Inanc Guvenc

The added value of the apparent diffusion coefficient calculation to magnetic resonance imaging in the differentiation and grading of malignant brain tumors.

Objective: ADC calculation can improve the diagnostic efficacy of MR imaging in brain tumor grading and differentiation. Methods: Apparent diffusion coefficient (ADC) values and ratios of 33 low-grade (23 astrocytomas, 10 oligodendrogliomas) and 40 high-grade (25 metastases and 15 high-grade astrocytomas) malignant tumors were prospectively evaluated. Results: Tumoral ADC values (r = −0.738, P < 0.000) and ratios (r = −0.746, P < 0.000) were well correlated with higher degree of malignancy and quite effective in grading of malignant brain tumors (P < 0.000). By using cutoff values of 0.99 for tumoral ADC value and 1.22 for normalized ADC ratio, the sensitivity of MR imaging could be increased from 72.22% to 93.75% and 90.63%, the specificity from 81.08% to 92.68% and 90.24%, PPV from 78.79% to 90.91% and 87.88%, and NPV from 75.00% to 95.00% and 92.50%, respectively. Conclusion: ADC calculation was quite effective in grading of malignant brain tumors but not in differentiation of them and added more information to conventional contrast-enhanced MR imaging.

Diffusion-weighted imaging in the characterization of focal liver lesions: efficacy of visual assessment.

Objectives: The objective of the study was to assess the value of visual assessment of signal intensities on b800 diffusion-weighted images and apparent diffusion coefficient (ADC) maps in differentiation of benign and malignant focal liver lesions (FLLs). Methods: Approval for this retrospective study was obtained from the institutional review board. One hundred forty-three FLLs in 65 patients (38 women, 27 men; mean age, 50.8 years) underwent magnetic resonance (MR) imaging and diffusion-weighted imaging (DWI) with a respiratory-triggered single-shot echo-planar imaging sequence. Focal liver lesions were evaluated visually according to the signal intensities on b800 and ADC map images, and ADC values were also calculated. The conventional MR imaging, follow-up imaging findings, and histopathologic data were regarded as gold standard. Normal distribution was assessed with Kolmogorov-Smirnov test. The accuracies of visual assessment and ADC values in differentiating benign and malignant FLLs were assessed with the Student t test, and threshold values were determined with receiver operating characteristic curve analysis. Results: By using a cutoff value of 1.21 × 10−3 mm2/s, ADC had a sensitivity of 100%, a specificity of 89.3%, and an accuracy of 92.3% in the discrimination of malignant FLLs. With the visual assessment of the DWIs and ADC maps, malignant lesions were differentiated from benign ones, with 100% sensitivity, 92.2% specificity, and 94.4% accuracy. Although some benign lesions were interpreted as malignant, no malignant lesion was determined as benign in visual assessment. Conclusions: Most FLLs are benign ones such as hemangiomas and cysts, which can be readily and practically characterized only by using visual assessment of DWIs without requiring time-consuming conventional and dynamic contrast-enhanced imaging sequences. Some benign lesions that are falsely interpreted as malignant can be further characterized by using conventional and contrast-enhanced MR studies.

Sciatic nerve compression due to femoral neck osteochondroma : MDCT and MR findings

A 34-year-old man presented with a 15-month history of pain along the left sciatic nerve. Radiographs and computed tomography (CT) revealed an exostosis on the postero-inferior aspect of the left femoral neck. Ultrasonographic examination of left upper thigh and a pelvic magnetic resonance (MR) imaging showed an enlarged sciatic nerve adjacent to the exostosis. Although peroneal and ulnar neuropathies due to the compression by exostosis are reported frequently, imaging findings of sciatic nerve involvement were not well documented in the literature. Multidetector CT and MR findings of a sciatic nerve compression caused by a femoral neck exostosis were presented.

HASTE diffusion-weighted MRI for the reliable detection of cholesteatoma.

PURPOSE To assess the detection efficiency of Half-Fourier acquisition single-shot turbo spin-echo (HASTE) diffusion-weighted magnetic resonance imaging (MRI) for cholesteatoma. MATERIALS AND METHODS A total of 21 patients with suspected primary (n=16) or recurrent cholesteatoma (n=5) underwent MRI in a 1.5 Tesla scanner using an adapted protocol for cholesteatoma detection that included a coronal HASTE diffusion-weighted MRI sequence. The cholesteatoma diagnosis was based on evidence of a hyperintense lesion at b-1000 on diffusion-weighted images. The imaging findings were correlated with findings from surgery or clinical evaluations in all patients. RESULTS HASTE diffusion-weighted MRI successfully detected 11 primary and 5 recurrent lesions out of 17 cholesteatomas (sensitivity, 94.1%). One primary cholesteatoma with a diameter of 4-5 mm was missed. MRI of patients without cholesteatoma were correctly interpreted as negative for cholesteatoma (specificity, 100%). The positive and negative predictive values for the HASTE diffusion-weighted MRI in detecting cholesteatoma were 100% and 80%, respectively. CONCLUSION HASTE diffusion-weighted MRI offers great promise for cholesteatoma screening. The addition of this sequence to the posterior fossa MRI protocol may preclude unnecessary cholesteatoma surgery.

Osteopoikilosis coexistent with ankylosing spondylitis and familial Mediterranean fever.

Osteopoikilosis (OPK) is a rare benign sclerosing disease of the skeleton and inherited as an autosomal dominant trait. OPK is associated with inflammatory rheumatic disorders, such as rheumatoid arthritis, scleroderma, reactive arthritis and familial Mediterranean fever (FMF). We report a rare case of OPK coexistent with ankylosing spondylitis and FMF. The patient presented multiple sclerotic lesions within and around the sacroiliac joints and a series of radiological diagnostic challenges.

Sonography of fat necrosis of the breast: correlation with mammography and MR imaging.

Fat necrosis (FN) of the breast is a benign nonsuppurative inflammatory process of the adipose tissue. The radiologic appearance ranges from benign to suspicious for malignancy; therefore, it is very important to know the distinguishing radiologic features of FN on different modalities. Mammography is more helpful in identifying FN than ultrasonography in most of the cases, and MRI may also be used to rule out malignancy as an adjunct to mammography and sonography. Even when modern diagnostic modalities are used, biopsy may still be unavoidable for some cases. In conclusion, an accurate history and familiarity with the radiologic findings are crucial to recognizing FN and avoiding unnecessary interventions.

Pararectal mass: An atypical location of splenosis

Splenosis is the autotransplantation of splenic tissue resulting from the dissemination of cells from the pulp of the spleen after splenic injury or splenectomy. Implants can be found anywhere in the peritoneal cavity, especially on the serosal surfaces of small and large bowel, in the mesentery and diaphragm, implanted in visceral organs, within the thorax and brain, and in surgical scars and may vary in number, shape, and size. We described the sonographic, computed tomography and magnetic resonance imaging findings of pararectal splenosis in a 23‐year‐old man. The lesions appeared as multiple, well‐circumscribed, small, round, homogenously solid masses of different sizes at the retrovesical and pelvic region detected during the imaging workup of Behçet disease.

Risk factors associated with breast arterial calcifications.

Background A number of studies have linked the presence of breast arterial calcifications (BACs) with an increased risk of diabetes, hypertension, coronary artery disease (CAD), and cardiovascular mortality. Because there is a well-established screening system for breast cancer, it has been proposed that the presence of BACs can be used as a warning sign indicating an increased risk of metabolic and vascular diseases. Purpose To determine the relation between BAC and early renal dysfunction. Material and Methods A retrospective review of 6118 mammograms identified 701 cases with BACs. Women with BACs were compared to a random selection of 362 women without BACs based on available laboratory data. Univariate analysis was conducted according to age groups. Results The prevalence of BACs was 11.5% in our study. Hyperglycemia increased the odds of BACs by 8.1 (95% CI 3.0–22.1, P < 0.001) in the 50–59-year age group. The presence of an elevated blood urea nitrogen (BUN) and serum creatinine increased the odds of BACs by 2.6 (95% CI 1.2–6.0, P = 0.016) and 2.3 (95% CI 1.0–5.2, P = 0.045) in women ≥70 years of age. Hyperlipidemia was not a significant risk factor for BACs in any age group. Conclusion Our results support the view that the presence of BACs on mammography may be indicative of diabetes in middle-aged women. On the other hand, BACs are not very useful for predicting early renal dysfunction in women <70 years of age.

Sonography of fat necrosis of the breast

Fat necrosis (FN) of the breast is a benign nonsuppurative inflammatory process of the adipose tissue. The radiologic appearance ranges from benign to suspicious for malignancy; therefore, it is very important to know the distinguishing radiologic features of FN on different modalities. Mammography is more helpful in identifying FN than ultrasonography in most of the cases, and MRI may also be used to rule out malignancy as an adjunct to mammography and sonography. Even when modern diagnostic modalities are used, biopsy may still be unavoidable for some cases. In conclusion, an accurate history and familiarity with the radiologic findings are crucial to recognizing FN and avoiding unnecessary interventions.

Sonography of fat necrosis of the breast: Correlation with mammography and MR imaging: Fat Necrosis of The Breast

Fat necrosis (FN) of the breast is a benign nonsuppurative inflammatory process of the adipose tissue. The radiologic appearance ranges from benign to suspicious for malignancy; therefore, it is very important to know the distinguishing radiologic features of FN on different modalities. Mammography is more helpful in identifying FN than ultrasonography in most of the cases, and MRI may also be used to rule out malignancy as an adjunct to mammography and sonography. Even when modern diagnostic modalities are used, biopsy may still be unavoidable for some cases. In conclusion, an accurate history and familiarity with the radiologic findings are crucial to recognizing FN and avoiding unnecessary interventions.