Differentiation of hepatocellular carcinoma from non-hepatocellular malignant tumours of liver by chemical-shift MRI at 3 T.

AIM: To evaluate the diagnostic performance of chemical shift magnetic resonance imaging (MRI) in distinguishing hepatocellular carcinomas (HCCs) from non-hepatocellular malignant tumours (non-HCCs) of the liver. MATERIALS AND METHODS: Patients with a diagnosis of malignant liver tumours examined at 3 T MRI were included in this retrospective study. Forty-seven HCCs and 75 non-HCCs that were studied with chemical-shift MRI between January 2012 and October 2016 were retrieved from the radiology database. Two blinded observers measured the signal intensities of the tumours, adjacent normal-looking liver parenchyma, and spleen on chemical-shift MRI. The fat quantification for HCCs, non-HCCs, and adjacent normal-looking liver parenchyma were calculated by using the spleen as a reference standard. The subtraction scores were calculated by subtracting fat percentages in liver parenchyma from those in tumours. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the fat percentage subtraction scores in distinguishing HCCs from non-HCCs were calculated. RESULTS: According to the optimal cut-off value acquired from both readers, a subtraction score >-0.26 was considered to be a HCC. Fat signal percentage subtraction scores were ≥-0.26 in 45 of 47 HCCs and were <-0.26 in 69 of 75 non-HCCs. The sensitivity, specificity, PPV, and NPV of fat signal percentage subtraction score to differentiate HCCs from non-HCCs were found to be 95.7%, 89.3%, 84.9%, and 97.1%, respectively. CONCLUSION: Intracytoplasmic lipid in HCCs demonstrated by quantitative chemical-shift MRI may be a potentially powerful imaging biomarker to distinguish HCCs from the other malignant liver tumours.

Contribution of thin-slice (1 mm) axial proton density MR images for identification and classification of meniscal tears: correlative study with arthroscopy.

OBJECTIVE: To evaluate the diagnostic efficacy of thin-slice (1 mm) axial proton density-weighted (PDW) MRI of the knee for meniscal tear detection and classification. METHODS: We prospectively assessed pre-operative MR images of 58 patients (41 males, 17 females; age range 18-62 years) with arthroscopically confirmed meniscal tear. First, we evaluated the performance of the sagittal and thin-slice axial MR images for the diagnosis of meniscal tears. Second, we compared the correlation of tear types presumed from sagittal and axial MRI with arthroscopy and tear classification from axial MRI. Tears were classified on the sagittal plane and the axial plane separately. The diagnostic performance and tear classification were compared statistically with arthroscopy results, which is accepted as the standard of reference. RESULTS: 8 of 58 patients were removed from the study group because they had complex or degenerative tears. A total of 62 tears were detected with arthroscopy in 50 patients. On the sagittal images, sensitivity and specificity values were 90.62% and 70.37%, respectively, for medial meniscus tears and 72.73% and 77.14%, respectively, for lateral meniscus tears. The corresponding values for axial images were 97.30% and 84.00%, respectively, for medial meniscus tears and 95.65% and 80.50%, respectively, for lateral meniscus tears. There was no significant difference in tear classification between the arthroscopy results and the thin-slice axial PDW MRI results (p>0.05). CONCLUSION: thin-slice axial PDW MRI increases the sensitivity and specificity of meniscal tear detection and especially classification, which is important for surgical procedure decisions.

Unusual causes of small bowel obstruction and contemporary diagnostic algorithm.

Intestinal obstruction is a common clinical abnormality. In 60-80% of cases, the small bowel is affected. Although postoperative adhesions are responsible in 60% of cases, the other frequently observed causes are hernia, strangulation and tumours, such as carcinoid, lymphoma or adenocarcinoma. In this pictorial essay, we presented the radiological findings of uncommon causes of small bowel obstruction as well as the suggested diagnostic algorithm.

The changing role of radiology in imaging liver tumors: an overview.

The surgical and the radiological advances in liver tumors in last two decades have made some malignant tumors operable which were considered inoperable and have completely changed the expectations from radiology. However, accurate staging, that is performed by imaging modalities, has critical importance in the selection of patients who can benefit from resection. Radiologists and referring physicians, therefore, should be aware of the current concepts in imaging liver tumors. This report updates both the changing role of radiology in hepatic neoplasms and the appropriate use of radiological modalities in liver tumors.

Treatment of obstructive epiphora in adults by balloon dacryocystoplasty.

AIMS: To determine the efficacy of dacryocystoplasty with balloon dilatation in the treatment of complete and partial obstruction of the lacrimal drainage system. METHODS: The procedure was performed on 26 patients with epiphora due to complete (n=16) or partial (n=10) obstruction of the lacrimal drainage system. A flexible tipped guide wire was introduced through the superior canaliculus into the inferior meatus and manipulated out of the nasal cavity. A 3 mm balloon was then introduced in a retrograde direction over the guide wire and dilated at the obstruction site. RESULTS: The procedure was technically successful in all patients with partial obstruction, but unsuccessful in four of 16 cases with complete obstruction. Reobstruction occurred in eight of 12 patients with complete obstruction, and in five of 10 patients with partial obstruction. The overall success rate was 25% for complete and 50% for partial obstructions. The mean follow up was 14 months (8-37 months). CONCLUSION: Although the balloon dacryocystoplasty is a simple and minimally invasive technique, the outcome from our study indicates that it is not advisable for treatment of complete obstruction of the lacrimal drainage system. Balloon dilatation may prove suitable for the treatment of patients with partial obstruction below the level of the lacrimal sac, especially in those who are poor candidates for surgery, or who do not wish to undertake dacryocystorhinostomy. Even in the partial obstruction group the success rate was only 50%, so that further modification to the technique and controlled studies are likely to be required before it could be recommended for general use.

Assessment of depth of myometrial invasion by endometrial carcinoma: comparison of T2-weighted SE and contrast-enhanced dynamic GRE MR imaging.

A prospective study was undertaken to assess the value of both T2-weighted spin-echo (SE) and contrast-enhanced dynamic gradient-echo (GRE) sequences using MR imaging in differentiating the deep myometrial invasion from lower stages produced by endometrial carcinoma. For the correlation of MR findings with the histopathologic findings, patients who had no myometrial invasion (stage 1 a) and patients in whom tumors were confined to the superficial myometrium (stage 1 b) at pathologic examination were combined as lower stages. Twenty patients with endometrial carcinoma were studied using both techniques. The absence of any detectable tumor (stage 1 a) or the presence of a tumor confined to inner half of myometrium (stage 1 b) and extention of tumor to the outer half of myometrium (stage 1 c) were used as the diagnostic criteria. In pathologic examination of excised specimens, deep myometrial invasion was detected in 9 of 20 patients. The sensitivity, specificity, accuracy, positive predictive values (PPV) and negative predictive values (NPV) of T2-weighted SE in differentiating deep myometrial invasion from combined lower stages were 88, 91, 90, 88, and 91 %, respectively, whereas corresponding values for contrast-enhanced dynamic GRE sequences were 78, 100, 90, 100, and 85 %. Statistical difference between two sequences did not reach a significant level. We conclude that in cases of absence of visible junctional zone with SE sequence, contrast-enhanced dynamic GRE MR imaging may be helpful.

Choledochoduodenal fistula secondary to duodenal peptic ulcer. A case report.

Spontaneous choledochoduodenal fistula (CDDF) is a rare form of biliary enteric fistula which usually occurs as a complication of duodenal peptic ulcer disease. The more common form is cholecystoduodenal fistula (CCDF) which is generally associated with gallbladder disease. We report on a case of ulcerogenic CDDF diagnosed by upper gastrointestinal barium study, ultrasonography, and gastroduodenal endoscopy.

Polyarteritis nodosa presenting with hemobilia and intestinal hemorrhage.

Polyarteritis nodosa is a multisystem disease primarily involving the small and medium-sized vessels. Prognosis depends on the presence and severity of visceral involvement. Thrombosis and aneurysm formation commonly occur in kidney and gastrointestinal tract. Although hepatic involvement is also common, hepatic aneurysmal rupture with intrahepatic or perihepatic hematoma formation is infrequent. Hemobilia secondary to aneurysmal rupture is a very rare condition. We present a case of polyarteritis nodosa accompanied by hemobilia and intestinal hemorrhage secondary to hepatic and mesenteric aneurysmal rupture.

A contrast agent delivery nomogram for hepatic spiral CT.

PURPOSE: A nomogram for hepatic spiral CT (SCT) was constructed based on randomization of patients into a prospective study using four different injection protocols. Its utility in a separate prospective randomized trial was subsequently evaluated in a new group of patients. METHODS: Thirty-nine patients randomized into four groups underwent SCT (Somatom-Plus S; 24 s exposure, 10 mm collimation, 10 mm/s) using 90 ml Omnipaque 240 (22 g I) at 2.5, 4, 5, or 6 ml/s. Peak and mean aortic and liver enhancement and time to peaks were measured and correlated with patients' age, weight, dose, rate, and contrast agent concentration, and a nomogram was constructed. In the validation experiment, 20 new patients were randomized to nomogram-guided and control groups for contrast dose administration during SCT. All patients underwent SCT (Somatom-Plus S; 32 s exposure, 10 mm collimation, 10 mm/s) using 90 ml Omnipaque 240 or 140 ml Hypaque 60 at 1.5-6 ml/s. Peak and mean aortic and liver enhancement and time to peaks were measured and correlated with patients' age, weight, dose, rate, and contrast agent concentration. Mean and peak aortic and hepatic enhancements were measured and rated by three blinded reviewers. RESULTS: Peak hepatic enhancement occurred 32 s after termination of contrast bolus administration in all groups. Correlation between the predicted and actual enhancement was very good (r = 0.7-0.9). Ninety-eight percent of the nomogram-guided group had optimal timing and utilized 10% less contrast agent than the control group. CONCLUSION: The phenomenon of peak hepatic enhancement occurring 32 s after the termination of contrast bolus regardless of injection rate may be of use in a nomogram for optimal contrast delivery for hepatic SCT.

Thoracoabdominal duplication cyst: US, CT and MR findings.

A rare case of thoracoabdominal duplication is reported. Radiological workup including US, CT and MR provided the correct diagnosis. The US revealed the cystic nature of the lesions, whereas CT and MR showed their relationship with the diaphragm and each other. Coronal- and sagittal-plane MR images were helpful in demonstrating the extension of the lesions. The patient was discharged after an uneventful surgery and recovery. The histological evaluation revealed the cyst lined with single-layered columnar epithelium and the cyst wall contained submucosal mucous glands with underlying smooth muscle and also some mature chondroid elements with bronchogenic origin. Radiological findings and differential diagnosis are discussed.

Quantitative computed tomography for measuring bone mineral density in athletes.

We studied the effect of different training patterns on vertebral trabecular and cortical bone mineral density (BMD) in male athletes using quantitative computed tomography. Vertebral trabecular (t) and cortical (c) BMDs of the first three lumbar vertebrae were measured using single energy quantitative computed tomography in 51 athletes including 10 weight lifters (mean age 20 years), 13 soccer players (mean age 27 years), 28 wrestlers (mean age 17 years), and 45 age-matched volunteers (mean age 21 years). Measured BMDs were correlated with age, body height and weight, training hours per week, sports years, and type of physical activity. Vertebral tBMDs were found to be 44%, 23%, and 24% higher in the weight lifters, soccer players, and wrestlers, respectively, compared with the volunteers. The corresponding cBMDs were 18%, 6%, and 11% higher than that of volunteers. There was significant correlation between the trabecular and cBMD, and height of the athletes, sports years, training hours per week, and physical activity. The most significant correlation with BMD was the type of physical activity. Both the height of the subjects and physical activity variables showed variations of 47% and 32% in trabecular and cBMD, respectively. According to the multiple analysis of variance (MANOVA) only the physical activity factor was effective, with a significance level of P < 0.01; the other factors and interactions were not effective (P > 0.05) on trabecular and cBMD. Different training patterns have a different anabolic effect on both trabecular and cBMDs of the vertebrae, and this effect is more pronounced on the trabecular compartment. Weight lifting showed the highest anabolic effect on both trabecular and cBMDs compared with soccer playing and wrestling. Of the independent variables, physical activity showed the highest anabolic effect on the vertebrae. These results may have implications for devising exercise strategies to reduce the possibility of fracture in old age.

Solid and papillary epithelial neoplasm of the pancreas: CT and MR findings.

Solid and papillary epithelial neoplasm of the pancreas is a very rare low-grade malignant neoplasm with only 126 cases reported in the literature and seen mostly in young female patients. Surgical excision means cure in cases before malignant degeneration developed. Its characteristic findings are typical location in the tail of the pancreas, peripheral capsule formation, hypodensity on CT images, and hyperintense internal signal characteristics on T1-weighted MR images secondary to hemorrhage and accumulation of methemoglobine molecule. These findings are enough for the preoperative diagnosis that may lead to early surgery and cure. We present the CT and MR findings of this very rare neoplasm in a case report.

Bone mineral density measurement by quantitative computed tomography in a normal Turkish population.

PURPOSE: To observe the trabecular and cortical bone mineral density values of a normal Turkish population, to examine the effect of age in males, and age and duration of menopause in a female population on bone mineral density. Also to compare Turkish population bone mineral density values with the reference values in developed countries. MATERIALS AND METHODS: Trabecular and cortical bone mineral densities were measured by the quantitative CT method in 255 (110 male and 145 female) normal cases. RESULTS: According to the linear regression test results, loss of bone mineral density per year was 1.97 mg/ml and 2.09 mg/ml for females and 1.37 mg/ml and 1.04 mg/ml for males in the trabecular and cortical bone compartments, respectively. A 70-year-old female loses 56.7% and 31.3% of the bone mass at 20 years of age for the trabecular and cortical compartments, respectively. These ratios were 41% and 16.1% for the male population. Most loss in bone mass was observed in the premenopausal and early postmenopausal period. In the postmenopausal period, duration of menopause had more effect on bone mass than age. Loss of trabecular bone mass per year in the postmenopausal period was 2.36 mg/ml and 2.84 mg/ml with respect to age and duration of menopause, respectively. CONCLUSIONS: Quantitative CT is a valuable method to determine bone mass because it allows to detect bone mass of trabecular and cortical bone separately. Loss in trabecular bone was found to be higher than in cortical bone for both sexes, while overall bone loss was higher in females. Rate of loss increases in the menopause period. Duration of menopause had more effect on bone mass than age. Bone mineral density values in Turkey were similar to reference values of western countries.

Spiral computed tomography of the liver: contrast agent pharmacokinetics and the potential for improved hepatic enhancement.

RATIONALE AND OBJECTIVES: We conducted a prospective study of 131 patients to evaluate the contrast agent dose-response relationship for liver spiral computed tomography (CT) and to test the hypothesis that spiral CT scanning provides greater enhancement than does dynamic CT scanning. METHODS: Patients were assigned to one of two control groups (dynamic CT) or to one of five experimental groups (spiral CT). Dynamic CT patients received 150 ml and spiral CT patients received either 75, 100, or 150 ml of diatrizoate meglumine. All groups had a monophasic injection rate of 2.5 ml/sec. Hepatic enhancement was compared among experimental and control groups. RESULTS: In the experimental groups, there was a linear dose-response relationship (p < .0001) among the enhancements achieved for the three dosages. The enhancement of the last slice of liver for the spiral CT versus dynamic CT groups receiving 150 ml was significantly greater (p = .002). Peak, first liver slice, and average liver enhancement values were higher with spiral CT scanning, but the difference was not statistically significant (power > .55). CONCLUSION: Using uniphasic injection rates and identical doses of contrast agent, spiral CT scanning has the advantage of improved enhancement of the last part of the liver to be imaged.

Evaluation of the foramen magnum dimensions.

The metric values of the foramen magnum (FM) were studied both by dry skull measurements and tomographic measurements. Anteroposterior (AP) and transverse diameters of 88 skulls in three different groups were taken into consideration. The mean AP value for the 38 skulls of the first group (Late Byzantine Era, A.D. 13th century) was 35.6 +/- 2.3 mm, while the mean transverse value was 29.9 +/- 2.1 mm. Twenty-seven skulls of the 20th century had the mean values of 35.1 +/- 2.8 and 28.7 +/- 2.2 mm for AP and transverse measurements, respectively. The third group consisted of computed tomography (CT) measurements of 23 outpatients in the radiology department. Their mean AP value was 36.4 +/- 2.8 and the mean transverse value was 30.0 +/- 1.4 mm. When the measurements of 88 skulls of the three groups were considered together, the mean AP value was 35.6 +/- 2.7 and the transverse value was 29.5 +/- 2.1 mm. There is no significant difference between the total mean value of the present study and that of other authors. However, if the three groups are considered separately, the mean transverse value shows significant differences, especially that of the second group. Also the radiographic and tomographic measurements of other authors have higher results than the present results, perhaps due to methodologic differences.