Hasan Dinç

Contribution of Diffusion-Weighted Imaging to Dynamic Contrast-Enhanced MRI in the Characterization of Breast Tumors

OBJECTIVE The purpose of our study was to evaluate the diagnostic value of an imaging protocol that combines dynamic contrast-enhanced MRI (DCE-MRI) and diffusion-weighted imaging (DWI) in patients with suspicious breast lesions and to determine if additional information provided by DWI improves the diagnostic value of breast MRI. MATERIALS AND METHODS Eighty-four patients with breast tumors (37 benign, 47 malignant) underwent DCE-MRI and DWI before biopsy. Morphologic and kinetic analyses were performed on DCE-MRI and findings were classified according to the BI-RADS lexicon. Apparent diffusion coefficient (ADC) values were calculated from the DWI. The ADCs of the benign and malignant lesions were compared. For the combined MRI protocol, morphologic kinetic features and ADCs were evaluated together. Diagnostic values of DCE-MRI, DWI, and combined MRI were calculated. RESULTS Median ADCs of the benign and malignant lesions were 1.26 × 10(-3) mm(2)/s and 0.75 × 10(-3) mm(2)/s, respectively. Cutoff value of 0.92 × 10(-3) mm(2)/s for ADC provided 91.5% sensitivity and 86.5% specificity. DCE-MRI alone showed 97.9% sensitivity and 75.7% specificity. The combination of DCE-MRI with DWI provided 95.7% sensitivity and 89.2% specificity. The specificity of breast MRI improved by 13.5% (p = 0.063) without a significant decrease in the sensitivity (p = 1.000). CONCLUSION The combination of DWI and DCE-MRI has the potential to increase the specificity of breast MRI.

Pituitary dimensions and volume measurements in pregnancy and post partum : MR assessment

Purpose: Our purpose was to clarify and further characterize the changes in height, length, width, volume, and shape in the normal pituitary gland and in width in the infundibulum during pregnancy and the first 6 months post partum. Material and Methods: Cranial MR imaging was performed in 78 women who were pregnant in the second or third trimester or who were post partum, and in 18 age-matched control subjects who were not pregnant. Volume measurements were performed in 2 ways; volume 1=1/2xheightxlengthxwidth; and volume 2=area (measured by trackball)xslice thickness Results: Gland volume, height, width, length, and convexity, and infundibular width increased during pregnancy. the highest values were seen during the 3 days immediately post partum. When compared with volunteers, volumes 1 and 2 showed the largest increase (120%) among the parameters. Gland height showed the best correlation (r=0.94, p>0.00001) with gestational age. the mean height of the gland was 8.76 mm in the third trimester. None of the pregnant women had a gland height of above 10 mm during pregnancy. Only 2 subjects had gland heights of 10.04 and 10.2 mm during the 0–3 days post partum. After this first post-partum period of 3 days, the gland size, shape, and volume and the infundibular width returned to normal within 6 months Conclusion: the pituitary gland enlarges in three dimensions throughout pregnancy. During pregnancy, the volume of the gland shows the highest percentage of increase compared to its length, height, and width. the maximum height of the gland does not exceed 10 mm during pregnancy but it may exceed 10 mm during the 3 days immediately post partum.

Percutaneous catheter drainage of tuberculous and nontuberculous psoas abscesses.

OBJECTIVE To assess the utility of percutaneous catheter drainage in the management of tuberculous and nontuberculous psoas abscesses associated without any bony involvement or with minimal bony lesions that could not cause vertebral instability. MATERIALS AND METHOD Eleven patients with psoas, iliopsoas and pelvic abscesses were drained under computed tomography and ultrasonography guidance. RESULTS There were 15 (10 tuberculous, 5 pyogenic) abscesses in 11 patients. Six of the tuberculous abscesses and one of the pyogenic abscess were associated with vertebral involvement. Vertebral lesions were located in one or two vertebrae without causing any serious disturbance in the vertebral stabilization. In one case, the abscess was bilateral. Nine cases were drained under computed tomography guidance, while two cases were drained under both computed tomography and ultrasonography guidance. One session drainage was sufficient for abscess resolution in uniloculated cases. In the two of four multiloculated cases, catheter drainage was performed twice. Relapse of the abscess was found in only one patient. The mean abscess volume was 520 ml and mean drainage duration was 12 days. None of the cases required surgery. CONCLUSION Percutaneous drainage, chemotherapy and additional external brace application with the cases associated with bony lesion may be used for treatment of tuberculous and nontuberculous unilocule and multiloculated abscesses.

Umbilical and middle cerebral artery Doppler indices in patients with preeclampsia

OBJECTIVE To compare changes in Doppler ultrasound studies of fetal circulation in normal pregnancies with those of a group of preeclamptic patients both with and without intrauterine growth retardation and to demonstrate the best index for predicting adverse perinatal outcome or IUGR. STUDY DESIGN A cross-sectional study was performed on 125 normal pregnancies and 62 preeclamptic patients at 31-40 weeks of gestation. The umbilical artery systolic-diastolic ratio (UA S/D), UA pulsatility index (PI), the middle cerebral artery (MCA) PI, and the ratio of MCA PI to UA PI were measured. The mean values of the Doppler indices were compared. Different cut-off values (mean +/-2 S.D.) were used for the 31st-35th and the 36th-40th weeks. RESULTS Significant differences were found between normal pregnancies and preeclamptic patients without IUGR using the mean MCA PI and the MCA PI/UA PI ratio. In the preeclamptic patients with IUGR, all the mean Doppler indices were different from those of the normal pregnancies. In the preeclamptic patients with IUGR the values were different from the preeclamptic patients without IUGR, except for the MCA PI at 31-35 weeks. The UA S/D had the highest sensitivity (88%) and diagnostic accuracy (94%) in predicting the adverse perinatal outcome. The MCA PI/UA PI ratio showed the highest predictive value in determining IUGR by a sensitivity of 84% and a diagnostic accuracy of 87%. CONCLUSION Both abnormal umbilical Doppler indices and cerebral-umbilical ratio are strong predictors of IUGR and of adverse perinatal outcome in preeclampsia. The MCA PI alone is not a reliable indicator. The combination of umbilical and fetal cerebral Doppler indices may increase the utility of Doppler ultrasound in preeclamptic subjects.

Retrieval of prolapsed coils during endovascular treatment of cerebral aneurysms

One of the feared complications during detachable coil embolization of cerebral aneurysms is herniation of a coil loop into the parent artery. Although coil protrusion of one or two loops into the parent vessel may not cause adverse events and in some instances can be ignored, the authors believe that coil retrieval is indicated if a free end is seen pulsating along the blood flow stream to prevent migration of the entire coil mass. In one patient, a microballoon was inflated across the neck of the aneurysm during retrieval of a herniated coil to prevent further coil herniation from the aneurysm sac. We present two cases in which prolapsed coils were successfully retrieved either using a microsnare and balloon combination or a microsnare alone. This report focuses on the efficacy of the Amplatz microsnare for such retrievals and the circumstances in which a herniated coil needs to be retrieved. We report two cases in which embolization coils partially migrated into the parent artery during endovascular treatment of cerebral aneurysm and were retrieved using the Amplatz Nitinol microsnare.

VALUE OF RESISTIVE INDEX IN PATIENTS WITH CLINICAL DIABETIC NEPHROPATHY

OBJECTIVE To determine whether the intrarenal resistive index (RI) can be used as a predictor in patients with advanced clinical diabetic nephropathy. METHODS Sixty-eight kidneys belonging to 34 patients with type II diabetes mellitus and 100 kidneys of 50 healthy persons (control group) were evaluated with Doppler ultrasonography. RI values were obtained from intraparenchymal arteries, either the arcuate or interlobar arteries. Patients with diabetes were divided into two groups based on serum creatinine concentration: group 1 (n = 21 patients, 42 kidneys) had a serum creatinine concentration <1.4 mg/dL and group 2 (n = 13 patients, 26 kidneys) had a serum creatinine concentration >1.4 mg/dL. Regression analysis was used to examine the relations between intrarenal RI and age, serum creatinine concentration, and creatinine clearance rate. RESULTS The mean RI value (0.69+/-0.1) in patients with diabetes was significantly different from that of healthy subjects (0.56+/-023) (P < 0.00001). The RI value of the patients in group 2 (0.79+/-0.07) was significantly different from that of the patients in group 1 (0.61+/-0.04, P < 0.00001). Serum creatinine concentration and creatinine clearance rate showed high correlations (r = 0.84 and r = -0.76, respectively) with intrarenal RI values. CONCLUSIONS Because the intrarenal RI shows a high level of correlation with serum creatinine concentration and creatinine clearance rate, it can be used as a predictor in patients with advanced clinical diabetic nephropathy. Intrarenal RI does not offer any advantage over serum creatinine concentration and creatinine clearance rate in patients with early-stage diabetic nephropathy with normal renal function.

Contrast-Enhanced MR Angiography of the Breast: Evaluation of Ipsilateral Increased Vascularity and Adjacent Vessel Sign in the Characterization of Breast Lesions

OBJECTIVE The purpose of this study was to investigate the role of evaluation of breast vascularity with contrast-enhanced MR angiography in the differentiation of malignant from benign lesions. MATERIALS AND METHODS Contrast-enhanced 3D MR angiograms of the breasts of 102 patients with unilateral and histopathologically confirmed breast lesions were evaluated retrospectively. All images were evaluated for both ipsilateral increased vascularity and adjacent vessel sign, and the values of these signs in the diagnosis of malignancy were assessed. RESULTS Histopathologic analysis of 102 patients revealed 50 malignant and 52 benign results. In 31 of the 50 patients with breast cancer and in 11 of the 52 patients with benign lesions, ipsilateral breast vascularity was increased. The resulting sensitivity and specificity of ipsilateral increased vascularity were 62% and 79%. The adjacent vessel sign was present in 37 of the 50 patients with breast cancer and six of the 50 patients with benign lesions. The resulting sensitivity and specificity of the adjacent vessel sign were 74% and 89%. The overall accuracies of ipsilateral increased vascularity and the adjacent vessel sign were 71% and 81%. CONCLUSION Both ipsilateral increased vascularity and the adjacent vessel sign were found to be associated with breast cancer in a significant percentage of patients. The adjacent vessel sign is more practical and generally applicable. There is a borderline significance in favor of the higher accuracy of the adjacent vessel sign in comparison with ipsilateral increased vascularity (p = 0.043).

Contribution of MRI to ultrasound in the diagnosis of fetal anomalies.

To evaluate the contribution of MRI to ultrasound (US) in the diagnosis of fetal anomalies.

Interrupted aortic arch in a adult: diagnosis with MSCT

Interrupted aortic arch (IAA) is a rare severe congenital heart defect defined as a complete loss of luminal and anatomic continuity between ascending and descending aorta. It is important that we made a good diagnosis and accurate evaluation of their morphologic conditions before a heart operation. We presented an 18-year-old girl of interrupted IAA diagnosed by multi-slice computed tomography angiography.

Subacute spinal subdural hematoma associated with intracranial subdural hematoma.

We describe a subacute spinal subdural hematoma in a patient with psot-traumatic subacute intracranial subdural hematoma. CT and MRI demonstrated hematoma within the interhemispheric subdural space and at the lumbar posterior subdural space which extended from the L1 to the S2 level. The lesion showed high signal intensity on both T1 and T2 weighted images. Surgical decompression of the spinal subdural hematoma was performed. The symptoms completely resolved after surgery. Spinal subdural hematoma may be concomitant with or may occur after intracranial subdural hematoma. If a patient with intracranial subdural hematoma complains of low back pain and weakness in both legs; lumbosacral MR examination should be performed to exclude spinal subdural hematoma.