Rajeev Suri

Aortitis: imaging spectrum of the infectious and inflammatory conditions of the aorta.

Aortitis is a general term that refers to a broad category of infectious or noninfectious conditions in which there is abnormal inflammation of the aortic wall. These inflammatory conditions have different clinical and morphologic features and variable prognoses. The clinical manifestations are usually vague and nonspecific and may include pain, fever, vascular insufficiency, and elevated levels of acute phase reactants, as well as other systemic manifestations. As a result, aortitis is often overlooked during the initial work-up of patients with constitutional symptoms and systemic disorders. A multimodality imaging approach is often required for assessment of both the aortic wall and aortic lumen, as well as for surveillance of disease activity and treatment planning. Noninvasive cross-sectional imaging modalities such as magnetic resonance (MR) imaging, MR angiography, and computed tomographic angiography play a critical role in initial evaluation and further assessment of aortitis. Radiologists should be familiar with the clinical features and imaging findings of the different types of aortitis.

Distal Embolic Protection During Femoropopliteal Atherectomy

We report on a series of 10 consecutive cases of superficial femoral and popliteal artery atherectomy with the SilverHawk device, carried out for the treatment of peripheral vascular atherosclerosis. All cases were done with the use of a distal embolic protection device. Debris were retrieved in the filter in each case. Implications are discussed, along with a review of the available literature on this device.

Idiopathic and diabetic skeletal muscle necrosis: evaluation by magnetic resonance imaging.

ObjectiveIdiopathic and diabetic-associated muscle necrosis are similar, uncommon clinical entities requiring conservative management and minimal intervention to avoid complications and prolonged hospitalization. An early noninvasive diagnosis is therefore essential. We evaluated the magnetic resonance imaging (MRI) characteristics of muscle necrosis in 14 patients, in eight of whom the diagnoses were confirmed histologically.Design and patientsTwo experienced musculoskeletal radiologists performed retrospective evaluations of the MRI studies of 14 patients with the diagnoses of skeletal muscle infarction. In 10 cases gadolinium-enhanced (T1-weighted fat-suppressed) sequences were available along with T1-weighted, T2-weighted images and STIR sequences, while in four cases contrast-enhanced images were not available.ResultsEight patients had underlying diabetes and in six patients the cause of the myonecrosis was considered idiopathic. T1-weighted images demonstrated isointense swelling of the involved muscle, with mildly displaced fascial planes. There was effacement of the fat signal intensity within the muscle. Fat-suppressed T2-weighted images showed diffuse heterogeneous high signal intensity in the muscles suggestive of edema. Perifascial fluid collection was seen in eight cases. Subcutaneous edema was present in seven patients. Following intravenous gadolinium administration, MRI demonstrated a focal area of heterogeneously enhancing mass with peripheral enhancement. Within this focal lesion, linear dark areas were seen with serpentine enhancing streaks separating them in eight cases. In two cases, a central relatively nonenhancing mass with irregular margins and peripheral enhancement was noted. The peripheral enhancement involved a significant part of the muscle. No focal fluid collection was noted.ConclusionsWe believe that the constellation of imaging findings on T1- and T2-weighted images and post-gadolinium sequences is highly suggestive of muscle necrosis. We consider certain specific findings on gadolinium-enhanced images to be characteristic. The findings reported here should provide radiologists with useful information in making the diagnosis of skeletal muscle necrosis without resorting to invasive procedures.

Causes of TIPS Dysfunction

OBJECTIVE Transjugular intrahepatic portosystemic shunt (TIPS) creation is an effective method to control portal hypertension. TIPS creations with bare stents have shown limited and unpredictable patency. In nearly all cases of rebleeding or recurrent ascites after TIPS creation, there is shunt stenosis or occlusion. The purpose of this article is to review the biologic and technical factors that predispose to TIPS failure and how the use of an expandable polytetrafluoroethylene (PTFE)-covered-stent has significantly improved TIPS patency. CONCLUSION Biologic and technical factors may predispose to shunt failure. The combination of improved technique and expandable PTFE has significantly improved TIPS patency. The need for follow-up venography and secondary interventions has been reduced significantly as a result of improved shunt patency.

Vascular malformations and arteriovenous fistulas of the kidney

Vascular malformations of the kidney are disease processes that involve renal veins and arteries and include congenital arteriovenous malformations (AVMs) and arteriovenous fistulas. AVMs are congenital communications between arteries and veins with a vascular nidus that bypass the capillary bed. Congenital AVMs are rare and subclassified in cirsoid, angiomatous, and aneurysmal types. Congenital AVMs are different from iatrogenic or traumatic arteriovenous fistulas (AVF), which are characterized by a single direct communication between an artery and a vein without an intervening vascular nidus. These lesions may present with a wide range of signs and symptoms that vary from hypertension to renal masses. Imaging is valuable in the detection and characterization of AVM and AVF. The presence of arteriovenous shunting characterizes AVM and AVF. These lesions represent an important group of entities for diagnostic consideration, and understanding the vascular anatomy helps in guiding for proper treatment. This article describes the imaging features of each lesion that help to differentiate it from the others and the endovascular therapies to treat these vascular processes and their possible complications.

Renal aneurysms and pseudoaneurysms.

Pseudoaneurysms and aneurysms are abnormal dilatations of the vessel lumen. Pseudoaneurysm is a perfused hematoma contained by the adventitia and perivascular tissues that is in communication with the lumen of an adjacent artery or vein. Aneurysm is a dilatation of the vessel lumen involving all three layers of the blood vessel wall. Renal artery aneurysms (RAA) are uncommon but the widespread use of cross-sectional imaging and incidental detection of RAA may result in an increasing number of cases diagnosed. Renal artery pseudoaneurysms are suspected in bleeding patients after penetrating renal trauma. Imaging plays a major role in the detection of renal pseudoaneurysms and aneurysms and diagnoses aneurysm rupture and active bleeding. Computed tomography (CT), magnetic resonance imaging, and digital subtraction angiography can characterize lesion size, shape, and location and identify other aneurysms and pseudoaneurysms, helping to narrow the differential diagnosis and to understand the vascular anatomy for guiding proper treatment. Endovascular treatments have contributed considerably in the management of renal pseudoaneurysms and aneurysms. The use of coil embolization or covered stent placement prevents the mortality and mobility of surgery. The article describes imaging features and the endovascular therapies to treat these vascular processes and their possible complications.

Traumatic Occlusion and Dissection of the Main Renal Artery: Endovascular Treatment

PURPOSE To report experience with endovascular treatment of traumatic injuries of the main renal artery. MATERIALS AND METHODS A retrospective review of traumatic injuries to the main renal artery was performed in three major trauma institutions. Eight patients (age range, 17-46 y; mean age, 27 y) presented with main renal artery occlusion (n = 7) or dissection (n = 1) after major blunt abdominal trauma. Associated injuries were present in the majority of patients. The mean time from injury to intervention was 5 hours (range, 2-8 h). RESULTS Recanalization of the occluded renal artery with stent placement was successfully achieved in six patients. In two of the eight patients, interventions resulted in extravasation of contrast medium, and embolization of the main renal artery was performed. At follow-up 2-24 months after injury, four patients had kidney atrophy (two treated with embolization and two with stents), two had proven stent patency with functional kidneys, one was normotensive with unknown stent patency, and one was lost to follow-up. One of the patients with an occluded stent developed severe renal hypertension and required nephrectomy. CONCLUSIONS The majority of occlusions and dissections of the main renal artery after major blunt abdominal trauma can be successfully treated with recanalization and stent placement. However, long-term kidney salvage is not always achieved, and there is a potential of development of renovascular hypertension, which may require late nephrectomy.

Transjugular Intrahepatic Portosystemic Shunt Flow Reduction with Adjustable Polytetrafluoroethylene-covered Balloon-expandable Stents

Creation of a transjugular intrahepatic portosystemic shunt (TIPS) can effectively treat complications of portal hypertension, but excessive shunting can cause life-threatening hepatic encephalopathy and hepatic insufficiency. The present report describes a novel technique that allows for controlled and adjustable flow reduction through the TIPS via partial closure of the shunt with a balloon-mounted covered stent. The method results in clinical improvement of hepatic encephalopathy and hepatic insufficiency and immediate increase in the portosystemic pressure gradient. However, among the four patients described herein, survival beyond 1 year was seen in only one, who underwent liver transplantation after TIPS reduction.

Embolization of a large high-flow renal arteriovenous fistula using 035″ and 018″ detachable coils

Transcatheter embolization of renal arteriovenous fistula (AVF) is a minimally invasive procedure that, in some occasions, can replace surgery and potentially save the kidney. The embolization techniques for the renal AVFs have evolved considerably with the availability of newer hardwares. Still, the risk of inadvertent migration of the embolization materials to the pulmonary circulation is a concern. This article describes a novel technique of coiling the feeding segmental artery to a large high-flow renal AVF using 035″ and 018″ detachable coils only, and briefly reviews the previously described strategies to safely embolize renal AVFs.

MDCT angiography of mesenteric bypass surgery for the treatment of chronic mesenteric ischemia

OBJECTIVE Chronic mesenteric ischemia (CMI) is a serious condition that requires surgical or endovascular intervention. Surgical revascularization for the treatment of CMI uses different operative techniques including endarterectomy, vessel reimplantation, and mesenteric bypass. A basic understanding of the operative techniques is essential for the adequate interpretation of imaging studies in patients who have undergone surgery for CMI. In this article, we review the different operative techniques used in the treatment of CMI, discuss the results of surgical intervention for CMI, and illustrate how MDCT angiography (MDCTA) can be used for follow-up and for the detection of early and late complications after surgery. CONCLUSION MDCTA is a powerful tool for the postoperative evaluation of patients with CMI. Early detection of graft dysfunction is critical to prevent graft occlusion and the development of potentially fatal mesenteric ischemia. MDCTA can detect early and late complications after surgery and guide additional surgical or endovascular interventions.