How Can New Imaging Modalities Help in the Practice of Radiology?

Thoracic Magnetic Resonance Imaging Applications in Children

Lung pathologies in the pediatric population can usually be detected using chest radiography. Multidetector computed tomography (MDCT) imaging is often used as a supplementary method in the evaluation of lung diseases. Recently, magnetic resonance imaging (MRI) techniques were found to be reliable in the evaluation of pulmonary diseases in the pediatric population. This review study describes the routine application of MRI examinations and the use of thoracic MRI with a particular focus in pediatric patients.

Brain herniation into the transverse sinuses' arachnoid granulations in the pediatric population investigated with 3 T MRI

We aimed to evaluate the frequency, radiological-clinical findings of brain herniation into arachnoid granulation (BHAG) in pediatric age group using 3 T magnetic resonance imaging. Patients were under 18 years of age and underwent brain MRI examination which consists of 3D T1, 3D T2 FLAIR and 3D T2 sequences. A total of 2320 patients were enrolled in the study. All cases of AG into transverse sinus were included. The location of the AG, the deep, transverse, vertical and neck diameters and volume of AG were recorded. Clinical findings and imaging findings of patients were also recorded. The patients were categorized as BHAG and AG without brain herniation (AGWBH). The mean diameters (deep, transverse, vertical and neck) of AG, volume of AG, age, sex, clinical findings and imaging findings were evaluated and compared in each group. 135 patients (71 female, 64 male) had AG in a total of 2320 patients (prevalence 5.81%). Fifteen patients (10.7% of all patients, 11 female, 4 male) had BHAG. The mean diameters (deep, transverse, vertical and neck) and volume of AGWBH were 5.23 ± 1.91, 4.07 ± 1.58, 4.99 ± 1.68, 3.64 ± 1.84 mm and 85.05 ± 89.10 mm³, respectively. The mean diameters (deep, transverse, vertical and neck) and volume of BHAG were 7.46 ± 2.6, 6.85 ± 2.34, 8.32 ± 2.35, 5.41 ± 1.79 mm and 331 ± 361.26 mm³, respectively. The mean diameters and volume of BHAG were significantly larger than AGWBH (p < 0.001 for all parameters). There was no significant difference related to clinical and imaging findings between groups (p > 0.05). Brain herniation into arachnoid granulation is seen in pediatric age group as frequently as adults. Its frequency is not related to age. It is not significantly associated with neurological symptoms. As the AG size increases, the risk of BHAG increases.

Huge Extra Cranial Arteriovenous Malformation Presenting as Fluctuant Mass in Scalp

Arteriovenous malformation (AVM) of the scalp is an uncommon condition. Clinical manifestations usually include local pain, pulsatile mass, headache, numbness, tinnitus; and less frequently, necrosis and hemorrhage. This study discusses and illustrates an unusual case of AVM in scalp with its radiologic appearance and clinical features.

MR arthrographic characterization of posterior capsular folds in shoulder joints

METHODS:

This was a retrospective study of 604 consecutive shoulder MR images and MR arthrograms obtained from April 2010 to January 2018. Extension in the vertical-oblique plan of the posterior synovial fold on MR arthrography was identified according to the posterosuperior, posteroinferior, superoposterior, and inferoposterior portions. The morphologies of the posterior synovial folds on MR arthrography were divided three subtypes. Morphologic appearances of the posterior labrocapsular complex on conventional MR images were described with four subtypes.

RESULTS:

A posterior synovial fold in the shoulder joint was identified in 35 of 604 (5.8%) MR arthrography patients. 8 of 35 posterior synovial fold identified on MR arthrography were confirmed at arthroscopy. The most common MR arthrographic type of the posterior synovial fold was triangular-this was detected in 17 of 35 (48.6%) patients. The most common MRI morphology of the posterior labrocapsular complex was doubled posterior labrum. This was detected in 15 of 35 (42.9%) patients. 17 % of patients with posterior synovial folds who were diagnosed with MR arthrography had normal MRI features. The most common localization of the posterior synovial fold was posterosuperior and posteroinferior portions of the posterior labrocapsular structures. The mean of the shortest distance between the posterior synovial fold and the posterior labrum was significantly higher in the positive arthroscopic synovial fold group than in the negative arthroscopic synovial fold group (p = 0.047).

CONCLUSION:

Posterior synovial folds, normal capsular anatomic variants, are seen rarely on MR arthrography, and tend to be in the posterosuperior and posteroinferior portions of the posterior capsule. Some types of the posterior synovial fold can mimic a posterior labral tear in conventional MRI.

ADVANCES IN KNOWLEDGE:

On a direct MR arthrographic image, a posterior capsular synovial fold may be a normal anatomic variant. A fold is more commonly occur in the posterosuperior and posteroinferior capsular portions. The results of our study may allow differentiation of normal variations from abnormalities in patients with symptomatic shoulder joint.

Low-Dose Noncontrast Examination of the Paranasal Sinuses Using Volumetric Computed Tomography

OBJECTIVES

The objective of this study was to evaluate image quality of low dose in noncontrast paranasal sinus computed tomography (CT) using single volumetric 320-row multidetector CT technique.

METHODS

The low-dose protocol including tube voltage of 135 kV and tube current of 5 mAs was chosen based on results of the present phantom study. Forty-six patients were assigned to control group with factory standard settings (120 kVp, 75 mAs), and 46 patients were assigned to study group and underwent noncontrast CT of paranasal sinus with low-dose protocol using single volumetric 320-row multidetector CT device. Objective and subjective image qualities were performed.

RESULTS

Effective radiation dose calculated for control group scans was 0.45 (SD, 0.39) mSv. It was 0.038 (SD, 0.004) mSv for study group scans. The effective radiation dose of study group was statistically significant lower than control group (P < 0.001).

CONCLUSIONS

Noncontrast paranasal sinus CT imaging can be performed at very low radiation exposure maintaining high image quality with 135 kVp and 5 mAs.

Primary Alveolar Echinococcosis Presenting with Simultaneous Cerebral and Craniofacial Involvement

Alveolar echinococcosis (AE) is an important parasitic infestation caused by the larval stage of the Echinococcus multilocularis. Turkey is one of the countries occurred endemic of the disease. The disease primarily affects the liver. Cerebral and craniofacial involvements are very rare. Here the authors report a 46-year-old woman with simultaneous cerebral and craniofacial involvement of E. multilocularis. Although primary AE lesions with simultaneous cerebral and craniofacial involvement are exceedingly rare, radiologist must suspect from other unusual involvement such as craniofacial and muscular location in patients with cerebral AE.

Magnetic Resonance Angiographic Demonstration of Unusual Duplication of Left Vertebral Artery

BACKGROUND

Vertebral artery origin and course anomalies have clinical importance in neck surgery and diagnostic angiography.

CASE DESCRIPTION

A dual origin of the left vertebral artery from the aortic arch between the left common carotid and left subclavian arteries was incidentally detected by magnetic resonance angiography.

CONCLUSION

Magnetic resonance angiography is an important imaging method to be preferred in evaluating vascular structures in the neck area.

Differentiation between hepatic alveolar echinococcosis and primary hepatic malignancy with diffusion-weighted magnetic resonance imaging

PURPOSE

To determine the value of diffusion-weighted magnetic resonance imaging (DW-MRI) in discriminating between hepatic alveolar echinococcosis (AE) and hepatocellular carcinoma and intrahepatic cholangiocarcinoma.

METHODS

We included 49 patients (27 men, 22 women; mean age: 52.02±9.76 [SD] years; range: 25-72years) with 57 histopathologically confirmed hepatic AE lesions. Fifty patients (18 men, 32 women; mean age: 58.93±8.42 [SD] years; range: 42-71years) with 61 histopathologically confirmed hepatocellular carcinoma and 50 patients (24 men, 26 women; mean age: 50.11±7.70 [SD] years; range: 38-69years) with 54 histopathologically confirmed intrahepatic cholangiocarcinoma lesions were used as control groups. All patients had MRI examination of the liver that included conventional MRI sequences and DW-MRI using b values of 50, 400 and 800s/mm². Two radiologists evaluated conventional MRI and DW-MRI images and calculated ADC values of hepatic lesions.

RESULTS

The mean ADC value of solid components of hepatic AE lesions was 1.34±0.41×10^-3 mm²/s (range: 0.9-1.59×10^-3 mm²/s) and was significantly higher than that of the solid components of hepatocellular carcinoma lesions (mean ADC value, 0.99±0.29×10^-3 mm²/s; range: 0.7-1.15×10^-3 mm²/s) and of intrahepatic cholangiocarcinoma lesions (mean ADC value, 1.05±0.22×10^-3 mm²/s; range: 0.86-1.18×10^-3 mm²/s) (P<0.001).

CONCLUSION

In general ADC values can help discriminate between AE and hepatocellular carcinoma and intrahepatic cholangiocarcinoma. However, the use of ADC values cannot help differentiating Type 4 AE from hepatocellular carcinoma or intrahepatic cholangiocarcinoma.

Craniocervical Pseudomeningocele Following Cerebellar Meningioma Resection: Demonstration of Neck of Pseudomeningocele With Three-Dimensional Isotropic T2-Weighted SPACE Sequence at 3 Tesla (3T) Magnetic Resonance Imaging

Postoperative pseudomeningocele is an uncommon complication of craniospinal surgery. Diagnosis is reached on a postoperative computed tomography and magnetic resonance (MR) imaging. Demonstration of the location and dimension of the dural defect before surgical therapy is a very important. T1- and T2-weighted MR images revealed a significant pseudomeningocele extending from left cervicooccipital region. Magnitude and phase-contrast-MR images showed a cerebrospinal fluid (CSF) flow into pseudomeningocele, but they no revealed dural defect. Three-dimensional isotropic T2-weighted SPACE sequence revealed a signal void indicating CSF flow into pseudomeningocele and location and exact size of dural tear. Three-dimensional isotropic T2-weighted SPACE sequence is certainly the noninvasive and optimal method for demonstrating postoperative pseudomeningocele sacs. It demonstrates a pseudomeningocele regardless of an existing communication with the dural membrane.

Comparing subjective and objective image quality at two different radiation exposure ranges of the paranasal sinus CT examinations using a volumetric 320-row detector CT system

OBJECTIVES

To evaluate image quality of protocol including 135 kVp, 5 mAs and 80 kVp, 5 mAs in the paranasal sinus CT examinations using single volumetric 320-row multidetector CT technique.

METHODS

From September to December 2016, both of our control group including 135 kVp and 5 mAs and our study group including 80 kVp and 5 mAs paranasal CT protocols were simultaneously performed on 40 patients using single volumetric 320-row multidetector CT device. Image quality for bony structures, air-filled structures and soft tissues were independently assessed for each group by three blinded observers using a 3-point grading scale (0 = not diagnostic, 1 = partially diagnostic, 2 = diagnostic). Objective image quality was also performed by region of interests were placed on axial soft tissue reconstructions in both eye bulbs, retrobulbar fat and maxillary sinuses to obtain different values for aqueous tissue, soft tissue and air, respectively. Effective dose was calculated from the dose-length product.

RESULTS

The effective radiation dose which calculated for the control group scans was 0.037 ± 0.003 mSv. But, it was 0.0099 ± 0.001 mSv for the study group scans. The effective radiation dose of study group was statistically significant lower than control group (p < 0.001). Despite significant lowering of the radiation doses, image qualities were sufficient for evaluating all the bony structures, air-filled structures and soft tissues except for eye muscle, retrobulbar fat and eye bulb.

CONCLUSIONS

Our results present that our protocols for study and control group provide significant dose reduction without the loss of diagnostic image quality for paranasal sinus CT. Paranasal sinus CT imaging can be performed at very low radiation exposure maintaining high image quality using a single volume 320-row detector CT device using 135 kVp and 5 mAs.

Comparison of Ultrasonography and Low-Dose Computed Tomography for the Diagnosis of Pediatric Urolithiasis in the Emergency Department

OBJECTIVE

This study aimed to compare ultrasonography (US) and low-dose computed tomography (LDCT) for diagnosing pediatric urolithiasis in the emergency department.

MATERIALS AND METHODS

This retrospective study was approved by our institutional ethics committee, and informed consent was waived. From March 2016 to March 2017, 100 consecutive patients met the selection criteria and were enrolled in the study. Patients were randomly selected in a 1:1 ratio and were allocated to one of the following two imaging groups: US or abdominal LDCT. LDCT examinations were performed using a 320-detector row CT. Radiation dose analysis was performed using Radimetrics. US examinations were performed using the Aplio 500 ultrasound system. The presence of urolithiasis, anatomical location of urolithiasis, and measurements of renal stones were evaluated and recorded.

RESULTS

There were statistically significant differences between US and standard-dose CT (SDCT) with respect to the diagnosis of urolithiasis, anatomical location of urolithiasis, and measurements of renal stones (p<0.001, p=0.005, and p=0.03, respectively). The mean effective radiation dose of LDCT was 1.44±0.34 mSv and that of SDCT was calculated to be 4.36±1.33 mSv. There was no statistically significant difference between LDCT and SDCT with regard to the diagnosis of urolithiasis, anatomical location of urolithiasis and measurements of renal stones (p=1 for all). The diagnostic accuracy of US and LDCT was 0.68 and 1.0, respectively.

CONCLUSION

Low-dose computed tomography had 1/3 SDCT radiation dose, and LDCT and SDCT accurately diagnosed pediatric urolithiasis in the emergency department. US had a lower accuracy than SDCT and LDCT for diagnosing pediatric urolithiasis in the emergency department. LDCT can be an alternative for SDCT for diagnosing pediatric urolithiasis.

Expansion of the Rib Head: A Novel Computed Tomographic Feature of Supernumerary Intrathoracic Ribs

Intrathoracic ribs are very rare congenital anomalies. Approximately 50 cases have been reported in the literature till date. They are usually present on the right side, between the third and eighth ribs without sex predominance. They may originate from a vertebral body or the proximal or distal part of a rib. In most cases, they are asymptomatic, but they may be associated with developmental abnormalities of ribs and vertebrae. The diagnosis is important to prevent further investigation or intervention. Here we present two rare cases with supernumerary intrathoracic rib and describe a novel sign, namely expansion of the rib head. To the best of our knowledge, this is the shortest supernumerary intrathoracic rib, reported in the literature, on the left side originating from the head of the second rib, which could have been misdiagnosed as osteochondroma due to its atypical features.