Umit Aksoy Ozcan

Evaluation of the placenta with relative apparent diffusion coefficient and T2 signal intensity analysis.

PURPOSE We aimed to test the null hypothesis that relative apparent diffusion coefficient (rADC) and relative signal intensity values (rSI(HASTE)) do not change in the evaluation of placental maturation with advancing gestational age. MATERIALS AND METHODS Fifty-six fetuses with diffusion-weighted magnetic resonance imaging (DW-MRI) data were enrolled in this retrospective study. Fetuses were analyzed in three different gestational age groups: group 1, 18-23 weeks; group 2, 24-28 weeks; and group 3, 29-38 weeks. The rADC (mean ADC/ADC(globe)) and rSI(HASTE) values (mean SI(HASTE)/SI(globe)) were obtained. Two radiologists experienced in fetal MRI who were blinded to the patient information reviewed MRI images independently. Kruskal-Wallis Test was used to compare the rADC and rSI(HASTE) with gestational age groups. The agreement between the two blinded readers was tested using Krippendorffs alpha ratio. RESULTS Both placental rADC values and placental rSI(HASTE) values were not significantly different between the gestational age groups (P = 0.688 and P = 0.280, respectively). rADC and rSI(HASTE) measurements were reproducible with a good agreement between the two readers (Krippendorffs alpha ratio was 0.613 and 0.778, respectively). CONCLUSION The rADC and rSI(HASTE) values do not change with advancing gestational age.

Rapidly involuting congenital hemangioma: a case of complete prenatal involution.

We report a case of rapidly involuting congenital hemangioma of the flank, which was diagnosed in the 2nd trimester of gestation and showed complete involution before term. In our case sonography revealed a highly vascular soft tissue mass with smooth contours, which was isointense with the placenta on T2‐weighted MR images. The fetus was born with scar tissue at the site of the lesion. To our knowledge this is the 1st reported case of rapidly involuting congenital hemangioma showing complete involution before term.

Diffusion-Weighted MR Imaging Findings of Cortical Vein Thrombosis at 3 T.

PurposeDiagnosis of cortical vein thrombosis (CVT) on the basis of clot hyperintensity on diffusion-weighted imaging (DWI) has been reported as limited. Our aim was to evaluate different DWI findings of CVT either in isolated form or in combination with sinus thrombosis.MethodsIn this review-board-approved study, patients with the diagnosis of CVT on magnetic resonance venography (MRV) between 2004 and 2011 were evaluated, and 13 patients with 26 CVT (3 isolated and 23 combined CVT) sites were recruited. The evaluated DWI findings were as follows: (1) the hyperintense clot signal (CS) itself, and (2) clot susceptibility signal (CSS) that appears next to the CVT. Two blinded radiologists evaluated the data. Kappa (κ) statistics was applied for interobserver agreement.ResultsBoth readers reported CS within the vascular clot itself in 6 of 26 (23 %) CVT sites on DWI. CSS was reported in 16 of 26 (61.5 %) CVT sites by reader 1, and in 14 of 26 (54 %) of the CVT sites by reader 2. At four CVT sites with thrombosed veins on MRV, both readers reported no DWI findings. When both CS and CSS were evaluated together, reader 1 reported a positive DWI finding in 22 of 26 (84 %) of the CVT sites, and reader 2 reported in 20 of 26 (79 %) of the sites. κ Statistics showed a very good agreement (κ: 0.87).ConclusionsBesides the hyperintense CS, with additional evaluation of the presence of CSS, DWI can provide an additional clue in CVT patients and may suggest its diagnosis, which is important in clinically unsuspected patients.

Assessment of sedated pediatric brain with 3D-FLAIR sequence at 3T MRI.

BACKGROUND AND PURPOSE In sedated pediatric brains, 2D-FLAIR causes increased signal intensity of the cerebrospinal fluid (CSF) leading to false-positive diagnoses. Our aim is to determine whether increased CSF signal intensity is observed on 3D-FLAIR images. METHODS In this institutional review board-approved study, a 2-year retrospective analysis of our MRI database was conducted which revealed 48 sedated pediatric patients with normal cranial MRI findings and 3D-FLAIR sequence. One adult volunteer was imaged before and after O2 inhalation with 2D and 3D-FLAIR sequences. The hyperintensity in the subarachnoid spaces and basal cisterns were quantified as follows: 0: artifact free; 1: homogeneous minimal CSF signal; 2: abnormal CSF signal. Inter-observer agreement was assessed with kappa agreement analysis. RESULTS Grade 0 and grade 1 signals were observed at inferior to Liliequist membrane (LLQ) in 48/48 and 0/48 cases; prepontine cistern 47/48 and 1/48; superior to LLQ 26/48 and 22/48; 4th ventricle 16/48 and 32/48; 3rd ventricle 34/48 and 14/48; lateral ventricle 3/48 and 45/48; subarachnoid space 36/48 and 12/48, respectively. No patients showed grade 2 signal. Inter-observer agreement was 0.81-1. In the volunteer, after O2 inhalation, grade 2 signal intensity was evident on 2D-FLAIR however; 3D-FLAIR did not show any signal increase. CONCLUSIONS In sedated pediatric brains, 3D-FLAIR suppresses CSF signal, and enables reliable assessment free from CSF artifacts.

Is there a role for BLADE acquisition in T2-weighted breast MRI?

Background: Standard T2-weighted (T2W) magnetic resonance imaging (MRI) is a necessary component of routine breast MRI. However, breast MRI suffers from minor subject movements, which degrade the image quality. BLADE acquisition MRI is a promising motion degradation method currently used in brain imaging. Purpose: To compare T2W BLADE acquisition breast MR images with routine T2W images in the evaluation of motion artifacts and overall image quality. Material and Methods: MRI was performed with a 1.5 T system on 25 volunteers and 25 consecutive patients with identical imaging parameters for both MRI sequences (TR 5240 ms, TE 112–108 ms, acquisition 1, spatial resolution 0.9×0.9× 4 mm). Motion and flow artifacts and pectoral muscle and lesion contour delineations were assessed. Signal to noise ratios (SNRs) of images and contrast to noise ratios (CNRs) of the incidental lesions were calculated. The results were evaluated with the Wilcoxon signed-ranks test. Results: Of the 50 patients, 44 were included in the analysis (mean age 42.1 years). Motion artifacts were prominent in 48% cases on routine T2W and in only 2% of BLADE cases. The SNR values of BLADE images were significantly higher than routine T2W (P<0.05). Pectoral muscle contours were better assessed on BLADE in all cases. Sequence performances were similar in flow artifacts, CNR values, and contour delineation of incidental lesions. The readers chose BLADE sequence MRI in 25 cases and found the overall performance of sequences equal in 19 cases. None of the readers preferred routine T2W to BLADE. Conclusion: The performance of BLADE is superior to routine T2W images in eliminating motion artifacts, provides better SNRs, shows detailed pectoral muscle contours, and may be the sequence of choice.

An unusual cause of small bowel obstruction: CT diagnosis of dried apricots.

Small bowel obstruction is a common cause of acute abdominal pain, and up to 75% of cases are caused by adhesions followed by hernias and neoplasm [1]. Acute intraluminal occlusion of small bowel is uncommon, and among the intraluminal causes of small bowel obstruction are gallstones, foreign bodies, retained meconium, bezoars, and tangles of ascarides. Obstruction by bezoars and especially by undigested food is rare and mostly seen in children, old people, and patients with mental disorders [1– 3]. Hereby, we present the computed tomography (CT) findings of a rare case of intestinal obstruction due to dried apricots with review of the relevant literature.

Identification of fetal precentral gyrus on diffusion weighted MRI

To investigate the association of the diffusion-weighted MR imaging characteristics of fetal preCG and gestational age. Forty-four fetuses with normal brain MRI findings were included in the study. Gestational ages ranged from 18 to 36 weeks (mean 25.2 weeks). All exams were performed with a 1.5-T scanner using a body array coil during free maternal breathing without sedation. Precentral gyrus was defined as the hyperintense strip anterior to the central sulcus, on the superior section of axial brain images at the level of superior frontal cortex. The presence of preCG hyperintensity was noted as observed/subtle/not observed at different b values (500, 1000 s/mm(2)) and on apparent diffusion coefficient (ADC) maps and compared to the imaging characteristics of the superior frontal cortex. Precentral gyrus was first detected at 25 weeks as a hyperintense strip on DWI and hypointense strip on ADC maps. Display of preCG b 1000 s/mm(2) images were better than b 500 s/mm(2). Between 25 and 27 weeks, in 40% of fetuses preCG was observed on one hemisphere, and it was evident bilaterally in 60% of cases. Starting from the 28th week, preCG was observed on both hemispheres in 100% of cases. Diffusion weighted imaging helps better understanding of the evolution of fetal preCG. The hyperintense preCG strip starts to appear at 25 weeks, and when interpreting fetal DWI after 28 weeks this may be a sign to be sought for in all fetuses and an indicator for normal development.

Can breast MRI facilitate decision-making in equivocal mammography and ultrasonography findings?

3. Results Sixty-eight breasts in 59 women were included in the study (mean age 48.6 years (28–80 years). Forty-two cases underwent biopsy (30 benign, 12 malignant). The remaining 26 breasts were diseasefree for 2 years follow-up by clinical exam, MG and US. There were 31 cases of MG asymmetry and sensitivity was 40% for MG, 60% US, specificity 73% for both, PPV 22% MG, 30% US, NPV 86% MG, 90% US. When MG and US were combined, sensitivity increased to 80%, specificity 61.5%, PPV 29%, NPV 94%. MRI specificity was 69%, and PPV 38%. In architectural distortion cases sensitivity was 20% for both MG and US, specificity 73 vs 74%, PPV 14% and NPV 81% were the same for both. Results for combined assessment were almost the same. When MRI was performed specificity was 65% and PPV 38%. For microcalcifications MG sensitivity was 100%, specificity 40%, PPV 50%, NPV 100%. US sensitivity in correlated location was 17%, specificity 80%, PPV 33%, NPV 61%. Combined evaluation results had sensitivity 100%, specificity 40%, PPV 50%, and NPV 100%. Correlated MRI findings had a specificity of 60% and PPV of 60%. MRI sensitivity and NPV were 100% in all evaluated cases.

Whole-Body MRI Screening in Asymptomatic Subjects; Preliminary Experience and Long-Term Follow-Up Findings

Summary Background The aim of this study is to describe the technique and to evaluate the results of whole-body magnetic resonance imaging in an asymptomatic population. Material/Methods Between March 2009 and December 2011, 118 consecutive subjects undergoing thorough medical check-up were prospectively included in the study. MRI was performed with a 205-cm moving table, parallel imaging and automatic image composing software. Results In 83 subjects (70%), 103 benign lesions were detected. Two malignant (adrenal and renal carcinoma) lesions and one precancerous (pancreatic mucinous carcinoma) lesion were detected. The most common lesions were renal cysts, liver hemangiomas, liver cysts, thyroid nodules, and uterine leiomyomas. Conclusions WB-MRI is able to cover area from head to toes in one diagnostic work-up, and besides the anatomic regions evaluated by conventional radiological modalities, i.e. brain parenchyma, bones and extremities, can be evaluated in one examination.

Ultrasound-Guided Fine Needle Aspiration (USFNA) of Thyroid Nodules; Does Aspiration Site Matter?

Background: The goal of ultrasound guided fine-needle aspiration (USFNA) is to obtain most cellular specimen that represents the nodule. However, there is substantial variability in specimen cellularity depending on the obtaining techniques. While performing USFNA, it is not clear whether the needle tip should be placed at hypovascular or hypervascular site of the nodule to obtain more cells for cytological analysis. Objectives: The aim of the study was to assess whether USFNA of the hypovascular or hypervascular site of a thyroid nodule would reveal more cells for cytological analysis. Patients and Methods: Twenty-three consecutive patients with solid thyroid nodules larger than 2 cm were aspirated under color Doppler sonography guidance. First pass was from the hypovascular site and the second pass from the hypervascular site. The aspirates were scored from 1-3 by cytologist according to number of cell groups. Results: When only hypervascular site was used, adequate sampling was limited to 65% of the cases. When both sites were evaluated together, overall adequate sampling was 91%. Adding a sample from the hypervascular site to hypovascular aspirate increased the adequate sampling by 8%. The highest pathological score was achieved when both hypo- and hypervascular site aspirates were evaluated together. Conclusions: The aspirates from the hypovascular and hypervascular sites of solid nodules are complementary and should be performed consecutively.