CT, MRI, PET, PET/CT, and ultrasound in the evaluation of obstetric and gynecologic patients

The role of imaging in obstetrics and gynecology has undergone a revolution over the past few decades. Well-established methods such as endovaginal ultrasound have had a central role in the evaluation of nongravid patients with pelvic pain, as well as in the workup for ectopic pregnancy and evaluation of adnexal masses. Additional tools include MRI in the evaluation of appendicitis and other potentially surgical conditions in pregnant patients and MRI and CT in the evaluation of surgical complications. Newer tools in the radiology armamentarium include PET scanning which, alongside MRI and CT, are often helpful in staging gynecologic malignancy. The role of imaging in the obstetric and gynecology patient will continue to change as new modalities and techniques are introduced.     

A prospective study of the value of conventional CT, dynamic CT, ultrasonography and arteriography for staging renal carcinoma

The value of dynamic CT scanning for staging renal carcinoma was studied prospectively in 28 patients and the results compared with those of ultrasonography, arteriography and conventional CT. Arteriography correctly staged 48% of tumours; ultrasonography and conventional CT correctly staged 50% and dynamic CT correctly staged 72%. Dynamic CT staged renal carcinoma more accurately than ultrasonography, conventional CT or arteriography and it is suggested that arteriography should be restricted to specific indications such as the mapping of arterial anatomy and therapeutic renal artery embolisation.     

Tarsal Coalitions: Radiographic,CT, and MR Imaging Findings

Background

Tarsal coalitions affect up to 13% of the population and can be a cause of chronic ankle and hindfoot pain. They can be subdivided as osseous, cartilaginous, or fibrous types, each with unique radiographic, CT, and MR imaging findings. In particular, MR imaging offers the unique ability to determine the exact type of tarsal coalition that is present as well as whether any associated soft tissue abnormalities are present.

Questions/Purposes

The purposes of this paper were to (1) review the anatomy of the hindfoot; (2) review the radiographic, CT, and MR imaging findings of tarsal coalitions; and (3) review the imaging appearance of the specific types of tarsal coalitions.

Methods

Online searches were performed using Google Scholar with the search criteria of “tarsal coalition,” “hindfoot anatomy,” and “subtalar coalition,” and limiting the searches to papers published in the last 10 years in major radiology journals.

Results

The anatomy of the hindfoot is complex but essential to understand. There are various radiographic, CT, and MR imaging findings that can be consistently noted in cases of tarsal coalition. The specific types of tarsal coalition demonstrate characteristic imaging findings.

Conclusions

Knowledge of the normal anatomy of the foot, in particular the hindfoot, combined with the knowledge of the imaging characteristics of different histologic subtypes of coalitions (osseous, cartilaginous, and fibrous) is essential for interpreting radiographic, CT, and MR images of the ankle and foot.     

Focal splenic lesions: Imaging spectrum of diseases on CT,MRI and PET/CT

The spleen can be affected by a variety of diseases. Some of them are readily identified as variations of normal or benign diseases on imaging. However, for a substantial number of focal splenic abnormalities, the diagnosis can be difficult so that histopathologic analysis may be required for a definite diagnosis. In this review, the typical splenic abnormalities that can be diagnosed with imaging with a high degree of confidence are illustrated. The complementary role of computed tomography (CT), magnetic resonance imaging and positron emission tomography/CT that helps make a diagnostic approach is discussed. Finally, current applications and future trends of radiomics and artificial intelligence for the diagnosis of splenic diseases are addressed.     

64排CT与DSA及C臂 CT检出肝癌小病灶的对比

目的比较64排CT、DSA和C臂CT对肝癌小病灶（直径≤3.0 cm）的检出能力。方法对48例肝癌患者先行64排CT扫描,再行肝动脉DSA、TACE和C臂CT扫描。2周内复查CT（碘化油CT）,由3名影像科医师对64排CT、DSA、C臂CT和碘化油CT图像进行分析,计数4种方法对直径≤3.0 cm病灶的显示情况,并以碘化油CT诊断结果作为标准,用McNemar检验比较64排CT、DSA和C臂CT诊断肝癌小病灶的检出率。结果碘化油CT证实48例患者共133个病灶（直径0.5~3.0 cm）,其中64排CT检出55个（55/133,41.35%）,DSA检出110个（110/133,82.70%）,C臂CT检出130个（130/133,97.74%）,三者间两两比较,差异均有统计学意义（P〈0.0001）。根据病灶大小将133个病灶分为3组,A组（直径0.5~1.0 cm）98个病灶,B组（直径1.1~2.0 cm）27个,C组（直径2.1~3.0 cm）8个。64排CT、DSA、C臂CT分别检出A组病灶29、76和95个,B组19、26和27个,C组7、8和8个。结论 C臂CT可提高对肝癌小病灶的检出率。     

皮质旁软骨瘤的CT、MRI与病理分析

目的分析皮质旁软骨瘤的CT、MRI表现及病理学特点。方法分析8例经手术病理证实的皮质旁软骨瘤影像学和病理学表现。8例均接受X线平片检查,3例接受CT检查,7例接受MR检查。结果位于肱骨6例、股骨1例、指骨1例。肿瘤最大径2~6cm。7例X线表现为骨皮质旁钙化性或骨化性肿块,其中5例邻近骨皮质增生,6例骨皮质凹陷,4例呈"火山口"样外观,2例肿块表面绕有不完整骨壳;另1例X线表现为骨皮质浅碟形凹陷,未见钙化或骨化。3例CT表现类似X线平片。6例伴钙化或骨化性的肿瘤T2WI呈明显高信号伴数量不等低信号;另1例无钙化或骨化的肿瘤T2WI呈明显高信号。增强扫描肿瘤不均匀强化,邻近骨髓腔未见受累。8例术后病理学表现为分化良好的软骨组织,掺杂钙化或骨化灶。结论皮质旁软骨瘤好发于长骨的皮质旁,影像学表现具有一定特征。     

Cerebral Gangliogliomas: Clinical Characteristics, CT and MRI

Summary  Eight patients with ganglioglioma who received surgical treatment at our institute between January 1989 and January 1997 were reviewed to determine their clinical, CT and MRI characteristics. Tumours were located in the temporal lobe (four patients), trigone of the lateral ventricle (two patients), basal ganglia (one patient) and fronto-temporal lobe (one patient). On imaging, two types of tumours were seen, a solid mass in 5 patients (62.5%) and a cystic mass in three patients (37.5%). Six complete tumours (75%) and all of the solid components of the cystic tumours were enhanced by contrast medium. Seven tumours (88%) had no peripheral oedema. On CT, the tumours being studied appeared as iso-(62.5%) or low density (37.5%) intra-axial tumours. Four tumours (50%) contained calcification. On MRI, the tumours appeared as well-circumscribed, iso- (62.5%) or low intensity (37.5%) intra-axial tumours on T1 weighted images, and as high (75%) on T2 weighted images. Three underwent total resection, 2 subtotal resection and 3 partial resection. No patients had have any further treatment such as radiation therapy or chemotherapy. Postoperative sudies were conducted on all patients with an average follow-up period 56 months (range 4–147 months) after surgery. There was no evidence of recurrence of tumours or of growth of residual tumours. We observed gangliogliomas which were located in unusual regions such as the trigone in two of the patients. To our knowledge, our series is the first report to describe trigonal gangliogliomas. We conclude, therefore, that ganglioglioma should be included as a possibility in the differential diagnosis of intracranial masses, even when they are located in the trigone.     

Current Role of PET, CT, MR for Invasive Bladder Cancer

Imaging for urothelial cancer, particularly that located in the bladder, has generally been based on computed tomography (CT). However in more recent times the role of positron emission tomography-CT (PET-CT) has emerged and increasingly magnetic resonance (MR) imaging has become utilised. This concise review will outline the role of these modalities when dealing with muscle-invasive bladder cancer (MIBC).     

Clinical staging of esophageal carcinoma. CT, EUS, and PET

CT is readily available to all patients. It is relatively inexpensive and fees are usually reimbursed. It provides exquisite anatomic detail of the chest and abdomen in patients with esophageal cancer. The only reliable use of CT in the determination of T is the exclusion of T4 tumors, which is suggested by the preservation of fat planes. Enlarged lymph nodes are suspicious for metastatic disease but require further study or tissue sampling if nodal metastases will determine treatment. Its major use is in the detection of distant metastatic disease; however, 30% to 60% of distant metastases may be radiographically occult. There is a significant learning curve for EUS staging of esophageal cancer. It is suggested that this study be performed at institutions where there is a dedicated, experienced endoscopic ultrasonographer with adequate instrumentation that allows specialty imaging and EUS-FNA. EUS is the best means of clinically determining T. The addition of EUS-FNA to routine EUS evaluation of lymph nodes allows an accuracy similar to the EUS determination of T. EUS has no purpose in assessment of non-nodal distant metastatic disease; however, the serendipitous finding of distant metastases in adjacent structures visualized during the evaluation of the primary tumor and lymph nodes has, on occasion, detected M1b disease. FDG-PET represents an advance over CT scanning in the screening for distant metastases. The major problems with FDG-PET staging of esophageal cancer is failure to detect metastatic deposits less than 1 cm in diameter and lack of anatomic definition. It is unable to determine T and has been inaccurate in the detection of lymph node metastases. Because this test is not readily available, is expensive, and is not routinely reimbursed, its use in staging esophageal cancer continues to be limited. Today, CT and EUS are the mainstays in the clinical staging of esophageal carcinoma. When possible, FDG-PET should be added to CT to improve the evaluation of non-nodal M1b disease. Results of these studies should determine the necessity for invasive staging techniques and direct their use.     

Spectral CT imaging: Technical principles of dual-energy CT and multi-energy photon-counting CT

Spectral computed tomography (CT) imaging encompasses a unique generation of CT systems based on a simple principle that makes use of the energy-dependent information present in CT images. Over the past two decades this principle has been expanded with the introduction of dual-energy CT systems. The first generation of spectral CT systems, represented either by dual-source or dual-layer technology, opened up a new imaging approach in the radiology community with their ability to overcome the limitations of tissue characterization encountered with conventional CT. Its expansion worldwide can also be considered as an important leverage for the recent groundbreaking technology based on a new chain of detection available on photon counting CT systems, which holds great promise for extending CT towards multi-energy CT imaging. The purpose of this article was to detail the basic principles and techniques of spectral CT with a particular emphasis on the newest technical developments of dual-energy and multi-energy CT systems.     

CT calcium scoring. History,current status and outlook

Cardiovascular risk assessment has assumed a prominent role in the course of preventive care of all adults. Traditionally cardiovascular risk assessment has been performed using risk factors including gender, age, smoking history, lipid status, diabetes status, and family history. Increasingly, imaging has been deployed to directly detect coronary atherosclerotic disease. Quantification of coronary calcium (e.g., Agatston method, calcium mass and volume) is readily detected using helical CT scanners. Large multicenter cohort studies have enabled a better understanding of the relevance of coronary calcium detection. The purpose of this review is to review the methods for quantification of coronary artery calcium, as well as to present current and future perspectives on calcium scoring for cardiovascular risk stratification.     

The frontiers of diagnostic radiology--PET/CT, 3DCT--

Recently, positron-emission tomography (PET) systems have been introduced in many institutions around Japan and their clinical importance should increase in the management of many malignant diseases particularly systems using 2-[fluorine-18] fluoro-2-deoxy-D-glucose (FDG). Since March 2004, we have been using the first PET/computed tomography (CT) scanner in Japan with 4-slice multidetector CT (MDCT) and now have introduced a second PET/CT scanner with 8-slice MDCT because of its excellent diagnostic capability and higher throughput capacity than that of the ordinal PET scanner. MDCT was a landmark in the history of CT in 1998. Subsequently, 8-, 16-, 32-, and 40-slice MDCT was developed in rapid succession. Finally, 64-slice MDCT became commercially available in 2005. In the future, 256-slice MDCT and flat-panel CT will appear in the clinical setting. Using these MDCT systems, we can now obtain multidimensional CT images very easily. These multidimensional images are less-invasive methods that are gradually phasing out the use of invasive angiography including digital subtraction angiography. In this article we describe the current features of PET/CT and multidimensional CT using MDCT.