Computed tomography angiography: principles and clinical applications

Clinical applications of computed tomography (CT) angiography have increased with the improved technology of multidetector CT systems. Adequate contrast enhancement and the timing of image acquisition are key elements in producing technically adequate CT angiograms. This review article provides guidelines and protocols for four-, eight- and 16-channel multidetector systems in studies of the thoracoabdominal aorta, aortoiliac, and abdominal visceral vasculature, abdominal and extremity run-off studies, and carotid/cerebral CT angiography.     

Unusual mechanism of isolated torsion of fallopian tube following minor trauma. Herniation through a broad ligament tear

Isolated torsion of the fallopian tube without ovarian involvement and associated pathology is a rare event. We report an 18-year-old single female who presented with acute lower abdominal pain during menstruation after a minor trauma of the pelvis. It was diagnosed as isolated torsion of normal right tube during laparatomy due to herniation of the tube through a tear in the broad ligament.     

Prevalences of subclinical and overt hypothyroidism with universal screening in early pregnancy

To reveal the prevalence of subclinical and overt hypothyroidism among Turkish population during pregnancy. Also to investigate the prevalence of hypothyroidism using ATA 2017 criteria. This is a cross-sectional study. Patients were consisted of 1416 consecutive pregnant women who were universally screened for thyroid disease in their first trimester between 2013 and 2015. Thyroid-stimulating hormone (TSH) and free T4 (FT4) levels were analyzed during the first antenatal visit (before 12 weeks of gestation). We compared different cutoffs for TSH. We further determined the 2.5th and 97.5th percentiles for TSH and FT4. Initially, the cutoff of 2.5 IU/ml was selected. Accordingly, 305 women (22.3%) had subclinical hypothyroidism and 22 (1.6%) was diagnosed with overt hypothyroidism. When the cutoff was increased to 4 IU/ml, only 40 (2.9%) women were diagnosed with hypothyroidism. Prevalences of overt hypothyroidism and subclinical hypothyroidism were 0.6% and 2.3%, respectively. Universal screening of pregnant women with TSH, using the 2.5 mIU/L cutoff; one in four women was found to be a candidate for thyroid hormone replacement in our cohort. When the cutoff was determined to be 4 mIU/L, prevalence of hypothyroidism decreased approximately 10 times.     

Imaging findings of liver involvement of Wilson's disease

Purpose

The major purpose of this paper is to outline and correlate US, CT and MR imaging findings of liver in patients with Wilson's disease.

Materials and methods

Twenty-eight patients (10 male, 18 female, median age 16) with Wilson's disease were examined with US, CT and MRI. Liver echogenicity, echo pattern, contour irregularity, periportal thickness, perihepatic fat layer thickness, the presence of focal parenchymal lesion, and other associated findings were recorded by US in every patient. CT and MRI were done in 20 and 12 patients, respectively.

Results

Contour irregularity was observed in 24 patients and heterogeneous parenchymal echo pattern was seen in 26 patients with US. The presence of increased perihepatic fat layer was observed in eight patients. Severe parenchymal atrophy was seen in all lobes of the liver including caudate in contrast to post-viral chronic liver disease. Nineteen patients had periportal thickening. US showed multiple hyper and/or hypoechoic nodules smaller than 1 cm in 13 patients. MRI demonstrated small nodular hypointense areas on T2-weighted images in five patients. In only one patient these nodules showed contrast enhancement in CT and MR and pathologically proved to be dysplastic nodule.

Conclusion

Wilson's disease involving the liver has several unique radiological findings in comparison to other types of cirrhosis. These specific features include multiple nodular lesions in the liver, presence of perihepatic fat layer and normal caudate lobe which is contrary to other types cirrhosis. Liver injury in the Wilson's disease can be defined by imaging modalities, especially by US which we think is the most precise imaging modality to detect early parenchymal changes in the progress of the disease.     

Small bowel wall thickening: MDCT evaluation in the emergency room

Small bowel wall thickening detected on computed tomography is a frequent finding in patients referring to emergency room with acute abdominal pain. In this pictorial review, we aim to discuss patterns of small bowel wall thickening and to explain hints for differential diagnosis with imaging findings.     

CT differentiation of distal pancreas fat replacement and distal pancreas agenesis

We aimed to describe CT signs useful for differentiation of distal agenesis from distal or dorsal pancreas lipomatosis. Multidetector CT (MDCT) studies of five patients with distal pancreas agenesis (n = 2), distal lipomatosis (n = 1), distal short pancreas (n = 1), and distal pancreatectomy (n = 1) were retrospectively reviewed. Agenesis of dorsal pancreas can be diagnosed by the absence of body and tail of pancreas. In the absence of distal pancreas, distal pancreatic bed can be filled by stomach or intestine (dependent stomach or dependent intestine signs), which abut splenic vein. Same findings can be seen in patients with distal pancreatectomy, however, splenic vein is absent in these patients. In case of distal lipomatosis abundant fat tissue is observed anterior to splenic vein. Dependent stomach and/or dependent intestine signs on MDCT imaging can allow differentiation of distal pancreas agenesis from distal lipomatosis obviating further diagnostic studies.     

Paediatric multidetector CT angiography: spectrum of congenital thoracic vascular anomalies

Multidetector row CT (MDCT) is a non-invasive and rapid technique used for the evaluation of paediatric vascular diseases as an alternative to conventional angiography. Three-dimensional (3D) images allow excellent display of vascular anomalies that can be used as a vascular road map by surgeons. The aim of this pictorial review is to demonstrate diagnostic MDCT angiographic findings of various congenital thoracic vascular anomalies in paediatric patients. It is important to recognize these anomalies early for proper treatment and follow-up, and also to prevent morbidities and mortalities.