Interstitial dual-mode ultrasound with a 3-mm MR-compatible catheter for image-guided HIFU and directional in-vitro tissue ablations.

Current interstitial techniques of tumor ablation face challenges that ultrasound technologies could meet. The ablation radius and directionality of the ultrasound beam could improve the efficiency and precision. Here, a 9-gauge MR-compatible dual-mode ultrasound catheter prototype was experimentally evaluated for Ultrasound Image-guided High Intensity Focused Ultrasound (USgHIFU) conformal ablations. The prototype consisted of 64 piezocomposite linear array elements and was driven by an open research programmable dual-mode ultrasound platform. After verifying the US-image guidance capabilities of the prototype, the HIFU output performances (dynamic focusing and HIFU intensities) were quantitatively characterized, together with the associated 3D HIFU-induced thermal heating in tissue phantoms (using MR thermometry). Finally, the ability to produce robustly HIFU-induced thermal ablations in in-vitro liver was studied experimentally and compared to numerical modeling. Investigations of several HIFU dynamic focusing allowed overcoming the challenges of miniaturizing the device: mono-focal focusing maximized deep energy deposition, while multi-focal strategies eliminated grating lobes. The linear-array design of the prototype made it possible to produce interstitial ultrasound images of tissue and tumor mimics in situ. Multi-focal pressure fields were generated without grating lobes and transducer surface intensities reached up to Isapa = 14 W·cm-2. Seventeen elementary thermal ablations were performed in vitro. Rotation of the catheter proved the directionality of ablation, sparing non-targeted tissue. This experimental proof of concept demonstrates the feasibility of treating volumes comparable to those of primary solid tumors with a miniaturized USgHIFU catheter whose dimensions are close to those of tools traditionally used in interventional radiology, while offering new functionalities.

Conservative management by embolization of a ruptured renal arterio-venous malformation (AVM) in Hereditary Hemorrhagic Telangiectasia (HHT).

BACKGROUND: Renal arteriovenous malformation (AVM) in Hereditary Hemorrhagic Telangiectasia (HHT) is uncommon and only few cases have been described, mainly with surgical management because of uncontrolled hematuria. CASE PRESENTATION: We managed a 70-year-old patient with HHT who presented with hematuria and left flank pain. Computed Tomography and ultrasound showed left renal AVM of 18 mm with clotting in the urinary tract. An external ureteral catheter was placed during 3 days to allow rinsing and facilitate elimination of clots. Given the patient's hemodynamic stability, a non-surgical management was chosen. Treatment of the AVM was performed by trans-arterial embolization using micro-coils and ethylene-vinyl alcohol copolymer. CONCLUSIONS: Our case study shows a conservative management by embolization of ruptured left renal AVM revealed by hematuria in a 70-year-old patient with HHT.

Portal vein embolization following arterial portography for the management of an active portal bleeding after blunt liver trauma in a cirrhotic patient.

BACKGROUND: The management of blunt liver trauma in cirrhotic patients is challenging, because while bleeding is most often of arterial origin, the increased pressure in the portal system associated with cirrhosis can increase the risk of portal bleeding, which is sometimes difficult to confirm on contrast-enhanced abdominal computed tomography. CASE PRESENTATION: We managed a 54-year-old cirrhotic patient who presented with blunt liver trauma. Computed Tomography showed active intraperitoneal bleeding presumed to be of hepatic origin. Given the patient's hemodynamic stability, the decision was made to manage the patient non-surgically. The patient underwent hepatic arteriography to rule out an arterial origin to the bleeding. A superior mesenteric arterial portography confirmed the portal venous origin of the bleeding. To stop the bleeding, a distal portal vein embolization using coils and glue was performed by approaching a large paraumbilical vein. CONCLUSIONS: Our case study shows the value of arterial portography in the management of these patients, when they are clinically stable enough to benefit from non-surgical management; This allows arterial bleeding to be excluded on hepatic arteriography, portal bleeding to be confirmed on portography following arteriography in the superior mesenteric artery, and guidance of portal vein embolization.

Performance of the Fresno-Quebec Rule in identifying patients with concomitant fractures not requiring a radiograph before shoulder dislocation reduction: a multicenter retrospective cohort study.

BACKGROUND AND IMPORTANCE: Although shoulder dislocation diagnosis is often solely based on clinical examination, physicians may order a radiograph to rule out a concomitant shoulder fracture before performing reduction. The Fresno-Québec decision rule aims to identify patients requiring a radiograph before reduction to avoid unnecessary systematic imaging. However, this novel approach needs further validation. OBJECTIVE: To evaluate the performance of the Fresno-Québec rule in identifying patients who do not require a prereduction radiograph and assess the variables associated with a clinically significant fracture. DESIGN, SETTINGS, AND PARTICIPANTS: A multicenter, retrospective cohort study from 2015 to 2021. Data were extracted from three ED university-affiliated tertiary-care centers. Patients aged ≥18 years with a final diagnosis of anterior glenohumeral dislocation were included. OUTCOMES MEASURE AND ANALYSIS: Accuracy metrics [sensitivity (Se), specificity (Sp), positive (PPV), negative predictive value (NPV), positive likelihood ratio (PLR) and negative likelihood ratio (NLR)] of the Fresno-Québec rule were measured. Multivariable logistic regression model was used to identify variables associated with the presence of a concomitant clinically significant fracture. MAIN RESULTS: A total of 2129 patients were included, among whom 9.7% had a concomitant fracture. The performance metrics of the Fresno-Québec rule were as follows: Se 0.96 95% confidence interval (0.92-0.98), Sp 0.36 (0.34-0.38), PPV 0.14 (0.12-0.16), NPV 0.99 (0.98-0.99), PLR 1.49 (1.42-1.55) and NLR 0.12 (0.06-0.23). A total of 678 radiographs could have been avoided, corresponding to a reduction of 35.2%. Age ≥40 years, first dislocation episode [odds ratio (OR) = 3.18 (1.95-5.38); P  < 0.001], the following mechanisms: road collision [OR = 6.26 (2.65-16.1)], low-level fall [OR = 3.49 (1.66-8.28)], high-level fall [OR = 3.95 (1.62-10.4)], and seizure/electric shock [OR = 10.6 (4.09-29.2)] were associated with the presence of a concomitant fracture. CONCLUSION: In this study, the Fresno-Québec rule has excellent Se in identifying concomitant clinically significant fractures in patients with an anterior glenohumeral dislocation. The use of this clinical decision rule may be associated with a reduction of approximately a third of unnecessary prereduction radiographs.