腓动脉穿支小腿后外侧皮神经营养血管皮瓣的临床应用策略

回顾国内外文献,结合作者经验,总结和探讨腓动脉穿支小腿后外侧皮神经营养血管皮瓣的血供特点、个体化设计方法和手术要点。该皮瓣综合了穿支皮瓣、皮神经营养血管皮瓣和游离皮瓣各自的优点,在应用彩色多普勒血流显像及CT血管成像获得腓动脉穿支体表定位、解剖形态等信息的前提下,通过穿支蒂螺旋桨皮瓣和游离移植2种方法,结合超薄皮瓣、皮肤筋膜瓣、嵌合皮瓣、组合皮瓣、多叶皮瓣等技术,可以自由、准确、高效地修复全身不同部位创面。     

Magnetic resonance of acute appendicitis: pearls and pitfalls

Acute appendicitis is the most common surgical abdominal emergency. Although the clinical diagnosis can be made accurately in typical cases, imaging plays an important role in improving diagnostic accuracy of this condition, especially when the clinical diagnosis is uncertain. Magnetic resonance imaging is an emerging promising technique for the diagnosis of acute appendicitis, especially in patients with nondiagnostic ultrasound and in patients where radiation is a clinical concern. In the following review, the role of magnetic resonance in the diagnosis of appendicitis will be discussed.     

Computed tomographic enterography and enteroclysis: pearls and pitfalls

Computed tomographic (CT) enterography and enteroclysis improve visualization of the small bowel mucosa and wall in comparison with traditional CT and fluoroscopic studies by distending the small bowel through enteric hyperhydration with a negative contrast agent. Although CT enterography is performed with oral hyperhydration, CT enteroclysis requires the placement of an enteroclysis tube, often in patients who are unable to orally consume the amount of liquid. When tolerated, CT enterography is often preferred due to its lack of invasiveness. Magnetic resonance enterography and enteroclysis are other modalities that are still being studied and show promise in the imaging of small bowel. Unlike small bowel follow-through, conventional enteroclysis, or capsule endoscopy, extraenteric findings are best assessed on CT enterography. These include findings in the surrounding mesentery, perienteric fat, and the adjacent solid organs that may be associated with the small bowel process and include fistulas or abscesses, mural hyperenhancement, prominent vasa recta, and other inflammatory changes. CT enterography has developed into the first-line modality in the imaging of Crohn's disease and is considered the most appropriate imaging modality in patients with suspected Crohn's disease. It is also increasingly being used in the assessment of small bowel infections, neoplasms, adhesions, and polyps.     

Chest radiography in acute aortic syndrome: pearls and pitfalls

Acute aortic syndrome is a group of life-threatening diseases of the thoracic aorta that usually present to the emergency department. It includes aortic dissection, aortic intramural hematoma, and penetrating aortic ulcer. Rare aortic pathologies of aorto-esophageal fistula and mycotic aneurysm may also be included in this list. All these conditions require urgent treatment with complex clinical care and management. Most patients who present with chest pain are evaluated with a chest radiograph in the emergency department. It is important that maximum diagnostic information is extracted from the chest radiograph as certain signs on the chest radiograph are extremely useful in pointing towards the diagnosis of acute aortic syndrome.     

Pediatric emergency gastrointestinal ultrasonography: pearls & pitfalls

Ultrasonography is an essential tool in pediatric imaging, particularly in the emergency setting. Although ultrasound is often the favored initial modality for abdominal imaging in children, it is highly operator-dependent and therefore prone to misinterpretation which can lead to false positive or negative exams, or even incorrect diagnoses. Conditions discussed in this series include ileocolic intussusception, hypertrophic pyloric stenosis, appendicitis, and ingested foreign bodies. We will review diagnostic criteria, highlight crucial findings, and illustrate commonly-encountered difficulties and mimics.     

Imaging of facial nerve schwannomas: diagnostic pearls and potential pitfalls

Schwannomas are uncommon in the facial nerve and account for less than 1% of tumors of temporal bone. They can involve one or more than one segment of the facial nerve. The clinical presentations and the imaging appearances of facial nerve schwannomas are influenced by the topographical anatomy of the facial nerve and vary according to the segment(s) they involve. This pictorial essay illustrates the imaging features of facial nerve schwannomas according to their various anatomical locations and also reviews the pertinent differential diagnoses and potential diagnostic pitfalls.Facial nerve schwannomas (FNSs) are rare slow-growing tumors, accounting for less than 1% of all temporal bone tumors. They are typically solitary, unilateral, and sporadic in nature. FNSs may be bilateral as part of neurofibromatosis-2 spectrum (1, 2). Rarely, multiple schwannomas may involve peripheral branches of the facial nerve (FN) (3). The age of presentation varies from 5 to 84 years. No gender or side predilection is seen (4, 5).Histologically, FNSs are neuroectodermal in origin. They are encapsulated, benign tumors arising from the Schwann cells. They may show intratumoral cystic change and hemorrhage (3, 4, 5). Malignant schwannoma of the FN is extremely rare (6). FNSs commonly present with peripheral facial neuropathy and/or various otologic symptoms including sensorineural and conducting hearing loss (2–5). Facial paralysis is often seen at a later stage or may not be seen at all. The reasons for this are thought to be neuronal tolerance induced by the extremely slow growth of the tumor, abundant tumor vascularity, and commonly associated dehiscence of adjacent bone (7). Occasionally, FNSs may present as an intraparotid mass or as an intracranial lesion (2–5).The clinical presentations and the imaging appearances of FNSs are influenced by the topographical imaging anatomy of the FN and vary according to the segment(s) they involve (8). Here, we briefly describe the anatomy of the FN, followed by general imaging features of FNSs on computed tomography (CT) and magnetic resonance imaging (MRI), and appropriate imaging protocols. Tumor involving each segment is reviewed in relation to its characteristic clinical presentations emphasizing diagnostic pearls and potential pitfalls. The imaging examples of FNSs illustrated in this pictorial review are all histopathologically proven cases.     

Modern emergent stroke imaging: pearls, protocols, and pitfalls

Stroke remains one of the most important clinical diagnoses for which patients are referred to the radiologist for emergent imaging. Timely and accurate imaging guides admission from the emergency department or transfer to a hospital with a dedicated stroke service, triage to the intensive care unit, anticoagulation, thrombolysis, and many other forms of treatment and management. It is important to approach each patient's imaging needs logically and tailor each work-up, and constantly to review the entire process for potential improvements. Time saved in getting an accurate diagnosis of stroke may indeed decrease morbidity and mortality. This article discusses the current management of stroke imaging and reviews the relevant literature.     

Hepatic venous-portal gradient (HVPG) measurement: pearls and pitfalls

Hepatic venous pressure gradient (HVPG) is the gold-standard for measurement of portal hypertension, a common cause for life-threatening conditions such as variceal bleeding and hepatic encephalopathy. HVPG also plays a crucial role in risk stratification, treatment selection and assessment of treatment response. Thus recognition of common pitfalls and unusual hepatic venous conditions is crucial. This article aims to provide a radiographical and clinical guide to HVPG with representative clinical cases.     

MDCT evaluation of postoperative aortic root pseudoaneurysms: imaging pearls and pitfalls

OBJECTIVE: Aortic root pseudoaneurysm is a rare but potentially lethal complication after cardiac surgery. The objective of this article is to review the CT appearance of postoperative aortic root pseudoaneurysms, with emphasis on imaging pearls and pitfalls. CONCLUSION: The most common location for postoperative aortic root pseudoaneurysm is the graft anastomosis site. MDCT with ECG gating and multiplanar and 3D reconstruction can provide critical information for preoperative planning.     

Imaging patterns of hepatic steatosis on multidetector CT: pearls and pitfalls

Fatty liver disease is an important cause of chronic liver disease in Western countries. The?purpose of this article is to describe and illustrate the diagnostic criteria and various morphological patterns of fatty liver disease on multidetector computed tomography (MDCT) with an emphasis on potential limitations and diagnostic pitfalls.     

Radionuclide imaging of the thyroid gland: patterns, pearls, and pitfalls

Optimal thyroid scintigraphy requires an understanding of 1) the embryology, anatomy, and physiology of the thyroid gland; and 2) the properties of the 2 common imaging agents, technetium-99m pertechnetate (Tc-99m) and radioiodine (1-123). The normal gland has a characteristic scintigraphic pattern with these tracers and its uptake can be quantified with 1-123. Thyroid diseases often produce characteristic abnormal patterns. These abnormal patterns could be described as diffuse or focal, homogeneous or heterogeneous, increased or decreased. "Extrathyroidal" localization can be seen with esophageal activity, ectopic tissue, thyroglossal duct cyst, and substernal goiter. Thyroid scintigraphy of neonates, as a follow up to abnormal blood screening, demonstrates typical etiologic patterns. The first step in evaluating a patient with suspected thyroid disease is correlating the normal or abnormal scintigraphic pattern with available biochemical data, clinical history, and physical examination. By integrating the interpretive and technical "pearls" and "pitfalls" outlined in this article, the radiologist can be more confident in establishing a proper diagnosis.     

Ultrasound assessment in distal biceps tendon injuries: Techniques,pearls and pitfalls

Ultrasound assessment of the distal biceps tendon is challenging. The tendon has two components which are continuations of the long and short heads of the muscle, and these undergo 90° of rotation along their course. The tendon has a deep insertion to the radial tuberosity. Therefore, a combination of approaches and examination techniques are utilized to ensure complete evaluation. The various ultrasound approaches used to assess the distal biceps tendon, with their advantages and limitations, will be described. Selected examples of distal biceps tendon injuries, with magnetic resonance imaging (MRI) correlation in challenging cases, will be demonstrated.     

Digital breast tomosynthesis (DBT)-guided biopsy of calcifications: pearls and pitfalls

As digital breast tomosynthesis (DBT) is quickly becoming the standard of care in clinical practice, DBT-guided procedures are being more frequently utilized. DBT-guided biopsies of calcifications are efficient and easy to perform. As radiologists seek proficiency in these biopsies, there are some unique features of DBT-guided biopsies that they must consider. In this review, we provide a step-by-step guide on performing DBT-guided biopsies of calcifications, with a focus on pearls and pitfalls for problem solving in difficult biopsy cases.     

Spiral CT of pulmonary embolism: diagnostic approach, interpretive pitfalls and current indications

The introduction of spiral CT has recently modified the diagnostic work-up of pulmonary embolism, because it is possible to depict noninvasively endoluminal clots in second- to-fourth-division pulmonary arteries. If this technique is currently considered a powerful imaging alternative for the detection of acute central emboli, it is mainly related to the possibility to obtain a uniform and high degree of arterial enhancement of pulmonary arteries down to 2–3 mm in diameter. Minimal experience in spiral CT angiography is necessary to achieve this goal and requires familiarity with both data acquisition and contrast medium injection. Numerous interpretive pitfalls exist in assessing spiral CT images, and certain caveats have to be heeded. However, their recognition becomes increasingly less problematic as the radiologist gains experience with spiral CT of the pulmonary vasculature. Therefore, the purpose of this article is to review the diagnostic approach to pulmonary embolism with spiral CT, with special emphasis on protocol parameters and scan interpretation. Received 21 January 1998; Accepted 4 February 1998