Paulo Donato

Silencing of phosphonate-gadolinium magnetic resonance imaging contrast by hydroxyapatite binding

Rationale and Objectives:GdDOTP5− is a highly charged, bone-seeking paramagnetic complex that could potentially detect bone lesions by magnetic resonance imaging (MRI). To date, its pharmacokinetics, effects on organ relaxivity, and interaction with hydroxyapatite (HA) has not been described. Methods:Liver, kidney, and bone MRI images were obtained on male white rabbits after the administration of GdDOTP5− or a gold standard MRI contrast agent, GdDTPA2−. Parallel in vitro experiments quantified the effect of HA binding on GdDOTP5− -induced changes in relaxivity. Results:The 2 compounds showed similar MRI enhancements in visceral tissues, but no enhancement of bone was evident with GdDOTP5− despite confirmation of bone and HA binding of the radioactive 153SmDOTP5− and 111InDOTP5− derivatives. In vitro experiments demonstrated that GdDOTP5−-induced changes in relaxivity were silenced upon HA binding but could be recovered by acid elution of the complex. Conclusions:HA binding assays revealed that GdDOTP5− is essentially MR silent when bound to bone, likely because of the exclusion of all outer sphere water molecules from the surface of the complex. These data suggest a novel strategy for creating highly sensitive, switchable MRI contrast agents.

Thoracic, abdominal and musculoskeletal involvement in Erdheim-Chester disease: CT, MR and PET imaging findings

AbstractBackgroundErdheim-Chester disease (ECD) is a rare, non-Langerhans cell histiocytosis with characteristic radiological and histological features. This entity is defined by a mononuclear infiltrate consisting of lipid-laden, foamy histiocytes that stain positively for CD68 and negatively for CD1a. Osseous involvement is constant and characteristic. Extra-osseous lesions may affect the retroperitoneum, lungs, skin, heart, brain and orbits.MethodsBoth radiography and technetium-99m bone scintigraphy may reveal osteosclerosis of the long bones, which is a typical finding in ECD. For visceral involvement, computed tomography (CT) is most useful, while magnetic resonance (MR) imaging is more sensitive for cardiovascular lesions; 2-[fluorine-18] fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET)/CT scanning is useful in assessing the extension of ECD lesions.ResultsThe prognosis is extremely variable and is often worse when there is cardiovascular system involvement. Diagnosis is based on the combination of radiographic, CT, MR imaging and nuclear medicine features and a nearly pathognomonic immunohistochemical profile.ConclusionThe aims of this work are to perform a systematic review of Erdheim-Chester disease as seen on imaging of the chest, abdomen and musculoskeletal system and to discuss the diagnostic workup and differential diagnoses according to the imaging presentation. Teaching points• Bone involvement is usually present in patients, and the imaging findings are pathognomonic of ECD.• The circumferential periaortic infiltration may extend to its branches, sometimes becoming symptomatic.• Cardiac involvement—the pericardium, right atrium and auriculoventricular sulcus—worsens its prognosis.• Perirenal infiltration extending to the proximal ureter is highly suggestive of this disease.

Normal vascular and biliary hepatic anatomy: 3D demonstration by multidetector CT

Due to constant innovations in radiological and surgical techniques, more accurate results are expected in the diagnostic and therapeutic procedures related to hepatic pathology. The aim of this work was to demonstrate the normal hepatic vascular and biliary anatomy using cadaveric livers and CT scans of the affected livers. Furthermore, using the CT scans, the authors intended to illustrate the most common morphological variations of the vascular and biliary anatomy. Four human cadaveric livers were injected with colored silicone mixed with radiological contrast solution in the common bile duct, in the proper hepatic artery, in the portal vein and in the inferior vena cava near the ostia of the hepatic veins (only one of these structures was injected in each liver). After obtaining the CT scans, 3D rendered models were created, which demonstrated the normal hepatic anatomy of the vascular and biliary structures. The International Anatomical Nomenclature was used for their classification (based on Couinaud’s work). The 3D rendered CT models were also modified to illustrate the most common normal variations of the hepatic anatomy (found in the literature).

Left ventricular diastolic function in type 2 diabetes mellitus and the association with coronary artery calcium score: a cardiac MRI study.

OBJECTIVE The purpose of this study was to compare cardiac MRI-derived parameters of left ventricular (LV) diastolic function between uncomplicated type 2 diabetes mellitus (DM2) and normoglycemic control subjects and to evaluate whether these parameters of LV diastolic function are related to coronary atherosclerosis. SUBJECTS AND METHODS We prospectively studied 41 subjects with DM2 and 21 normoglycemic control subjects (30 women and 32 men; mean age, 57.2 ± 7.1 [SD] years) with no evidence of overt cardiovascular disease. We used cardiac MRI to measure LV volumes, LV peak filling rate (PFR), and transmitral flow and CT to determine coronary artery calcium scores. RESULTS Absolute values of the peak filling rate (PFR) were significantly lower in DM2 patients than in control subjects (mean ± SD, 293.2 ± 51.7 vs 375.7 ± 102.8 mL/s, respectively; p < 0.001). Mitral peak E velocities (mean ± SD, 42.8 ± 10.7 vs 48.8 ± 10.4 cm/s; p = 0.040) and peak E velocity-to-peak A velocity ratios (0.88 ± 0.3 vs 1.1 ± 0.3; p = 0.002) were also lower in DM2 patients compared with control subjects. DM2 patients with coronary artery calcification showed a lower PFR normalized to stroke volume (SV) (mean ± SD, 4.4 ± 1.0 vs 5.3 ± 1.4, respectively; p = 0.038) and lower mitral peak E velocities (40.1 ± 11.3 vs 48.0 ± 7.3 cm/s; p = 0.024) than DM2 patients without coronary calcification. PFR normalized to SV was independently associated with the presence of coronary artery calcification (β = -1.5, p = 0.005). CONCLUSION DM2 decreases cardiovascular MRI-derived parameters of LV diastolic function. Patients with DM2 and coronary atherosclerosis show a more impaired LV diastolic function than patients without coronary atherosclerosis.

Autoimmune myocarditis in systemic sclerosis: an unusual form of scleroderma heart disease presentation

Primary cardiac involvement in systemic sclerosis is common, often subclinical, and is associated with significant mortality. We report the case of a patient who developed autoimmune myocarditis at an early stage of systemic sclerosis, who completely recovered from cardiac dysfunction under optimal medical therapy for heart failure and immunosuppression. This challenging case aims at increasing awareness around the fact that the heart is a target organ of scleroderma disease. It also highlights the importance of screening and early diagnosis of cardiac involvement, because a timely treatment may impact the quality of life of these patients and improve their prognosis.

Symptomatic bilateral coronary artery fistula to pulmonary artery in elderly patient

We report the imaging findings of an uncommon coronary vascular termination anomaly, with fistula to the pulmonary artery. This 70 year old female patient presented unstable angina, showing a coronary artery fistula depicted in coronary angiogram from the left coronary to the pulmonary artery, with no significant atherosclerotic pathology. Due to development of ventricular tachycardia in stress echocardiogram examination, she was proposed for coronary fistula closure. Coronary CT was performed for procedure planning and allowed the identification of a second unsuspected fistula from the right coronary to the right pulmonary artery. Congenital coronary anomalies are a possible cause of symptomatic coronary pathology in patients of any age. In older patients, coronary artery fistulas are rare, especially when symptomatic. Adequately performed CT examinations, using its post processing capabilities, with 3D and MIP reconstructions are invaluable in delineating coronary anatomy, essential for further treatment planning.

Collteral loop approach from left to right liver lobe: Endovascular recanalization of a hepatic vein in Budd-Chiari syndrome.

We report the approach to a 29 year old patient presenting with the diagnosis of a Budd-Chiari Syndrome, with clinical deterioration after initial anticoagulation treatment. The patient was proposed to endovascular treatment. Through intra-hepatic shunting seen at angiography, and from a left to right liver lobe, a guide-wire was passed retrogadely and allowed sufficient support to perform hepatic vein angioplasty and stenting. The patient responded favourably and liver transplant was avoided.

Congenital Thoracic Venous Anomalies in Adults: Morphologic MR Imaging

Congenital anomalies of the thoracic veins are rare yet important developmental abnormalities, usually classified into systemic and pulmonary. They may be encountered incidentally; as such the radiologist must be aware of their imaging presentation and clinical relevance. Furthermore, to understand these anomalies, knowledge of the embryological development and of the normal anatomy of the thoracic veins is required. In the age of non-invasive imaging modalities, magnetic resonance is paramount for the characterization of these developmental abnormalities.

Ecografia de Nervos Periféricos – Um Tutorial Guiado por Imagem para Iniciante

Avancos tecnicos na ecografia facilitou de forma fiavel a avaliacao de pequenas estruturas. Atualmente, a avaliacao de nervos perifericos depende ainda de dados clinicos suplementados por estudos eletrofisiologicos. A ultrassonografia pode ser aplicada na avaliacao de patologia de nervos perifericos, contribuindo para o diagnostico diferencial de patologias musculo-esqueleticas. O crescimento exponencial de publicacoes sobre esta tematica nos ultimos 10 anos foi fortemente fomentado pelo desenvolvimento de intervencao guiada por imagem, frequentemente utilizada em procedimentos analgesicos e anestesicos, tais como bloqueios nervosos. A Medicina da Dor e outro campo para a ecografia de nervos perifericos, onde a intervencao pode ser usada como forma de tratamento ou diagnostico. A ecografia e uma tecnica segura, embora fortemente dependente do utilizador, implicando firmes conhecimentos de anatomia. Elaborou-se uma revisao pictorica, assim como dos parâmetros e peculiaridades tecnicas utilizadas para otimizar a imagem obtida. Serao demonstrados os marcos anatomicos mais frequentes e reconheciveis no pescoco, membro superior, virilha, membro inferior, assim como a forma de colocacao da sonda. Sera efetuada uma breve revisao dos achados descritos em casos patologicos. Um firme conhecimento da ecografia dos nervos perifericos e um pre-requisito para os interessados na avaliacao destes. O papel da intervencao guiada por ecografia tem evoluido no campo da anestesia e no campo da medicina da dor. Os radiologistas estao em excelente posicao para relacionar a adequada tecnica e o conhecimento anatomico, permitindo expandir o papel dos procedimentos guiados por imagem.

Documento de consenso sobre codificação de exames de ressonância magnética cardíaca em Portugal

One of the obstacles to more frequent and appropriate use of cardiac magnetic resonance (CMR) in Portugal has been the lack of specific codes that accurately describe these examinations as they are currently performed. In this consensus document, recommendations are made for updating and standardizing CMR codes in Portugal. Guidance on which techniques and codes should be used in the most common clinical scenarios is also provided.