Reduced Radiation Dose with Model-based Iterative Reconstruction versus Standard Dose with Adaptive Statistical Iterative Reconstruction in Abdominal CT for Diagnosis of Acute Renal Colic.

PURPOSE: To evaluate the accuracy of reduced-dose abdominal computed tomographic (CT) imaging by using a new generation model-based iterative reconstruction (MBIR) to diagnose acute renal colic compared with a standard-dose abdominal CT with 50% adaptive statistical iterative reconstruction (ASIR). MATERIALS AND METHODS: This institutional review board-approved prospective study included 118 patients with symptoms of acute renal colic who underwent the following two successive CT examinations: standard-dose ASIR 50% and reduced-dose MBIR. Two radiologists independently reviewed both CT examinations for presence or absence of renal calculi, differential diagnoses, and associated abnormalities. The imaging findings, radiation dose estimates, and image quality of the two CT reconstruction methods were compared. Concordance was evaluated by κ coefficient, and descriptive statistics and t test were used for statistical analysis. RESULTS: Intraobserver correlation was 100% for the diagnosis of renal calculi (κ = 1). Renal calculus (τ = 98.7%; κ = 0.97) and obstructive upper urinary tract disease (τ = 98.16%; κ = 0.95) were detected, and differential or alternative diagnosis was performed (τ = 98.87% κ = 0.95). MBIR allowed a dose reduction of 84% versus standard-dose ASIR 50% (mean volume CT dose index, 1.7 mGy ± 0.8 [standard deviation] vs 10.9 mGy ± 4.6; mean size-specific dose estimate, 2.2 mGy ± 0.7 vs 13.7 mGy ± 3.9; P < .001) without a conspicuous deterioration in image quality (reduced-dose MBIR vs ASIR 50% mean scores, 3.83 ± 0.49 vs 3.92 ± 0.27, respectively; P = .32) or increase in noise (reduced-dose MBIR vs ASIR 50% mean, respectively, 18.36 HU ± 2.53 vs 17.40 HU ± 3.42). Its main drawback remains the long time required for reconstruction (mean, 40 minutes). CONCLUSION: A reduced-dose protocol with MBIR allowed a dose reduction of 84% without increasing noise and without an conspicuous deterioration in image quality in patients suspected of having renal colic.

Severe non-traumatic bleeding events detected by computed tomography: do anticoagulants and antiplatelet agents have a role?

PURPOSE: Bleeding is the most common and most serious complication of anticoagulant (AC) and antiplatelet agents (APA) which are increasingly used in every day practice. The aim of this study was to enlist and analyze the most severe bleeding events revealed during computed tomography scanner (CT scan) examinations over a 1-year period at our University Hospital and to evaluate the role of ACs and APAs in their occurrence. METHODS: This descriptive monocentric retrospective study included all patients who benefited from an emergency CT scan with a diagnosis of severe non-traumatic bleeding. Patients were divided into two groups: those treated with ACs and/or APAs, and those not treated with ACs or APAs. RESULTS: After applying the inclusion criteria, 93 patients were enrolled. Sixty-one patients received an anticoagulant or antiplatelet treatment, and 32 did not receive any AC or APA therapy. Seventy nine percent presented with an intracranial hemorrhage, 17% with a rectus sheath or iliopsoas bleeding or hematoma, and 4% with a quadriceps hematoma. Only patients who received ACs or APAs suffered a muscular hematoma (p < 0.0001). Among patients treated with vitamin K antagonists, 6/43 (14%), had an international normalized ratio (INR) higher than the therapeutic range (INR > 3). CONCLUSIONS: In our series, intracranial hemorrhage was preponderant and muscular hematomas occurred exclusively in patients treated with ACs and/or APAs. This study needs to be extended to evaluate the impact of new anticoagulant and antiplatelet agents.

Management of isolated non-traumatic renal artery dissection: report of four cases.

BACKGROUND: Isolated non-traumatic renal artery dissection (RAD) is a rare disorder with uncertain natural history. The management may be surgical reconstruction, endovascular repair, or conservative medical treatment, yet no official consensus had been established. PURPOSE: To report the management of four cases of isolated non-traumatic RAD, emphasizing the beneficial role of conservative medical treatment. MATERIAL AND METHODS: From the year 2000 till 2011, four male patients with mean age of 42.5 years (range 34-48 years) presented with isolated non-traumatic RAD and were initially treated with medical therapy. Transcatheter in situ thrombolysis was performed in a case with thrombotic occlusion. RESULTS: Isolated non-traumatic RAD in four patients involving at least seven branches progressed to thrombotic occlusion in two branches, luminal narrowing in five, dual lumens in two, and aneurysmal dilatation in three. Medical treatment was efficacious in three patients, who showed persistent preserved renal function, controlled blood pressure, and favorable arterial remodeling. After failure of medical therapy, the fourth patient was referred to surgery. Thrombolysis was successful to dissolute an occluding thrombotic dissection. CONCLUSION: Conservative therapy is safe and effective when the renal artery is patent and blood pressure is controlled: we propose it as the first line of treatment, reserving interventional management for refractory cases.

Endovascular treatment of eight renal artery aneurysms.

BACKGROUND: Renal artery aneurysms (RAA) are a relatively rare vascular entity. Treatment could be either surgical or via an endovascular route. The main aim of therapy is to prevent lethal rupture. PURPOSE: To evaluate the angiographic and clinical results after endovascular treatment (EVT) of eight renal artery aneurysms. MATERIAL AND METHODS: From January 2000 to June 2011, 18 patients presented with 18 renal artery aneurysms. One was classified as Rundback type I, 15 were type II, and two aneurysms were type III. Endovascular treatment was considered unsafe in 10 cases (all were Rundback type II), and were referred to surgery. The remaining eight aneurysms were treated endovascularly during altogether nine sessions. Among these, four patients were asymptomatic, three were hypertensive, and one presented with ipsilateral flank pains. Aneurysmal sac diameter varied between 12 and 50 mm. EVT included selective coil embolization in five cases, covered stents in two cases, and parent artery occlusion in one. RESULTS: Follow-up with CT angiography was obtained in all endovascularly treated aneurysms (range 6-54 months, mean 15 months). Complete durable occlusion was achieved in all aneurysms except one, which showed re-expansion after 20 months and was retreated with covered stent implantation. Clinically silent, branch occlusion occurred after four procedures with subsequent limited (less than 25%) ischemic parenchymal loss. All patients were discharged with preserved renal function. Clinical improvement was noted in all symptomatic patients. CONCLUSION: Endovascular treatment of renal artery aneurysms is an adequate treatment and can be proposed, if feasible, as first step.

Acute thrombotic mesenteric ischemia: primary endovascular treatment in eight patients.

INTRODUCTION: The purpose of this study was to evaluate our experience with initial percutaneous transluminal angioplasty (PTA) ± stenting as valuable options in the acute setting. METHODS: Between 2003 and 2008, eight patients with abdominal angio-MDCT-scan proven thrombotic AMI benefited from initial PTA ± stenting. We retrospectively assessed clinical and radiological findings and their management. Seven patients presented thrombosis of the superior mesenteric artery, and in one patient both mesenteric arteries were occluded. All patients underwent initial PTA and stenting, except one who had balloon PTA alone. One patient was treated by additional in situ thrombolysis. RESULTS: Technical success was obtained in all patients. Three patients required subsequent surgery (37.5%), two of whom had severe radiological findings (pneumatosis intestinalis and/or portal venous gas). Two patients (25%) died: both had NIDD, an ASA score ≥4, and severe radiologic findings. Satisfactory arterial patency was observed after a follow-up of 15 (range, 11-17) months in five patients who did not require subsequent surgery, four of whom had abdominal guarding but no severe CT scan findings. One patient had an ileocecal stenosis 60 days after the procedure. CONCLUSIONS: Initial PTA ± stenting is a valuable alternative to surgery for patients with thrombotic AMI even for those with clinical peritoneal irritation signs and/or severe radiologic findings. Early surgery is indicated if clinical condition does not improve after PTA. The decision of a subsequent surgery must be lead by early clinical status reevaluation. In case of underlying atherosclerotic lesion, stenting should be performed after initial balloon dilatation.

Cardiac tamponade after malignant superior vena cava stenting: Two case reports and brief review of the literature.

Percutaneous stenting of the superior vena cava (SVC) is usually recommended as a palliative procedure for malignant SVC obstruction with low reported morbidity. Complications are uncommon and usually of minor consequence. We report two unusual cases of cardiac tamponade following SVC stenting in patients with malignant SVC syndrome. Echocardiography allows rapid diagnosis and guides pericardial drainage in the interventional radiology suite.

Revascularization of traumatic renal artery dissection by endoluminal stenting: three cases.

Traumatic injury of renal arteries is rare and can induce renal dysfunction and hypertension. Management options include observation, nephrectomy, surgical repair, and, more recently, percutaneous angioplasty. We report three cases of renal artery thrombosis occurring in young multitrauma patients (mean age 28.7 years) treated with stenting. Immediate satisfactory results were obtained in all cases. Postprocedure anticoagulant and antiplatelet treatment were given according to associated contraindicating lesions. During follow-up, in-stent restenosis occurred in one patient and was treated successfully with a second stenting procedure. No renal dysfunction or hypertension was observed after 28.6 months follow-up. Percutaneous angioplasty is a valuable alternative to surgical treatment in selected patients.

[Vascular interventional procedures in oncology]. / Radiologie vasculaire interventionnelle en oncologie.

Indications for interventional radiology have increased, and various arterial and venous procedures are nowadays possible in oncology. Besides emergency procedures, scheduled palliative or curative procedures require multidisciplinary cooperation emphasizing on cautions related to iodine contrast media and concerning immunosuppresion, hemostasis disorders, analgesia, and the choice of the adequate approach. Diagnostic endovascular biopsies and venous sampling may be performed. Embolisation procedures are useful for achieving hemostasis, tumor devascularisation, or chemo-embolisation. Revascularisation procedures concern central vein obstructions, catheter occlusion or arterial stenoses and occlusions. Vena cava filtering, retrieval of intravascular foreign bodies and percutaneous implantation of ports can also be indicated, as well other treatments of central venous access complications. The principles, technical aspects, results, and indications of these various endovascular procedures are described in this review.

Palliative transarterial embolization of renal tumors in 20 patients.

OBJECTIVES: The aim of this study is to evaluate immediate technical and clinical results of palliative transarterial renal embolization in patients with symptomatic renal tumors. METHODS: Parenchymal embolization of 20 renal tumors was performed in 20 symptomatic patients with hematuria and/or lumbar pain and/or para-neoplastic syndrome. Seven patients were inoperable because of poor general condition, and 15 patients had metastatic lesions. RESULTS: Immediate technical success was observed, with post-infarction pain in all patients requiring analgesia in 12 cases (which was successful in 90%); 8 patients had transitory fever. With a median follow up of 8.1 (range 4-27) months, recurrent hematuria was noted in two patients for which partial embolization was initially chosen; pain did not recur in any patients. CONCLUSIONS: Palliative embolization of advanced symptomatic renal tumors is easy to accomplish with low morbidity. It helps to alleviate invalidating symptoms in a multidisciplinary management of advanced renal tumors.

Endovascular treatment of chronic mesenteric ischemia: results in 14 patients.

We evaluated immediate and long-term results of percutaneous transluminal angioplasty (PTA) and stent placement to treat stenotic and occluded arteries in patients with chronic mesenteric ischemia. Fourteen patients were treated by 3 exclusive celiac artery (CA) PTAs (2 stentings), 3 cases with both Superior Mesenteric Artery (SMA) and CA angioplasties, and 8 exclusive SMA angioplasties (3 stentings). Eleven patients had atheromatous stenoses with one case of an early onset atheroma in an HIV patient with antiphospholipid syndrome. The other etiologies of mesenteric arterial lesions were Takayashu arteritis (2 cases) and a postradiation stenoses (1 case). Technical success was achieved in all cases. Two major complications were observed: one hematoma and one false aneurysm occurring at the brachial puncture site (14.3%). An immediate clinical success was obtained in all patients. During a follow-up of 1-83 months (mean: 29 months), 11 patients were symptom free; 3 patients had recurrent pain; in one patient with inflammatory syndrome, pain relief was obtained with medical treatment; in 2 patients abdominal pain was due to restenosis 36 and 6 months after PTA, respectively. Restenosis was treated by PTA (postirradiation stenosis), and by surgical bypass (atheromatous stenosis). Percutaneous endovascular techniques are safe and accurate. They are an alternative to surgery in patients with chronic mesenteric ischemia due to short and proximal occlusive lesions of SMA and CA.

Circulating levels of the neuropeptide hormone somatostatin may determine hepatic fibrosis in Schistosoma mansoni infections.

The neuropeptide hormone somatostatin reduces fibrosis and Schistosoma-caused clinical morbidity in the rodent model. In our study we aimed to delineate an association between fibrosis and the inability to generate critical levels of endogenous somatostatin in S. mansoni infected subjects. In June 2001, 85 subjects from the district dispensary at Richard Toll in the Medical Region of Saint-Louis, Senegal, were selected. Fifty-seven subjects were infected with S. mansoni of whom 32 were suffering from severe morbidity (SM). Twenty-eight subjects showed an inactive disease status with no evident infection at the actual time of study. All subjects were classified according to age, sex, occupation, height, weight, and parasite eggs per gram. All 85 participated in a water contact and morbidity questionnaire, underwent a clinical examination and donated 5ml of peripheral blood for detecting plasma levels of somatostatin. Ultrasonography detected fibrosis grade in all the subjects. To address whether inherent somatostatin levels determined clinically evident disease severity (epg, hepatomegaly, splenomegaly, hematemesis, ascites), the mean somatostatin values of the inactive disease status group and severe morbidity group were compared. Low somatostatin levels were depicted in subjects with severe morbidity symptoms associated with schistosomiasis as compared to exposed but inactive disease status subjects residing in the same region. Logistic regression analysis indicated that with decreasing somatostatin values the probability of severe morbidity increased with age being a confounding factor. To address whether inherent somatostatin levels determined fibrosis and if this association was significant, plasma somatostatin levels of non-fibrotics (ultrasonographic grading A), and fibrotics (ultrasonographic grading B-E) were compared. In all age groups as well as in adults alone, mean somatostatin levels were higher in the non-fibrotic group as compared to the fibrotics group, the difference being significant. The group B comprised of borderline fibrotic cases, therefore a separate analysis was done between groups A (non-fibrotics) and groups C, D (confirmed fibrotics). Mean somatostatin values were higher in the non-fibrotic group as compared to the fibrotics group, the difference being borderline significant. In schistosomiasis patients, circulating levels of somatostatin by binding to hepatic stellate cells (HSC) may modulate fibrosis. This phenomenon is regulated by age whereas gender and prior treatment have no effect on this association. Host specific somatostatin levels may create a 'preset environment' status that can determine progression to severe fibrosis.