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.

Unruptured giant lateral thoracic meningocele: extremely rare cause of cerebrospinal fluid (CSF) hypotension in neurofibromatosis type 1.

Neurofibromatosis type 1 (NF1) is a multisystem neurocutaneous disorder. Scoliosis and dural ectasia are features of the associated mesodermal dysplasia. Lateral thoracic meningoceles can develop in NF1 and progressively enlarge due to cerebrospinal fluid (CSF) pulsations. Large meningoceles can cause compressive symptoms in the thorax. We are reporting a case of a NF1 presenting with acute onset respiratory distress, who also had chronic orthostatic headaches. CT chest showed unruptured enlarging bilateral lateral thoracic meningoceles causing lung compression. MRI of the brain and spine showed features of CSF hypotension, explaining the headaches. CSF hypotension with unruptured meningoceles is extremely rare. Management of the condition is challenging since surgical removal is prone to complications due to underlying mesodermal abnormalities. Cystoperitoneal shunting to relieve lung compression may worsen CSF hypotension. A shunt with a programmable valve allowed controlled drainage and successfully relieved lung compression without worsening of orthostatic headaches in our case.

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.

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.

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.

Doppler hemodynamic liver index and hepatic elastic modulus: Advanced ultrasonographic techniques for non-invasive prediction of esophageal varices in cirrhosis.

PURPOSE: Currently esophagoscopy is the gold standard for assessment of esophageal varices in cirrhosis. Predicting the presence of esophageal varices, varices needing treatment (VNT) and variceal grade by advanced ultrasonographic techniques using a combination of Doppler hemodynamic liver index (HDLI) (quantifying portal hypertension) and hepatic elastic modulus (quantifying hepatic fibrosis) would be a cost-effective and non-invasive alternative to routine endoscopy. METHODS: Our cross-sectional study consisted of cirrhotic patients diagnosed using clinical features and laboratory parameters. Portal venous Doppler and liver sonoelastography were performed in selected subjects for obtaining measurements of HDLI (portal vein diameter/mean velocity) and hepatic elastic modulus respectively. Within 3 days of ultrasound, the subjects underwent upper GI endoscopy for assessment of presence, VNT and grade (F1, F2, F3) of varices. Subjects were divided into two groups (without and with varices) and data analyzed using XLSTAT. RESULTS: A total of 60 subjects (26 without and 34 with varices) were evaluated. Mean Doppler HDLI of subjects with varices was significantly higher (0.72 vs. 0.59, p < 0.0001) with progressive increase in values with variceal grade, being highest in grade-F3 (mean 0.77). Likewise, mean hepatic elastic modulus was also higher in subjects with varices (28.9 vs. 12.6 kPa, p < 0.0001) and showed progressive increase with grade (51.1 kPa for F3). For predicting presence of varices, maximum accuracy of elastic modulus was at cut-off of 14.5 kPa (sensitivity, specificity 83% and 84.6%) and Doppler HDLI was at 0.66 (66% and 92.3%). Good inter-rater agreement was present (κ 0.66). CONCLUSION: Combination of Doppler HDLI and hepatic elastic modulus is an excellent non-invasive method for predicting the presence, VNT, and variceal grade and may obviate need for routine endoscopic screening in cirrhosis.

Ultrasound diagnosis of syndromic cases with vascular malformations and soft tissue overgrowth: A rare case of CLOVES syndrome.

Introduction: Syndromes associated with vascular malformation and soft tissue overgrowth in the paediatric population present with multiple soft tissue swellings. Ultrasound is the initial investigation of choice for paediatric soft tissue swellings. Ultrasound evaluation can accurately assess the nature of vascular malformations and pattern of lipomatous hypertrophy in areas of soft tissue overgrowth to facilitate early diagnosis of such syndromes. Case Report: Here, we report a case of CLOVES (congenital lipomatous overgrowth (CLO), vascular malformations (V), epidermal nevi (E), and spinal/skeletal anomalies/scoliosis (S)) syndrome in a 6-year-old girl referred for evaluation of soft tissue swellings. CLOVES syndrome is a rare overgrowth syndrome in the paediatric population which presents with multiple soft tissue swellings. The ultrasound and clinical features of the syndrome have been illustrated to help radiologists accurately diagnose this rare syndrome based on detailed ultrasound and clinical evaluation. Discussion: Radiological features of CLOVES syndrome and differentiating ultrasound features of other such syndromes have been described in detail. A systematic stepwise approach to diagnosing complex syndromic associations of vascular malformations with lipomatous overgrowth has been proposed. Role of ultrasound in the management, Wilms tumour screening and follow-up of CLOVES syndrome have also been discussed. Conclusion: Ultrasound plays a crucial role in the early diagnosis and management of complex syndromes presenting with soft tissue swelling in the paediatric population. It also aids in the differentiation of such syndromes, tumour screening, guided sclerotherapy and follow-up of vascular lesions encountered in such syndromes.

Interventional radiology in the management of renal vascular injury: A prospective study.

INTRODUCTION: Endovascular and percutaneous interventions are promising alternatives to surgical management of traumatic renal injuries and often avert the need for nephrectomies. In this study, we aimed to evaluate the role of interventional radiology and angiographic interventions in the management of renal vascular injury. MATERIALS AND METHODS: Our prospective study was performed over a period of 6 months. Twenty-five patients who presented with either persistent hematuria or hemodynamic instability after traumatic or iatrogenic renal injuries were selected. Angiographic embolization using varying combinations of coils, glue, and Gelfoam® was performed to address the vascular injuries, either directly in hemodynamically unstable patients or after preprocedural imaging in hemodynamically stable patients. Patients were then followed up till discharge from hospital 48 h later and at 2 weeks and 4 weeks postprocedure for any recurrence of hematuria or hemodynamic instability. Technical and clinical success rates were calculated using descriptive statistics. RESULTS: Pseudoaneurysms were the most common form of arterial injury (22 cases), followed by arteriovenous fistula (8) and active extravasation (5). Segmental arteries are the most commonly involved (12 cases), followed by interlobar (9) and arcuate (3) arteries. Gelfoam® was used in five patients with active contrast extravasation and was 100% effective in arresting active bleeding. Coiling alone had a 79.16% technical success rate in management, while additional use of glue in four failed cases led to a 95.83% technical success rate in the first attempt. The ultimate technical and clinical success rate of interventional radiology in renal trauma management (after the second attempt in one failed case) was 100%. CONCLUSION: Endovascular management is an effective and safe alternative to surgical management of both iatrogenic and accidental renal vascular injuries.

Hepatocellular carcinoma in non-cirrhotic versus cirrhotic liver: a clinico-radiological comparative analysis.

AIM: To compare clinico-radiological pattern of non-cirrhotic versus cirrhotic HCC and correlate them with histopathological tumor grade. MATERIALS AND METHODS: This prospective study was carried out on 94 patients enrolled following ultrasound diagnosis of a liver mass measuring > 3 cm. Multiphasic MDCT was performed on all treatment-naïve cases and 56 cases with imaging pattern consistent with unifocal HCC were selected. Background liver parenchyma was assessed on ultrasound for cirrhosis and NAFLD. Cases were categorized into cirrhotic liver (CL) and non-cirrhotic liver (NCL) groups with 26 and 30 cases, respectively, and guided biopsy of each liver mass was performed. AFP levels were compared in both groups. Serum markers for hepatitis B and C were assessed. Masses in both groups were compared for morphology, attenuation on each phase and washout time. Presence of capsule, corona enhancement, satellite nodules and portal vein invasion was noted. RESULTS: AFP level was higher in CL group. HBV serum marker was raised in both groups. Most HCCs in NCL were moderately differentiated (histopathology), larger, had well-defined margins, showed mosaic pattern of enhancement, complete capsule and delayed phase washout. Majority in CL group were poorly differentiated, smaller, had ill-defined margins, showed heterogeneous enhancement, absent capsule and portal venous phase washout. Time of washout correlated with histopathological differentiation of masses, with earlier washout indicating poorer differentiation. CONCLUSION: HCCs in NCL have different clinico-radiological characteristics than HCCs in CL. Time of contrast washout correlates with histopathological grade of HCC. Non-cirrhotic NAFLD may require formulation of new screening guidelines for HCC.

Intracranial Fetus In Fetu-a Pediatric Rarity.

BACKGROUND: Intracranial fetus in fetu is an extremely rare entity in which a discrete vertebrate fetiform mass is found inside a diamniotic, monochorionic twin. It is a benign mass and can manifest with symptoms owing to mass effect. To establish the diagnosis, a vertebra must be present within the mass. CASE DESCRIPTION: A 5-year-old child presented at a multispecialty hospital with gradual weakness of both lower limbs. Magnetic resonance imaging of the brain revealed a midline intraventricular mass with lobulated margins having both cystic and fatty components with areas of blooming within. A provisional diagnosis of teratoma/primitive neuroectodermal tumor was made. The patient subsequently presented to our hospital with drowsiness and vomiting for 1 day. Noncontrast computed tomography revealed a mass of heterogeneous density occupying the third ventricle. The mass contained a few well-formed long bones representative of the appendicular skeleton and a vertebra-like bone representative of the axial skeleton, fulfilling the Willis criteria. A biopsy sample was taken from the mass; no malignant cells were seen on histopathologic examination. Based on noncontrast computed tomography findings of well-formed long bones and a vertebra and no significant increase in the size of the mass over 2 years, an intracranial fetus in fetu was diagnosed. CONCLUSIONS: Whenever bony structures are identified in an intracranial mass in a pediatric patient, we should always look for bones of the axial skeleton, as this finding will point toward a diagnosis of intracranial fetus in fetu and will help in differentiating it from teratoma, which can have malignant transformation.

Role of intrarenal resistive index and ElastPQ® renal shear modulus in early diagnosis and follow-up of diabetic nephropathy: A prospective study.

Introduction: We aimed to establish baseline normal values of ElastPQ® (Philips Healthcare, Bothell, Washington, USA) renal shear modulus, evaluate changes in intrarenal resistive index and renal shear modulus in various stages of diabetic nephropathy, their diagnostic potential and role in follow-up. Methods: Our prospective observational study was performed over two years. In total, 130 adult cases with diabetic nephropathy and 130 normal adult controls were selected. Diabetic nephropathy was confirmed by persistent albuminuria on 24-hour urinary albumin testing at three month intervals and staged by albuminuria quantification. Measurement of intrarenal resistive index and renal shear modulus in all subjects was performed and their variation with stage of nephropathy was statistically analyzed using Pearson's correlation. Receiver operating characteristic curves were plotted and their individual and combined diagnostic potentials were assessed. Statistical significance was tested using t tests and analysis of variance. Interrater agreement was tested using Cohen's kappa coefficient. Results: Mean intrarenal resistive index was significantly higher for cases (mean 0.72 ± 0.05) than controls (mean 0.62 ± 0.04) and showed significant age variation (p < 0.05). Normal values of ElastPQ® renal shear modulus ranged from 3.87 to 4.72 kPa and was significantly higher for cases (mean 8.59 ± 1.77 kPa) than controls (mean 4.32 ± 0.45 kPa) and showed significant differences between each stage of nephropathy, being highest in stage 2. Maximum diagnostic accuracy was at 0.65 (sensitivity 90%, specificity 76.2%, area under curve 0.916) for intrarenal resistive index and at 5.31 kPa (sensitivity 90.8%, specificity 84.6%, area under curve 0.923) for renal shear modulus. Combination of the two further improved diagnostic performance (highest accuracy of 89%, sensitivity 81.7%, specificity 96.3%). Conclusions: Normal range of ElastPQ® renal shear modulus values could be established. Intrarenal resistive index and renal shear modulus can be used as imaging parameters for early diagnosis and follow-up of diabetic nephropathy.

Atypical exophytic liver mass: Giant pedunculated hepatic haemangioma masquerading as a gastrointestinal stromal tumour of the gastric wall.

Haemangioma is the most common benign tumour of the liver. However, an exophytic hepatic haemangioma, especially the pedunculated form, is very rare. Giant pedunculated haemangiomas are prone to complications because of the narrow size of the pedicle. A large number of lesions can potentially present as exophytic liver masses, and accurate diagnosis can sometimes be challenging. We report a case of an incidentally discovered asymptomatic giant pedunculated liver haemangioma in the region of the lesser sac in a prospective renal donor, which was initially suspected to be a gastrointestinal stromal tumour of the stomach wall. Multiphasic computed tomography and confirmatory magnetic resonance imaging scans ultimately revealed the true nature of the lesion, which turned out to be an exophytic pedunculated hepatic haemangioma from the left lobe of the liver. The lesion was then surgically resected and histopathologically confirmed to be a haemangioma. The patient subsequently underwent successful renal donation as planned. Being a benign lesion with characteristic imaging features, accurate radiological diagnosis is absolutely essential for the appropriate management of such atypical haemangiomas.

Imaging spectrum of meningiomas: a review of uncommon imaging appearances and their histopathological and prognostic significance.

Meningiomas are the most common primary non-glial intracranial neoplasms. In most cases, meningiomas have typical imaging appearances and locations, enabling a straightforward radiological diagnosis. However, a myriad of unusual appearances potentially complicate the imaging picture. Furthermore, certain imaging features can also predict the specific histopathological nature and WHO grade of the meningioma. 'Typical' meningiomas include meningothelial, fibrous, and transitional variants and have the characteristic imaging features described for meningiomas. Several 'atypical' variants exist, which, although less common, also generally have a less favourable prognosis and necessitate early diagnosis. In addition, meningiomas can occur in a variety of unusual intracranial and even extra-cranial locations and need to be distinguished from the more common tumours of these regions on imaging. Any associated oedema or haemorrhagic changes may alter the prognosis and have to be carefully assessed and reported. Cystic changes in meningiomas have been divided into five subtypes, and accurate characterisation is essential to predict the prognosis. An extensive review of the several possible variations in imaging appearances of meningiomas including the differential features of common and uncommon variants would facilitate informative radiological reporting of meningiomas. This would be expected to improve pre-operative planning prior to surgical biopsy and thereby improve disease prognosis and patient outcomes.

Magnetic resonance imaging spectrum of intracranial tubercular lesions: one disease, many faces.

Tuberculosis is a devastating disease and has shown resurgence in recent years with the advent of acquired immunodeficiency syndrome. Central nervous system involvement is the most devastating form of the disease, comprising 10% of all tuberculosis cases. The causative organism, Mycobacterium tuberculosis, incites a granulomatous inflammatory response in the brain, the effects of which can be appreciated on magnetic resonance imaging (MRI), which can thus be used for diagnosis of the same. Neurotuberculosis can present in various patterns, which can be identified on MRI. The meningeal forms include leptomeningitis and pachymeningitis. Parenchymal forms of neurotuberculosis include tuberculoma in its various stages, tubercular cerebritis and abscess, tubercular rhombencephalitis, and tubercular encephalopathy. Each pattern has characteristic MRI appearances and differential diagnoses on imaging. Complications of neurotuberculosis, usually of tubercular meningitis, include hydrocephalus, vasculitis, and infarcts as well as cranial nerve palsies. Various MRI sequences besides the conventional ones can provide additional insight into the disease, help in quantifying the disease load, and help in differentiation of neurotuberculosis from conditions with similar imaging appearances and presentations. These can enable accurate and timely diagnosis by the radiologist and early institution of treatment in order to reduce the likelihood of permanent neurological sequelae.