Clinical and radiological evaluation of caudal regression syndrome.

Caudal regression syndrome is a form of segmental spinal dysgenesis involving the caudal spinal column, ranging from segmental coccygeal agenesis to extensive thoracolumbar agenesis with varying degrees of spinal cord dysgenesis. A majority of caudal regression cases are sporadic but maternal pre-gestational diabetes mellitus is an important risk factor. Imaging is an integral part of management of caudal regression syndrome. Antenatal diagnosis on obstetric ultrasound and evaluation with fetal MRI is ideal. Early postnatal diagnosis and/or detailed evaluation with MRI is essential for early management to improve outcomes. Pang classification categorizes caudal regression syndrome into two categories based on the position of the conus while Renshaw classification is based on the degree of vertebral column agenesis. Caudal regression syndrome may be associated with several additional anomalies, both spinal and extraspinal. A number of genitourinary and gastrointestinal anomalies have been described in association with caudal regression syndrome. The field of view of MRI of the lumbosacral spine in caudal regression syndrome needs to be extended to visualize the retroperitoneal structures without the use of a saturation band. Syndromic associations may be suspected, and additional imaging performed, based on findings of extended field of view MRI of the spine. Associated sacral masses and filar abnormalities need to be identified and may also require surgical treatment. The multisystem nature of this disease necessitates a multimodality approach to the evaluation and management of caudal regression syndrome with close cooperation between pediatric neuroradiologists and body radiologists as well as multiple clinical teams. Appropriate early management with surgical correction as necessary can significantly improve prognosis and survival in caudal regression syndrome.

Birth-related subdural hemorrhage in asymptomatic neonates: evolution over time and differentiation from traumatic subdural hemorrhage.

BACKGROUND: Intracranial birth-related subdural hemorrhage frequently occurs in asymptomatic newborns and has no adverse long-term sequelae. It is medically and medicolegally important to differentiate birth-related subdural hemorrhage from other pathological causes of intracranial hemorrhage. There is limited literature available on the incidence of birth-related subdural hemorrhage, its imaging features, and evolution over time, mainly because asymptomatic infants do not routinely undergo cranial MRI. OBJECTIVE: To establish the incidence and distribution of birth-related subdural hemorrhage and evaluate their association with various modes of delivery, identify associated features, and evaluate the sequential evolution of signal changes of the birth-related hemorrhages on MRI. MATERIALS AND METHODS: A total of 200 healthy term neonates and young infants were included in this retrospective review study. All infants underwent MRI of the brain and cervical spine at postnatal age of 0-2 months with acquisition of a 3D T1-weighted (T1W), 3D or 2D T2-weighted (T2W), and axial diffusion-weighted imaging (DWI) sequences. The scans were evaluated for the presence and distribution of subdural hemorrhages, other intracranial hemorrhages, and associated injuries. Prevalence of intracranial hemorrhage in various modes of delivery was analyzed. Relationship between the signal intensities of the bleeds on T1W, T2W, and DWI scans and the age of the infants was analyzed. Appropriate tests were applied to test for statistical significance of the data. RESULTS: Out of 200 neonates, 66 (33%) had detectable intracranial hemorrhage on MRI with an age range of 11-25 days, including 31 (47%) males and 35 (53%) females. All of them had subdural hemorrhages, 54 (81.8%) of which were in the posterior fossa. Additional parenchymal hemorrhages were present in a few, but no subarachnoid hemorrhages, cervical spinal canal hemorrhages, cortical bridging vein injury, or cervical spinal ligamentous injury were identified within the limitations of the study. No detectable intracranial hemorrhage was found in subjects above 25 days of age. Overall incidence of subdural hemorrhage by mode of delivery was 8/68 (11.8%) in babies born by cesarean section and 58/132 (43.9%) in babies born by vaginal delivery. Among the vaginal deliveries, the highest incidence was observed in assisted vaginal delivery (19/30, 63.3%). Subjects with birth-related subdural hemorrhage were categorized into three age groups: <13 days, 13-21 days, and >21 days. All detected hemorrhages were T1W hyperintense. In the <13 days group, all bleeds were T2W hypointense. In the 13-21 days group, 73.1% were T2W hypointense, while 26.9% were T2W mixed. All bleeds in the >21 days group were T2W hypointense. All DWI hyperintense bleeds were found in the 13-21 days group. CONCLUSION: Birth-related subdural hemorrhage occurs in over a third of normal deliveries and has a characteristic distribution, predominantly in the posterior fossa. Associated cervical spinal subdural hemorrhages, cervical spinal ligamentous injury, or cortical bridging vein injury, which are concerning for traumatic etiology, were not identified. Birth-related subdural hemorrhages follow a characteristic pattern of signal changes on MRI. Although not completely reliable, this can help in differentiating them from traumatic intracranial hemorrhages which usually occur postnatally. No birth-related subdural hemorrhages were seen after 25 days of age in our cohort.

Imaging update on gallbladder adenomyomatosis and its mimics.

Radiologists across many imaging modalities commonly encounter gallbladder adenomyomatosis. The classic imaging appearances of gallbladder adenomyomatosis are well described and confirm benignity. However, in clinical practice, adenomyomatosis can be challenging to differentiate from other gallbladder pathologies that require cholecystectomy. In this article, we describe the common and uncommon appearances of gallbladder adenomyomatosis on multimodality imaging, helping differentiate adenomyomatosis from non-benign gallbladder abnormalities. Accurately differentiating adenomyomatosis from its mimics provides the surgical team with important clinical and surgical management information, improving patient outcomes.

Imaging of the hepatic arterial infusion pump: Primer for radiologists.

Hepatic arterial infusion (HAI) pumps are used to deliver liver-directed therapy by allowing the administration of selective chemotherapy to the liver via a catheter implanted most commonly into the gastroduodenal artery connected to a subcutaneous pump. This selective administration helps maximize the chemotherapeutic effect within the hepatic tumors while minimizing systemic toxicity. While HAI therapy has primarily been used to treat liver-only metastatic colorectal cancer, the indications have expanded to other malignancies, including intrahepatic cholangiocarcinoma. Radiologists play an important role in pre-operative planning, assessment of treatment response, and evaluation for potential complications using various imaging studies, including computed tomography angiography, magnetic resonance imaging, and perfusion scintigraphy. This article describes the radiologist's role as part of a multi-disciplinary oncology team to help maximize the success of HAI therapy and also helps radiologists familiarize themselves with various aspects of HAI pumps.

Collapse or distention of the perioptic space in children - What does it mean to pediatric radiologists? Comprehensive review of perioptic space evaluation.

The perioptic space comprises the subarachnoid space [SAS] of the optic nerve communicating with the SAS of the central nervous system. Pressure variations in the SAS of the central nervous system can be transmitted to the optic papilla through the perioptic space. Variations in the diameter of the perioptic space serve as an important indicator for select intracranial pathologies in the pediatric population. Though the perioptic space can be evaluated using various imaging modalities, MRI is considered highly effective due to its superior soft tissue resolution. With advancement in MR imaging techniques, high-resolution images of the orbits can provide improved visualization of the perioptic space. It is imperative for the pediatric radiologist to routinely assess the perioptic space on brain and orbit MR imaging, as it can prompt exploration for additional features associated with select intracranial pathologies, thus improving diagnostic accuracy. This article reviews basic anatomy of the perioptic space, current understanding of the CSF dynamics between the perioptic space and central nervous system SAS, various imaging modalities utilized in the assessment of the perioptic space, MRI sequences and the optimal parameters of specific sequences, normal appearance of the perioptic space on MR imaging, and various common pediatric pathologies which cause alteration in the perioptic space.

Arachnoid cyst in the pediatric patient: What the radiologist needs to know.

Arachnoid cysts are the most common incidentally discovered intracranial lesions on imaging and the most common cystic intracranial lesions. They may be developmental or secondary. A relative lack of recent literature and any comprehensive radiological review on arachnoid cysts has led to a general lack of awareness among radiologists of symptomatic or complicated arachnoid cysts. This is particularly concerning in pediatric patients. While arachnoid cysts are asymptomatic in most cases, they can cause clinical symptoms in a minority of cases, especially when they occur in unusual sites. These include intraventricular locations where they may cause hydrocephalus, the basal cisterns where they may compress cranial nerves, the cerebellopontine angle where they have to be differentiated from a number of cystic lesions, the cavum septum pellucidum or cavum velum interpositum, the choroid fissure where they can entrap the temporal horn and compress the hippocampus, the posterior fossa where they need to be differentiated from other posterior fossa cystic lesions, and within the spinal canal where there is a concern for cord or nerve root compression. Larger cysts are more prone to complications such as mass effect, hemorrhage, and rupture. Hemorrhage and rupture often present with acute symptoms. Ruptured cysts lose their characteristic imaging appearance and can mimic several ominous pathologies. It therefore becomes vital to accurately diagnose these cases as complications of pre-existing arachnoid cysts for appropriate management. A detailed review of all diagnostic imaging aspects of arachnoid cysts will help fill in the existing information void on this important entity.

Our Experience in Tracking the Tract: Normal Biliary Anatomy and Variants on Magnetic Resonance Cholangiopancreatography in Living Donor Liver Transplantation.

Objective Biliary anatomy is of paramount importance for hepatobiliary pancreatic surgeons for operative planning. Preoperative assessment with magnetic resonance cholangiopancreatography (MRCP) to evaluate the biliary anatomy plays a vital role, especially for prospective liver donors in living donor liver transplantation (LDLT). Our objective was to evaluate the diagnostic accuracy of MRCP in assessing the anatomical variations of the biliary system and the frequency of biliary variation in the donors of LDLT. Materials and Methods Sixty-five donors of living donor liver transplantation in the age range of 20 to 51 years were studied retrospectively to evaluate the anatomical variations of the biliary tree. As a part of the pre-transplantation donor workup, MRI with MRCP was performed in a 1.5T machine for all these candidates. MRCP source data sets were processed with maximum intensity projections, surface shading, and multi-planar reconstructions. Images were reviewed by two radiologists, and the classification system of Huang et al. was utilized to evaluate the biliary anatomy. The results were compared with the intraoperative cholangiogram, considered the gold standard. Results We identified standard biliary anatomy in 34 candidates (52.3%), and variant biliary anatomy was observed in 31 candidates (47.7%) on MRCP. An intraoperative cholangiogram showed standard anatomy in 36 candidates (55.4%) and biliary variation in 29 candidates (44.6%). Our study showed a sensitivity of 100% and a specificity of 94.5% for identifying biliary variant anatomy on MRCP in comparison with the gold standard intraoperative cholangiogram. The accuracy of MRCP in detecting the variant biliary anatomy in our study was 96.9%. The most common biliary variation was the right posterior sectoral duct draining into the left hepatic duct, Huang type A3. Conclusion The frequency of biliary variations is high in potential liver donors. MRCP is sensitive and highly accurate in identifying the biliary variations of surgical significance.

Improving Outcomes in Catheter-Directed Thrombolysis for the Management of Acute Budd-Chiari Syndrome: A Case Report.

Traditionally catheter-directed thrombolysis is performed for recanalization of hepatic vein thrombosis in acute Budd-Chiari syndrome. Successful recanalization of the hepatic veins requires a continuous infusion of the thrombolytic agent for an adequate duration due to increased resistance to blood flow in the setting of luminal thrombosis. Here, we describe a case of acute Budd-Chiari syndrome in a young female in whom prolonged catheter-directed thrombolysis of the right hepatic vein was performed for a duration of 84 hours using alteplase as the thrombolytic agent. This was followed by angioplasty and stent placement. We observed that prolonged catheter-directed thrombolysis was associated with a progressive reduction in clot burden with improved luminal patency of the hepatic vein and improved outcome of subsequent angioplasty and stenting. There was a rapid improvement in liver function tests after the procedure and liver enzymes returned to baseline within a week. A follow-up ultrasound scan showed normal blood flow and a patent lumen of the right hepatic vein. In the absence of complications, prolonged catheter-directed thrombolysis in acute Budd-Chiari syndrome can achieve adequate recanalization of the hepatic veins and improved long-term clinical outcomes. This may obviate the need for other invasive procedures like TIPS (transjugular intrahepatic portosystemic shunt)/DIPS (direct intrahepatic portosystemic shunt) and liver transplantation.

Spectrum of synovial pathologies: a pictorial assay.

The synovium, a specialized vascular tissue, lines the diarthrodial joints, bursae, and tendon sheaths of the body. It helps in nourishment of articular structures. The synovium is affected by a variety of disorders that can be either localized or systemic. Although normal synovium is barely perceptible on magnetic resonance imaging, it provides an excellent imaging modality for the evaluation of pathologic processes involving the synovium. The pathologic processes affecting the synovium include 1 of the following etiologies: inflammatory, infectious, degenerative, traumatic, or neoplastic and tumor-like conditions. In this article, we discuss the magnetic resonance imaging technique and the sequences used in the evaluation of synovial pathologies and review the characteristic imaging findings of specific conditions thus narrowing the differential diagnoses.

Musculoskeletal manifestations of hemophilia: imaging features.

The purpose of this pictorial assay is to demonstrate the imaging features of the various musculoskeletal manifestations of hemophilia, an X-linked disorder. Depending on the site of recurrent bleeding, musculoskeletal manifestation can be in the form of hemophilic arthropathy and/or soft tissue, intraosseous, or subperiosteal pseudotumors. Radiography, sonography, computed tomography, and especially magnetic resonance imaging help in the evaluation of hemophilic arthropathy and pseudotumors, providing accurate diagnosis, thus avoiding inadvertent procedures and related complications. Treatment includes replacement of clotting factors either continuously or when indicated, radionuclide or open synovectomy in cases of disabling arthropathy.

Bleeding scrotal vascular lesions: interventional management with transcatheter embolization.

Vascular lesions of the scrotum are uncommon; the most common among them are varicocele lesions. The other vascular lesions that may involve the scrotum are hemangioma, lymphangioma, and arteriovenous malformations, which are exceedingly rare. The imaging modalities useful in the diagnosis and management of scrotal vascular lesions are grayscale sonography, color Doppler sonography, magnetic resonance imaging, magnetic resonance angiography, and digital subtraction angiography. We present two cases of scrotal vascular lesions involving the extratesticular scrotal soft tissues. Patients presented with bleeding and were treated by radiological interventional technique. We emphasize the importance of superselective catheterization and distal embolization.

SPECT/CT in the Diagnosis of Skull Base Osteomyelitis.

Skull base osteomyelitis is a potentially fatal disease. We demonstrate here the utility of SPECT/CT in diagnosing this entity, which was not obvious on a planar bone scan. A (99m)Tc MDP bone scan with SPECT/CT was carried out on a patient with clinically suspected skull base osteomyelitis. Findings were correlated with contrast-enhanced CT (CECT) and MRI. Planar images were equivocal, but SPECT/CT showed intense uptake in the body of sphenoid and petrous temporal bone as well as the atlas corresponding to irregular bone destruction on CT and MRI. These findings indicate that SPECT/CT may have an additional role beyond planar imaging in the detection of skull base osteomyelitis.