Thursday, December 30, 2010

Cervical Carcinoma-MRI

MR Imaging of 46 Year old female with carcinoma cervix- T2 FS sagittal and axial images showing well defined homogeneously hyperintense mass lesion in the region of   cervix involving the lower segment of uterus and the upper third of the vagina and mild parametrial extension. The pelvic side walls are clear. No pelvic lymphadenopathy.

Cervical carcinoma is the third most common malignancy in woman and is seen in fourth to fifth decade. It often causes serious consequences and common cause of death is uremia in this condition due to involvement of the ureters. 

The International Federation of Gynecology and Obstetrics (FIGO) staging system provides worldwide epidemiologic and treatment response statistics. MR imaging is not included in the system, however it is widely accepted modality for evaluation of cervical cancer.....

What all can MRI do with cervical cancer.........
  • Can quantify the volume of the tumor especially in the early stages.
  • Metastatic lymphnode evaluation.
  • Obviates the use of invasive procedures like cystoscopy and proctoscopy.
  • Brachytherapy and external beam radiation therapy can be optimised with the MR imaging.
  • Detect and confirm invasion of the adjacent organs.
  • Identify fistulous tracts if any.
For more information on the MR imaging of the cervical carcinoma go through this wonderful article in the Radiographics by Viviane Nicolet et al.

Thursday, December 16, 2010

Bone infarct - MRI

Bone infarct is ischemic death of the cellular elements of the bone and marrow in metaphysis and diaphysis. Lesions in the epiphysis are called avascular necrosis (AVN). Presently the term osteonecrosis is accepted and used widely.

Causes: Idiopathic, Trauma, Idiopathic causes such as Legg-CalvĂ©-Perthes disease, Renal transplantation, Increase in endogenous steroid levels, as in patients with Cushing syndrome, Collagen vascular disorders such as systemic lupus erythematosus (SLE), rheumatoid arthritis, and scleroderma, Hemoglobinopathies such as sickle cell disease and thalassemia, Hemophilia, Gaucher disease, Fabry disease, Infection, Pancreatitis, Pregnancy, Gout and hyperuricemia, Diabetes, Use of immunosuppressants and other drugs such as exogenous steroids, indomethacin, and phenylbutazone, Alcohol use, Dysbaric osteonecrosis, Radiation therapy, Arteritis.


Radiograph: Findings are characteristic in established case. Early stages radiograph is not of much use. In the epiphysis region, an arc like, subchondral, lucent lesion may be associated with areas of patchy loss of bone opacity intermingled with sclerotic areas and bone collapse. In the diametaphyseal region, a sheet like lucency of varying size is usually surrounded by shell-like sclerosis and/or calcification and periostitis. In flat or complex bones, patchy lucencies and sclerosis are often associated with bone collapse or fractures.

Steinberg has classified the radiologic appearance into 6 stages, as follows12 :
  • Stage 0 - Normal findings are demonstrated.
  • Stage I - The appearance may vary from normal to subtle trabecular mottling, but an isotopic bone scan or MRI shows abnormal bone.
  • Stage II
    • Stage IIa - Focal radiopacity is associated with osteopenia.
    • Stage IIb - Radiopacity is associated with osteoporosis and an early crescent sign.
  • Stage III
    • Stage IIIa - An established crescent sign is associated with cyst formation.
    • Stage IIIb - Mild alteration in the configuration of the femoral head is caused by a subchondral fracture, but the joint space is maintained.
  • Stage IV - Marked collapse of the femoral head is demonstrated with an associated acetabular abnormality.
  • Stage V - Joint space narrowing is demonstrated with changes of secondary osteoarthrosis.
CT scans: Central or peripheral areas of reduced attenuation. Reformatted sagittal and coronal images show subchondral fractures and collapse of the articular surface. May show subtle trabecular irregularity associated with bone necrosis in early stages.

MRI: Ischemic bone changes become apparent in hematopoietic tissues on MRIs within 6-12 hours. MRI characteristics of bone infarction are patchy areas of low signal intensity on T1-weighted spin-echo images. Diffuse abnormal signal intensity may be present in osteonecrosis of the femoral head; these changes are reflected on both T1- and T2-weighted images.
The most characteristic appearance is the double-line sign, which consists of a hyperintense inner ring and a hypointense outer ring, on T2-weighted MRIs. This finding reflects the reactive interface between ischemic and non ischemic bone. 

Saturday, December 11, 2010

Achilles Tendonitis - MRI

46 Year old male with pain in the left ankle MRI T2 FS sagittal and T2 FSE axial images showing diffuse hyperintensities in the distal Achilles tendon with mild marrow edema in the calcaneous at the insertion site and mild peritendinous inflammatory changes suggestive of Achilles Tendinitis.


Tendinitis develops insidiously after sudden changes in activity or training level, use of inappropriate footwear, or training on poor running surfaces, especially if high-risk factors are present (Eg, age, cavus feet, tibia vara, heel and forefoot varus deformities).
Achilles tendon injuries may be classified as:
Tendonitis: Overuse of the Achilles tendon can cause inflammation that can lead to pain and swelling.
Tendinosis: Usually, this injury is an asymptomatic, noninflammatory, degenerative disease process (mucoid degeneration). The patient may complain of a sensation of fullness or a nodule in the back of the leg.

A Thompson test is performed to detect rupture of the Achilles tendon. In this test, the patient lies face downward on the examining table with bent knees and the doctor squeezes the back of the lower leg (calf). If the Achilles tendon is at least partially intact, this test causes the foot to flex.

Radiographs: May detect soft tissue thickening and fractures if any associated.
Ultrasound may be usefull to detect thickening of the Achilles tendon and peritendinous collection.
MRI of tendonitis show diffuse for T2 hyperintensity within the tendon and inflammatory changes around the tendon with or without peritendinous collection. My show mild enhancement on contrast study.  Focal T2 hyperintensities seen at the tendon insertion suggestive of insertional tendinitis.
MRI helps to differentiate tendonitis from tendinosis and partial/complete tendon rupture. In tendinosis there will be only tendon degenerative changes without inflammatory changes around the tendon.
TREATMENT: Resting the tendon to allow the inflammation to settle down.

Search This Blog