Abdulhakim Coskun

Wavelet-packet-based texture analysis for differentiation between benign and malignant liver tumours in ultrasound images

The purpose of this study was to apply a novel method of multiscale echo texture analysis for distinguishing benign (hemangiomas) from malignant (hepatocellular carcinomas (HCCs) and metastases) focal liver lesions in B-mode ultrasound images. In this method, regions of interest (ROIs) extracted from within the lesions were decomposed into subimages by wavelet packets. Multiscale texture features that quantify homogeneity of the echogenicity were calculated from these subimages and were combined by an artificial neural network (ANN). A subset of the multiscale features was selected that yielded the highest performance in the classification of lesions measured by the area under the receiver operating characteristic curve (Az). In an analysis of 193 ROIs consisting of 50 hemangiomas, 87 hepatocellular carcinomas and 56 metastases, the multiscale features yielded a high A: value of 0.92 in distinguishing benign from malignant lesions, 0.93 in distinguishing hemangiomas from HCCs and 0.94 in distinguishing hemangiomas from metastases. Our new multiscale texture analysis method can effectively differentiate malignant from benign lesions, and thus has the potential to increase the accuracy of diagnosis of focal liver lesions in ultrasound images.

Torticollis secondary to posterior fossa and cervical spinal cord tumors: report of five cases and literature review

Torticollis is either congenital or acquired in childhood. Acquired torticollis is not a diagnosis but rather a sign of an underlying disorder. The causes of acquired torticollis include ligamentous, muscular, osseous, ocular, psychiatric, and neurologic disorders and may be a symptom of significant abnormalities of the spinal cord and brain, such as spinal syrinx or central nervous system neoplasia. Torticollis is rarely considered to be an initial clinical presentation of posterior fossa and cervical spinal cord tumors. We report five cases of pediatric tumors with torticollis at the onset: an astrocytoma originating from the medulla oblongata, another presumptive astrocytoma of the spinal cord located between C1 and C6 cervical vertebrae (not operated), an ependymoma located throughout the whole cervical spinal cord extending into the bulbomedullary junction, an astrocytoma originating from the bulbus and extending into the posterior fossa, and another case of a eosinophilic granuloma located extradurally through the anterior and posterior portions of the vertebral bodies from C3 to C7 producing the collapse of the sixth cervical vertebra. All five cases were seen in children, aged between 3 and 12 years. All these cases reflect the misinterpretation of this neurological sign and the lack of association with the possibility of spinal or posterior fossa tumor. This delay in the diagnosis of these diseases led to progressive neurological deterioration and to the increase in the tumor size, which made surgical intervention difficult and the prognosis unfavorable. Although torticollis secondary to tumors is rarely seen, it is necessary to be kept in mind in the differential diagnosis.

Macrosomic newborns of diabetic mothers are associated with increased aortic intima-media thickness and lipid concentrations

Background/Aims: Exposure to diabetes in utero has been established as a significantrisk factor for some of components of metabolic syndrome. A few studies have examined relationship between the metabolic syndrome and echocardiographic left ventricular (LV) mass. We aimed to investigate relationship between abdominal aortic intima-media thickness (aIMT), LV mass and lipid profile in macrosomic newborns. Methods: Abdominal aIMT was measured in 30 macrosomic neonates of diabetic mothers (group A), 30 macrosomic neonates of healthy mothers (group B) and 30 healthy neonates (group C). Lipid profile and LV mass were determined. Result: Mean aIMT was significantly higher in groups A and B (0.489 ± 0.015, 0.466 ± 0.019 mm, respectively) than in controls (0.375 ± 0.024 mm). Weight-adjusted aIMT in group A was significantly higher than in groups B and C. Macrosomia was associated with increased lipid concentrations. Both LV mass indexed for BSA (body surface area) and birth weight measurements were significantly increased in group A compared with control. Conclusions: Macrosomic neonates of diabetic mothers have significant aIMT and LV mass indexed for BSA and birth weight with lipid alterations. It might play a role in the pathogenesis of atherosclerosis in adult life.

Magnetic resonance imaging findings in chronic carbon monoxide intoxication.

Purpose: To define the cranial magnetic resonance imaging (MRI) features of the chronic stage of carbon monoxide (CO) poisoning in patients with and without neuropsychiatric sequelae. Material and Methods: Eight patients who had neither symptoms nor neurological sequelae and eight patients with neuropsychiatric sequelae were included in the study. Patients aged between 9 to 57 (mean 32.2 years). All patients had been comatose at initial admittance and awoke after normobaric 100% oxygen therapy within 1–7 days. In this study, the patients were being examined with routine cranial MRI between 1 and 10 years (mean 3.4 years) after exposure to CO. Results: The most common finding was bilateral symmetric hyperintensity of the white matter, which was more significant in the centrum semiovale, with relative sparing of the temporal lobes and anterior parts of the frontal lobes on T2‐weighted and FLAIR images in all patients. Cerebral cortical atrophy was seen in 10 patients; mild atrophy of cerebellar hemispheres in 8; and vermian atrophy in 11. Corpus callosum was atrophic in one patient. Bilateral globus pallidus lesions were seen in three patients. The lesions were hypointense on T1‐weighted images and hyperintense on T2‐weighted and FLAIR images. Conclusion: Patients with severe CO intoxication may develop persistent cerebral changes independently of their neuropsychiatric findings in the chronic stage. They may present with characteristic MRI findings as described here, even if asymptomatic. The history of CO exposure is therefore helpful for recognizing and interpreting the MRI findings of chronic stage CO intoxication.

Quantitative Grading Using Grey Relational Analysis on Ultrasonographic Images of a Fatty Liver

A quantitative graduation system based on Grey Relational Analysis is proposed to recognize fatty livers in B-scan ultrasonic images. We evaluated ultrasonography liver images from 95 subjects having fatty livers (Grade I, II, III) and 45 normal subjects, as diagnosed by an expert radiologist. In practice, ultrasonographical findings of fatty liver are based on the brightness level of the liver in comparison to the renal parenchyma. The development of a non-invasive and accurate method would be of great clinical value as an alternative to diagnosing fatty liver based on the radiologist’s visual perception. In this study, we also evaluated AST and ALT liver enzymes for fatty liver having different grades. A high correlation between enzymes and Grey Relational Grades were found. The Receiver Operating Characteristic (ROC) curves were obtained and yielded satisfactory classification results using sensitivity, specificity and area under the curve for computing graduation and distinguishing fatty livers from healthy livers. With the proposed method based on Grey Relational Analysis, not only misdiagnosis caused by subjective differences in clinical evaluation will be reduced, but also the early diagnosis fatty liver and quantitative assessment of its degree will be achieved.

Joubert syndrome: review and report of seven new cases

Joubert syndrome (JS) is an autosomal‐recessive disorder, characterized by hypotonia, ataxia, global developmental delay and molar tooth sign on magnetic resonance imaging. A variety of other abnormalities have been described in children with JS, including abnormal breathing, abnormal eye movements, a characteristic facial appearance, delayed language, hypersensitivity to noise, autism, ocular and oculomotor abnormalities, meningoencephaloceles, microcephaly, low‐set ears, polydactyly, retinal dysplasia, kidney abnormalities (renal cysts), soft tissue tumor of the tongue, liver disease and duodenal atresia. Even within siblings the phenotype may vary, making it difficult to establish the exact clinical diagnostic boundaries of JS. We review the clinical characteristics of seven cases that fulfill the criteria of JS.

Carotid artery thickness in children and young adults with end stage renal disease

Atherosclerosis is a major cause of morbidity and mortality for ESRD patients and we have little knowledge about the presence and risk factors of atherosclerosis in children with CRF. The measurement of carotid artery intima-media thickness (cIMT) using high-resolution ultrasonography is suggested as an excellent marker of subclinical atherosclerosis. In this study, we aimed to investigate the presence of atherosclerosis and to determine the relationship between atherosclerosis and some risk factors in children and young adults with ESRD. Thirty-four patients with ESRD and 20 controls were included in this study. The measurement of cIMT was performed by using a linear B-mode 7.5-MHz ultrasound transducer. We determined anemia, abnormal calcium/phosphate metabolism, hyperhomocysteinemia, hypertriglyceridemia and increased lipoprotein (a) levels in the ESRD group. The cIMT in the ESRD group was higher than in the control group (P<0.05). SBP, DBP, MAP, LVMI and LVH prevalence were statistically higher in the ESRD group (P<0.05). There were significant positive correlations between cIMT and LVMI, MBP, whereas a significant negative correlation was determined between cIMT and PTH in the ESRD group (P<0.05). When a multiple linear regression analysis was performed with cIMT as a dependent variable and LVMI, MBP, PTH, as independent variables, a significant positive correlation was determined between cIMT and LVMI (P<0.05). In conclusion, we think that arteriopathy occurs in children with ESRD. Left ventricular hypertrophy and hypertension may associate with vascular changes in children and young adults with ESRD. Further investigations are necessary to explain association of LVMI index with cIMT.

Alveolar echinococcosis of the liver: correlative color Doppler US, CT, and MRI study

Purpose: To determine and compare the imaging features of hepatic alveolar Echinococcosis using color Doppler US, CT, and MRI. Material and Methods: Abdominal CT and MRI with and without contrast agents and color Doppler US were performed on seven patients with hepatic alveolar Echinococcosis. The lesions were evaluated for location, features of echogenicity, intensity and density, calcification, and vascular, hilar, and perihepatic involvement. The diagnosis was confirmed histopathologically in all patients. Results: Six patients had solitary lesions, and one displayed multiple lesions. The lesions were generally seen as heterogeneous and hyper‐ or hypoechoic when imaged with color Doppler US, hypodense with CT, and hypointense with MRI, in comparison with the liver parenchyma. Calcification, central necrosis, and small peripheral cysts were observed in six, seven, and four patients, respectively. Vascular flow or contrast enhancement was not observed in any of the cases. A look at the respective advantages of each method reveals that calcification was best rendered visible via CT, small peripheral cysts with T2‐weighted MRI, central necrosis with CT and MRI, and perihepatic invasion with multiplanar MRI. Vascular involvement was revealed by all methods. Conclusion: Color Doppler US, CT, and MR imaging function extremely well as complementary methods in the diagnosis of HAE. Color Doppler US should be performed in these patients owing to its ability to efficiently detect the disease. Knowledge of imaging characteristics makes it possible to radiologically ascertain an early diagnosis.

Evaluation of pneumonia in children: comparison of MRI with fast imaging sequences at 1.5T with chest radiographs

Background Although there has been a study aimed at magnetic resonance imaging (MRI) evaluation of pneumonia in children at a low magnetic field (0.2T), there is no study which assessed the efficacy of MRI, particularly with fast imaging sequences at 1.5T, for evaluating pneumonia in children. Purpose To investigate the efficacy of chest MRI with fast imaging sequences at 1.5T for evaluating pneumonia in children by comparing MRI findings with those of chest radiographs. Material and Methods This was an Institutional Review Board-approved, HIPPA-compliant prospective study of 40 consecutive pediatric patients (24 boys, 16 girls; mean age 7.3 years ± 6.6 years) with pneumonia, who underwent PA and lateral chest radiographs followed by MRI within 24 h. All MRI studies were obtained in axial and coronal planes with two different fast imaging sequences: T1-weighted FFE (Fast Field Echo) (TR/TE: 83/4.6) and T2-weigthed B-FFE M2D (Balanced Fast Field Echo Multiple 2D Dimensional) (TR/TE: 3.2/1.6). Two experienced pediatric radiologists reviewed each chest radiograph and MRI for the presence of consolidation, necrosis/abscess, bronchiectasis, and pleural effusion. Chest radiograph and MRI findings were compared with Kappa statistics. Results All consolidation, lung necrosis/abscess, bronchiectasis, and pleural effusion detected with chest radiographs were also detected with MRI. There was statistically substantial agreement between chest radiographs and MRI in detecting consolidation (k = 0.78) and bronchiectasis (k = 0.72) in children with pneumonia. The agreement between chest radiographs and MRI was moderate for detecting necrosis/abscess (k = 0.49) and fair for detecting pleural effusion (k = 0.30). Conclusion MRI with fast imaging sequences is comparable to chest radiographs for evaluating underlying pulmonary consolidation, bronchiectasis, necrosis/abscess, and pleural effusion often associated with pneumonia in children.

Segmentation of liver tumors in ultrasound images based on scale-space analysis of the continuous wavelet transform

We have developed a simple, yet robust method for segmentation of low-contrast objects embedded in noisy images. Our technique has been applied to segmenting of liver tumors in B-scan ultrasound images with hypoechoic rims. In our method, first a B-scan image is processed by a median filter for removal of speckle noise. Then several one-dimensional profiles are obtained along multiple radial directions which pass through the manually identified center of the region of a tumor. After smoothing by a Gaussian kernel smoother, these profiles are processed by Sombreros continuous wavelets to yield scalograms over a range of scales. The modulus maxima lines, which represent the degree of regularity at individual points on the profiles, are then utilized for identifying candidate points on the boundary of the tumor. These detected boundary points are fitted by an ellipse and are used as an initial configuration of a wavelet snake. The wavelet snake is then deformed so that the accurate boundary of the tumor is found. A preliminary result for several metastases with various sizes of hypoechoic rims showed that our method could extract boundaries of the tumors which were close to the contours drawn by expert radiologists. Therefore, our new method can segment the regions of focal liver disease in sonograms with accuracy, and it can be useful as a preprocessing step in our scheme for automated classification of focal liver disease in sonography.