Everything you need to know about Computed Tomography (CT)
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Inflammatory Disease

What is Thallasemia?
- Thalassemia is a group of inherited diseases of the blood that affect a person's ability to produce hemoglobin, resulting in anemia. Hemoglobin is a protein in red blood cells that carries oxygen and nutrients to cells in the body. About 100,000 babies worldwide are born with severe forms of thalassemia each year. Thalassemia occurs most frequently in people of Italian, Greek, Middle Eastern, Southern Asian and African Ancestry.
- The more severe form of the disease is thalassemia major, also called Cooley's Anemia. It is a serious disease that requires regular blood transfusions and extensive medical care.
- Those with thalassemia major usually show symptoms within the first two years of life. They become pale and listless and have poor appetites. They grow slowly and often develop jaundice. Without treatment, the spleen, liver and heart soon become greatly enlarged. Bones become thin and brittle. Heart failure and infection are the leading causes of death among children with untreated thalassemia major.
- National Human Genone Research Institute
“Thalassemia is an inherited multisystemic disorder with skeletal and non-skeletal manifestations. Plain-film radiography is generally adequate in defining the routine osseous abnormalities of thalassemia. The CT and MRI techniques can document the abnormal deposition of iron, ExmH, and bone marrow changes.”
Imaging features of thalassemia
M. Tunacõ, A. Tunacõ, G. Engin et al.
Eur. Radiol. 9, 1801-1809 (1999)
Extramedullary Hematopoeisis in Thallasemia: Skeletal Manifestations
- Expansion of the medulla, thinning of cortical bone, resorption of the cancellous bone and widening of diploic spaces in the skull
- Ribs most commonly involved followed by vertebral bodies, skull and other bones ((humerus, sternum,clavicle, scapula)
Extramedullary Hematopoeisis: Common Causes
- myelofibrosis
- diffuse osseous metastatic disease replacing the bone marrow
- leukaemia
- sickle cell disease
- thalassemia.
Imaging Studies before a biopsy may be valuable
- 99mTc-colloid scintigraphic imaging
- PET scanning
- MRI
- CT
“Infectious complications are the most common reason for inpatient admission in PWID. Soft tissue infection due to intravenous injection with contaminated needles or subcutaneous/intramuscular injection may manifest as a range of disorders of varying severity which include cellulitis, abscess, myositis and necrotizing fasciitis. These infections are often polymicrobial and Staphylococcus aureus and Streptococcus pyogenes are among the most common organisms. Prompt diagnosis and determination of the extent of infection is important as more severe pathologies, such as necrotizing fasciitis, require urgent surgical management.”
The needle and the damage done: musculoskeletal and vascular complications associated with injected drug use
Francis T. Delaney , Emma Stanley and Ferdia Bolster
Insights into Imaging (2020) 11:98 https://doi.org/10.1186/s13244-020-00903-5
"CT is required to assess for suspected abscess forma- tion in deeper locations where ultrasound assessment is limited such as the retroperitoneum or deep pelvis. In PWID, abscesses may develop in deep locations due to direct extension from the site of injection, such as from the groin into the pelvis or retroperitoneum, or as a result of haematogenous seeding of distant locations. The risk of abscess formation in association with soft tissue infection is increased in immunocompromised patients or by the presence of a retained foreign body, meaning PWID are often at an increased risk. On CT, abscesses appear as a well-defined collection with internal fluid density and a peripheral rim-enhancing pseudocapsule.”
The needle and the damage done: musculoskeletal and vascular complications associated with injected drug use
Francis T. Delaney , Emma Stanley and Ferdia Bolster
Insights into Imaging (2020) 11:98 https://doi.org/10.1186/s13244-020-00903-5
"CT is the imaging modality of choice for mycotic aneu- rysms, although ultrasound or MR angiography may also be used for evaluation depending on the location. Gas within the aneurysm is a rare but characteristic sign which is best seen on CT. Additional imaging features more commonly seen on CT include a lobulated vascular mass, an irregular and poorly defined arterial wall and peri- aneurysmal soft tissue stranding and oedema. Inflammatory soft tissue surrounding the artery can develop a mass-like appearance and be associated with necrosis.”
The needle and the damage done: musculoskeletal and vascular complications associated with injected drug use
Francis T. Delaney , Emma Stanley and Ferdia Bolster
Insights into Imaging (2020) 11:98 https://doi.org/10.1186/s13244-020-00903-5
“Recreational drug use continues to be a significant healthcare problem and is associated with myriad multi- system complications. Musculoskeletal and vascular complications are commonly seen and are particularly prevalent in injected drug use. Awareness of the imaging manifestations and timely diagnosis of the complications related to injected drug use is important in daily radi- ology practice as clinical presentation may be non- specific and the history of illicit drug use often not forth- coming. A focused multimodal imaging approach is typ- ically required, depending on the nature of suspected complications.”
The needle and the damage done: musculoskeletal and vascular complications associated with injected drug use
Francis T. Delaney , Emma Stanley and Ferdia Bolster
Insights into Imaging (2020) 11:98 https://doi.org/10.1186/s13244-020-00903-5 
“Although the primary imaging modality for the evaluation of inflammatory arthritis of the foot and ankle is currently magnetic resonance imaging, computed tomography may be performed in some patients and can aid in diagnosis. This article reviews a number of inflammatory arthritic conditions that involve the feet. Computed tomographic findings and the role of computed tomography in diagnosing infection, gout, and rheumatoid arthritis of the foot are discussed.”
CT of the foot: select inflammatory arthridites
Johnson PT, Fayad LM, Fishman EK
J Comput Assist Tomogr 2007 Nov-Dec;31(6):961-9
Castleman’s Disease: Two Types
- Plasma cell type (less vascular)
- Hyaline vascular form (vascular)
Castleman’s Disease: Location
- Thorax (67-70%)
- Neck (14-40%)
- Abdomen including retroperitoneum (2-7%)
Castleman’s Disease is also known as
- Angiofollicular hyperplasia
- Giant lymph node hyperplasia

"In particular the combination of ascites, elevated CA-125 levels, and pelvic and peritoneal masses found in tuberculosis can be easily mistaken for coelomic spread of ovarian cancer."

Tuberculosis: A Benign Imposter
Tan CH et al.
AJR 2010; 194:555-561

"Peritoneal involvement in tuberculosis is present in 5% of cases and is usually associated with widespread abdominal disease involving the lymph nodes or bowel"

Tuberculosis: A Benign Imposter
Tan CH et al.
AJR 2010; 194:555-561

 

"Spondylitis is the most common form of skeletal tuberculosis infection, accounting for 60% of cases."

Tuberculosis: A Benign Imposter
Tan CH et al.
AJR 2010; 194:555-561

Musculoskeletal Infection: Who is at risk?

- HIV/AIDS patients
- IVDA patients
- Sickle cell disease
- Diabetic patients
- Periperal vascular disease
- Immunocomprimised patients
"CT provides an analysis of compartmental anatomy, thereby helping to distinguish among the various types of musculoskeletal infection and to guide treatment options."

Musculoskeletal infection: Role of CT in the Emergency Department
Fayad LM, Carrino JA, Fishman EK
RadioGraphics 2007;27:1723-1736
“ Spondylitis is the most common form of skeletal tuberculosis infection, accounting for 60% of cases.”

Tuberculosis: A Benign Imposter
Tan CH et al.
AJR 2010; 194:555-561
“ Peritoneal involvement in tuberculosis is present in 5% of cases and is usually associated with widespread abdominal disease involving the lymph nodes or bowel.”

Tuberculosis: A Benign Imposter
Tan CH et al.
AJR 2010; 194:555-561
“ In particular the combination of ascites, elevated CA-125 levels, and pelvic and peritoneal masses found in tuberculosis can be easily mistaken for coelomic spread of ovarian cancer.”

Tuberculosis: A Benign Imposter
Tan CH et al.
AJR 2010; 194:555-561
Fournier's Gangrene

- Described in 1883
- Unexplained fulminating gangrene of the male genitalia
- Young healthy males, no discernible cause
- Today, broader age range, Males and Females
- Source can be identified in up to 95% of cases
- Successful treatment depends on early diagnosis and aggressive surgical intervention
- 76% mortality if delay > 6 days
- 12% mortality rate if < 24 hours before surgical debridment.
Fournier's Gangrene

- Causes Are:
- Trauma: Provides access of organisms to subcutaneous tissues
- Extension of UTI
- Extension from infection in perineal area
- Comorbid conditions often present
- ETOH, DM, Malignancy, Advanced age, Prolonged hospitalization
- Clinical Presentation Fever, pain, pruritis, swelling, vesicles, discharge, crepitus
Fournier's Gangrene

- Pathogenesis:
- Severe subcutaneous infection that begins adjacent to the portal of entry (urethral, rectal, cutaneous)
- Localized cellulitis progresses to diffuse inflammatory reaction involving the deep tissue planes
- Can progress 2-3 cm per hour
- The subcutaneous infection and edema impairs blood supply and results in cutaneous and subcutaneous vascular thrombosis (Necrotizing fasciitis)
Fournier's Gangrene

- Pathogenesis:
- Most common organisms (usually 4 or more)
- Klebsiella, Proteus, Streptococcus, Staphlococcus, Peptostreptococcus, E.coli
- Organisms act synergistically to produce fascial and soft tissue necrosis
- Gas is byproduct of anaerobic metabolism (Nitrogen, nitrous oxide, hydrogen and hydrogen sulfate).