Brain abscess and necrotic or cystic brain tumor: discrimination with signal intensity on diffusion-weighted MR imaging.

Objective: Acuity of deep vein thrombus/ thrombosis (DVT) may affect effectiveness of anti-thrombotic therapy. However, the acuity of DVT is not reliably detected by current noninvasive imaging techniques. This study investigated whether diffusion weighted magnetic resonance (MR) imaging can detect DVT and define the acuity of thrombus in patients with DVT and a rabbit model of venous thrombus. Methods: Diffusion weighted MR imaging was performed with a 1.5-T MR system in 8 patients with DVT. Venous thrombus was induced in rabbit jugular vein by endothelial denudation and 10 minutes blood stasis with a balloon catheter. The thrombus was imaged with a 3.0-T MR system at 4 hours and at 1, 2 and 3 weeks, and the jugular veins were histologically assessed. Results: All patients were detected DVT with diffusion weighted MR imaging, and the DVT showed high or mixed high and iso signal intensity on the diffusion sequence. The rabbit venous thrombi were rich in erythrocyte and fibrin at 4 hours, and showed focal organizing reaction at 1 and 2 weeks, and was replaced by fibrous tissue at 3 weeks. The rabbit thrombi showed high signal intensity on diffusion weighted MR imaging at 4 hours, mixed high and iso signal intensity at 1 and 2 weeks, or mixed iso and low signal intensity at 3 weeks. The signal intensity was positively correlated with erythrocyte and fibrin contents, and negatively correlated with macrophage and collagen contents. Conclusions: Diffusion weighted MR imaging can detect DVT and high signal intensity on the sequence may reflect acuity of DVT.

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Use of diffusion-weighted magnetic resonance imaging in differentiating purulent brain processes from cystic brain tumors

Journal of Neurosurgery ◽

10.3171/jns.2002.97.5.1101 ◽

2002 ◽

Vol 97 (5) ◽

pp. 1101-1107 ◽

Cited By ~ 72

Author(s):

Raphael Guzman ◽

Alain Barth ◽

Karl-Olof Lövblad ◽

Marwan El-Koussy ◽

Joachim Weis ◽

...

Keyword(s):

Magnetic Resonance ◽

Brain Tumors ◽

Mr Imaging ◽

Brain Abscess ◽

Subdural Empyema ◽

Similar Data ◽

Content Type ◽

Diffusion Weighted ◽

Adc Values ◽

Fine Print

Object. Brain abscesses and other purulent brain processes represent potentially life-threatening conditions for which immediate correct diagnosis is necessary to administer treatment. Distinguishing between cystic brain tumors and abscesses is often difficult using conventional imaging methods. The authors' goal was to study the ability of diffusion-weighted (DW) magnetic resonance (MR) imaging to differentiate between these two pathologies in patients within the clinical setting. Methods. Diffusion-weighted MR imaging studies and calculation of the apparent diffusion coefficient (ADC) values were completed in a consecutive series of 16 patients harboring surgically verified purulent brain processes. This study group included 11 patients with brain abscess (one patient had an additional subdural hematoma and another also had ventriculitis), two with subdural empyema, two with septic embolic disease, and one patient with ventriculitis. Data from these patients were compared with similar data obtained in 16 patients matched for age and sex, who harbored surgically verified neoplastic cystic brain tumors. In patients with brain abscess, subdural empyema, septic emboli, and ventriculitis, these lesions appeared hyperintense on DW MR images, whereas in patients with tumor, the lesion was visualized as a hypointense area. The ADC values calculated in patients with brain infections (mean 0.68 × 103 mm2/sec) were significantly lower than those measured in patients with neoplastic lesions (mean 1.63 × 103 mm2/sec; p < 0.05). Conclusions. Diffusion-weighted MR imaging can be used to identify infectious brain lesions and can help to differentiate between brain abscess and cystic brain tumor, thus making it a strong additional imaging modality in the early diagnosis of central nervous system purulent brain processes.

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Phase Shift MRI in Assessement of Vertebral Compression Fracture: Trial for a New Scoring System

10.21203/rs.3.rs-129229/v1 ◽

2020 ◽

Author(s):

Khaled Matrawy ◽

Nadia Abdel Fattah ◽

Abdel Aziz ElNekidy ◽

Mohamed Abdel Gawad ◽

Alaa Elnaggar ◽

...

Keyword(s):

Chemical Shift ◽

Mr Imaging ◽

Signal Intensity ◽

Scoring System ◽

Diffusion Weighted Imaging ◽

Vertebral Compression Fracture ◽

Compression Fracture ◽

Vertebral Compression Fractures ◽

Diffusion Weighted ◽

New Scoring

Abstract PurposeTo assess the value of in /opposed-phase quantitative chemical shift MRI in differentiating malignant from benign vertebral compression fractures (VCF).Patients and methodsTwenty patients (8 men), mean age 56 years, with low back and radiological proof of VCF were included in the study. MRI of spine with standard conventional sequences and special chemical shift sequence (in/opposed phase) as well as diffusion weighted imaging were performed (at 1.5 Tesla). Quantitative image analysis of regions of interest (ROI) on the abnormal marrow in the compressed (study group) and related normal vertebra in same patient (control group) was done in each patient. The signal intensity ratio (SIR) of the marrow was determined by dividing the mean signal intensity on the opposed-phase and in-phase images was performed.ResultsMean SIR of benign VCF [0.6 ± 0.27 (range 0.23–1.1)] was significantly lower than malignant VCF values [1.115 ± 0.14 (range 0.87–1.45)] (p < 0.0001, ROC 0.97). The optimal SIR cutoff value for separating benign and malignant VCF was found to be 0.9 with a calculated sensitivity of 91.5%, specificity of 87.5% and accuracy of 90%. We also found a cut-off value of 0.9, to be a statistically significant in differentiating benign from malignant causes of VCF. If SIR of 0.91 as a cutoff is applied, with >0.91 indicating malignant result and <0.91 defined as a benign result.ConclusionQuantitative chemical shift MR imaging could be a valuable addition to standard MR imaging techniques in differentiating benign from malignant vertebral compression fracture. We designed a new scoring system based on conventional MRI, in/opposed phase chemical shift and diffusion weighted imaging. The new scoring system may be a useful tool and add value in the diagnosis of compression vertebral fractures.

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