Computed tomography (CT) plays an important role in diagnosis of acute intestinal obstruction and planning of surgical treatment. Although internal hernias are uncommon, they may be included in the differential diagnosis in cases of intestinal obstruction, especially in the absence of a history of abdominal surgery or trauma. CT findings of internal hernias include evidence of small bowel obstruction (SBO); the most common manifestation of internal hernias is strangulating SBO, which occurs after closed-loop obstruction. Therefore, in patients suspected to have internal hernias, early surgical intervention may be indicated to reduce the high morbidity and mortality rates. In a study of 13 cases of internal hernias, nine different types of internal hernias were found and the surgical and radiologic findings were correlated. The following factors may be helpful in preoperative diagnosis of internal hernias with CT: (a) knowledge of the normal anatomy of the peritoneal cavity and the characteristic anatomic location of each type of internal hernia; (b) observation of a saclike mass or cluster of dilated small bowel loops at an abnormal anatomic location in the presence of SBO; and (c) observation of an engorged, stretched, and displaced mesenteric vascular pedicle and of converging vessels at the hernial orifice.

Purpose:To evaluate morphological and signal intensity (SI) changes of placental insufficiency on magnetic resonance imaging (MRI) and to assess morphological changes and decreased flow voids (FVs) on T2-weighted rapid acquisition with relaxation enhancement (RARE) images for diagnosing placental insufficiency.Methods:Fifty singleton fetuses underwent MRI using a 1.5-T MR scanner. Placental thickness, area, volume, SI, amniotic fluid SI, and size of FVs between the uterus and the placenta were measured on MR images. Two radiologists reviewed T2-weighted RARE images for globular appearance of the placenta and FVs between the uterus and the placenta. Data were analyzed using t-tests, McNemar’s tests, and areas under the receiver operating characteristic curve (AUCs) at 5% level of significance.Results:Twenty-five of the 50 pregnancies were categorized as having an insufficient placenta. Significant differences were observed between insufficient and normal placentas in mean placental thickness, area, volume, placenta to amniotic fluid SI ratio, and size of FVs (49.0 mm vs. 36.9 mm, 1.62 × 104 mm2 vs. 2.67 × 104 mm2, 5.13 × 105 mm3 vs. 6.56 × 105 mm3, 0.549 vs. 0.685, and 3.4 mm vs. 4.3 mm, respectively). The sensitivity and accuracy using globular appearance plus decreased FVs were greater than those using decreased FVs (P < 0.01). There was no significant difference among AUCs using globular appearance and decreased FVs, and globular appearance plus decreased FVs.Conclusions:Placental insufficiency was associated with placental thickness, area, volume, placenta to amniotic fluid SI ratio, and size of FVs. Evaluating FVs on T2-weighted RARE images can be useful for detecting placental insufficiency, particularly in placentas without globular appearance on MR images.

Purpose: We evaluated the ability of diffusion-weighted imaging (DWI) at 3 tesla for diagnosing T stage and detecting stalks in bladder cancer.Methods: In total, 39 consecutive patients with bladder tumors underwent magnetic resonance (MR) imaging that included T 2 -weighted imaging (T 2 WI) and DWI using a 3T MR scanner. Two radiologists interpreted T 2 WI plus DWI and T 2 WI for diagnosis of T stage and for detection of stalks. We used McNemar's test to examine differences in diagnostic performance and Fisher's exact test to evaluate differences in stalk detection frequency.Results: Specificity and accuracy in differentiating T1 tumors from T2 to T4 tumors were significantly better with T 2 WI plus DWI (83% [20/24] Conclusion: DWI at 3T was superior to T 2 WI for evaluating the T stage of bladder cancer, particularly in differentiating T1 tumors from those T2 or higher, and in detecting stalks of papillary bladder tumors.

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Objectives: The aim of this study was to examine attenuation values in the central vein and perivenous artefacts at the subclavian vein in cervical CT angiography (CTA) when using 40 ml contrast material (CM) followed by different volumes (25 ml vs 40 ml) of saline flush (SF). Methods: 61 patients underwent CTA between the aortic arch (AA) and distal to the circle of Willis (cW). After calculating test-bolus time to peak enhancement at the cW (Tc), scanning delay was represented as [(Tc + 4) -scan duration between AA and cW] s. 28 patients (Group A) received 40 ml of 370 mg iodine (I) ml -1 CM followed by 25 ml of SF, and 33 patients (Group B) received the same CM followed by 40 ml of SF, both administered through the right antecubital vein. Arterial attenuation was measured at seven points in the aorto-carotid artery and at three points in the vertebrobasilar artery. Venous attenuation in the central vein was measured at four points. Mean attenuation values were analysed quantitatively. Axial and post-processing threedimensional images were assessed qualitatively. Results: When Groups A and B were compared, there were no differences in the mean attenuation values in either the aorto-carotid artery (p50.78) or the vertebrobasilar artery (p50.82). Mean venous attenuation values were lower (p50.002) in Group B than in Group A. Although the qualitative assessment of arterial images showed no differences between the two groups overall, perivenous artefacts at the subclavian vein were assessed as less prominent (p,0.01) in Group B. Conclusions: When compared with CTA followed by 25 ml of SF, CTA followed by 40 ml of SF can reduce venous attenuation values and perivenous artefacts at the subclavian vein. Cervical CT angiography (CTA) has high sensitivity and specificity for the detection of carotid artery stenosis, suggesting that it is suitable for screening symptomatic patients with atherosclerotic disease in anterior and posterior circulation [1]. In modern 32-or 64-multidetector row CT (MDCT) systems, small volumes of contrast material (CM) can provide sufficient early arterial enhancement in the cervical CTA [1][2][3].Several reports on thoracic CT and CTA have stated that saline flush (SF) after injection of the main CM bolus into the central veins can help to reduce perivenous streak artefacts at the brachiocepalic vein and superior vena cava [4][5][6][7]. In general, the suggested flush volumes range from 15 to 50 ml, but most authors report using 15-20 ml of SF [4][5][6][7][8][9].To reduce perivenous artefacts in cervical CT on a 16-MDCT system, Yoon et al [9] used 80 ml CM followed by 40 ml of SF [9], and de Monyé at al [2] suggested the craniocaudal scan direction. We recently reported that CTA on a 32-MDCT in the caudocranial direction can provide adequate arterial enhancement using 40 ml of highly concentrated CM followed by 25 ml of SF [3]; however, perivenous artefacts were often present in the subclavian vein. To improve images of the subclavian artery and upper extremity vasculature, pushing an extra ...