Articles

Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.

230 results found
Article

2016 Histiocyte Society classification of histiocytoses

The 2016 Histiocyte Society classification of histiocytoses and neoplasms of macrophage-dendritic cell lineages is a proposed revision of the organization's initial classification system from 1987. Terminology Histiocytes are mononuclear phagocytes that reside in tissues, including macrophages...
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Acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is a malignant disorder of the bone marrow characterized by the proliferation of the lymphoid progenitor cells. Epidemiology ALL is the commonest form of childhood leukemia, accounting for ~80% of pediatric leukemia cases 1. In adults, ALL corresponds to ~20%...
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Acute myeloid leukemia

Acute myeloid leukemia (AML), also referred to as acute myelogenous leukemia, is a hematological malignancy characterized by the abnormal clonal proliferation of immature myeloid precursors (myeloblasts) or poorly differentiated cells of the hematopoietic system. It primary infiltrates the bone ...
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Acute promyelocytic leukemia

Acute promyelocytic leukemia (APML) is a distinct subtype of acute myeloid leukemia. Pathology Genetics It is defined by a balanced translocation between chromosomes 15 and 17 resulting in fusion of the promyelocytic leukemia gene (PML) on chromosome 15 with the retinoic acid receptor alpha g...
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Adenoid tonsils

The adenoid tonsils, or often just simply the adenoids, (also known as the nasopharyngeal or pharyngeal tonsils) are paired foci of lymphatic tissue located on the superoposterior wall of the nasopharynx and form part of Waldeyer's ring.
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AIDS-defining illness

AIDS-defining illnesses are conditions that in the setting of a HIV infection confirm the diagnosis of AIDS, and do not commonly occur in immunocompetent individuals 2. According to the CDC surveillance case definition 1, they are: Infectious bacterial infections: multiple or recurrent candid...
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AIDS-related pulmonary lymphoma

AIDS-related pulmonary lymphoma (ARPL) is classified as a distinct form of pulmonary lymphoma. Pulmonary involvement is a common extranodal site in AIDS-related NHL. Pathology ARPL is typically a high-grade B-cell non-Hodgkin's lymphoma and the majority of patients have advanced HIV infection,...
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All-trans retinoic acid syndrome

All-trans retinoic acid (ATRA) syndrome, more recently known as differentiation syndrome (DS) 8, is a condition that can occur with patients with acute promyelocytic leukemia who are on therapeutic all-trans-retinoic acid (ATRA). All-trans-retinoic acid (ATRA) is a normal constituent of plasma ...
Article

Anemia

Anemia is the presence of reduced hemoglobin in the blood. Formally, the World Health Organization (WHO) defines anemia by the hemoglobin concentration in the blood according to age and sex 1: adult men: <130 g/L adult women: <120 g/L Values for pregnant women and children are different. Pat...
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Anatomy curriculum

The anatomy curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core anatomy knowledge for radiologists and imaging specialists. General anatomy Neuroanatomy Head and neck anatomy Thoracic anatomy Abdominal and pelvic anatomy Spinal anat...
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Angioimmunoblastic T cell lymphoma

Angioimmunoblastic T-cell lymphoma (AITL) is a rare, aggressive (fast-growing) form of peripheral T-cell lymphoma. It only accounts for around 1-2% of all non-Hodgkin lymphoma. It is one of the more common subtypes of mature T-cell lymphomas.  Epidemiology It can be more common in the elderly....
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Ann Arbor staging system

The Ann Arbor staging system is the landmark lymphoma staging classification system for both Hodgkin lymphoma and non-Hodgkin lymphoma.  It is named after the town of Ann Arbor in the US state of Michigan where the Committee on Hodgkin's Disease Staging Classification met in 1971 to agree on it...
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Antiphospholipid syndrome

Antiphospholipid syndrome is a systemic autoimmune disorder. It is usually defined as the clinical complex of vascular occlusion and ischemic events occurring in patients who have circulating antiphospholipid antibodies. Clinical presentation Antiphospholipid syndrome is characterized by venou...
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Antithrombin III deficiency

Antithrombin (AT) III deficiency (now simply called antithrombin deficiency) refers to a congenital lack of the endogenous anticoagulant antithrombin. Epidemiology Antithrombin deficiency is considered the least common of the three main anticoagulant deficiencies (the other two being protein C...
Article

Aplastic anemia

Aplastic anemia is a rare hematopoietic stem-cell disorder. The condition results in pancytopenia and hypocellular bone marrow. Most cases are acquired, however, there are unusual inherited forms. Pathology Aplastic anemia manifests as a marked reduction in the number of pluripotent hematopoie...
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Ariboflavinosis

Ariboflavinosis is the term given to riboflavin (vitamin B2) deficiency.  Epidemiology Ariboflavinosis has been seen in both developed and developing countries, and across the socioeconomic spectrum. It is usually present in the context of other hypovitaminoses. It has been found to more comm...
Article

Autosplenectomy

Autosplenectomy denotes spontaneous infarction of the spleen with resulting hyposplenism. Epidemiology Autosplenectomy is most frequently encountered in patients with homozygous sickle cell disease, although it has also been reported in pneumococcal septicemia 1, and SLE 2. The demographics th...
Article

BALT lymphoma

BALT lymphoma is an abbreviated term for bronchus-associated lymphoid tissue lymphoma. These neoplasms fall under the broader umbrella of mucosa associated lymphoid tissue (MALT) lymphomas. It is sometimes considered a type of primary pulmonary lymphoma. Clinical presentation Up to half of pat...
Article

Binet staging system for chronic lymphocytic leukemia

The Binet staging system is one of the two staging systems currently adopted in assessment of chronic lymphocytic leukemia (CLL). It classifies CLL according to the number of lymphoid tissues that are involved (i.e. the spleen and the lymph nodes of the neck, groin, and underarms), as well as t...
Article

Bing-Neel syndrome

Bing-Neel syndrome is an extremely rare neurological complication of Waldenström macroglobulinemia where there is malignant lymphocyte infiltration into the central nervous system (CNS). Epidemiology The exact incidence is unknown, however in one study of patients with Waldenström macroglobuli...
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Blastic plasmacytoid dendritic cell neoplasm

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematological malignancy. It was previously termed as blastic natural-killer lymphoma or agranular CD4+ natural killer cell leukemia. Epidemiology It only represent a very small proportion (~0.44%) of all hematological malignancies...
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Bone marrow

Normal bone marrow is divided into red and yellow marrow, a distinction made on the grounds of how much fat it contains. Gross anatomy Red marrow is composed of: hematopoietic cells supporting stroma reticulum (phagocytes and undifferentiated progenitor cells) scattered fat cells a rich v...
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Breast lymphoma

Breast lymphoma refers to the involvement of the breast with lymphoma and may be primary or secondary. Epidemiology Both primary and secondary breast lymphomas are rare, accounting for ~ 0.5% (range 0.3-1.1%) of all breast malignancies. Clinical presentation Breast lymphoma may present eithe...
Article

Burkitt lymphoma

Burkitt lymphoma is an aggressive B-cell lymphoma predominantly affecting children. Epidemiology Burkitt lymphoma is the most common (40%) type of non-Hodgkin lymphoma in childhood. Median age is eight years with a male predominance (M:F = 4:1) 1. It is less common in adults, accounting for 1-...
Article

Capillary leak syndrome

Capillary leak syndrome is is a situations characterized by the escape of blood plasma through capillary walls, from the blood vessels to surrounding tissues, muscle compartments, organs or body cavities. Clinical presentation The idiopathic form of the syndrome is characterized by three phase...
Article

Carbon monoxide poisoning

Carbon monoxide (CO) poisoning may result in an anoxic-ischemic encephalopathy, with acute as well as delayed effects. Epidemiology Carbon monoxide poisoning is mostly preventable with common causes including malfunctioning heating systems, improperly ventilated motor vehicles, and residential...
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Catheter-directed thrombolysis

Catheter-directed thrombolysis (CDT) is an endovascular approach to the treatment of acute iliofemoral deep vein thrombosis. It involves the administration of a lytic agent directly into a thrombus.  Indications precise diagnosis of iliofemoral deep vein thrombosis  first episode of acute ili...
Article

Chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a hematological malignancy characterized by the proliferation of mostly mature but abnormal leukocytes.  Epidemiology CLL is considered the most common type of leukemia in the Western hemisphere; its prevalence in Europe and North America ranges from 29-38...
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Chronic myeloid leukemia

Chronic myeloid leukemia (CML), also known as chronic myelogenous leukemia, is a myeloproliferative neoplasm characterized by the overproduction of granulocytes with fairly normal differentiation. Epidemiology The annual incidence is about 1 per 100,000 1,3. The typical age at presentation is ...
Article

Chronic myelomonocytic leukemia

Chronic myelomonocytic leukemia (CMML) is a relatively rare clonal hematologic disorder. In the World Health Organization classification, it is listed as a disorder with features of both myelodysplastic syndromes and myeloproliferative neoplasms. Clinical presentation Can be variable but many ...
Article

CNS lymphoma

CNS lymphoma refers to the involvement of the central nervous system with lymphoma. It can be broadly divided into primary and secondary, with a number of special types of also recognized.  primary CNS lymphoma (PCNSL) intravascular lymphoma MALT lymphoma of the dura 5 secondary CNS lymphoma...
Article

Copper deficiency

Copper deficiency (also known as hypocupremia) is unusual due to the ubiquity of copper in the normal diet. Epidemiology Copper deficiency is thought to be rare, but exact numbers are difficult to ascertain. Clinical presentation The typical presentation of copper deficiency mimics the more ...
Article

Cryoglobulinaemic vasculitis

Cryoglobulinaemic vasculitis (CV) is a form of immune mediated primary vasculitis involving small to medium sized vessels. It may involve multiple organs and can have a range of clinical presentations. Terminology There are three main types of cryoglobulinaemia which are grouped, as per the Br...
Article

Deauville five-point scale

The Deauville five-point scale (Deauville 5PS) is an internationally-recommended scale for routine clinical reporting and clinical trials using FDG-PET/CT in the initial staging and assessment of treatment response in Hodgkin lymphoma (HL) and certain types of non-Hodgkin lymphomas (NHL).  Incl...
Article

Diamond-Blackfan anemia

Diamond-Blackfan anemia, also known as pure red cell aplasia, is a rare congenital anemia that typically presents in the first few years of life as a normocytic or macrocytic anemia usually only affecting cells of the erythroid lineage 2. However, neutropenia and thrombocytopenia may occasionall...
Article

Diffuse T1 bone marrow signal loss

Diffuse T1 vertebral bone marrow signal loss has a number of causes. T1-weighted imaging without fat suppression is one of the most important sequences for distinguishing between normal and abnormal bone marrow. Given the homogeneity, this appearance can often be difficult to spot as abnormal.  ...
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Disseminated intravascular coagulation

Disseminated intravascular coagulation (DIC), also known as consumption coagulopathy and defibrination syndrome, refers to a systemic phenomenon of overactivation of coagulation and fibrinolysis resulting in widespread clots forming inside blood vessels. Clinical presentation Patients present ...
Article

Ebola virus disease

Ebola virus disease (EVD) (also known as Ebola hemorrhagic fever (EHF) or simply Ebola) is a viral hemorrhagic disease caused by the Ebola Filovirus. Ebola is an extremely virulent virus with case fatality rates of approximately 70% 1. Epidemiology First recognized in 1967 after polio vaccine ...
Article

Engraftment syndrome

Engraftment syndrome (ES) refers to a potential early complication of haematopoetic stem cell transplantation. It is thought to be related to increased capillary permeability and comprises of a combination of symptoms and signs which include fever erythrodermatous skin rash noncardiogenic pul...
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Eosinophil

Eosinophils, also less commonly known as acidophils, are myeloid granulocytes and form one of the main types of white blood cells. Their counts are routinely measured as part of a full blood count. They have important roles in fighting parasitic infections, but are increasingly recognized as hav...
Article

Erythrocyte sedimentation rate

Erythrocyte sedimentation rate (ESR) is a non-specific marker of acute inflammation which is seen in a very wide spectrum of pathologies. In recent years it has been sidelined by the use of C-reactive protein and other acute phase markers but it still has an important role to play in the managem...
Article

Erythrocytosis

Erythrocytosis (or polycythemia) is the presence of an excessive number of red blood cells in the circulation. It can be primary or arise secondarily to another pathology. Definition Absolute erythrocytosis is defined as a red cell mass which is >125% predicted for sex and age 2. Although the...
Article

Essential thrombocythaemia

Essential thrombocythaemia (ET) is a myeloproliferative neoplasm characterized by an expansion of the megakaryocytic lineage, leading to an isolated elevation of platelets. It increases the risk of both thrombosis and hemorrhage.  Pathology The disease has traditionally been a diagnosis of exc...
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Extramedullary hematopoiesis

Extramedullary hematopoiesis is a response to the failure of erythropoiesis in the bone marrow. This article aims to a general approach on the condition, for a dedicated discussion for a particularly involved organ, please refer to the specific articles on:  extramedullary hematopoiesis in the...
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Extramedullary hematopoiesis in the adrenal gland

Extramedullary hematopoiesis in the adrenal gland is a rare physiologic compensatory event in many hematologic diseases. For a general discussion on this subject, please refer to the main article on extramedullary hematopoiesis. Epidemiology Extramedullary hematopoiesis in the adrenal gland i...
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Extramedullary plasmacytoma

Extramedullary plasmacytoma, also known as extraosseous plasmacytoma, are the less common form of solitary plasmacytoma, manifesting as isolated plasma cell tumors located at a non-osseous site. In contrast to multiple myeloma (MM), solitary plasmacytoma have little or no systemic bone marrow in...
Article

Extranodal extension

Extranodal extension refers to the growth of a nodal cancer metastasis beyond the confines of the capsule of the lymph node into adjacent tissues. Less preferred synonyms include extranodal spread, extracapsular extension, or extracapsular spread. This finding holds prognostic implications. For ...
Article

Factor V Leiden

Factor V Leiden is a primary hypercoagulable state due to a variant (mutated form) of human factor V. Factor V is one of several coagulation factors that assist in the clotting pathway. Epidemiology Heterozygous factor V Leiden may be present is around 5% of the European population and is most...
Article

Fanconi anemia

Fanconi anemia is a rare disorder characterized by progressive bone marrow failure, various congenital abnormalities, and predisposition to malignancies (often acute myeloid leukemia). Bone marrow failure usually results in decreased production of all blood cells. It is considered the commonest ...
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Fetal anemia

Fetal anemia can result from many causes. Pathology Etiology hemolytic disease of the newborn fetomaternal ABO incompatibility fetomaternal rhesus (Rh) incompatibility fetal infections fetal parvovirus B19 infection haematopoetic abnomalities homozygous alpha thalassemia 7 syndromes A...
Article

Folate deficiency

Folate deficiency (hypovitaminosis B9) is the most common vitamin deficiency in the Western world. It is especially important in pregnant women and common amongst alcoholics.  Epidemiology Deficiency arises in two distinct populations: increased demand (pregnancy and lactation) decreased abs...
Article

Follicular lymphoma

Follicular lymphoma is the most common subtype of non-Hodgkin lymphoma (NHL) Epidemiology Estimated to account for ~45% of all NHL cases 1. Higher rates in North America and Europe 4.  Pathology Nodal effacement by closely packed follicles containing small cleaved cells without nucleoli (cen...
Article

Gallbladder cholesterol polyps

Gallbladder cholesterol polyps are the most common subtype of gallbladder polyps, representing more than 50% of all polyps. They are frequently seen in middle-aged women and are benign lesions, with no malignant potential.  For further details, please refer to the parental article on gallbladde...
Article

Gaucher disease

Gaucher disease (GD) is the most common lysosomal storage disease in humans. It is an autosomal recessive, multisystem disease arising from a deficiency of glucocerebrosidase or beta-glucosidase activity, resulting in accumulation of a glycolipid (glucocerebroside) within the lysosomes of macrop...
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Graft versus host disease (pulmonary manifestations)

Pulmonary graft versus host disease (GvHD) is one of the thoracic manifestations that can complicate hematopoietic stem cell transplantation. Pulmonary GvHD can be broadly divided into acute and chronic disease 1-4: acute pulmonary GvHD pulmonary involvement is rare the median time of onset o...
Article

Hematopoietic stem cell transplantation

Hematopoietic stem cell transplantation (HSCT) is a relatively common procedure used to treat a wide spectrum of conditions 1,2: lymphoproliferative disorders, e.g. lymphoma, multiple myeloma (most common indication) leukemia solid tumors, e.g. neuroblastoma, Ewing sarcoma, extragonadal germ ...
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Hematopoietic stem cell transplantation (abdominal complications)

Abdominal complications of hematopoietic stem cell transplantation can occur early (0-100 days) or late (>100 days) post-transplant.  Complications Early bacterial infections, e.g. pseudomembranous colitis fungal infections, often affecting the esophagus or as hepatic/splenic microabscesses ...
Article

Hemochromatosis

Hemochromatosis is an iron overload disorder characterized by a progressive increase in total body iron stores and deposition of iron in some non-reticuloendothelial system (RES) body organs which results in some instances in organ dysfunction. This article focus on the general principles of he...
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Hemochromatosis (cardiac manifestations)

Cardiac involvement in hemochromatosis typically occurs with primary hemochromatosis, as the organ is usually spared in the secondary form of the disease. For a general discussion, and for links to other system specific manifestations, please refer to the article on hemochromatosis.  Epidemiol...
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Hemochromatosis (CNS manifestations)

Central nervous system manifestations of hemochromatosis are uncommon and can occur in either primary or secondary hemochromatosis. For a general discussion, and for links to other system specific manifestations, please refer to the article on hemochromatosis. Epidemiology Studies reporting p...
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Hemochromatosis (pancreatic manifestations)

Pancreatic manifestations of hemochromatosis typically occur with primary hemochromatosis, as the organ is usually spared in the secondary form of the disease. For a general discussion, and for links to other system specific manifestations, please refer to the article on hemochromatosis. Clini...
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Hemochromatosis (skeletal manifestations)

Hemochromatosis is a systemic disease which affects many organs systems, including the joints, characterized by hemosiderin and calcium pyrophosphate deposition. For a general discussion, and for links to other system specific manifestations, please refer to the article on hemochromatosis.  Ra...
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Hemoglobinopathies

A hemoglobinopathy is a genetic disorder which alters the structure of hemoglobin 1. The result is reduced oxygen-carrying capacity of the blood to the tissues. Terminology Types of hemoglobinopathies include the following: sickle cell disease (Hb S) sickle cell trait (HB AS) sickle cell-he...
Article

Hemolytic anemia

Hemolytic anemia is a form of anemia where red blood cells (RBCs) are destroyed either intravascularly or extravascularly. Clinical presentation The patient presents with anemia and jaundice. Diagnosis is based on several laboratory parameters 1: reticulocytosis increased unconjugated biliru...
Article

Hemolytic uremic syndrome

Hemolytic uremic syndrome (HUS) is a multisystem thrombotic microangiopathic disease characterized by the triad of renal failure, hemolytic anemia and thrombocytopenia. It is the most common cause of renal failure in infancy and childhood requiring dialysis.  There are two forms of this syndrom...
Article

Hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH), also known as macrophage activation syndrome when occurring in the setting of a rheumatologic disorder, is a non-malignant but often-fatal disorder of immune dysregulation affecting multiple organs. Epidemiology It typically affects infants and young c...
Article

Hemophilia

Hemophilia is an inherited bleeding disorder which is X-linked recessive and therefore occurs almost exclusively in males. There are two subtypes - hemophilia A (80%) and hemophilia B (20%).  Epidemiology The incidence of hemophilia A is around 1 in 5000 male births, and the incidence of hemop...
Article

Haemophilic arthropathy

Haemophilic arthropathy refers to permanent joint disease occurring in hemophilia sufferers as a long-term consequence of repeated hemarthrosis. Around 50% of patients with hemophilia will develop a severe arthropathy. Epidemiology Hemophilia is an X-linked recessive disease affecting males. H...
Article

Hemosiderosis

Hemosiderosis is a general term referring to the accumulation of hemosiderin, which particularly occurs in the reticuloendothelial system (RES) and does not cause organ damage. Pathology Some causes include: frequent transfusion  mainly depositional siderosis in RES if >40 units transfused:...
Article

Hand-foot syndrome (sickle cell disease)

Hand-foot syndrome, also simply referred to as dactylitis, is a self-limiting manifestation of a vaso-occlusive crisis in individuals with sickle cell anemia. Terminology Dactylitis is not a specific finding in sickle cell disease, therefore cautious usage is advised if one chooses to employ i...
Article

Hand-Schüller-Christian disease

Hand-Schüller-Christian disease is a clinically intermediate form of a spectrum of histiocytic disorders, which ranges from acute fulminant to chronic indolent disease. It primarily affects children, less often young adults, and rarely older adults. Hand-Schüller-Christian disease has been desc...
Article

Hematopoietic stem cell transplantation (thoracic complications)

There are many thoracic complications that can occur following hematopoietic stem cell transplantation. These can precipitate during various stages following transplantation and can be either infectious or noninfectious. Complications Early pulmonary edema engraftment syndrome diffuse alveo...
Article

Heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is a paradoxical thrombotic state resulting from an immune response to heparin. Epidemiology Occurs in 1:5000 patients who have received heparin, most commonly unfractionated heparin. Pathology HIT is induced by IgG antibodies. Clinical presentation T...
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Hepatic lymphoma

Hepatic lymphoma is a term given to any form of hepatic involvement with lymphoma. This can be broadly divided into: secondary hepatic involvement with lymphoma: most common by far, many tend to be non-Hodgkin lymphoma (NHL) 1 primary hepatic lymphoma: extremely rare Pathology Risk factors f...
Article

Hepatic myeloid sarcoma

Hepatic myeloid sarcomas, also referred to as hepatic granulocytic sarcoma or hepatic chloromas, are rare neoplasms comprised of myeloid precursor cells happening in the liver. They are commonly associated with acute myeloid leukemia (AML), but they may also occur with other myeloproliferative a...
Article

Hepatic veno-occlusive disease

Hepatic veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS), is a condition arising from occlusion of hepatic venules. Clinical presentation right upper quadrant pain painful hepatomegaly ascites abnormal liver function tests Pathology Toxic injury to liver s...
Article

Hereditary spherocytosis

Hereditary spherocytosis (HS) (also known as Minkowski-Chauffard disease 1) is a group of hemolytic anemias due to a genetic abnormality of the erythrocyte cell membrane resulting in spherocytes. The clinical spectrum is broad, from a subclinical state to a severe transfusion-dependent anemia. ...
Article

Histiocytic sarcoma

Histiocytic sarcoma is a rare malignant hematopoietic neoplasm that has been reported in association with other hematological malignancies (particularly B and T cell lymphomas). Pathology It comprises of tumor cells derived from the monocyte/macrophage lineage. Location It usually occurs in ...
Article

Hodgkin lymphoma

Hodgkin lymphoma or Hodgkin disease (HD) is a type of lymphoma and accounts for ~1% of all cancers. HD spreads contiguously and predictably along lymphatic pathways and is curable in ~90% of cases, depending on its stage and sub-type. Epidemiology There is a bimodal distribution in the age of ...
Article

Hodgkin lymphoma (pulmonary manifestations)

Pulmonary manifestations of Hodgkin lymphoma are relatively rare, present in  5-12% of patients at the time of diagnosis. It is relatively more common with the nodular sclerosing subtype. Pulmonary involvement usually indicates stage IV disease.  Radiographic features Bilateral involvement is ...
Article

How you can help build Radiopaedia.org

Contributing to Radiopaedia.org does not need to be a massive commitment. Even a few minutes here and there can make a real difference. This page is a great place to start if you want to get involved. There are many ways to do this: create your own case library and make your existing cases comp...
Article

H-shaped vertebra

H-shaped vertebrae, also known as Lincoln log vertebrae, are a characteristic finding of sharply delimited central endplate depression, classically seen in approximately 10% of patients with sickle-cell anemia, and results from microvascular endplate infarction (figure 1) 3. It may occasionally...
Article

Hypersplenism

Hypersplenism is a cytopenia resulting from blood pooling in the spleen and is almost always associated with splenomegaly.  Pathology Etiology There is an almost overwhelming list, some more common causes are given below 1,3,4: congestive splenomegaly: cirrhosis, Budd-Chiari syndrome, portal...
Article

Hypervitaminosis E

Hypervitaminosis E (or hypertocopherolaemia) is very rare as vitamin E has low toxicity even in large doses. Clinical presentation  In published case reports, patients have presented with a bleeding tendency e.g. cerebral hemorrhage 1. These affected individuals have imbibed supraphysiological...
Article

Hypogammaglobulinaemia

Hypogammaglobulinaemia is an immune disorder characterized by a reduction in all types of gammaglobulins.  Terminology While hypogammaglobulinaemia means some of loss of gammaglobulins, a total loss is termed agammaglobulinaemia which can occur in as an x linked form - X-linked agammaglobuline...
Article

Idiopathic hypereosinophilic syndrome

Idiopathic hypereosinophilic syndrome (IHES) is a leukoproliferative disorder and refers to a situation when there is an unexplained prolonged eosinophilia with associated organ system dysfunction. The condition can affect several organ systems which includes: heart: cardiac involvement in idio...
Article

Idiopathic portal hypertension

Idiopathic portal hypertension (non-cirrhotic portal hypertension or Banti syndrome) is a term that has been given to portal hypertension occurring without hepatic cirrhosis, parasitic infection, or portal venous thrombosis. Epidemiology Rare condition. More common in India and Japan. Patholo...
Article

Immunity

The human body regularly encounters harmful micro-organisms, and because of this it has developed a system of defenses to help identify and eliminate infective pathogens in the body, known as the immune system. Humans have two types of immunity: innate immunity and acquired immunity. innate im...
Article

Infectious mononucleosis

Infectious mononucleosis (also known as glandular fever) is the term for infection with Epstein-Barr Virus (EBV). The infection classically occurs in teenagers and young adults. It usually is diagnosed clinically supported by serum testing, but also may have suggestive imaging findings. Epidemi...
Article

Inflammatory myofibroblastic tumor of the spleen

Inflammatory myofibroblastic tumors of the spleen are rare spindle cells tumors of indeterminate clinical behavior. Please refer to the article on inflammatory myofibroblastic tumors for a broad discussion on the subject.  Radiographic features Ultrasound They usually present as a well define...
Article

Iron

Iron (chemical symbol Fe) is one of the trace elements that is essential for normal human health due to its central importance in the structure and function of hemoglobin and the cytochromes. Chemistry Basic chemistry Iron is a transition metal with atomic number 26 and an atomic weight of 55...
Article

Labeled imaging anatomy cases

This article lists a series of labeled imaging anatomy cases by system and modality. Brain CT head: non-contrast axial CT head: non-contrast coronal CT head: non-contrast sagittal CT head: angiogram axial CT head: angiogram coronal CT head: angiogram sagittal MR head: T2 axial MR head: ...
Article

Lactate dehydrogenase

Lactate dehydrogenase (LDH or LD) is a key enzyme in most cells, catalyzing the reversible conversion of pyruvate to L-lactate. Its contemporaneous main clinical uses are limited primarily to the investigation of hemolysis, serous collections and as a tumor marker. Physiology L-lactate dehydro...

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