Magnetic resonance imaging of cervical ligamentous anatomy and traumatic ligamentous injuries.

Cervical spine trauma accounts for majority of spinal injuries, and approximately one-third involve the craniocervical junction (CCJ). Due to its high sensitivity, magnetic resonance imaging (MRI) has become the standard tool for imaging suspected ligamentous injuries in an unstable spine and in patients with neurological deficits having a normal CT. The ligamentous anatomy of the CCJ is complex, and thorough knowledge is a prerequisite for accurate interpretation of the MRI findings. This pictorial essay aims to familiarise radiologists with the ligamentous anatomy, mechanisms of injury and MRI appearances of injuries in the cervical spine, with emphasis on the CCJ.

Review of diagnostic uses of shunt fraction quantification with technetium-99m macroaggregated albumin perfusion scan as illustrated by a case of Osler-Weber-Rendu syndrome.

Bilateral pulmonary arteriovenous malformations (AVMs) are rare and are often associated with the hereditary hemorrhagic telangiectasia (HHT/Osler-Weber-Rendu) syndrome. We present a woman who presented with neurological symptoms due to a cerebral abscess. On further evaluation, bilateral pulmonary AVMs were identified. The patient was diagnosed with HHT, based on positive family history and multiple cerebral AVMs recognized on subsequent catheter angiogram, in addition to the presence of bilateral pulmonary AVMs. Craniotomy with drainage of the brain abscess and endovascular embolization of the pulmonary AVMs was offered to the patient. As a preembolization work-up, the patient underwent nuclear lung perfusion scan with technetium-99m macroaggregated albumin (Tc-99m MAA) to assess the right-to-left shunt secondary to the pulmonary AVMs. Postembolization follow-up perfusion scan was also obtained to estimate the hemodynamic response. The case is presented to describe the role of Tc-99m MAA perfusion lung scan in preoperatively evaluating patients with pulmonary AVMs and to emphasize on the scan's utility in posttreatment follow-up. Various present day usages of the Tc-99m MAA lung perfusion scan, other than diagnosing pulmonary thromboembolism, are discussed. Providing background knowledge on the physiological and hemodynamic aspects of the Tc-99m MAA lung perfusion scan is also attempted. Various imaging pitfalls and necessary precautions while performing Tc-99m MAA lung perfusion scan are highlighted.

Imaging features and transcatheter treatment of a giant pulmonary arteriovenous malformation in an elderly patient.

Pulmonary arteriovenous malformations (PAVMs) comprise an anomalous communication between the pulmonary arterial and systemic circulation. The drainage is usually into one of the pulmonary veins, although rare instances of direct drainage into the left atrium or inferior vena cava have been reported. The result is a high-flow, low-resistance, right-toleft shunt. Although considered uncommon, PAVMs are being diagnosed with increasing frequency in this era of enhanced cross-sectional imaging with CT for lung screening. There is a strong association between PAVMs and hereditary haemorrhagic telangiectasia (HHT); PAVMs are more commonly found in females, with a female to male ratio of 8:1. These have varying clinical presentation, with most symptomatic PAVMs being diagnosed in the first three decades of life. The most common mode of presentation is dyspnoea on exertion. Other reported symptoms are epistaxis, chest pain, cough and, in the event of rupture, haemoptysis. Endocarditis, stroke and brain abscess formation occur frequently in patients with undiagnosed HHT with PAVMs. A 76-year-old female, with a presumed clinical diagnosis of asthma, presented to the emergency department with worsening shortness of breath. The imaging studies revealed a giant PAVM and a radionuclide scan demonstrated a large right-to-left shunt, likely accounting for her symptoms. She underwent successful transcatheter embolization (TCE) with a vascular plug performed by the interventional radiology team. The aim of this case report is to describe the imaging findings and TCE treatment of a giant PAVM.

Os Trigonum - Sheer Incidental or Quite Significant? Single Photon Emission Computed Tomography/Computed Tomography's Role in a Case of Ankle Impingement.

Accessory ossicles are widely prevalent in the ankle and foot. Although they are often asymptomatic, they can present clinically with symptoms at times. When they occur bilaterally in a patient who presents with unilateral complaints, it is clinically difficult to attribute the symptoms to the presence of these common anatomic variants. One needs specific imaging to assess the clinical relevance of the accessory ossicles, in order to tailor the treatment plan. The case presented in this article is one such example, where the patient presented with chronic unilateral ankle pain and initial radiographs revealed bilateral os trigonum and os subtibiale. He underwent a technetium-99m methyl diphosphonate (Tc-99m MDP) bone scan and single photon emission computed tomography/computed tomography (SPECT/CT). The Tc-99m MDP scan showed a focal uptake in the ankle of concern. SPECT/CT complemented the finding by exactly localizing the uptake to the posterior subtalar joint and around the os trigonum, thereby pointing to the diagnosis of os trigonum syndrome.

Extramedullary pulmonary hematopoiesis causing pulmonary hypertension and severe tricuspid regurgitation detected by technetium-99m sulfur colloid bone marrow scan and single-photon emission computed tomography/CT.

Extramedullary pulmonary hematopoiesis is a rare entity with a limited number of case reports in the available literature only. We report the case of a 66-year-old man with known primary myelofibrosis, in whom a Technetium-99m sulfur colloid bone marrow scan with single-photon emission computed tomography (SPECT)/CT revealed a pulmonary hematopoiesis as the cause of pulmonary hypertension and severe tricuspid regurgitation. To the best of our knowledge, this is the first description of Technetium-99m sulfur colloid SPECT/CT imaging in this rare condition.

The role of PET/CT in the evaluation of skeletal metastases.

Osseous metastatic disease from malignancy is a common occurrence with significant patient morbidity and mortality as well as increasing health care expenditures. Patient management plans frequently change with the identification of skeletal metastasis and the upstaging of disease status. Bone scintigraphy remains the current mainstay of diagnostic imaging procedures in nuclear medicine for the early detection of skeletal metastasis owing to their high sensitivity. Emerging positron tracers and the increasing use and availability of hybrid single-photon emission computed tomography and positron emission tomography (PET)/computed tomography machines enable physicians to diagnose metastatic disease in bones with superior accuracy. This review introduces the basics of PET and the commonly used positron tracers used to evaluate skeletal metastases.

Incidental detection of clinically nondiagnosed inguinal hernia in (131)I whole-body scan.

I whole-body bone scan was performed for an adult male patient after postradioactive iodine ablation of thyroid carcinoma. Besides the small thyroid remnants in the neck region, an incidental detection of left inguinal hernia was made in the scan, which was later confirmed by clinical examination. Despite the large size of the hernia, the patient was unaware of the condition. It can be concluded that, similar to other imaging procedures, incidental detection of unrelated clinical problems is possible in I scan also, and such early diagnosis prevents further complications that the patient may develop in the future.

Extraosseous uptake of technetium-99m methylene diphosphonate by an acute territorial cerebral infarct in a classical biodistribution pattern.

Technetium-99m methylene diphosphonate scintigraphy is usually performed to assess bone lesions, especially skeletal metastases in patients with a history of malignancy. However, it is important to recognize some specific conditions with a unique pattern of tracer uptake, especially in extraosseous locations as they are not related to primary neoplasm or metastases. Diagnosing such unusual presentation is essential as it significantly influences the clinical management. This case report describes an unusual presentation detected in a bone scan of an elderly female patient, who was a treated case of breast cancer and was referred for a bone scan to rule out bone metastases. Incidentally, a large acute territorial cerebral infarct was diagnosed, which was later confirmed by magnetic resonance imaging on diffusion-weighted images. Diagnosis of the typical presentation and timely management saved the patient life.

Isolated retroaortic left innominate vein in an adult without cardiac or aortic anomalies.

Retroaortic innominate vein is an uncommon variant reported in patients with congenital heart disease. However, isolated retroaortic innominate vein without associated cardiac or arch anomalies is extremely rare. We present a case of a 68-year-old man who was found to have this anomalous variant incidentally on computed tomography (CT) of the thorax. We also briefly discuss its associations, embryology, and clinical significance.