Intracranial Aneurysms: Coil Embolization

Fig.1 & 2: Angiographic image of the left internal caroid artery injection shows an aneurysm of the left supraclinoid internal carotid artery. Fig.1 without subtraction, Fig.2 with.
Fig.3: Angiographic image after coil embolization (performed because the patient had SAH) reveals a coil within the aneursym.

Coil Embolization Complications

• Complicaton rate 8.6% to 18.6% (median 10.6%), lower than surgical clipping
• Common complications: thrombo-embolic events, perforation of aneurysm, parent artery obstruction, collapsed coil, coil malposition, and coil migration

Coil Embolization versus Aneurysm Clipping

• Less risks of death
• Higher rate of rebleeding (2.4% versus 1%) - why*
  
• Advantages vary depending on location of aneurysm, but coil embolization is beneficial for all sites

*Percentage of complete aneurysm occlusion after coil embolization is lower than with surgical clipping
* Recurrence = refilling of thee neck, sac, dome of a successfully treated aneurysm

What to Choose?

• Not all aneurysms required coil embolization. This depends on size, anatomy and location of aneurysms.
  
• People at increased risk for craniotomy (>65 years, poor clinical status, comorbid conditions)
• Suitability depends on size, anatomy, location of aneurysms (in ophthalmic artery or basilar tip artery)
• Better perform craniotomy if
• >10 mm size
• > 4mm neck
  

Reference:
Ontario Heath Technology Advisory Committee. Coil Embolization for intracrinal aneurysms.

Breast Hematoma

Fig. 1&2: Ultrasound of the right breast of a 79-year-old woman with a lump shows a mass with a fluid-fluid level (between arrows). The more dependent 'debris' appears to be more echogenic than the non-dependent fluid. There is no color flow within the mass.
Fig. 3: CT scan without IV contrast showed a large mass, again with a fluid-fluid level. The denser portion of the mass measured 60 HU, consistent with blood clot. The scan also revealed a markedly enlarged left atrium. The patient is on anticoagulant therapy for chronic atrial fibrillation.

Facts:

• Common causes: post procedure (biopsy, surgery), direct trauma, coagulopathy
• Breast hematoma occurs in approximately 2% - 10% after breast surgery
• Risk factors: use of some medications (aspirin, NSAIDs, anticogulants)

US Findings:

• Depends on stage of blood product
• Clotted blood appears echogenic, lysed blood (serum) appears cystic.
• No internal flow

Our case - follow up ultrasound was performed and the mass has evolved into a lysed hematoma and then disappeared. Diagnosis was breast hematoma related to anticoagulant use.

Reference:

Vitug AF, Newman LA. Complications in breast surgery. Surg Clin N Am 2007;87:431-451.

FDG-PET and Solitary Pulmonary Nodule Assessment (2)

Fig. 1: Axial CT image shows an ill-defined 1 cm nodule in the left upper lobe with internal cavity (arrow).
Fig. 2: Axial FDG-PET image at the same level as on CT shows no uptake of the nodule. Wedge resection of the nodule reveals bronchioloalveolar carcinoma.

False negative FDG-PET for lung malignancy

• Bronchioloalveolar carcinoma
• Carcinoid tumor
• Mucinous tumors

Reasons for false negativity of these tumors may be:

• Less number of cells in tumor (low cellarity relative to tumor volume)
• Better degree of differentiation (well-differentiated), not much nuclear atypia or less mitotic figures
• Lower metabolic rate
• Less peritumoral inflammation
• Small tumor size

How to Deal?
Goes by CT appearance and clinical scenario. If there is no characteristics of benignity of the nodule, at minimum - do a closed follow up with CT.

Reference:
Gilman MD, Aquino SL. State-of-the-art FDG-PET imaging of lung cancer. Semin Roentgenol 2005;40:144.

Lipohemarthrosis

Fig.1&2: Cross-table lateral radiograph (1) and sagittal-reformatted CT image (2) of the knee show a fat-blood interface (arrow) in the suprapatellar bursa of a 57-year-old woman who was a pedestrian hit by a car. Yellow asterisk = fat in the bursa, red asterisk = blood.

Lipohemarthrosis

• Mixture of blood and fat in a joint cavity following trauma
• Fat from the marrow space enters the joint through intra-articular fracture
• Fat is less dense than blood; therefore it layers above blood.
• On x-ray, fat is less dense than blood; therefore it can be seen as different density using radiography and CT
• Horizontal beam of x-ray needs to be parallel to the fat-blood interface, to be able to demonstrate the interface.
  
• Described in intra-articular fractures of the knee, shoulder, hip and elbow. However, it is not seen in all cases of intra-articular fracture. On the other hand, it is helpful for the diagnosis of an occult fracture.

Reference:
Arger PH, Oberkircher PE, Miller WT. Lipohemarthrosis. AJR 1974;121:97-100.

Drug-Induced Eosinophilic Pneumonia

Fig.1: Chest radiograph of a 49-year-old woman, presenting with low-grade fever and cough for a month, shows patchy airspace opacities in both upper lobes.
Fig2&3: Axial CT images show asymmetric patchy consolidations and groundglass opacities mainly in the periphery of the upper lobes and superior segments of the lower lobes.

Differential Diagnosis of Subacute Bilateral Upper Lobe Airspace Opacities

• Cryptogenic organizing pneumonia (COP)
• Churg-Strauss syndrome (vasculitis)
• Pulmonary infarction
  

Eosinophilic Lung Disease

• A group of disorders characterized by 1) abnormal lung opacities with peripheral eosinophilia, 2) tissue eosinophilia confirmed at either open or transbronchial lung biopsy, or 3) increased eosinophil in bronchoalveolar lavage (BAL) fluid
  
• Known causes: asthma, infection (coccidiodomycosis, PCP, mycobacteria), tumor (NSCLC, lymphoma, lymphocytic leukemia), collagen vascular disease (RA, Wegener's, IPF, LCH) and drugs

Drugs Associated with Eosinophilic Lung Disease

• Amiodarone,
  
• Methotrexate,
  
• Nitrofurantoin,
  
• Phenytoin,
  
• B-blockers,
  
• Iodinated contrast media,
  
• ACE inhibitor

Pattern of Abnormalities in Chest CT

• Bilateral, asymmetric, peripheral consolidations and groundglass opacities
  
• Upper lung zone > random > lower
  
• Ancillary findings: centrilobular nodules, reticulations, septal thickening
  

Our case is an eosinophilic pneumonia (confirmed by BAL fluid eosinophilia) associated with Minocycline, which had been improved after a short course of corticosteroid therapy.

Reference:
1. Souza CA, et al. Drug-induced eosinophilic pneumonia: high-resolution CT findings in 14 patients. AJR 2006;186:368-373.
2. Jeong YJ, et al. Eosinophilic lung diseases: a clinical, radiologic, and pathologic overview. Radiographics 2007;27:617-637.