Longitudinal Stress Fracture of the Femur: A Rare Entity.

Exercise-induced stress reactions and stress fractures are common causes of pain in athletes. Although most stress fractures are trans- verse in orientation, rarely longitudinal stress fractures may occur in the tibia and femur. Early detection is important to start prompt and appropriate treatment to prevent complications. Thus, familiarity with the clinical presentation, imaging findings, and treatment of this rare entity are important for proper and timely treatment.

Unusual Breast Calcifications: Complete Replacement of Fibroglandular Tissue with Dystrophic Calcifications in End-Stage Renal Disease.

We present a rare case of breast calcifications in a patient with end-stage renal disease (ESRD) who was noncompliant with peritoneal dialysis. She presented with rapid onset of a palpable breast mass. Breast ultrasound (US) demonstrated ill-defined areas of dense tissue in the breasts bilaterally. Mammography demonstrated coarse, branching calcifications, completely replacing normal fibroglandular tissue. A review of the literature yields one similar case. The current hypothesis for patients with increased breast calcifications includes elevated serum calcium, phosphate, and parathyroid hormone (PTH) levels; calcium phosphate products may be critical to calcification in ESRD. However, our patient presented with low-normal serum calcium and phosphate, suggesting that this rare entity of breast calcifications is probably related to other unknown factors.

Caudal Regression Syndrome: A Case Series of a Rare Congenital Anomaly.

BACKGROUND: Caudal regression syndrome is a rare, neural tube defect characterized by an abnormal development of the caudal aspect of the vertebral column and the spinal cord., It results in neurological deficits ranging from bladder and bowel involvement to severe sensory and motor deficits in the lower limbs. Maternal diabetes, genetic factors and some teratogens have been shown to be associated with its pathogenesis. Caudal regression syndrome is usually diagnosed initially by antenatal ultrasound with more definitive diagnosis made by antenatal or postnatal MRI. In this case series, we report four cases of caudal regression syndrome in different age groups including prenatal, infant and adult. CASE REPORT: We are presenting multimodal imaging findings of 4 cases of caudal regression syndrome in 4 different age groups including fetus, infant, early childhood and adult. The pathogenesis, associated risk factors, complications, treatment options and prognosis of caudal regression syndrome are discussed as well. CONCLUSIONS: Caudal regression syndrome is a rare entity, characterized by sacrococcygeal dysgenesis with an abrupt termination of a blunt-ending spinal cord. Ultrasound and fetal MRI can be used to make a prenatal diagnosis, while MRI is the imaging modality of choice in adults. Early detection and prompt treatment is very important to decrease the risk of complications, and thus, to improve the prognosis.

Some Mushrooms are Hard to Digest: Gastrostomy Tube Exchange.

BACKGROUND: Percutaneous endoscopic gastrostomy (PEG) is an effective and safe mode of enteral nutrition for patients needing chronic enteric nutritional support. Exchanging PEG tubes may result in complications due to inexperience as well as due to lack of protocol. CASE REPORT: We encountered a 73 year-old female with unnoticed, accidently detached portion of the internal bumper of a PEG tube in the gastric lumen after a challenging gastrostomy tube exchange. CONCLUSIONS: This case report discusses the complications associated with gastrostomy tube exchange and proposes a planned protocol for successful gastrostomy tube exchange.

Toxins in Brain! Magnetic Resonance (MR) Imaging of Toxic Leukoencephalopathy - A Pictorial Essay.

Toxic leukoencephalopathy results from damage to the white matter caused by various toxins. It manifests itself as white matter signal abnormalities with or without the presence of restricted diffusion. These changes are often reversible if the insulting agent is removed early, with the exception of posthypoxic leukoencephalopathy that can manifest itself 1-2 weeks after the initial insult. However, many other potential causes of white matter signal abnormalities can mimic the changes of toxic leukoencephalopathy. Thus, familiarity with the causes, clinical presentation and particularly imaging findings of toxic leukoencephalopathy is critical for early treatment and improved prognosis. The purpose of this pictorial essay is to familiarize the reader with the various causes of toxic leukoencephalopathy along with its differential diagnoses and mimics.

Poland Syndrome with Ipsilateral Hypoplasia of Gluteal Muscles and Contralateral Hidradenitis Suppurativa.

BACKGROUND: Poland syndrome (PS) is a rare congenital anomaly associated with absent or hypoplastic pectoralis major muscle and a wide spectrum of ipsilateral thoracic and upper extremity deformities. Hidradenitis suppurativa (HS) is a recurrent inflammatory follicular disease that commonly affects the apocrine-bearing skin and involves follicular occlusion and hyperkeratosis. CASE REPORT: We report a case of a 46-year-old male with a history of chronic recurrent hidradenitis suppurativa who was incidentally found to have a simple type of Poland syndrome with incidental hypoplasia of ipsilateral gluteal muscles. CONCLUSIONS: Not only can PS present with HS, which we describe for the first time, but it is also associated with a wide variability of symptoms such as previously unknown co-existence of gluteal muscles hypoplasia.

A Case Report of Isolated Oculomotor Nerve Nucleus Infarct: A Rare Cause of Parinaud's Syndrome.

Parinaud's syndrome, also known as dorsal midbrain syndrome, includes multiple clinical signs, with the most prominent being paralysis of upward gaze. This syndrome has most commonly been described in association with pineal region masses. Other relatively common causes of this syndrome include hydrocephalus, intrinsic midbrain masses, and ischemic lesions. MRI is very helpful in determining the cause and thus guiding appropriate treatment.

Successful Treatment of a Common Femoral Arterial Pseudoaneurysm with US-Guided Thrombin Injection: A Case Report.

We are presenting a case of a patient who developed a pseudoaneurysm following cardiac catheterization. This is one of the most common complications related to invasive cardiovascular procedures. A pseudoaneurysm forms when an arterial puncture site fails to seal, allowing blood to leak and form a pulsatile hematoma contained by fibromuscular tissues. Color Doppler imaging has been the investigative method of choice for this diagnosis, which demonstrates swirling flow in a mass connected to the parent artery in the neck. The pseudoaneurysm neck shows "to and fro" Doppler waveforms. The treatment options for pseudoaneurysms include ultrasound (US)-guided compression, minimally invasive percutaneous treatments including US-guided thrombin injection, coil embolization and covered stent placement, and open surgical treatment. All of these treatment options have their own advantages and disadvantages, which will be discussed in detail.

Morel-Lavallée Lesion: A Case of an American Football Injury.

Morel-Lavallée Lesion (MLL) is a posttraumatic, closed degloving injury where the skin and superficial fascia get separated from deep fascia (fascialata) in the trochanteric region and upper thigh, hence creating a potential space. Similar lesions at other locations (e.g., abdominal wall and lumbar regions) have been described as Morel-Lavallée effusion, hematoma, or extravasation. Injury to an area with rich vascular and lymphatic supply leads to filling of this space with blood, lymph, fat, and necrotic debris. MLL usually presents as painful fluctuant swelling in the anterolateral portion o fthe upper thigh. Many of these maybe missed at initial evaluation and present weeks to months after the initial trauma.

A Case of Spontaneous Intracranial Hypotension: The Role of Dynamic CT Myelography and Epidural Blood Patch in Diagnosis and Treatment.

Spontaneous intracranial hypotension (SIH) most commonly results from cerebrospinal fluid (CSF) leaks in the upper spinal canal. Alterations in the equilibrium between the volumes of intracranial blood and CSF lead to compensatory dilatation of the vascular spaces, mostly on the venous side. Dynamic computerized tomogram (CT) myelography can be very helpful in diagnosing the site of a CSF leak in the spinal canal. Subsequently, the site of the leak can be sealed with epidural blood patch (EBP).

Orbital apex disorders: Imaging findings and management.

Orbital apex disorders include orbital apex syndrome, superior orbital fissure syndrome and cavernous sinus syndrome. These disorders result from various etiologies, including trauma, neoplastic, developmental, infectious, inflammatory as well as vascular causes. In the past, these have been described separately based on anatomical locations of disease process; however, these three disorders share similar causes, diagnostic evaluation and management strategies. The etiology is diverse and management is directed to the causative process. This imaging review summarizes the pertinent anatomy of the orbital apex and illustrates representative pathological processes that may affect this region. The purpose of this review is to provide an update on the current status of diagnostic imaging and management of patients with orbital apex disorders.

Internal carotid artery agenesis: A case report and review of literature.

Congenital agenesis of the internal carotid artery is a very rare anomaly. Intracranial circulation in the involved internal carotid artery territory is maintained by collateral circulation from the contralateral internal carotid artery through the anterior communicating artery and from the vertebrobasilar system through the posterior communicating artery. Usually, patients with internal carotid artery agenesis are asymptomatic due to collateral circulation, but they may present with headache, seizures, or transient ischemic attack. Aneurysms have also been reported to be associated with this entity. Computed tomography angiography, magnetic resonance angiography, and digital subtraction angiography are commonly used modalities to make the diagnosis. Unenhanced skull base computed tomography will show the absence of carotid canal, thus differentiating from carotid hypoplasia. We report on a case of right internal carotid artery agenesis with discussion of embryogenesis, clinical presentation, and imaging findings.

Comparison between MR Perfusion and 18F-FDG PET in Differentiating Tumor Recurrence from Nonneoplastic Contrast-enhancing Tissue

Objective: Comparison of the accuracy of MR perfusion and 18-FDG-PET for differentiating tumor progression from nonneoplastic contrast-enhancing tissue. Methods and Materials: Retrospective review of MR perfusion and 18-FDG-PET in 23 cases of primary brain tumors (17 high grade and 6 low grade glial neoplasms) and 5 cases of metastatic lesions with enhancing lesions on post-treatment MRI was performed. The accuracy of MR perfusion versus 18-FDG-PET for distinguishing between nonneoplastic contrast-enhancing tissue and tumor recurrence was assessed. Results: Both CBV (p<0.004) and SUV (p<0.02) are higher in recurrent tumors than necrosis. MR perfusion has an accuracy of 94.5% for differentiating between tumor recurrence and necrosis, while 18-FDG-PET has an accuracy of 85.1% for differentiating between tumor recurrence and nonneoplastic contrast-enhancing tissue. Conclusion: Overall, recurrent tumor demonstrates significantly higher CBV and SUV than nonneoplastic contrast-enhancing tissue. However, MR perfusion appears to be more accurate than FDG PET for distinguishing the two entities.

Abdominal aortic aneurysm: pictorial review of common appearances and complications.

Abdominal aortic aneurysms (AAAs) are defined as focal dilatations of the abdominal aorta that are 50% greater than the proximal normal segment or when it is more than 3 cm in maximum diameter. The early diagnosis and treatment is very important to prevent catastrophic complications. Due to its ability to assess the peri-aortic soft tissue and the exact extension of aneurysm, as well as its excellent vascular opacification and multiplanar reconstruction capabilities, computed tomography angiography (CTA) has become an integral part of the evaluation of AAA and has virtually replaced conventional angiography for the evaluation of AAA. Knowledge of the characteristic imaging features of AAA is essential for the prompt diagnosis of life-threatening complications. In this pictorial essay, we will discuss the CTA findings in AAA and its complications including rupture, infection, aorto-enteric fistula and aorto-caval fistula.

Morel-Lavallee Lesions-Review of Pathophysiology, Clinical Findings, Imaging Findings and Management.

Morel-Lavallee lesion is a post-traumatic soft tissue degloving injury. This is commonly associated with sports injury caused by a shearing force resulting in separation of the hypodermis from the deeper fascia. Most common at the greater trochanter, these injuries also occur at flank, buttock, lumbar spine, scapula and the knee. Separation of the tissue planes result in a complex serosanguinous fluid collection with areas of fat within it. The imaging appearance is variable and non specific, potentially mimicking simple soft tissue haematoma, superficial bursitis or necrotic soft tissue neoplasms. If not treated in the acute or early sub acute settings, these collections are at risk for superinfection, overlying tissue necrosis and continued expansion. In this review article, we discuss the clinical presentation, pathophysiology, imaging features and differential diagnostic considerations of Morel-Lavallee lesions. Role of imaging in guiding prompt and appropriate treatment has also been discussed.

Neonatal cranial sonography: ultrasound findings in neonatal meningitis-a pictorial review.

Neonatal bacterial meningitis is a common manifestation of late onset neonatal sepsis. Cranial sonography (CRS) has a crucial role in assessment of infants with clinical suspicion of bacterial meningitis as well as follows up of its complications. CRS is performed with high frequency transducer through anterior fontanelle in both coronal and sagittal planes. Various sonographic findings range from echogenic and widened sulci, ventriculomegaly, ventriculitis, hydrocephalus, extra-axial fluid collections, cerebritis and brain abscess. Sonography is extremely beneficial in evaluating intraventricular contents, especially debris and intraventricular septations. Linear high frequency probe along with color Doppler interrogation are of utmost importance in evaluating extra-axial fluid collection and helps differentiating it from benign subarachnoid space enlargement. Due to low cost, easy portability, speed of imaging, no need for sedation and above all lack of ionizing radiation make it superior to other cross sectional imaging, like CT and MRI, in evaluation of these sick neonates. Apart from textbooks, there is paucity of recently available literature on cranial sonographic findings in neonatal meningitis. This article is written with an educational intent to review the spectrum of findings in neonatal meningitis, with stress on findings that will be beneficial in the clinical practice.

Different Sonographic Faces of Ectopic Pregnancy.

Vaginal bleeding in the first trimester has wide differential diagnoses, the most common being a normal early intrauterine pregnancy, with other potential causes including spontaneous abortion and ectopic pregnancy. The incidence of ectopic pregnancy is approximately 2% of all reported pregnancies and is one of the leading causes of maternal mortality worldwide. Clinical signs and symptoms of ectopic pregnancy are often nonspecific. History of pelvic pain with bleeding and positive ß-human chorionic gonadotropin should raise the possibility of ectopic pregnancy. Knowledge of the different locations of ectopic pregnancy is of utmost importance, in which ultrasound imaging plays a crucial role. This pictorial essay depicts sonographic findings and essential pitfalls in diagnosing ectopic pregnancy.

A case of pulmonary arteriovenous malformation: role of interventional radiology in diagnosis and treatment.

Pulmonary arterio-venous malformations (PAVMs) are abnormal pulmonary arteries and pulmonary veins communicating directly without interposition of a capillary bed and about 80-90% of patients with PAVMs eventually may present with hereditary hemorrhagic telangiectasia (HHT), remaining ones are sporadic cases. On the other hand, about 15-35% of HHT patients may present with PAVMs. The PAVMs have a tendency to grow and increase in size over time and various factors like puberty, pregnancy and pulmonary arterial hypertension (PAH) affect growth. This condition needs early diagnosis, aggressive management and vigilant follow up. Our article aims to review pulmonary AVMs as a rare cause of strokes in young patients. We will discuss the clinical presentation, diagnosis, complications, the therapeutic options and the follow up.

Role of diffusion-weighted imaging in head and neck lesions: Pictorial review.

Head and neck cancers are very common worldwide, causing significant morbidity and mortality. Squamous cell carcinoma originating from the epithelial lining of the upper aerodigestive tract is the most common histology. Many patients with head and neck cancers present with advanced stage disease requiring aggressive treatment consisting of extensive surgery and chemo-radiation. Appropriate treatment planning as well as prognosis of tumors depends to a large extent on accurate histological diagnosis and differentiation of malignant from benign lesions. Routine imaging modalities such as computed tomography and magnetic resonance imaging give volumetric and morphologic information. However, these modalities cannot be reliably used as a substitute for biopsy in treatment planning. However, diffusion-weighted imaging has shown promise in tissue characterization for primary tumors and nodal metastases, differentiation of recurrent tumor from post therapeutic changes, prediction and monitoring of treatment response, and many other clinical scenarios as described later in this article. In this review article, we describe the imaging findings in applications of diffusion-weighted imaging in the head and neck lesions and discuss their added value over anatomic imaging.