Hydatid disease (HD) is a unique parasitic disease that is endemic in many parts of the world. HD can occur almost anywhere in the body and demonstrates a variety of imaging features that vary according to growth stage, associated complications, and affected tissue. Radiologic findings range from purely cystic lesions to a completely solid appearance. Calcification is more common in HD of the liver, spleen, and kidney. HD can become quite large in compressible organs. Hydatid cysts (HCs) can be solitary or multiple. Chest radiography, ultrasonography (US), computed tomography (CT), magnetic resonance (MR) imaging, and even urography can depict HCs. The imaging method used depends on the involved organ and the growth stage of the cyst. US most clearly demonstrates the hydatid sands in purely cystic lesions, as well as floating membranes, daughter cysts, and vesicles. CT is best for detecting calcification and revealing the internal cystic structure posterior to calcification. MR imaging is especially helpful in detecting HCs of the central nervous system. Radiologic and serologic findings can generally help establish the diagnosis of HD, but an HC in an unusual location with atypical imaging findings may complicate the differential diagnosis. Nevertheless, familiarity with imaging findings, especially in patients living in endemic regions, is advantageous in this context.

Hydatid disease from head to toe.

The echinococcoses are chronic, parasitic diseases that are acquired after ingestion of infective taeniid tapeworm eggs from certain species of the genus Echinococcus. Cystic echinococcosis (CE) occurs worldwide, whereas, alveolar echinococcosis (AE) is restricted to the northern hemisphere, and neotropical echinococcosis (NE) has only been identified in Central and South America. Clinical manifestations and disease courses vary profoundly for the different species of Echinococcus. CE presents as small to large cysts, and has commonly been referred to as 'hydatid disease', or 'hydatidosis'. A structured stage-specific approach to CE management, based on the World Health Organization (WHO) ultrasound classification of liver cysts, is now recommended. Management options include percutaneous sterilization techniques, surgery, drug treatment, a 'watch-and-wait' approach or combinations thereof. In contrast, clinical manifestations associated with AE resemble those of a 'malignant', silently-progressing liver disease, with local tissue infiltration and metastases. Structured care is important for AE management and includes WHO staging, drug therapy and long-term follow-up for at least a decade. NE presents as polycystic or unicystic disease. Clinical characteristics resemble those of AE, and management needs to be structured accordingly. However, to date, only a few hundreds of cases have been reported in the literature. The echinococcoses are often expensive and complicated to treat, and prospective clinical studies are needed to better inform case management decisions.

The Echinococcoses: Diagnosis, Clinical Management and Burden of Disease.

Echinococcosis or hydatid disease (HD) is a zoonosis caused by the larval stages of taeniid cestodes belonging to the genus Echinococcus. Hepatic echinococcosis is a life-threatening disease, mainly differentiated into alveolar and cystic forms, associated with Echinoccus multilocularis (E. multilocularis) and Echinococcus granulosus (E. granulosus) infection, respectively. Cystic echinococcosis (CE) has a worldwide distribution, while hepatic alveolar echinococcosis (AE) is endemic in the Northern hemisphere, including North America and several Asian and European countries, like France, Germany and Austria. E. granulosus young cysts are spherical, unilocular vesicles, consisting of an internal germinal layer and an outer acellular layer. Cyst expansion is associated with a host immune reaction and the subsequent development of a fibrous layer, called the pericyst; old cysts typically present internal septations and daughter cysts. E. multilocularis has a tumor-like, infiltrative behavior, which is responsible for tissue destruction and finally for liver failure. The liver is the main site of HD involvement, for both alveolar and cystic hydatidosis. HD is usually asymptomatic for a long period of time, because cyst growth is commonly slow; the most frequent symptoms are fatigue and abdominal pain. Patients may also present jaundice, hepatomegaly or anaphylaxis, due to cyst leakage or rupture. HD diagnosis is usually accomplished with the combined use of ultrasonography and immunodiagnosis; furthermore, the improvement of surgical techniques, the introduction of minimally invasive treatments [such as puncture, aspiration, injection, re-aspiration (PAIR)] and more effective drugs (such as benzoimidazoles) have deeply changed life expectancy and quality of life of patients with HD. The aim of this article is to provide an up-to-date review of biological, diagnostic, clinical and therapeutic aspects of hepatic echinococcosis.

Hepatic echinococcosis: Clinical and therapeutic aspects

Selection of the most appropriate treatment to obtain the best results with the lowest rate of recurrence and minimal morbidity and mortality is mandatory for the management of hepatic hydatid disease. The surgical approach is the mainstay of treatment, and there has been a tendency toward laparoscopic surgery and, more recently, percutaneous treatment (PT), which has become increasingly popular with revolutions in techniques. We aimed to evaluate the results of current therapeutic methods in the context of a 10-year single-institution experience. Between 1992 and 2003, 355 patients with 510 hydatid cysts of the liver were treated by open operation, laparoscopic surgery, or PT. The series included 128 females and 227 males ranging in age from 10 years to 73 years. Preferred treatment modalities, perioperative complications, interventions, recurrences, and length of hospital stay were retrospectively analyzed. There were two postoperative deaths (1.08%) in the open surgery group. Biliary leakage was observed in 28 patients treated with open surgery, in 10 patients after PT, and in 2 after laparoscopic treatment. Recurrence rates were 16.2%, 3.3%, and 3.5% after open surgery, laparoscopic surgery, and percutaneous treatment, respectively. Characteristics of the cyst, presence of cystobiliary communications, and the availability of a multidisciplinary team are the factors that we believe directly affect the results. Radical surgery can be done safely for suitable cases; conventional procedures are associated with greater morbidity. Laparoscopic surgery seems effective and safe, with low morbidity and recurrence rates for type I–III cysts in accessible localizations. Our experience with PAIR (puncture, aspiration, injection, and reaspiration) and catheterization provides evidence that the procedure is an effective and safe option.

Results of Surgical, Laparoscopic, and Percutaneous Treatment for Hydatid Disease of the Liver: 10 Years Experience with 355 Patients

PURPOSE: To determine the predisposing factors to transplant renal arterial stenosis (TRAS) and assess the outcome of percutaneous transluminal angioplasty (PTA) as the primary treatment. MATERIALS AND METHODS: Of 831 renal allograft recipients (584 cadaveric, 247 living related) between January 1991 and December 1998, 72 had hypertension and/or renal dysfunction. All 72 underwent arteriography, and their medical charts were retrospectively reviewed. RESULTS: Prevalence of TRAS was 3.1% (26 of 831). Technical success rate of PTA was 94% (16 of 17), and clinical success rate was 82% (14 of 17). Those with renal dysfunction had a mean pre-PTA creatinine value of 2.6 mg/dL (230 μmol/L) ± 0.5 (SD) versus a 1-week post-PTA value of 1.7 mg/dL (150 μmol/L) ± 0.3 (P < .001). Of those with hypertension, all but one had substantial improvement in mean diastolic blood pressure. At 26.9 months mean follow-up in 16 patients with successful PTA, two stenoses reoccurred, and two grafts were lost to chronic rejection. TR...

Renal arterial stenosis in renal allografts: retrospective study of predisposing factors and outcome after percutaneous transluminal angioplasty.

Hydatid disease primarily affects the liver and typically demonstrates characteristic imaging findings. However, there are many potential local complications (eg, intrahepatic complications, exophytic growth, transdiaphragmatic thoracic involvement, perforation into hollow viscera, peritoneal seeding, biliary communication, portal vein involvement, abdominal wall invasion). Furthermore, secondary involvement due to hematogenous dissemination may be seen in almost any anatomic location (eg, lung, kidney, spleen, bone, brain). Ultrasonography (US) is particularly useful for the detection of cystic membranes, septa, and hydatid sand. Computed tomography (CT) best demonstrates cyst wall calcification and cyst infection. CT and magnetic resonance (MR) imaging may demonstrate cyst wall defects as well as the passage of contents through a defect. Chest radiography, US, CT, and MR imaging are all useful in depicting transdiaphragmatic migration of hydatid disease. CT is the modality of choice in peritoneal seeding. US and CT demonstrate rupture in most cases that involve wide communication. Indirect signs of biliary communication include increased echogenicity at US and fluid levels and signal intensity changes at MR imaging. CT allows precise assessment of osseous lesions, whereas MR imaging is superior in demonstrating neural involvement. Familiarity with atypical manifestations of hydatid disease may be helpful in making a prompt, accurate diagnosis.

Hydatid Disease: Radiologic and Pathologic Features and Complications

Our objective was to evaluate use of gadolinium-enhanced three-dimensional (3D) MR angiography in the assessment of suspected arterial inflow stenosis after kidney transplantation.Twenty-eight consecutive patients receiving kidney transplants (26 single-kidney transplants and two en block transplants) with suspected arterial inflow stenosis were examined with two MR angiography sequences: gadolinium-enhanced 3D fast spoiled gradient-recalled (SPGR) imaging and 3D phase-contrast imaging. Twenty-four of these patients then were examined using the gold standards: either digital subtraction angiography (DSA) (n = 23) or surgery (n = 1). MR angiography and DSA studies were independently and prospectively analyzed for the presence of arterial stenoses (mild [ 90%]) in the iliac, anastomotic, and renal artery segments. Two independent observers retrospectively evaluated the MR angiography sequences for ability to detect or exclude significant (> or = 50%) arterial stenoses.In...

Using gadolinium-enhanced three-dimensional MR angiography to assess arterial inflow stenosis after kidney transplantation.

OBJECTIVES Left ventricle trabeculae (LVT) are frequently seen in different cardiac diseases. Normal reference values of LVT in different cardiac conditions are not known. The aim of the study was to quantify with cardiac magnetic resonance (CMR), LVT mass (LVTM) and LVTM percentage (LVTM%) in different heart diseases and to evaluate their influence on left ventricular morphological and functional parameters. METHODS Fifty-nine patients (14 controls, 17 ischemic cardiomyopathy, 15 nonischemic dilated cardiomyopathy, 7 valvular heart disease and 6 with left ventricle hypertrophy) were enrolled. Cine-MR images were acquired with steady-state free-precession sequence in a short-axis view. LVTM was calculated as the difference between LVM excluding/including trabecuale from the blood cavity. LVTM% was calculated as the percentage of the whole left ventricle mass excluding trabeculae from the blood cavity. RESULTS Mean age was 47.60 +/- 22.03 years; male 62.7%. Mean LVTM was of 33.38 +/- 16.1 g with mean LVTM% of 19.22 +/- 6.5%. Significant differences between groups for both parameters with P values of 0.02 were obtained. Nonischemic dilated cardiomyopathy showed the highest degree of LVTM (44.73 +/- 16.0 g) and LVTM% (23.26 +/- 6%). Significant differences were noted in left ventricular morphological and functional parameters with inclusion/exclusion of LVT in the myocardial mass. CONCLUSIONS Reference values and differences of LVTM and LVTM% in various cardiac conditions are given for the first time. Quantification of these parameters with CMR may be clinically useful in the differential diagnosis between left ventricular noncompaction and other cardiac diseases. Exclusion of LVT from myocardium alters left ventricular morphological and functional parameters, which have significant clinical importance.

Left ventricular trabeculae: quantification in different cardiac diseases and impact on left ventricular morphological and functional parameters assessed with cardiac magnetic resonance.

Thoracic aortic dissection is a life-threatening disease with a high mortality rate and an elevated incidence of early and long-term complications. Advances in surgical treatment of ascending (Stanford type A) aortic dissection have helped improve patient survival, but follow-up imaging is critically important for the identification of postsurgical complications. Gadolinium-enhanced three-dimensional (3D) magnetic resonance (MR) angiography, along with multisection computed tomography, is the technique of choice for this purpose. For accurate assessment of 3D MR angiograms, it is important to know what surgical procedure was performed and to be familiar with the appearance of the normal postsurgical anatomy. A thorough understanding of potential postsurgical complications also is essential. Some complications (eg, formation of a periprosthetic hematoma or pseudoaneurysm, stenosis in a graft anastomosis) may derive from the prosthesis. Complications also may occur in the remnant of the native aorta, where persistent dissection distal to the prosthesis is common and may result in false channel thrombosis or aneurysmatic dilatation with collapse of the true lumen. Residual dissection that involves the supra-aortic trunks or the visceral aortic branches may produce neurologic effects or renal and mesenteric ischemia, respectively.

https://pubs.rsna.org/doi/pdf/10.1148/rg.264055082

Joaquín Ferreirós

Papers

Hydatid Disease: Radiologic and Pathologic Features and Complications

Using gadolinium-enhanced three-dimensional MR angiography to assess arterial inflow stenosis after kidney transplantation.

Left ventricular trabeculae: quantification in different cardiac diseases and impact on left ventricular morphological and functional parameters assessed with cardiac magnetic resonance.

MR Angiographic Evaluation of Complications in Surgically Treated Type A Aortic Dissection

Clinical outcomes of patients with intramyocardial bridging diagnosed by multi-detector cardiac computed tomography