Magnetic resonance spectroscopy and diffusion imaging in the evaluation of neoplastic brain lesions

MR spectroscopy and apparent diffusion coefficient (ADC) calculation have been used frequently for tumour grading and differentiation during the last decade. The aim of this study is to evaluate whether the combination of these two techniques can improve the diagnostic effectiveness in patients with brain tumour. Patients and methods: Thirty-six patients with histologically proven brain tumours (7 low, 13 high grade astrocytomas, 11 metastases, and 5 meningiomas) were evaluated with cMRI, MRS and DWI before surgery. Results: MR spectroscopy could differentiate benign from malignant tumours but was not useful in tumour grading. In the differentiation of malignant from benign tumours, N-acetylaspartate (NAA), Choline (Cho), Creatine, lactate/lipid, and alanin ratios were significant. Increase in lipid and alanin could distinguish metastases and meningiomas from other tumours. Increase in the lactate level correlated with the degree of malignancy. ADCs were effective for grading malignant tumours but not for distinguishing tumour types with the same grade. High grade malignant tumours had lower ADC values (0.428 + 0.006 × 10–3 mm2/s) than did low grade malignant (1.6 + 0.325 × 10–3 mm2/s), and benign (1.200 + 0.707 × 10–3 mm2/s) tumours. Conclusion: The combination of MRS with cMRI and calculated ADC values added more and more information to MR imaging in the differentiation and grading of brain tumours and were more useful when done together than each alone

MRI imaging of posterior reversible encephalopathy syndrome associated with pregnancy

Purpose: Our purpose is to characterize MRI, and diffusion-weighted imaging (DWI) findings in pregnant patients who were identified clinically to have PRES. We study the conversion of reversible vasogenic edema to irreversible cytotoxic edema and predict the progression to infarction. Patients and methods: Twenty two pregnant females, aged between 20 and 46 years with gestational age between 20 and 40 weeks of gestation and with neurological manifestations had undergone conventional MRI, diffusion weighted image study, and ADC map. Results: Lesions were mainly affecting the parieto-occipital regions, symmetrical or slightly asymmetrical distribution of the lesions in both cerebral hemispheres was found in most cases. The MRI findings in all the twenty two patients were: abnormal low SI in T1 WI, abnormal high SI on T2 and FLAIR WI. In DWI, hyperintensity with hyperintensity in ADC map was seen in 15 patients, hyperintensity with hypointensity in ADC map in 4 patients, normotensive in DWI with hyperintensity in ADC map in 3 patients. Conclusion: The diagnosis of PRES has important therapeutic and prognostic value. The use of diffusion-weighted imaging and ADC maps allows an earlier and clearer differentiation of cytotoxic and vasogenic edema, which can predict the development of infarction

The diagnostic value of PET/CT in recurrence and distant metastasis in breast cancer patients and impact on disease free survival

Aim of work: To detect the diagnostic value of PET/CT in breast cancer patients. We compared the performance of PET/CT with that of conventional imaging in detection of recurrence and distant metastasis and evaluated the impact PET/CT results have on disease free survival. Materials and methods: We retrospectively studied 50 patients with breast cancer with clinical suspicion of recurrent or metastatic lesion and who underwent PET/CT and conventional imaging procedures. The imaging results were retrospectively compared with histopathology and clinical follow-up as a reference standard. Results: PET/CT detected distant metastases with a sensitivity of 97% and a specificity of 93%. In contrast, the sensitivity and specificity of combined conventional imaging procedures were 75% and 73%, respectively, disease-free survival was significantly shorter in the 34 M1-PET/CT patients than in the 14 M0-PET/CT patients (log-rank P = 0.002) also PET/CT detected recurrence in 1 patient with equivocal mammographic findings. Conclusion: In breast cancer, PET/CT is superior to conventional imaging procedures for detection of recurrence, distant metastases and PET/CT can be used to improve prediction of the clinical outcome of breast cancer patients

The use of multi-detector computed tomography and ultrasonography for evaluation of pleural lesions

Background and objective: Multidetector CT (MDCT) and ultrasonography (US) are of increasing importance for assessment of many pulmonary disorders. Our aim was to evaluate their role in diagnosis of pleural diseases. Methods: Patients from Tanta University Hospital who were suspected to have pleural lesions (symptoms, signs and/or suggestive chest X-ray) during one year period were enrolled in the study. US and MDCT were done for all of them, then data were reported and analyzed. Results: Seventy-one patients were included, sixty of them had evident pleural lesions. Chest pain was the commonest presenting symptom. Malignancy represented 36.7% of pleural lesions, a percentage similar to lesions due to infection etiology. Free pleural effusions were the most common pleural lesions followed by pleural thickening. US was diagnostic in 72% of pleural lesions detectable by MDCT. Multiplanar reconstruction (MPR) images had an additional value than axial images in 39% of pleural lesions, mostly in cases of pleural thickening, free pleural effusion, pleural masses, encysted pleural effusions and pleural plaques. On the other hand, the MPR images had the same value as axial images in empyema and pneumothorax cases. Conclusion: MDCT is an important noninvasive imaging tool in accurate detection and characterization of pleural lesions with complementary MPR images that solve many diagnostic problems. Ultrasonography is a safer alternative but with less diagnostic value

Role of color Doppler ultrasonography and multidetector computed tomography angiography in diagnosis of uterine arteriovenous malformations

Aim of work: To assess the role of color Doppler ultrasonography and multidetector computed tomography angiography (MDCTA) in diagnosis of uterine arteriovenous malformations (AVMs). Methodology: Twenty patients were referred to the radiodiagnosis and imaging department, faculty of medicine, Tanta University from obstetric and gynecology department. All patients were suspected clinically to have uterine arteriovenous malformations. All were subjected to history taking regarding clinical state, laboratory investigation and color Doppler ultrasonography and multidetector computed tomography angiography of the pelvis. Results: Color Doppler ultrasound sensitivity was 100% in detecting a uterine hypervascular lesion and highly suggesting the diagnosis of uterine AVM and the sensitivity of MDCT angiography was 100% in diagnosing and evaluating uterine AVM. Conclusion: Doppler US can strongly suggest the presence of AVM but patient should undergo CT angiography for definitive diagnosis and possible embolization, as CTA helps in providing valuable cross sectional anatomical details about the lesion, its extent and its surroundings