Routine Contrasted Chest CT Accurately Identifies Anatomic Variations of the Proximal Subscapular System.

OBJECTIVE: The vascular anatomy of the proximal subscapular artery has been previously classified into 2 major types depending on the presence of a common subscapular trunk. The purpose of this study was to determine the utility, reliability, and cost of routine chest imaging to identify these anatomical variations. METHODS: Data were collected retrospectively at a tertiary medical center for patients who were undergoing CT chest for various indications between October 2019 and October 2020. Two independent and blinded readers interpreted CT chest with contrast of 52 patients for a total 104 sides. RESULTS: The proximal branching pattern of the subscapular system was identified to have a common trunk in 99 (95%) sides. The remaining five sides (5%) demonstrated two arterial pedicles; with one patient exhibiting the variant anatomy bilaterally. CONCLUSION: Preoperative CT chest with contrast can accurately identify anatomic variation of the subscapular vascular system. For complex reconstruction requiring a single anastomosis in the vessel depleted neck, preoperative imaging can assure selection of a type I vascular anatomy of the proximal subscapular system. Preoperative imaging with contrasted CT has value in assessing this anatomy when planning for chimeric flaps involving circumflex scapular and thoracodorsal arteries. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:684-687, 2024.

Interobserver agreement for the direct and indirect signs of pulmonary embolism evaluated using contrast enhanced magnetic angiography.

BACKGROUND: Accurate diagnosis of pulmonary embolism (PE) using contrast enhanced MRA (CE-MRA) requires awareness of both the direct and indirect findings of PE. PURPOSE: To evaluate reader agreement of the direct and indirect findings of PE on CE-MRA. METHODS: We evaluated pulmonary artery diameter, right ventricle/left ventricle ratio, and clot/vessel lumen signal intensity ratio. Also, eight direct and eight indirect findings of PE were interpreted twice by two radiologists with different experience levels. The prevalence, and intra- and inter-reader agreement for the direct and indirect findings of PE were recorded. Statistical analysis of the measurements was assessed using intraclass correlation while Cohen's kappa test determined inter- and intra-reader agreement. RESULTS: We reviewed 66 positive CE-MRA exams, 10 of which cases were used for training. The largest PE for each of the remaining 56 cases (40 woman) were included in this analysis (38.9 ± 19.7 (mean age (years) ± S.D.)). The highest interobserver agreement for the direct findings were vessel cutoff (κ = 0.52, 95 % CI = (0.30, 0.74), p < .0001) and bright clot (κ = 0.51, 95 % CI = (0.26, 0.78), p = .0001). The highest interobserver agreement for the indirect findings were for atelectasis (κ = 0.67, 95 % CI = (0.49, 0.87), p < .0001), pleural effusions (κ = 0.56, 95 % CI = (0.32, 0.79), p = 0001) and blank slate sing (κ = 0.56, 95 % CI = (0.18, 0.94), p < .0001). CONCLUSION: The indirect findings of atelectasis and pleural effusion had better interobserver reproducibility than the direct findings of vessel cutoff and bright clot. The intraobserver reproducibility of the direct and indirect findings is dependent on experience level. SUMMARY STATEMENT: Using contrast enhanced magnetic resonance angiography for the diagnosis of pulmonary embolism, the indirect findings of atelectasis and pleural effusion had better interobserver reproducibility than the direct findings of vessel cutoff and bright clot.

Magnetic Resonance Imaging for the Evaluation of Pulmonary Embolism.

Pulmonary embolism (PE) is a leading cause of acute cardiovascular death throughout the world. Although computed tomography angiography (CTA) is the primary imaging study used to diagnose acute PE, pulmonary magnetic resonance angiography (MRA) is increasingly being used in patients with contraindications for CTA. This manuscript reviews the MRA techniques used for the diagnosis of PE and discuss how these techniques can be implemented in routine clinical practice. In addition, the efficacy and effectiveness of these techniques will be compared to other modalities.

Contrast-enhanced pulmonary MRA for the primary diagnosis of pulmonary embolism: current state of the art and future directions.

CT pulmonary angiography (CTPA) is currently considered the imaging standard of care for the diagnosis of pulmonary embolism (PE). Recent advances in contrast-enhanced pulmonary MR angiography (MRA) techniques have led to increased use of this modality for the detection of PE in the proper clinical setting. This review is intended to provide an introduction to the state-of-the-art techniques used in pulmonary MRA for the detection of PE and to discuss possible future directions for this modality. This review discusses the following issues pertinent to MRA for the diagnosis of PE: (1) the diagnostic efficacy and clinical effectiveness for pulmonary MRA relative to CTPA, (2) the different pulmonary MRA techniques used for the detection of PE, (3) guidance for building a clinical service at their institution using MRA and (4) future directions of PE MRA. Our principal aim was to show how pulmonary MRA can be used as a safe, effective modality for the diagnosis of clinically significant PE, particularly for those patients where there are concerns about ionizing radiation or contraindications/allergies to the iodinated contrast material.

An alternating focused ultrasound system for thermal therapy studies in small animals.

PURPOSE: To develop an alternating focused ultrasound system (AFUS) for preclinical studies of thermal and acoustic responses of tumors in small animal models. This work was motivated by the need of noninvasively creating relatively small spheroidal thermal lesions in small targets (e.g., a murine tumor) without damaging the surrounding tissues. METHODS: The AFUS consists of two lead zirconate titanate (PZT-4) spherically curved ultrasound transducers with focal zones crossing each other at a 90 degrees angle. The transducers were independently powered following a programed alternating firing scheme. Before the device design and construction, an acoustic and biothermal model was developed to simulate the ultrasound pressure field and the resulting temperature and thermal dose distributions. A shape factor, sphericity, to quantify the roundness of the lesions was calculated based on the 240 equivalent minutes at 43 degrees C thermal dose contours. A prototype of the AFUS was constructed with two identical transducers of an operating frequency of 2.25 MHz, 38 mm in diameter, and F-number equal to 1.33. To evaluate the performance of the AFUS experimentally, a series of heating in polyacrylamide phantoms, ex vivo porcine liver tissues, and in implanted mouse tumors fibrosarcoma (FSaII) in vivo was conducted. In these experimental cases, the sphericity was calculated and compared based on the visible lesion (a marked change in coloration). RESULTS: As shown in the simulations, the lesions induced in polyacrylamide phantoms, ex vivo porcine liver tissues, and in vivo mouse tumors, the sphericities of the lesions yielded by AFUS heating were approximately 50% higher than those of single focused ultrasound heating as long as moderate intensities were used and the duty cycle pulses were distributed equally among the transducers. CONCLUSIONS: The AFUS is a device capable of noninvasively creating spheroidal thermal lesions in small targets such as murine tumors.