Editorial Comment: Estimation of venous sinus pressure drop in patients with idiopathic intracranial hypertension using 4D-flow MRI.

KEY POINTS: • Work-energy equation using 4D-flow MRI is a promising technique for non-invasive estimation of trans-stenotic pressure drop in patients with idiopathic intracranial hypertension.• Additional research with larger and multicentric prospective cohorts is needed to validate the results, along with improvement of the segmentation process with automated techniques and shortening of scanning times to allow for practical clinical use.

The value of qualitative and quantitative assessment of lesion to cerebral cortex signal ratio on double inversion recovery sequence in the differentiation of demyelinating plaques from non-specific T2 hyperintensities.

OBJECTIVES: To assess the usefulness of the visual assessment and to determine diagnostic value of the lesion-to-cerebral cortex signal ratio (LCSR) measurement in the differentiation of demyelinating plaques and non-specific T2 hyperintensities on double inversion recovery (DIR) sequence. MATERIAL AND METHODS: DIR and fluid-attenuated inversion recovery (FLAIR) sequences of 25 clinically diagnosed multiple sclerosis (MS) patients and 25 non-MS patients with non-specific T2-hyperintense lesions were evaluated visually and LCSRs were measured by two observers independently. RESULTS: On DIR sequence, the calculated mean LCSR ± SD for demyelinating plaques and non-specific T2-hyperintense lesions were 1.60 ± 0.26 and 0.75 ± 0.19 for observer1, and 1.61 ± 0.27 and 0.74 ± 0.19 for observer2. LCSRs of demyelinating plaques were significantly higher than other non-specific T2-hyperintense lesions on DIR sequence. By using the visual assessment demyelinating plaques were differentiated from non-specific T2-hyperintensities with 92.8 % sensitivity, 97.5 % specificity and 95.1 % accuracy for observer1 and 92.8 % sensitivity, 95 % specificity and 93.9 % accuracy for observer2. CONCLUSION: Visual assessment and LCSR measurement on DIR sequence seems to be useful for differentiating demyelinating MS plaques from supratentorial non-specific T2 hyperintensities. This feature can be used for diagnosis of MS particularly in patients with only supratentorial T2-hyperintense lesions who are categorized as radiologically possible MS. KEY POINTS: • Demyelinating plaques and non-specific T2-hyperintensities have different SI on DIR images. • These differences can be assessed by LCSR measurement or visual assessment. • There is an excellent inter-observer agreement for both methods. • This feature can be used in radiologically possible MS cases.

Brain herniations into the dural venous sinus or calvarium: MRI findings, possible causes and clinical significance.

OBJECTIVES: To determine frequency, imaging features and clinical significance of herniations of brain parenchyma into dural venous sinuses (DVS) and/or calvarium found on MRI. METHODS: A total of 6160 brain MRI examinations containing at least one high-resolution T1- or T2-weighted sequence were retrospectively evaluated to determine the presence of incidental brain herniations into the DVS or calvarium. MRI sequences available for review were evaluated according to their capability to demonstrate these herniations. Patients' symptoms and clinical findings were recorded. RESULTS: Twenty-one (0.32 %) brain parenchyma herniations into the DVS (n = 18) or calvarium (n = 3) in 20 patients were detected. The most common locations of the herniations were the transverse sinuses (n = 13) and those involving inferior gyrus of the temporal lobe (n = 9). High-resolution T1- and T2-weighted sequences were equally useful in the detection of these brain herniations. According to clinical symptoms, brain herniations were considered to be incidental but headaches were present in nine patients. CONCLUSION: Brain herniations with surrounding cerebrospinal fluid (CSF) into the DVS and/or calvarium are incidental findings and not proven to be associated with any symptoms. Although rare, these herniations are more common than previously recognized and should not be confused with arachnoid granulations, clots or tumours. KEY POINTS: • Brain herniations into the DVS are more common than previously assumed. • The most frequent locations are the transverse sinus. • These herniations are incidental findings. • The relationship between brain herniation into DVS and headache is uncertain. • High-resolution MR sequences are most useful in detection of brain herniations.

A case of tension pneumothorax during hyperbaric oxygen therapy in an earthquake survivor with crush injury complicated by ARDS (adult respiratory distress syndrome).

Pneumothorax (PTX) is rarely reported in patients receiving hyperbaric oxygen (HBO2) therapy. Patients with air-trapping lesions in the lungs and those with a history of spontaneous PTX, lung disease, mechanical ventilation or chest trauma are at an increased risk for PTX during HBO2 therapy. A 28-year-old male earthquake survivor was referred to our center for multiple wounds 21 days after being rescued from the debris. He had been intubated and put on mechanical ventilation for three days because of adult respiratory distress syndrome (ARDS). At initial presentation, he was conscious, well-oriented and hemodynamically stable. The initial six HBO2 treatments were uneventful. On the seventh HBO2 treatment, the patient lost consciousness and developed cardiopulmonary arrest near the end of decompression. The HBO2 specialist accompanying the patient inside the chamber immediately initiated CPR. A diagnosis of tension PTX was made. After the patient was removed from the chamber, a chest tube was inserted, which improved the symptoms. Although rare, tension PTX can occur during HBO2 therapy. Early diagnosis and intervention are crucial for saving a patient's life. Increased vigilance is required during treatment of patients with risk factors for PTX.

Normal anatomical features and variations of the vertebrobasilar circulation and its branches: an analysis with 64-detector row CT and 3T MR angiographies.

PURPOSE: To determine the normal anatomical features and variations of the vertebrobasilar circulation and its branches in patients who underwent multidetector computed tomography (CT) or magnetic resonance (MR) angiographies of the brain. METHODS: 135 patients (male, 83 and female, 52; mean age, 50.1 years) who underwent CT (n = 71) or MR (n = 64) angiographies of the vertebrobasilar vasculature for various reasons were analyzed retrospectively. The right and left distal vertebral arteries (VAs), posterior inferior cerebellar arteries (PICAs), anterior inferior cerebellar arteries (AICAs), superior cerebellar arteries (SCAs), posterior cerebral arteries (PCAs), and posterior communicating arteries (PCoAs) were analyzed individually. RESULTS: In 24.4% of the cases (33/135) right PICA, in 19.3% of the cases (26/135) left PICA, in 17.8% of the cases (24/135) right AICA, and in 18.5% of the cases (25/135) left AICA were absent. In cases without PICA or AICA, there was a statistically significant, moderately or well-developed AICA or PICA on the same side, respectively (P < 0.001). The most common variation was isolated absence of right PICA and was seen in 17.8% of the cases. CONCLUSIONS: The anatomic features of the branches of the vertebrobasilar circulation may be different from well-known normal anatomy. CT and MR angiographies allow a precise and detailed evaluation of vertebrobasilar circulation.

Imaging of Skull Base Tumors.

The skull base provides a platform for supporting the brain while serving as a conduit for major neurovascular structures. In addition to malignant lesions originating in the skull base, there are many benign entities and developmental variants that may simulate disease. Therefore, a basic understanding of the relevant embryology is essential. Lesions centered in the skull base can extend to the adjacent intracranial and extracranial compartments; conversely, the skull base can be secondarily involved by primary extracranial and intracranial disease. CT and MRI are the mainstay imaging methods and are complementary in the evaluation of skull base lesions. Advances in cross-sectional imaging have been crucial in the management of patients with skull base pathology, as this represents a complex anatomical area that is hidden from direct clinical exam. Furthermore, the clinician must rely on imaging studies for therapy planning and to monitor treatment response. It is crucial to have a thorough understanding of skull base anatomy and its various pathologies, as well as to recognize the appearance of treatment-related changes. In this review, we aim to describe skull base tumors and tumor-like lesions in an anatomical compartmental approach and present imaging methods that aid in diagnosis, management, and follow-up.

Serum lactate dehydrogenase levels significantly correlate with radiological extent of disease and spirometric values in patients with silicosis due to denim sandblasting.

BACKGROUND: The aim of the present study was to investigate serum lactate dehydrogenase (LD) levels in patients with silicosis due to denim sandblasting (SDDS) and also to investigate possible correlations between serum LD levels and the degree of radiological extent of disease (RED) and pulmonary function tests. METHODS: Forty-four males with SDDS and 32 healthy male subjects were included in the study. Patients and healthy controls were compared for serum LD levels. Correlations between serum LD levels, RED and spirometric values were investigated. RESULTS: Patients with SDDS had significantly higher serum LD levels than healthy controls. Patients with complicated SDDS had significantly higher serum LD levels than patients with simple SDDS. Significant correlations were found between serum LD levels and RED values. Significant correlations were found between serum LD levels and spirometric parameters. CONCLUSIONS: High serum LD levels might be considered as a marker of pulmonary parenchymal involvement in patients with SDDS. This study also suggests that the increase in serum LD levels might be closely related to the degree of pulmonary involvement in SDDS patients.

Sonographic measurement of diuretic-induced renal length changes: are they correlated with renal function?

OBJECTIVES: The purposes of this study were to prospectively identify diuretic-induced renal length changes and to determine whether the percentages of the renal length changes allow estimation of the differential renal function. METHODS: Twenty-three children (14 boys and 9 girls; mean age, 7.83 years) who were undergoing technetium Tc 99m diethylenetriamine pentaacetic acid or technetium Tc 99m mercaptoacetyltriglycine diuretic renography were included in this study. Renal lengths were measured by sonography just before and 15 to 20 minutes after diuretic injection. The Spearman test was used to assess the correlation between renal length increases due to diuretic injection and the differential renal function. RESULTS: The mean renal lengths ± SD measured before and after diuretic administration were 91.52 ± 20.87 and 95.38 ± 21.46 mm, respectively. The increase in renal length after diuretic administration was statistically significant (P < .001). There was a positive correlation between the renal length change and functional status (P = .006). CONCLUSIONS: Renal length may change after diuretic injection according to the functional status, and the sonographic measurements of these changes may be used as an alternative to other imaging methods in estimation of renal function.

Pararectal mass: an atypical location of splenosis.

Splenosis is the autotransplantation of splenic tissue resulting from the dissemination of cells from the pulp of the spleen after splenic injury or splenectomy. Implants can be found anywhere in the peritoneal cavity, especially on the serosal surfaces of small and large bowel, in the mesentery and diaphragm, implanted in visceral organs, within the thorax and brain, and in surgical scars and may vary in number, shape, and size. We described the sonographic, computed tomography and magnetic resonance imaging findings of pararectal splenosis in a 23-year-old man. The lesions appeared as multiple, well-circumscribed, small, round, homogenously solid masses of different sizes at the retrovesical and pelvic region detected during the imaging workup of Behçet disease.

Is there any relation between distal parameters of the femur and its height and width?

The purpose of this study was to reveal the association whether the distal morphometry of femur had a relation with femur height or width. Sixty-six adult (35 right and 31 left) dry femurs from Caucasians were used in this study. Computed tomography (CT) imaging was applied to obtain measurement values of the femur. Femur height (413.29 ± 28.40 mm) and width (29.86 ± 2.72 mm) were all checked one by one to determine the correlation with the parameters obtained. Both values exposed high rates of correlation with height (26 ± 2.34 mm) and width (20.85 ± 2.76 mm) of femur notch; also, measures of epicondylar, bicondylar and condylar diameters of femur were obtained. Measures were checked if there was a correlation with femur height and width. Differences displayed in distal morphometry of femur according to race and sex are due to other morphometric measures of femur rather than race and sex. We believe that displaying the high rates of correlation of distal morphometry of femur with femur height and width will be the factor which determines the selection and production of prosthesis among the long or short individuals of folks.

The demonstration of the number, course, and the location of nutrient artery canals of the femur by multidetector computed tomography.

PURPOSE: The aim of this study was to evaluate the number, course, width and location of nutrient artery canals of the femur by using multidetector computed tomography (MDCT). METHODS: Sixty-six adult (35 right and 31 left) dry femurs were included in this study and scanned by MDCT. Nutrient artery canals were evaluated on the multi-planar reformatted and volume rendered images which were reproduced on the basis of axial images. RESULTS: The median value of nutrient artery canals was two (minimum 1 and maximum 6). We determined that there was a negative correlation between the number of nutrient canals and the canal diameters. The outer ostia of the nutrient artery canals were most frequently located at the middle third segment of femoral diaphysis (65%). While the vast majority of the canals were showing upward courses (95%), only a few canals were having transverse (3%) or downward (2%) courses. Most encountered location of outer ostia of the canals according to linea aspera was the medial lip of the linea aspera (44%). Various variations were demonstrated in the number, course, and location of nutrient artery canals using MDCT. CONCLUSIONS: In conclusion, the knowledge of the topographic features of the nutrient artery canals may be useful in various clinical implications such as bone grafting or radiologic evaluation for the fracture lines.

Normal anatomical features and variations of bronchial arteries: an analysis with 64-detector-row computed tomographic angiography.

OBJECTIVE: To determine the normal anatomical features and variations of the bronchial arterial system and to determine the relationship among ectopic bronchial arteries, location (right-left) of the bronchial arteries, and variations of the aortic arch in patients as well as the sex of the patients who underwent multidetector computed tomographic angiography of the thorax for various reasons. METHODS: A total of 163 patients who underwent multidetector computed tomographic angiography of the thoracic vascular structures for various reasons were analyzed retrospectively. The right and left bronchial arteries were analyzed individually, and normal anatomic features and variations were recorded. The χ and Mann-Whitney U tests were used to evaluate relationships among the patients' sex, side and number of the bronchial arteries, aortic arch variations, and bronchial artery variations. RESULTS: There were 432 bronchial arteries (right, 229; left, 203) in 163 patients (117 men, 46 women; mean age, 51.7 years). All of the patients have at least one bronchial artery (mean, 2.65; maximum, 5). The number and diameters of the bronchial arteries were statistically higher on the right side. The number of the bronchial arteries was significantly higher in the men (P < 0.05). Ectopic bronchial arteries were present in 43 (26.4%) of the 163 patients. Aortic arch variations were present in 27 (22.5%) of 120 patients with normal bronchial arteries and in 11 (25.6%) of the 43 patients with ectopic bronchial arteries. There was no statistically significant correlation between aortic arch variations and ectopic bronchial arteries (P = 0.861). CONCLUSIONS: The anatomic features of the bronchial arteries show differences between individuals and the sexes. Multidetector computed tomographic angiography allows a precise and detailed evaluation of bronchial arterial system.

Diffusion-weighted imaging in the characterization of focal liver lesions: efficacy of visual assessment.

OBJECTIVES: The objective of the study was to assess the value of visual assessment of signal intensities on b800 diffusion-weighted images and apparent diffusion coefficient (ADC) maps in differentiation of benign and malignant focal liver lesions (FLLs). METHODS: Approval for this retrospective study was obtained from the institutional review board. One hundred forty-three FLLs in 65 patients (38 women, 27 men; mean age, 50.8 years) underwent magnetic resonance (MR) imaging and diffusion-weighted imaging (DWI) with a respiratory-triggered single-shot echo-planar imaging sequence. Focal liver lesions were evaluated visually according to the signal intensities on b800 and ADC map images, and ADC values were also calculated. The conventional MR imaging, follow-up imaging findings, and histopathologic data were regarded as gold standard. Normal distribution was assessed with Kolmogorov-Smirnov test. The accuracies of visual assessment and ADC values in differentiating benign and malignant FLLs were assessed with the Student t test, and threshold values were determined with receiver operating characteristic curve analysis. RESULTS: By using a cutoff value of 1.21 × 10⁻³ mm²/s, ADC had a sensitivity of 100%, a specificity of 89.3%, and an accuracy of 92.3% in the discrimination of malignant FLLs. With the visual assessment of the DWIs and ADC maps, malignant lesions were differentiated from benign ones, with 100% sensitivity, 92.2% specificity, and 94.4% accuracy. Although some benign lesions were interpreted as malignant, no malignant lesion was determined as benign in visual assessment. CONCLUSIONS: Most FLLs are benign ones such as hemangiomas and cysts, which can be readily and practically characterized only by using visual assessment of DWIs without requiring time-consuming conventional and dynamic contrast-enhanced imaging sequences. Some benign lesions that are falsely interpreted as malignant can be further characterized by using conventional and contrast-enhanced MR studies.

Cerebral venous thrombosis presenting with subarachnoid hemorrhage after spinal anesthesia.

A 22-year-old male had a meniscopathy operation using spinal anesthesia. After the operation, the patient reported a throbbing headache. His brain computed tomography (CT) showed subarachnoid hemorrhage (SAH) and hyperdense dural venous sinuses suspicious for thrombosis. Filling defects were observed in the superior sagittal and right transverse sinuses on the contrast-enhanced magnetic resonance images. The patient was diagnosed with cerebral venous sinus thrombosis (CVST). On the tenth day of his admission, his clinical findings progressed and heparin therapy was initiated after resorption of hemorrhage was observed in a second non-contrast CT scan. The patient developed decreased consciousness the day after heparin administration. A subsequent brain CT revealed intraparenchymal hemorrhage in the right anteroinferior frontal region. Heparin therapy was discontinued, and anti-edema therapy was started. The presentation of CVST with SAH is a rare condition. Furthermore, development of CVST after spinal anesthesia is very rare. In this case, CVST developed after spinal anesthesia, and its first clinical presentation was SAH. To our knowledge, this is the first case CVST presenting with SAH after spinal anesthesia.

Acute lymphoblastic leukemia presenting with oculomotor nerve palsy.

A 48-year-old man presented with left ptosis and double vision. Laboratory test findings indicated acute lymphoblastic leukemia (ALL). Lymphoblastic infiltration of both cavernous sinuses was observed on pituitary gland magnetic resonance imaging. Leukemias may present by many clinical conditions, but isolated cranial nerve palsy is very rare. To our knowledge, this is the first case of ALL presenting with oculomotor nerve palsy. Clinicians should consider oculomotor nerve palsy as the first ALL indication.

Optimum height from the roof of the choana for seeking the sphenoid ostium.

OBJECTIVE: The purpose of this study was to investigate the optimum height that the sphenoid sinus ostium can be probed safely from the roof of choana in a large group of patients. METHODS: The study was performed retrospectively. The 200 sphenoid ostia of the 100 patients whose thin-section computed tomography (CT) including the sphenoid sinus region, made for various reasons, were included in the study. The height of the sphenoid ostium and the skull base from the choana roof were measured on sagittal images of CT. Also, by calculating the ratio of first measurement to the second one, the location of the sphenoid ostium at the anterior wall of sphenoid sinus was determined proportionally. RESULTS: The mean height of the sphenoid ostium from the choana roof was 10.9 (SD, 2.3) mm (range, 5.7-21.5 mm), and the mean height of skull base along the anterior wall of sphenoid sinus from the choana roof was 21.3 (SD, 3.2) mm (range, 13.3-30.6 mm). The ratio of the first measurement to the second measurement was 0.5 (SD, 0.08) (range, 0.29-0.77). CONCLUSIONS: In conclusion, under endoscopic view, the sphenoid sinus ostium can be safely probed between 13.3 mm (the minimum skull base height) and 5.7 mm (the minimum sphenoid sinus ostium height) distance upward from the choana, but determining the height of the sphenoid sinus ostium preoperatively on CTs for each patient separately will increase the chance of success in probing the sphenoid sinus.

Pulmonary artery embolism due to a ruptured hepatic hydatid cyst: clinical and radiologic imaging findings.

Hydatid pulmonary embolism is an uncommon condition resulting from the rupture of a hydatid heart cyst or the opening of a visceral hydatid cyst into the venous circulation. We report a rare case with multiple intra-arterial pulmonary hydatid cyst emboli originating from a hepatic hydatid cyst ruptured into the hepatic segment of the inferior vena cava. We present the ultrasonography findings of hepatic hydatid cyst and multidetector computed tomography pulmonary angiography images demonstrating both multiple hydatid cyst emboli and their hepatic origin.