Visual grading analysis of digital neonatal chest phantom X-ray images: Impact of detector type, dose and image processing on image quality.

OBJECTIVES: To evaluate the impact of digital detector, dose level and post-processing on neonatal chest phantom X-ray image quality (IQ). METHODS: A neonatal phantom was imaged using four different detectors: a CR powder phosphor (PIP), a CR needle phosphor (NIP) and two wireless CsI DR detectors (DXD and DRX). Five different dose levels were studied for each detector and two post-processing algorithms evaluated for each vendor. Three paediatric radiologists scored the images using European quality criteria plus additional questions on vascular lines, noise and disease simulation. Visual grading characteristics and ordinal regression statistics were used to evaluate the effect of detector type, post-processing and dose on VGA score (VGAS). RESULTS: No significant differences were found between the NIP, DXD and CRX detectors (p>0.05) whereas the PIP detector had significantly lower VGAS (p< 0.0001). Processing did not influence VGAS (p=0.819). Increasing dose resulted in significantly higher VGAS (p<0.0001). Visual grading analysis (VGA) identified a detector air kerma/image (DAK/image) of ~2.4 µGy as an ideal working point for NIP, DXD and DRX detectors. CONCLUSIONS: VGAS tracked IQ differences between detectors and dose levels but not image post-processing changes. VGA showed a DAK/image value above which perceived IQ did not improve, potentially useful for commissioning. KEY POINTS: • A VGA study detects IQ differences between detectors and dose levels. • The NIP detector matched the VGAS of the CsI DR detectors. • VGA data are useful in setting initial detector air kerma level. • Differences in NNPS were consistent with changes in VGAS.

γ-H2AX foci as in vivo effect biomarker in children emphasize the importance to minimize x-ray doses in paediatric CT imaging.

OBJECTIVES: Investigation of DNA damage induced by CT x-rays in paediatric patients versus patient dose in a multicentre setting. METHODS: From 51 paediatric patients (median age, 3.8 years) who underwent an abdomen or chest CT examination in one of the five participating radiology departments, blood samples were taken before and shortly after the examination. DNA damage was estimated by scoring γ-H2AX foci in peripheral blood T lymphocytes. Patient-specific organ and tissue doses were calculated with a validated Monte Carlo program. Individual lifetime attributable risks (LAR) for cancer incidence and mortality were estimated according to the BEIR VII risk models. RESULTS: Despite the low CT doses, a median increase of 0.13 γ-H2AX foci/cell was observed. Plotting the induced γ-H2AX foci versus blood dose indicated a low-dose hypersensitivity, supported also by an in vitro dose-response study. Differences in dose levels between radiology centres were reflected in differences in DNA damage. LAR of cancer mortality for the paediatric chest CT and abdomen CT cohort was 0.08 and 0.13 ‰ respectively. CONCLUSION: CT x-rays induce DNA damage in paediatric patients even at low doses and the level of DNA damage is reduced by application of more effective CT dose reduction techniques and paediatric protocols. .

High-resolution perineal ultrasound of a paraurethral cyst in a neonate (2008: 8b).

We present high-resolution ultrasonography of a paraurethral cyst, a rare cause of an interlabial mass in a newborn. Although not always performed in these cases, ultrasonographic evaluation is an easily performed examination in assessment of the final diagnosis and therapeutic decisions.

Gyriform calcifications in tuberous sclerosis simulating the appearance of Sturge-Weber disease.

Two cases of tuberous sclerosis are presented. Extensive superficial occipital calcifications were found as classically described in Sturge-Weber syndrome. Other radiologic signs of tuberous sclerosis, such as subependymal calcifications in both patients and surgically proved giant cell astrocytoma in one patient, were present. At pathologic examination, the calcifications appeared to be located in extensive cortical tubers.

CT and MR in infants with pericerebral collections and macrocephaly: benign enlargement of the subarachnoid spaces versus subdural collections.

PURPOSE: To compare CT and MR in the differentiation of benign enlargement of the subarachnoid spaces and subdural collections in infants with macrocephaly. METHODS: MR was performed in 19 infants with macrocephaly, showing bifrontal enlargement of the subarachnoid spaces on CT. RESULTS: In 11 patients, a single fluid layer could be distinguished on MR of the pericerebral collections, suggesting benign enlargement of the subarachnoid spaces. In eight patients, two separate layers were clearly differentiated, an outer layer that was hyperintense on all sequences and an inner layer with the same intensity as the cerebrospinal fluid. This indicated the presence of subdural collections. These collections were mainly frontal in six and extended over the entire hemisphere in two patients. On CT, these separate lesions were seen only in three patients and missed in three others. In two final patients, CT findings were equivocal with evidence of membrane formation within the hypodense collections. In seven patients with a subdural collection, subdural-external drainage was performed. In three patients, the collection was hemorrhagic. The protein content of the fluid showed a mean of 1381.7 +/- 785.6 mg/dL. The MR and surgical findings of a subdural collection correlated with the absence of a family history of macrocrania, an age under 5 months, and acute clinical signs of vomiting, somnolence, and hypotonia. CONCLUSION: MR appears essential in the differential diagnosis between benign enlargement of the subarachnoid spaces and subdural collections in infants.

Three-dimensional imaging of acetabular dysplasia: diagnostic value and impact on surgical type classification.

OBJECTIVE: To investigate the diagnostic value and the impact on surgical type classification of three-dimensional (3D) images for pre-surgical evaluation of dysplastic hips. MATERIALS AND METHODS: Three children with a different surgical type of hip dysplasia were investigated with helical computed tomography. For each patient, two-dimensional (2D) images, 3D, and a stereolithographic model of the dysplastic hip were generated. In two separate sessions, 40 medical observers independently analyzed the 2D images (session 1), the 2D and 3D images (session 2), and tried to identify the corresponding stereolithographic hip model. The influence of both image presentation (2D versus 3D images) and observer (degree of experience, radiologist versus orthopedic surgeon) were statistically analyzed. The SL model choice reflected the impact on surgical type classification. RESULTS: Image presentation was a significant factor whereas the individual observer was not. Three-dimensional images scored significantly better than 2D images (P=0.0003). Three-dimensional imaging increased the correct surgical type classification by 35%. CONCLUSION: Three-dimensional images significantly improve the pre-surgical diagnostic assessment and surgical type classification of dysplastic hips.

Three-dimensional computed tomography-based, personalized drill guide for posterior cervical stabilization at C1-C2.

STUDY DESIGN: Cadaver and preliminary clinical study. OBJECTIVES: To enhance the precision of screw positions for posterior transarticular fixations according to Magerl at C1-C2. SUMMARY OF BACKGROUND DATA: The vertebral arteries are at risk during the Magerl operation and may be damaged in up to 4.1% of cases. Even intraoperative navigation, as often used nowadays, does not provide optimal screw positioning in all patients. METHODS: According to the three-dimensional CT data obtained for every individual cadaver or patient, a template was designed for the posterior course of C2: the template contains a drill guide allowing navigated screw positioning inside the left and right isthmus of C2. For a first series of five cadavers a template with clamps connecting only to the lamina of C2, excluding the spinous process from the interface, was carried out. For a second series of three cadavers the template was connected not only to the lamina but also to the spinous process of C2. Both cadaver series were performed without any fluoroscopic control at surgery. Eventually the technology was applied in two clinical cases. RESULTS: The rotational stability of the template toward the lamina C2 was insufficient in the first series, but for the second series both the entry points and screw trajectories were very satisfactory. CONCLUSIONS: Although the actual experience is limited, the idea of using a template with drill guide might simplify and shorten the surgical act and at the same time enhance the accuracy of C1-C2 transarticular screw positioning.

Pictorial essay: right aortic arch.

Right aortic arch is a rare congenital anomaly. It can be either an isolated finding or it can be part of a double aortic arch. This article discusses the radiographic appearance of this congenital anomaly on conventional chest X-ray, angiography, CT, and MRI.

Cortical hyperostosis: a complication of prostaglandin E1 treatment in congenital heart disease.

Prostaglandin E1 (PGE1) is an essential drug for infants with ductal-dependent congenital heart disease. Cortical hyperostosis of the long bones is one of the complications during and after PGE1 therapy and should be considered in the differential diagnosis of periostitis in the infant.

Xanthogranulomatous pyelonephritis in a child.

Xanthogranulomatous pyelonephritis is an uncommon form of chronic aggressive infection of the kidney and surrounding tissues usually affecting middle aged women. It is rarely seen in childhood. We report the case of a female child with a history of fatigue, progressive anorexia, and fever in whom a diagnosis of pyelonephritis on a predisposing factor of lithiasis was suggested. After initial antibiotic treatment, nephrectomy was needed for an acute general deterioration. Pathology demonstrated xanthogranulomatous pyelonephritis.

[Clinical application of three-dimensional spiral CT in skeletal disorders]. / Klinische toepassingen van driedimensionele spiraal CT bij skeletafwijkingen.

Three-dimensional (3D) computed tomographic reformations are used as an adjunct to standard axial computed tomography (CT) in the evaluation of disorders affecting areas of complex anatomy such as the skull, the spine, the pelvis, hands and feet. 3D-CT can provide a clear impression of lesion extent, pattern, shape and proximity to adjacent structures. This unique spatial information potentially has a significant impact on decisions regarding resectability, surgical approach and repair. The basic requirements for high-quality 3D-reformations are an absence of patient movement and narrow-width transaxial sections. Spiral CT significantly contributes to fulfilling these requirements. In addition, spiral CT scan data can be used to produce the ultimate representation of the third dimension: a life-size palpable medical model. In this review we describe the process of three-dimensional reconstruction and highlight potential problems arising during 3D-imaging processing. Useful clinical applications of spiral CT for 3D-visualization of skeletal pathology are discussed.

Mesenchymal hamartoma: radiological differentiation from other possible liver tumors in childhood.

We report a case of hepatic mesenchymal hamartoma in a young boy. The clinically huge abdominal mass was demonstrated on ultrasound and computed tomography as a cystic, minimally vascularized tumor, attached to the liver. The mass was surgically removed.

The Holt-Oram syndrome: radiological approach.

The clinical and radiological findings in a female child with Holt-Oram syndrome are reported. The most important features are cardiac anomalies associated with typical anomalies of the skeleton of the forearms.

[Three-dimensional imaging of acetabular fractures using spiral CT]. / Driedimensionele beeldvorming van acetabulumfrakturen met spiraal CT.

Seven adult patients with acetabular fractures were investigated with conventional X-rays, axial spiral computed tomographic (CT) images and three-dimensional (3D) surface rendered reconstructions. Spiral CT has the advantage that it acquires the data much faster than incremental CT, resulting in less motion artefacts. A semi-automatic three-dimensional environment for segmentation has been developed in our institution. It created significant reduction of user interaction and improved visualization of acetabular and femoral joint surfaces. The main advantages of three-dimensional visualization of acetabular fractures included: creation of unlimited and unique views by which fracture location, fracture extension, fragment shape and fragment position became more clear, better visualization of acetabular dome and quadrilateral plate and more simple and easier interpretation of these complex fracture patterns. On the other hand, 3D surface reconstructions do not accurately demonstrate undisplaced fractures, intra-articular fragments may be obscured, congruence assessment is uneasy, and soft tissue injuries are not shown. Therefore, we consider 3D images of acetabular fractures as being complementary to and not a substitute to plain radiographs and axial CT scans.

The use of duplex doppler ultrasound in a case of multifocal hepatic hemangioma.

A one-month-old girl presented with multiple cutaneous hemangiomas, abnormal weight gain, hepatomegaly, and symptoms of bleeding disorder. Abdominal ultrasound and CT revealed a multifocal hypervascular hepatic tumor and signs of vascular overload. Biopsy confirmed the presence of an infantile hepatic hemangioma. Conservative treatment with high dose steroids showed regression of the hepatic lesions and the signs of vascular congestion. Ultrasound was used for follow-up and its role in treatment monitoring is discussed in this manuscript.

Nonfunctioning neuroendocrine tumor of the pancreas in an 8-year-old girl.

We report a case of a nonfunctioning neuroendocrine pancreatic tumor in the pediatric age group. An 8-year-old child complains of vague abdominal pain and radiological investigations detect a tumoral mass in the pancreatic tail. Abdominal ultrasound, contrast enhanced computed tomography and magnetic resonance imaging demonstrate a round intrapancreatic solid moderately vascularized lesion of approximately 5 cm in diameter, with a smooth contour and well demarcated from the surrounding tissues. After surgical resection, the diagnosis of a hormonally inactive benign neuroendocrine tumor is histologically diagnosed. Patient's follow-up is uneventful.

Cervical ectopic thymus presenting as a painless neck mass in a child.

Ectopic cervical thymus is an uncommon entity to be considered in the differential diagnosis of neck masses in infants and children. The sonographic appearance of a hyporeflective mass with characteristic internal linear hyperreflections situated along the path of the thymopharyngeal duct should suggest diagnosis. On MRI, signal intensities differ significantly from other more common neck mass lesions in children such as a branchiogenic cyst, hemangioma and lymphangioma. Diagnosis can be confirmed by performing a sonographically guided thru-cut biopsy.

Ovarian torsion in a premenarcheal girl: MRI findings.

Adnexal torsion is an uncommon cause of severe lower abdominal pain in women and is often difficult to distinguish from other acute abdominal conditions. However, adnexal torsion should be considered in premenarcheal girls admitted with acute abdominal pain and evidence of an ovarian mass. Accurate and early radiological diagnosis is mandatory immediately after onset of clinical symptoms in order to preserve the viability of the ovary. Ultrasound (US) is usually the first line examination performed in an emergency setting, but computed tomography (CT) and magnetic resonance imaging (MRI) can be useful in case of ambiguous US findings, especially in patients with sub-acute symptoms and a suspected adnexal mass. This case report describes the additional value of MRI in a premenarcheal girl with sub-acute right fossa pain.

The solitary hyperdynamic pulsating superior mesenteric artery: an additional dynamic sonographic feature of midgut volvulus.

Midgut malrotation complicated by volvulus is a surgical emergency. The diagnosis is often suspected clinically and usually confirmed by barium meal. In this case the diagnosis of malrotation with midgut volvulus is made by ultrasound. We describe the solitary hyperdynamic pulsating superior mesenteric artery as an additional dynamic sonographic feature of midgut volvulus.