Contribution of diffusion-weighted imaging to dynamic contrast-enhanced MRI in the characterization of papillary breast lesions.

Papillary lesions have a broad spectrum of appearances on magnetic resonance imaging (MRI). The purpose of this study was to evaluate whether apparent diffusion coefficient (ADC) values of papillary lesions can be used to characterize lesion as benign or malignant. This retrospective study included 29 papillary lesions. Diagnostic values of dynamic contrast-enhanced MRI (DCE-MRI), DWI-ADC, and DCE-MRI plus DWI-ADC were separately calculated. The malignant papillary lesions (0.744×10-3  mm2 /s) exhibited significantly lower mean ADC values than the benign lesions (1.339×10-3  mm2 /s). Addition of DWI to standard DCE-MRI provided 100% sensitivity. We hypothesized that this combination may prevent unnecessary excisional biopsies.

Assessment of Liver Fibrosis with Diffusion-Weighted Magnetic Resonance Imaging Using Different b-values in Chronic Viral Hepatitis.

OBJECTIVE: To examine the effectiveness of apparent diffusion coefficient (ADC) values and to compare the reliability of different b-values in detecting and identifying significant liver fibrosis. SUBJECTS AND METHODS: There were 44 patients with chronic viral hepatitis (CVH) in the study group and 30 healthy participants in the control group. Diffusion-weighted magnetic resonance imaging (DWI) was performed before the liver biopsy in patients with CVH. The values of ADC were measured with 3 different b-values (100, 600, 1,000 s/mm2). In addition, liver fibrosis was classified using the modified Ishak scoring system. Liver fibrosis stages and ADC values were compared using areas under the receiver-operating characteristic (ROC) curve. RESULTS: The study group's mean ADC value was not statistically significantly different from the control group's mean ADC value at b = 100 s/mm2 (3.69 ± 0.5 × 10-3 vs. 3.7 ± 0.3 × 10-3 mm2/s) and b = 600 s/mm2 (2.40 ± 0.3 × 10-3 vs. 2.5 ± 0.5 × 10-3 mm2/s). However, the study group's mean ADC value (0.99 ± 0.3 × 10-3 mm2/s) was significantly lower than that of the control group (1.2 ± 0.1 × 10-3 mm2/s) at b = 1,000 s/mm2. With b = 1,000 s/mm2 and the cutoff ADC value of 0.0011 mm2/s for the diagnosis of liver fibrosis, the mean area under the ROC curve was 0.702 ± 0.07 (p = 0.0015). For b = 1,000 s/mm2 and the cutoff ADC value of 0.0011 mm2/s to diagnose significant liver fibrosis (Ishak score = 3), the mean area under the ROC curve was 0.759 ± 0.07 (p = 0.0001). CONCLUSION: Measurement of ADC values by DWI was effective in detecting liver fibrosis and accurately identifying significant liver fibrosis when a b-value of 1,000 s/mm2 was used.

Microstructural effects of Ramadan fasting on the brain: a diffusion tensor imaging study.

PURPOSE: We aimed to examine whether the brain displays any microstructural changes after a three-week Ramadan fasting period using diffusion tenson imaging. METHODS: This study included a study and a control group of 25 volunteers each. In the study group, we examined and compared apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values of the participants during (phase 1) and after (phase 2) a period of fasting. The control group included individuals who did not fast. ADC and FA values obtained in phase 1 and phase 2 were compared between the study and control groups. RESULTS: In the study group, ADC values of hypothalamus and, to a lesser extent, of insula were lower in phase 1 compared with phase 2 and the control group. The FA values of amygdala, middle temporal cortex, thalamus and, to a lesser extent, of medial prefrontal cortex were lower in phase 1 compared with phase 2 and the control group. Phase 2 ADC and FA values of the study group were not significantly different compared with the control group at any brain location. CONCLUSION: A three-week Ramadan fasting period can cause microstructural changes in the brain, and diffusion tensor imaging enables the visualization of these changes. The identification of brain locations where changes occurred in ADC and FA values during fasting can be helpful in diagnostic imaging and understanding the pathophysiology of eating disorders.

The effectiveness of power Doppler vocal fremitus imaging in the diagnosis of breast hamartoma.

OBJECTIVES: To evaluate the usefulness of power Doppler vocal fremitus (PDVF) breast sonography for differentiation of hamartomas from other breast (malign or benign) masses. MATERIAL AND METHODS: Two hundred and six breast masses in 180 women were evaluated. The breast lesions were scanned first by mammography (MG), then by ultrasonography (US) with PDVF imaging. Finally, biopsy was performed on lesions suspicious for malignancy (n=172). We used PDVF imaging to evaluate whether the Power acoustic Doppler artifact existed in all breast lesions. RESULTS: Pathology results of 172 biopsied lesions showed that 83 were malign and 89 masses were benign. Totally 39 breast hamartomas were diagnosed radiologically (n=25) or histopathologically (n=14). All hamartomas (n=39) produced the power acoustic Doppler artifact as the surrounding tissue at the same depth in PDVF imaging. On the other hand, none of the malign or benign lesions, apart from hamartomas, evidenced a similar vibrational artifact as the surrounding tissue at the same depth in the PDVF imaging. CONCLUSION: PDVF imaging during breast sonography is an invaluable technique in the identification of breast hamartomas from other benign or malign breast masses.

Cervical cystic vagal schwannoma mimicking a type 3 second branchial cleft cyst: a case report.

In this article, we report a rare case of a cervical cystic vagal schwannoma mimicking a type 3 second branchial cleft cyst clinically, radiologically and cytologically. Although schwannoma is rare, it should be considered in the differential diagnosis of cystic neck masses. This article suggests that Doppler ultrasonography, computed tomography and fine needle aspiration biopsy findings may not be sufficient to provide the correct preoperative diagnosis of cystic lateral neck masses and further imaging techniques may be required.

Myositic type of idiopathic orbital pseudotumor in a 4-year-old child: a case report.

Idiopathic orbital pseudotumor is a benign, noninfectious, and nonneoplastic disease with unknown cause. It is the third most common orbital disease after thyroid orbitopathy and lymphoproliferative disorder. Idiopathic orbital pseudotumor is extremely rare in pediatric age group and may cause real diagnostic problems. This paper describes a 4-year-old girl who presented with sudden ptosis in the right eye and swollen eyelid. She recovered completely with high-dose steroid therapy. We report clinical and magnetic resonance imaging findings of orbital myositis, which is a rare subtype of idiopathic orbital pseudotumor in children and needs to be differentiated from other orbital disease especially malignancy.

Utility of diffusion-weighted imaging in the evaluation of liver fibrosis.

OBJECTIVES: To evaluate the usefulness of diffusion- weighted MRI (DWI) in the detection and staging of liver fibrosis and inflammation. METHODS: DWI was performed with b-factors of 0, 500 and 1000 s/mm². ADC values were obtained by placing circular regions of interest in four segments of the liver. Differences between the study (n = 34) and control groups' (n = 25) ADC values were examined. Further, this study investigated if and how ADC values were related to fibrosis stages and histological activity index (HAI) scores. RESULTS: The mean ADC value of the liver was smaller in the study group compared with the control group (P < 0.001). Spearman rho correlation analyses showed lower ADC values were associated with higher fibrosis and HAI scores (P < 0.01). There were statistically significant differences in liver ADC values between each combination of fibrosis stages (e.g. stages 0 and 1, 0 and 2) except for stages 1 and 2. CONCLUSIONS: ADC values prove to be a valuable technique for the diagnosis of liver fibrosis and inflammation. They can also be useful in fibrosis staging, particularly in distinguishing later stages of fibrosis from intermediate and early stages. KEY POINTS: Diffusion Weighted MRI is a promising technique for diagnosis of liver fibrosis. Apparent Diffusion Coefficients provide valuable information for staging of liver fibrosis. DWI may offer alternative to biopsy for assessing liver fibrosis.

Asymptomatic fatty changes in the myocardium of a patient with tuberous sclerosis.

Rhabdomyomas are the most common primary cardiac tumors in childhood. They usually occur on ventricular and septal walls. In approximately half of the cases, rhabdomyoma is associated with tuberous sclerosis. Most rhabdomyomas regress during the first years of life. We present MRI findings of fatty replacement of the myocardium which was probably after spontaneous regression of solid mass (rhabdomyoma) in a 16-year-old boy with tuberous sclerosis.