Non-131I-scintigraphy in the treatment and follow-up of thyroid cancer. Single-photon-emitters or FDG-PET?

With respect to further therapeutic options, whole-body 131I scintigraphy (WBS) is the most important functional imaging technique during treatment and follow-up of differentiated thyroid cancer. But in many patients, thyroid cancer tissue does not concentrate 131I and can therefore not be localized using WBS. In addition to morphologic techniques, which have a low specificity in many cases, other methods are necessary to localize tumor tissue in these patients. Besides 201Tl, which has been used initially as a tumor-seeking agent, sestamibi, tetrofosmin and 18F-DG for PET imaging have been evaluated in differentiated thyroid carcinoma. This paper summarizes the clinical impact of functional imaging with tracers besides 131I. In direct comparison, 18F-DG-PET has the highest sensitivity, which exceeds 80% in cases with negative WBS. If available, this method should be considered in all patients suffering from differentiated thyroid cancer with suspected recurrence and/or metastases, particularly in cases with elevated thyroglobulin values and negative WBS. But also 99mTc-labeled tracers can be used to detect tumor tissue with a sufficient sensitivity. In medullary thyroid cancer, which presents frequently with diagnostic difficulties, 111In-octreotide, 99mTc-(V)-DMSA, 131I/123I-mIBG, and anti-CEA can be used, in addition.     

Imaging of benign and malignant soft tissue tumors of the neck

Soft tissue tumors of the neck are a heterogeneous group of neoplasms arising from adipose, muscular, and fibrous tissue. With the exception of lymphomas, they account for only a small fraction of neck masses. Nevertheless, accurate diagnosis is important since the behavior of these neoplasms differs markedly from each other and from other head and neck masses. Noninvasive imaging, usually with CT and MR imaging, plays an important role in diagnostic evaluation and treatment planning for these tumors. In some cases, imaging features may be suggestive of a single entity. In most cases, imaging is needed to assess the location and extent of the tumor prior to biopsy or excision. This article discusses imaging techniques used for such assessment, the imaging features that help to separate these neoplasms from other head and neck tumors, and the behavior and imaging features of each of the more common benign and malignant soft tissue tumors that occur in the neck.     

MRI对颈椎布鲁杆菌病性脊椎炎的治疗价值评价

目的 探讨以MRI为主的影像分型对颈椎布鲁杆菌病性脊椎炎(BS)的诊断意义及治疗方案评价.方法 将本院诊治39例颈椎BS患者的影像资料,依据MRI分型进行非手术、微创术与切开直视手术治疗;通过影像分析一致性检验、影像学评分、临床疗效评价分析相关性.采用SPSS15.0统计软件包进行分析.结果 本组39例治疗前行MRI检查,6个月37例复查;12个月33例复查.影像分析一致性检验Kappa值均>0.75.颈椎BS的MRI影像学具有特征性表现,依据术前MRI影像分型治疗结果:(1)药物治疗14例(A组);(2)微创治疗7例(B组);(3)病灶清除植骨术18例(C组);(4)临床疗效显示各组12个月治愈率与前一个时间点比较差异有统计学意义(P<0.05),且在6个月时间点C组治愈率明显优于其他2组.在12个月时间点3组治愈率比较,以及C组各方法治愈率比较差异无统计学意义(P>0.05).结论 颈椎BS的MRI影像学分型对临床保守、微创和手术治疗策略的制订具有重要价值及指导意义.     

Imaging cholesteatoma

Acquired cholesteatoma of the middle ear is usually diagnosed by otoscopy and treated by exploratory surgery. The role of imaging for such cases is as controversial now as it was 10 years ago, despite significant improvements in spatial and contrast resolution resulting from computerised sectional imaging. We examined 16 cases of straightforward acquired middle ear cholesteatomas with MR as well as high resolution CT scanning to assess the possibilities for tissue characterisation. Cases of the much rarer but more important congenital cholesteatoma of the petrous pyramid with a normal eardrum were also diagnosed by CT and MRI. Magnetic resonance will distinguish cholesteatoma from granulation tissue, fluid and the cholesterol granuloma in the middle ear but this differentiation is of no practical value. An expansile lesion in the petrous apex is most likely to be a cholesteatoma or cholesterol granuloma and is well shown but not differentiated by CT. The two types have quite different characteristics on MR protocols and this is important for planning surgical procedures.     

Value of computed tomography in planning medical and surgical treatment of chronic osteomyelitis

The contributions of computed tomographic (CT) images to the planning of medical and surgical treatment of osteomyelitis were assessed in seven patients. The scans helped medical therapy in two cases by guiding nonsurgical percutaneous biopsy of infected tissue, permitting prompt institution of proper antibiotics. The scans indicated the need for surgery and provided vital information on disease extent that helped plan the appropriate operation in five patients. Sequestra, medullary involvement, and the extent of sinus tracts that could not be seen on conventional imaging tests were detectable on CT. It is concluded that CT plays an important role in proper choices of both medical and surgical treatment in patients with osteomyelitis.     

Cervical ectopic thymus

Two cases of cervical aberrant thymus in infants are reported; it's important to identify such ectopia because thymic tissue involutes spontaneously later on; neither surgery nor other treatment is needed. Ultrasonography is a method of choice for tissue characterization of ectopic thymus and differential diagnosis with other cervical masses.     

Interventional and intraoperative MRI at low field scanner--a review

Magnetic resonance imaging (MRI) is a cutting edge imaging modality in detecting diseases and pathologic tissue. The superior soft tissue contrast in MRI allows better definition of the pathology. MRI is increasingly used for guiding, monitoring and controlling percutaneous procedures and surgery. The rapid development of interventional techniques in radiology has led to integration of imaging with computers, new therapy devices and operating room like conditions. This has projected as faster and more accurate imaging and hence more demanding procedures have been applied to the repertoire of the interventional radiologist. In combining features of various other imaging modalities and adding some more into them, interventional MRI (IMRI) has potential to take further the interventional radiology techniques, minimally invasive therapies and surgery. The term "Interventional MRI" consists in short all those procedures, which are performed under MRI guidance. These procedures can be either percutaneous or open surgical of nature. One of the limiting factors in implementing MRI as guidance modality for interventional procedures has been the fact, that most widely used magnet design, a cylindrical magnet, is not ideal for guiding procedures as it does not allow direct access to the patient. Open, low field scanners usually operating around 0.2 T, offer this feature. Clumsy hardware, bad patient access, slow image update frequency and strong magnetic fields have been other limiting factors for interventional MRI. However, the advantages of MRI as an imaging modality have been so obvious that considerable development has taken place in the 20-year history of MRI. The image quality has become better, ever faster software, new innovative sequences, better MRI hardware and increased computing power have accelerated imaging speed and image quality to a totally new level. Perhaps the most important feature in the recent development has been the introduction of open configuration low field MRI devices in the early 1990s; this enabled direct patient access and utilization of the MRI as an interventional device. This article reviews the current status of interventional and intraoperative MRI with special emphasis in low field surrounding.     

Soft-tissue venous malformations in adult patients: imaging and therapeutic issues.

Venous malformations are the most common vascular malformations. However, confusion with respect to terminology and imaging guidelines continues to result in improper diagnosis and treatment. An appropriate classification scheme for vascular anomalies is important to avoid the use of false generic terms. Adequate imaging in association with clinical findings is crucial to establishing the correct diagnosis. Doppler ultrasonography should be the initial imaging modality and demonstrates absence of flow or low-velocity venous flow. Computed tomography and magnetic resonance (MR) imaging are used primarily for pretreatment evaluation of lesion extension. These lesions are usually hypointense on T1-weighted MR images and markedly hyperintense on T2-weighted images with variable gadolinium enhancement. Direct phlebography helps confirm the diagnosis and exclude other soft-tissue tumors. Three distinct phlebographic patterns (cavitary, spongy, dysmorphic) have been identified. In most cases, conservative treatment is recommended. Sclerotherapy with or without surgery is useful in cases of functional impairment or significant aesthetic prejudice, even if recurrences are frequent. Direct phlebography is performed when a more detailed assessment of the vascular pattern is needed or as part of sclerotherapy. Use of the appropriate imaging technique is critical in establishing the diagnosis, evaluating extension, and planning appropriate treatment.     

Diphosphonate intestinal activity seen on two bone images in neuroblastoma

Neuroblastoma is well recognized as a cause of soft tissue uptake of Tc-99m MDP. Two cases of neuroblastoma arising in the midline from the celiac axis are reported. Bone imaging performed on two separate days showed not only typical soft tissue uptake, but also the appearance of the radiopharmaceutical in the bowel. At surgery, a midline upper abdominal neuroblastoma was found in both patients without evidence of involvement of the liver, kidneys, bowel, gallbladder or mesentery. It became apparent with delayed images in the second patient that this activity was in the bowel and moving around the abdomen in a typical large bowel pattern. Bowel activity was not seen in other patients having bone scans at this time. Follow-up bone imaging on the first patient after resection of the tumor did not demonstrate diphosphonate activity in the bowel. These authors have never seen or read of this finding previously in this condition, and report it in these two patients.     

Iatrogenic alterations in radionuclide biodistributions

The biodistribution of radiotracers used in diagnostic imaging is grossly and recognizably altered by a wide variety of drugs and other treatment modalities, such as surgery and radiotherapy. Knowledge of such altered biodistribution is important both in making diagnostic inferences from scans and in dosimetric considerations.     

What do we expect from imaging?

The objectives of imaging in gynecologic cancer include tumor detection, tumor diagnosis, staging, and follow-up. In addition, both monitoring response to treatment and differentiating tumor recurrence from post-treatment changes are important indications for imaging. In 2001 it was estimated that there would be 38,300 cases of endometrial cancer, 23,400 cases of ovarian cancer, and 12,900 cases of cervical cancer. This article reviews what information is required by the practicing gynecologist or gynecologic oncologist prior to surgery and briefly summarizes state-of-the-art imaging in answering clinically pertinent questions.     

Preoperative transarterial Embolisation in bone tumors

Bone tumors include a variety of lesions, both primary and metastatic. The treatment modalities for bone tumors vary with the individual lesion, but in general surgical excision is the treatment of choice with other adjunctive therapies. However, surgery for many bone tumors is complex due to several factors including tumor bulk, vascularity, vicinity to vital structures and potentially inaccessible location of the lesion. Transarterial Embolisation (TAE) is one of the important adjuvant treatment modalities and in some cases it may be the primary and curative treatment. Preoperative TAE has proved to be effective in both primary and metastatic bone tumors. It reduces tumor vascularity and intraoperative blood loss, the need for blood transfusion and associated complications, allows better definition of tissue planes at surgery affording more complete excision, and hence reduced recurrence. Preoperative chemoEmbolisation has also been shown to increase the sensitivity of some tumors to subsequent chemotherapy and radiotherapy. There are several techniques and embolic agents available for this purpose, but the ultimate aim is to achieve tumor devascularization. In this review, we discuss the techniques including the choice of embolic agent, application to individual lesions and potential complications.     

Residual mass and negative gallium scintigraphy in treated lymphoma

Two patients with treated lymphoma demonstrated a residual mass on CT following treatment. In both cases gallium-67 (67Ga) scintigraphy demonstrated increased uptake in the original tumor mass and no uptake in the mass after treatment. In both cases the entire residual tumor mass was resected and found to contain no cancer tissue. This is further evidence of the role 67Ga scintigraphy may play in monitoring response of lymphoma patients to treatment. In contrast, other imaging modalities such as ultrasound, plain film x-rays, or CT only show the presence of a mass but not its nature.     

Synchronous multicentric desmoid tumors (aggressive fibromatosis) of the extremities

Synchronous multicentric aggressive fibromatosis does not appear to have been previously reported. Two such cases are described. The tumors were identified by magnetic resonance (MR) imaging. The incidence of synchronous multicentric aggressive fibromatosis is not known. It is anticipated that increased use of coronal MR imaging will reveal more tumors of this type, both synchronous and metachronous. In a patient with known or suspected aggressive fibromatosis, every other soft tissue nodule or mass in the same limb has to be regarded as an additional tumor of the same histology.     

Is there still a place for angiography in the management of renal mass lesions?

In recent years, the development of noninvasive imaging modalities for exploration of the kidney has markedly reduced the use of angiography in the evaluation of renal masses. Presently, it is not required in routine practice to evaluate renal masses. Ultrasound is the most efficient procedure in detecting renal tumor. It is acknowledged that arteriography has a limited diagnostic and staging value compared with CT and MRI for the assessment of renal cell carcinomas (RCC). Most urologists recommend partial nephrectomy or tumor enucleation in an effort to preserve as much as possible functioning renal tissue. In such cases a preoperative map of the renal vasculature is not needed. Information on the main renal artery(ies) and segmental renal arteries can be provided with spiral CT or dynamic MR angiography. Arteriography remains useful in exceptional situations. Interventional arteriography is becoming an important part. It is indicated by means of selective embolization for the treatment of potentially bleeding tumor (i. e. angiomyolipoma) or in emergency in cases of acute hemorrhage. Less frequently, it may be proposed as a palliative procedure for inoperable patients with huge renal tumor. Two other indications of interventional arteriography are acknowledged. Some urologists request preoperative embolization of the tumor-harboring kidney to decrease/avoid extensive blood loss during surgery and/or to facilitate surgery with huge renal tumors when the renal vessels are difficult to reach. The complications of nephron-sparing surgery (partial nephrectomy or tumor enucleation) related to bleeding or arteriovenous fistulas may be cured by arterial embolization. Received: 18 May 1998; Revision received: 3 August 1998; Accepted: 6 August 1998     

第二鳃裂囊肿的MRI诊断价值探讨

目的:探讨BaileyⅡ型第二鳃裂囊肿在MRI上的特征表现,提高术前诊断的准确性。方法:回顾性分析11例经手术病理证实的第二鳃裂囊肿的MRI表现,其中6例行MRI增强扫描,总结其特征讨论其形成机制。结果:本组11例全部为BaileyⅡ型;MRI表现为薄壁、均质的囊性肿块,囊腔在T1WI上呈低、等、高信号(其中低信号7例,等信号2例,高信号2例),T2WI常呈等、高信号(等信号2例,高信号9例);DWI均呈等、高信号(等信号3例,高信号8例);囊壁强化或不强化,并发感染者囊壁增厚、强化;胸锁乳突肌受压向后外或向后移位,颈动脉间隙大血管向内或向后内移位,颌下腺受压移位;脂肪抑制序列可更清楚的显示病变与周围关系。结论:对于BaileyⅡ型鳃裂囊肿,磁共振图像具有明显的信号特征及部位特征,对术前及鉴别诊断有重要价值。     

Extramedullary hematopoiesis in unusual locations in hematologically compromised and noncompromised patients

Extramedullary hematopoiesis (EMH) occurs as a compensatory reaction to an underlying hematologic abnormality. EMH is most commonly seen in the liver and spleen but rarely has been reported in other locations, as well. On rare occasions, EMH may mimic a neoplasm in hematologically noncompromised patients. In this report, we present three cases of EMH in unusual locations, two in the presacral soft tissue and one in the synovial lining of the knee joint. The patients with presacral masses had no hematologic abnormality. In all patients with EMH, imaging plays an important role in both localization of the lesion and guidance for the biopsy; when imaging results are correlated with histological findings, the diagnosis of EMH can be confirmed.     

Current and future imaging of acute cerebral ischemia: assessment of tissue viability by perfusion imaging

With the advances and availability of new imaging modalities, the role of imaging of acute stroke has been broadened from making diagnosis to providing valuable information for patient management. We need to have rapid diagnostic modalities that distinguish reversible ischemic tissue from irreversibly damaged tissue for successful thrombolytic therapy. Although diffusion imaging has been reported to have both high sensitivity and specificity for acute ischemia in clinical studies, previous reports do not conclude whether the diffusion abnormality is indicative of reversibly or irreversibly injured tissue. Perfusion imaging such as perfusion magnetic resonance imaging and single-photon emission computed tomography may have the potential for providing useful information that determines tissue viability and/or reversibility. Cerebral blood flow thresholds evaluated by pretreatment single-photon emission computed tomography provide important information that is potentially useful in the management of acute stroke patients with intra-arterial thrombolysis. Perfusion imaging, when combined with diffusion imaging, may thus be potentially useful in improving patient selection for thrombolytic therapy.     

Ovary: MRI characterisation and O-RADS MRI

Ultrasound has a high specificity for the diagnosis of a benign lesion in cases of classic appearing simple cyst, hemorrhagic cyst, endometrioma and dermoid. However, ultrasound can sometimes be limited for definitive characterisation and risk stratification of other types of lesions, including those with echogenic content that may appear solid, with or without blood flow. Frequently, MRI can be used to further characterise these types of lesions, due to its ability to distinguish solid tissue from non-tissue solid components such as fat, blood, or debris. Incorporating the MR imaging into the evaluation of adnexal lesions can improve diagnostic certainty and guide clinical management potentially avoiding inappropriate surgery for benign lesions and expediting appropriate treatment for malignant lesions, particularly in the females with sonographically indeterminate adnexal lesions.     

Early rheumatoid arthritis and its differentiation from other joint abnormalities

The introduction of disease-modifying antirheumatic drugs has created new demands on imaging to early identify patients with rheumatoid arthritis and opened new prospects in therapeutic management of patients with aggressive disease. Therefore, new imaging modalities such as magnetic resonance imaging and ultrasound have developed during the past few years in this field. In some cases, both magnetic resonance imaging and ultrasound may be also useful in making the distinction between early rheumatoid arthritis and other joints abnormalities, including early psoriatic arthritis. This article will review key aspects of important advances in imaging in rheumatoid arthritis, particularly focusing on magnetic resonance imaging and ultrasound.