PCD) computed tomography (CT) and examine the association between radiation dose and spectral image settings.

Material and methods: A multi-energy CT phantom that simulated the blood pool and myocardium was used. The tube voltage was set at 120 kVp and three types of tube current-time products (105, 150, and 300 mAs) were applied for pre- and post-contrast scans. Virtual monoenergetic images (VMIs) at 50-100 keV were reconstructed. The ECV value was calculated from the CT numbers between pre-contrast and post-contrast. We compared the accuracy of ECV values at each VMI level.

Results: Each radiation dose setting demonstrated a small but significant difference in ECV values at each keV level. ECV was overestimated at higher keV in all radiation dose settings. A significant difference in ECV value variabilities was found among keV levels in all three radiation dose settings, with higher keV exhibiting greater variability. The variation was particularly large in the low-dose setting. The residual values were significantly larger at higher keV levels in all radiation dose settings. The residual values were smaller at 50 and 60 keV with no significant difference in 150- and 300-mAs settings.

Conclusion: Setting appropriate VMI keV and radiation dose settings was necessary when quantifying myocardial ECV with PCD-CT because the keV levels caused differences in the quantification value and measurement variation.

This review describes the radiographic findings in emergencies of head and neck cancers (HNCs) in both undiagnosed and previously treated patients, with an emphasis on the temporal urgency of each presentation and in association with the relevant clinical presentation and necessary treatments to enhance understanding and recognition. The various presentations of HNC will be described by the organ system of their presenting complaint. The development and complications of each will be elaborated, with a focus on the clinical presentation in the emergency department and the imaging findings that are critical to recognize in making the diagnosis. Each presentation will be exhibited with a specific patient case and the exact computed tomography, magnetic resonance imaging, ultrasound, or digital subtraction angiography images obtained will be shown. Cases include airway obstruction due to glottic tumor or metastatic cervical lymphadenopathy; airway obstruction due to surgical complications of hematoma, or post-radiation soft-tissue edema; vascular complications of tumor or nodal compression, carotid blowout, carotid stenosis, or occlusion; orbital complications of compartment syndrome; and orthopedic complications of osteomyelitis and osteoradionecrosis. Eleven HNC patient cases are presented with their associated 32 images. HNC patients present with challenging imaging features in the emergent setting. Difficulty in discerning the correct diagnosis arises from the complex head and neck anatomy, often compounded by an advanced stage at presentation and poor functional status. Radiologist familiarity with common HNC emergent presentations is essential for accurate diagnosis and timely treatment.

Objectives: Leiomyomatosis peritonealis disseminata (LPD) is a rare and specific type of leiomyomatosis that is often misdiagnosed as malignant tumor with peritoneal metastasis, and accurate diagnosis is critical to treatment planning. The purpose of this study is to investigate the radiological features of LPD, analyze, and summarize its differential diagnosis and clinical features to improve the understanding of this rare disease.

Material and methods: A retrospective analysis was conducted on clinical and radiological features from 10 patients with pathologically confirmed LPD between 2012 and 2024. The computed tomography (CT) and magnetic resonance imaging (MRI) findings were examined, focusing on parameters such as location, morphology, size, quantity, enhancement patterns, and their relationship with adjacent organs. In addition, the radiological features and the key points of differential diagnosis were summarized.

Results: All the 10 LPD patients presented with multifocal lesions in the abdomen and pelvis, and 7 of them had a history of hysteromyoma surgery. The number of lesions was all ≥2, most of them were round or quasi-circular, with clear boundaries and smooth edges, did not invade the neighboring parenchymal organs, with a length of about 1.5~16.8 cm. The lesions were located in the pelvic cavity in 6 cases, the abdominal wall in 6 cases, the intestinal wall in 3 cases, the rectouterine pouch in 1 case, the omentum in 5 cases, the abdominal cavity in 1 case, and the mesentery in 1 case. There were 7 cases with minimal pelvic fluid and 1 case with liver spread. CT showed circular solid nodules with clear boundaries. The density of small lesions was homogeneous. Cystic changes were observed in some large lesions. On MRI, T1-weighted imaging showed hypo to isointense, T2-weighted imaging (T2WI) mostly showed hypointense, and T2WI in some large lesions showed slightly high signal intensity, diffusion-weighted imaging signal intensity was not higher than that of myometrium, apparent diffusion coefficient showed isointense, and solid components of the lesions were significantly more homogeneous enhanced after enhancement, and the enhancement degree was similar to that of normal myometrium.

Conclusion: Although the imaging findings of LPD are similar to malignant tumors with peritoneal implantation and metastasis, they have certain characteristics, which are helpful for differential diagnosis combined with the clinical history of patients.

Cardiac sarcoidosis (CS) represents a rare yet potentially life-threatening condition characterized by non-specific clinical symptoms that maybe easily missed by clinicians. In this case series, the clinical presentations, various imaging modalities' characteristics, and the management of four patients, each with distinct phenotypes of CS confirmed through endomyocardial biopsy, are discussed. Advanced imaging techniques, including positron emission tomography, revealed the focal septal uptake of ¹⁸F fluorodeoxyglucose, which suggests an ongoing inflammation, whereas contrast-enhanced cardiac magnetic resonance demonstrates septal late gadolinium enhancement, which indicates replacement fibrosis. These features of multimodality imaging in CS can assist in patient diagnosis and treatment.