Nevzat Karabulut

Intracranial calcifications on CT.

Computed tomography (CT) is very sensitive for detection and localization of intracranial calcifications. We reviewed in this pictorial essay the diseases associated with intracranial calcifications and emphasized the utility of CT for the differential diagnosis.

Congenital thoracic arterial anomalies in adults: a CT overview.

Congenital thoracic arterial anomalies can be incidentally detected in adults from imaging studies performed for other indications. Multidetector computed tomography plays a critical role in the noninvasive assessment of these anomalies and associated cardiac, mediastinal, or parencyhmal changes by providing volumetric data. Radiologists should be familiar with imaging findings of these anomalies to avoid misinterpretation and to establish accurate diagnosis. In this article, we review the imaging characteristics of congenital aortic, pulmonary, and aortopulmonary anomalies with an emphasis on multidetector computed tomography findings. We illustrate the CT findings of congenital arterial anomalies such as double aortic arch, right aortic arch, aortic coarctation, pseudocoarctation, interrupted aortic arch, interruption (absence) of the pulmonary artery, pulmonary artery sling, pulmonary artery stenosis, transposition of great vessels, truncus arteriosus, aortopulmonary window, and patent ductus arteriosus.

Imaging of iliac horns in Nail-Patella syndrome

Hereditary osteo-onychodysplasia, also known as the nail-patella syndrome (NPS), consists of a clinical tetrad of nail dysplasia, hypoplastic or absent patella, radial head dislocation, and iliac horns. Bilateral posterior iliac horns are observed only in NPS and present in >80% of patients. We describe the appearance, location, and structure of iliac horns by CT, MRI, and 3-dimensional CT reconstruction.

Clinical situations in which coronary CT angiography confers superior diagnostic information compared with coronary angiography

In this review, we aimed to outline the clinical and pathological conditions for which multidetector computed tomography coronary angiography (MDCT-CA) should be the preferred method because of its advantages over conventional coronary angiography (CCA). A consistent body of literature suggests that MDCT-CA is more than just complementary to CCA and that it provides more valuable diagnostic information in certain clinical situations, such as complex coronary artery variations, aorto-ostial lesions, follow-up of bypass grafts, myocardial bridging, coronary artery fistulas, aortic and coronary artery dissections, and cases in which the coronary ostia cannot be cannulated by a catheter because of massive atherosclerosis or extremely tortuous vascular structures.

Gadolinium deposition in the brain: another concern regarding gadolinium-based contrast agents.

Nevzat Karabulut Life is continuously confronting us with new issues and sometimes breaking our routine. One case in point is the curious way radiologists’ knowledge about the benefits and risks of gadolinium-based contrast agents (GBCAs) continues to evolve. Significantly improving detection and characterization of lesions in a broad spectrum of diseases, GBCAs have become integral aides to magnetic resonance imaging (MRI) for almost three decades. Because free gadolinium is toxic, it needs to be chelated with a ligand ion to facilitate its excretion through the kidneys. Currently available GBCAs have different chemical properties primarily determined by the chelating ligand molecule. These agents had initially been believed to be risk-free with rapid elimination from the body, and administered to millions of patients somewhat indiscreetly for over a decade after the clinical approval of gadopentate dimeglumine in 1988. This naive belief was disproved by a string of studies revealing a relationship between the use of GBCAs and the development of nephrogenic systemic fibrosis (NSF) in 2006 (2, 3). The accrued data convincingly showed a causal link between GBCAs and the risk of NSF in patients with severely compromised renal function (glomerular filtration rate <30 mL/min). Due to insufficient excretion of GBCA in patients with poor renal function, the administered contrast material (gadolinium chelate) stays long enough in the body to pose the risk of dissociation (dechelation) which consequently triggers the cascade of events resulting in NSF. An editorial published in the December 2006 issue of this journal addressed the issue of NSF and provided some timely recommendations (4). Further studies revealed that the chemical structure of GBCAs matters in the development of NSF, and the risk is much higher with nonionic linear chelates, such as gadodiamide and gadoversetamide, due to rapid release of gadolinium (dechelation) in these agents. Conversely, macrocyclic GBCAs are more resistant to dechelation and considered to be more stable. These studies modified the practice of intravenous MRI contrast agent use and paved the way for the creation of new standards in the use of GBCAs. Many international and national authorities established guidelines for the use of GBCAs in MRI. These guidelines primarily categorized agents into three categories as low risk (macrocyclic agents), intermediate risk (ionic-linear chelates) and high risk (nonionic-linear chelates) for the development of NSF. Adherence to these guidelines and adoption of new contrast-enhanced MRI protocols, which restrict the administration of high-risk GBCAs only to subjects with normal renal function and replace these agents with more stable GBCAs in high-risk patients, resulted in a dramatic decline in the incidence of NSF (5). Nevertheless, it should be emphasized that there are considerable differences between GBCAs with similar structure. For instance, no unconfounded NSF case has been reported following administration of ionic-linear gadobenate dimeglumine whereas two NSF cases were reported after unconfounded administration of nonionic-macrocyclic gadobutrol (6). In 2014, radiologists (as well as clinicians) were in for another stunning report, this time of a study performed in Japan (7) implying deposition of gadolinium in the brain manifested as dose-related T1 shortening in the globus pallidus and the dentate nuclei in patients who had been administered repeated previous doses of gadodiamide and/or gadopentetate dimeglumine. This novel observation was subsequently confirmed by Errante et al. (8) who reported dose-dependent T1 shortening in the dentate nucleus in subjects with normal kidney and liver function who had serial prior administration of gadodiamide. Two recent studies performed on autopsy specimens proved that T1 shortening results from gadolinium retention in neuronal tissues of the global pallidus, thalamus, dentate nucleus, and pons (9, 10). It was shown that gadolinium deposition was detectable with as few as four lifetime

CT features of intrathoracic gossypiboma (textiloma).

Here, we present chest radiography and computed tomography (CT) findings for three cases of mediastinal and pleural gossypiboma. Radiological manifestations varied according to the locations and chronicities of the gauze sponges and the types of reactions that they caused. CT analysis readily diagnosed gossypibomas in the early postoperative period by showing well-defined mediastinal- or pleural-based masses with hyperdense rims and central air bubbles. However, one patient presented in the late postoperative period, and a CT scan revealed a well-defined, solid pleural mass that was devoid of air bubbles; a correct diagnosis could not be established and the patient had to be reoperated on. Radiologists should be aware of different manifestations of this rare condition in cases of prior thoracic surgery and persistent respiratory symptoms.Here, we present chest radiography and computed tomography (CT) findings for three cases of mediastinal and pleural gossypiboma. Radiological manifestations varied according to the locations and chronicities of the gauze sponges and the types of reactions that they caused. CT analysis readily diagnosed gossypibomas in the early postoperative period by showing well-defined mediastinal- or pleural-based masses with hyperdense rims and central air bubbles. However, one patient presented in the late postoperative period, and a CT scan revealed a well-defined, solid pleural mass that was devoid of air bubbles; a correct diagnosis could not be established and the patient had to be reoperated on. Radiologists should be aware of different manifestations of this rare condition in cases of prior thoracic surgery and persistent respiratory symptoms.

CT diagnosis of an unusual aortic dissection with intimointimal intussusception: the wind sock sign.

A unique combination of CT findings is reported in a rare case of aortic dissection with intimointimal intussusception. The CT showed a wind sock-like appearance in the contrast column of the aortic arch, which was felt to be characteristic of the intussuceptum. Complementary CT findings, including proximal flap in the dilated root of the aorta, no mid-ascending aortic flap, a descending aortic flap, and pericardial effusion, enabled establishment of the preoperative diagnosis.

Diffusion-weighted MRI of pulmonary lesions: Comparison of apparent diffusion coefficient and lesion-to-spinal cord signal intensity ratio in lesion characterization: DWI of Pulmonary Lesions

To evaluate the diagnostic performance of minimum apparent diffusion coefficient (ADCmin) and lesion‐to‐spinal cord signal intensity ratio (LSR) in the differentiation of benign and malignant pulmonary lesions.

Efficacy of ivabradin to reduce heart rate prior to coronary CT angiography: comparison with beta-blocker

PURPOSE The objective of our study was to assess the effect of ivabradine on image quality of ECG-gated multidetector computed tomography (MDCT) coronary angiography. MATERIALS AND METHODS Computed tomography coronary angiography (CTCA) was performed on two groups. In Group 1 (n=54), an intravenous beta-blocker was administered to patients with a heart rate >70 beats per minute (bpm) just before CTCA. In Group 2 (n=56), oral ivabradine 5 mg was administered twice a day for three days prior to CTCA examination to patients with a heart rate >70 bpm and contraindication to beta-blockers. Images acquired on two different MDCT scanners were scored in terms of image quality of the coronary artery segments using a 5-point grading scale (Grade 1, unreadable; Grade 5, excellent). RESULTS The mean heart rates during CTCA were 64 ± 6.7 bpm for Group 1 and 59 ± 4.1 bpm for Group 2 (P < 0.05). Mean heart rate reduction was 9 ± 5% and 14 ± 8% for Groups 1 and 2, respectively (P < 0.001). A total of 880 segments were evaluated in 110 patients. When the best reconstruction interval was used, 89.8% and 95.5% of all the coronary segments showed acceptable image quality in Groups 1 and 2, respectively. Acceptable image quality of the middle right coronary artery was obtained in 78.3% of Group 1 and 92.4% of Group 2. These ratios for the other segments were 88.4% for Group 1 and 95.2% for Group 2. CONCLUSION Reduction of heart rates with ivabradine premedication improves the image quality of CTCA. It should be considered as an alternative drug, particularly in patients with contraindications to beta-blockers.

CT evaluation of medial clavicular epiphysis as a method of bone age determination in adolescents and young adults

PURPOSE We aimed to investigate the use of computed tomography (CT) staging of the medial clavicular epiphysis ossification in forensic bone age determination, and find a CT criterion to determine whether an individual is adult or not. METHODS Chest CT and pulmonary CT angiography exams of 354 patients between 10 and 30 years of age (mean, 21.4 years) were retrospectively evaluated for epiphyseal ossification phase of the bilateral medial clavicles (708 clavicles) and compared with the sex and chronologic age of the individuals. The ossification phase of the medial clavicular epiphyses was classified from stage I to stage V using a modified staging system. RESULTS Epiphyseal ossification center appeared from 11 to 21 years of age. Partial fusion occurred between 16 and 23 years of age. Complete fusion was first achieved at the ages of 18 and 19 years for male and female individuals, respectively. The probability of an individual being ≥18 years old was 70.8% in stage III A and 100% in stages III B, IV, and V in females and males. CONCLUSION CT evaluation of the medial clavicular epiphysis is helpful in forensic age determination and stage III B can be used as a criterion to make the prediction that an individual is older than 18 years.