Evolution of imaging in rectal cancer: multimodality imaging with MDCT,MRI, and PET

Magnetic resonance imaging (MRI), multidetector computed tomography (MDCT), and positron emission tomography (PET) are complementary imaging modalities in the preoperative staging of patients with rectal cancer, and each offers their own individual strengths and weaknesses. MRI is the best available radiologic modality for the local staging of rectal cancers, and can play an important role in accurately distinguishing which patients should receive preoperative chemoradiation prior to total mesorectal excision. Alternatively, both MDCT and PET are considered primary modalities when performing preoperative distant staging, but are limited in their ability to locally stage rectal malignancies. This review details the role of each of these three modalities in rectal cancer staging, and how the three imaging modalities can be used in conjunction.     

肝脏原发性平滑肌瘤影像学表现

Objective: To investigate the imaging features of primary hepatic leiomyoma. Methods: 3 patients of primary hepatic leiomyoma confirmed by pathology without immunodeficiency were retrospectively analyzed about CT and MRI findings, clinical and pathological correlation. 2 cases had routine CT scan, 2 cases had routine MRI. Results: 2 case CT scans showed low-density lesions, 2 cases MRI showed lesions with long T1 and long T2 signal. One case of uniform density and signal showed homogeneous enhancement; two cases showed uneven density and signal, of which one case was inhomogeneous enhancement. 3 cases presented pseudocapsule without hepatic cirrhosis and venous tumor thrombus. Pathology showed spindle tumor cell proliferation and capillary hyperplasia; one case showed central hyalinization and one case central liquefaction necrosis. Conclusion: Primary hepatic leiomyoma is a hypervascular tumor, and CT and MRI help in the diagnosis.     

Magnetic Resonance Imaging (MRI) of Pseudosyrinxes

Six patients whose post-myelographic computed tomography (CT) showed syringomyelia but whose clinical findings were not consistent were evaluated with magnetic resonance imaging (MRI). In five of these patients no cavity was seen with MRI. A cavity was demonstrated in the sixth case but not in the region of abnormali ty on CT. MRI confirmed the clinical impression that intake of contrast into the cord did not represent a sryinx cavity. Possible causes are discussed. The term ‘pseudosyrinx’ is used for such a situation.     

The clinical value of combined use of MR imaging and multi-slice spiral CT in limb salvage surgery for orthopaedic oncology patients: initial experience in nine patients

Background

The purpose of this prospective study was to evaluate the value of the combined use of MR imaging and multi-slice spiral CT for limb salvage surgery in orthopaedic oncology patients.

Patients and methods

Nine consecutive patients with lower/upper limb malignant bone tumours (7 osteosarcomas and 2 chondrosarcomas) were treated with limb-salvaging procedures. Preoperative planning including determination of the osteotomy plane and diameters of the prosthesis was performed basing on the preoperative CT and MR images. The histopathology was performed as golden diagnostic criteria to evaluate the accuracy of CT and MR-based determination for tumour’s boundary.

Results

The tumour extension measured on MRI was consistent with the actual extension (P>0.05, paired Student’s t test), while the extension measured on CT imaging was less than the actual extension. The length, offset and alignment of the affected limb were reconstructed accurately after the operation. An excellent functional outcome was achieved in all patients.

Conclusions

In the present study, MRI was found to be superior to CT for determining the tumour extension, combined use of MRI and CT measurement provided high precision for the fit of the prosthesis and excellent functional results.     

Imaging findings of renal cell carcinoma

There are many imaging modalities used in the diagnosis of renal cell carcinoma, the most common cancer of the kidney, which accounts for approximately 2–3% of adult malignancies. Early detection of this tumor with the correct diagnostic approach using various cross-sectional imaging is very important, as are the clinical and laboratory findings. Familiarity with the spectrum of imaging findings of renal cell carcinoma will enable clinicians to consider appropriate treatment for patients and eliminate unnecessary further imaging studies.     

Magnetic Resonance Imaging (MRI) Appearances of Syringohydromyelia

Magnetic resonance imaging (MRI) examination of the spinal cord is now a first-line in vestigation for the evaluation of suspected syringohydromyelia. It is an accurate, non-invasive means of detecting cavities within the spinal cord and for assessing spinal cord size and the position of the cerebellar tonsils. It has considerable advantages over post-myelographic computerised tomography (CT). The current study discusses our initial experience of thirteen surgically proven cases of syringomyelia with special reference to appearances on T 1 and T2 weighted images and a discussion of the apparently confusing appearances of the cavities on the T2 weighted images.     

Lymphangioma: Imaging diagnosis

Lymphangiomas are congenital malformations of the lymphatics that are curable by extirpation. Accurate delineation of lesion extension is important for pre-operative diagnosis, surgical planning, and assessing recurrence. The radiologic findings were retrospectively evaluated to determine the imaging appearance of these benign tumours. The plain radiographs, barium meal, ultrasound, CT, and MR images of 18 patients with one or more pathologically proved lymphangiomas were reviewed. Plain radiography and barium study showed masses displacing adjacent organs. Ultrasound examination showed uni- or multilocular cystic masses with smooth, thin or irregular, thick walls. Enhancement of the cyst wall was variable on CT and MR studies. The CT density of the fluid ranged from ?4 to 34 HU depending on the lipid content and the presence of haemorrhage. The cysts were isointense to muscle on T1 -weighted and hyperintense to fat on T2-weighted MR images. The MR imaging delineated the tumour lesion extension more clearly than ultrasound and CT scans. Ultrasound, CT, and MR imaging are valuable for evaluating lymphangiomas. Magnetic resonance imaging allows accurate determination of lesion extension.     

Imaging of ascariasis

Ascaris lumbricoides is one of the most common parasitic infestations of the gastrointestinal tract worldwide. During the intestinal phase of the disease, the adult worms usually remain clinically silent, sometimes causing a variety of non‐specific abdominal symptoms. When present in large numbers, the worms may get intertwined into a bolus, causing intestinal obstruction, volvulus or even perforation. Occasionally, the adult Ascaris worm may migrate into the Vater’s ampulla and enter the bile duct, gall bladder or pancreatic duct, leading to a variety of complications such as biliary colic, gallstone formation, cholecystitis, pyogenic cholangitis, liver abscess and pancreatitis. Imaging plays a significant role in showing the presence of worms and possible complications in intestinal as well as hepatobiliary ascariasis. This pictorial essay aims to illustrate various imaging features of ascariasis and its associated complications.     

CT和 MRI对卵巢癌的诊断价值比较

目的：比较CT与MRI对于卵巢癌的诊断价值。方法对56例卵巢癌患者术前同时进行CT和MRI检查,并评估术后复发及转移情况。结果在对卵巢癌的临床诊断中,CT准确率为82．1％,MRI准确率为94．6％。在对卵巢癌的定性诊断中,CT准确率为71．4％,MRI准确率为87．5％。在对卵巢癌的分期诊断中,CT准确率为73．2％,MRI准确率为89．3％。在对卵巢癌侵袭和转移的诊断中,CT总的准确率为49．2％,MRI总的准确率为84．1％。结论对卵巢癌的诊断,MRI明显优于CT。     

Value of ~（18）F-FDG PET/CT and MRI in diagnosing primary endometrial small cell carcinoma

Primary small cell carcinoma（SCC） is a group of aggressive neoplasms that mainly arise from the lung and digestive tract. Endometrial small cell carcinoma（ESCC） is extremely rare. To our knowledge, less than 90 cases have been reported, and most of these reports were dedicated to describing the clinicopathologic or immunochemical features of ESCC. Herein, we present a new case of ESCC involving a 51-year-old woman and mainly focus on the magnetic resonance imaging（MRI） and positron emission tomography/computed tomography（PET/CT） findings. MRI showed that the uterus was significantly enlarged（11.6 cm × 11.1 cm × 14.4 cm）, and a giant irregular mass（7.5 cm × 8.4 cm × 8.5 cm） was observed in the uterine cavity. The lesion demonstrated an extremely low apparent diffusion coefficient（ADC） value [（0.553±0.088）×10^–3 mm^2/s] and a high FDG uptake value（22.7）. Multiple metastatic lymph nodes（LNs） were identified at different positions, with diameters ranging from 0.3 to 2.8 cm and a maximum standardized uptake value（SUV max） ranging from 6.9 to 19.3.     

A Review of Imaging Practice in Bone and Soft Tissue Lesions

Thirty six consectutive bone and soft tissue lesions which were referred to the Bone Transplantation Service between January 1987 and June 1989 were reviewed with respect to the information provided by pre-operative CT, MR and plain X-ray and the final histopathologic diagnosis. The ability of CT and MR to demonstrate cortical destruction, periosteal reaction, a soft tissue mass and soft tissue calcification was scored on a scale of one (low suspicion of abnormality) to four (definite abnormality) in each case. Of the thirty six cases reviewed there were twenty-two histologically confirmed tumours with all of the above three imaging modalities available for comparison. In each of these tumours MR was found to provide an equal or more accurate assessment of soft tissue extent. On a scale of 1 to 4 the average point scores were 3.6 and 2.6 for MR and CT respectively. Little difference was shown between CT and MR with respect to medullary involvement (4.0 points vs. 3.9) and cortical destruction (2.5 points vs. 2.7). CT (3.7 points) was more sensitive than MR (1.2 points) in detecting fine soft tissue calcification. In only five cases did the radiology report correctly nominate the histologic diagnosis and thus the role of imaging was more valuable in staging than diagnosis. For this reason a management oriented report should include comment regarding cortical destruction, the intramedullary extent of tumour and the extent of soft tissue involvement. MR is recommended in the investigation of all suspected malignant soft tissue or bone tumours.     

Identification and staging of pancreatic tumours using computed tomography,endoscopic ultrasound and mangafodipir trisodium‐enhanced magnetic resonance imaging

Pancreatic malignancy can be staged by a number of different investigations, either alone or in combination. The purpose of the present study was to compare the use of endoscopic ultrasound, CT and mangafodipir trisodium‐enhanced MRI for the staging of pancreatic malignancy, particularly with respect to determining resectability prior to surgery. Twenty‐seven patients referred for the investigation of a suspected pancreatic malignancy were entered into the trial. All patients had contrast‐enhanced CT, gadolinium and mangafodipir trisodium‐enhanced MRI, and endoscopic ultrasound (EUS). Images were assessed for nodal staging, tumour staging and resectability for each investigation, and the results compared with findings at surgery. The results for the accuracy of MRI, CT and EUS, in detecting T4 disease versus T3 or lower was 78, 79 and 68%, respectively; nodal involvement was 56, 63 and 69%, respectively; and overall resectability (including the T stage, presence of involved nodes and metastases) was 83, 76 and 63%, respectively. There was no significant difference demonstrated between the three tests. The present study suggests that for patients referred for investigation and staging of pancreatic malignancy, EUS and MRI scanning convey little advantage over contrast‐enhanced CT. Furthermore, although mangafodipir trisodium improved the conspicuity of pancreatic tumours, it has little influence on T staging.     

鼻咽癌的CT与MRI对比分析

[目的]探讨CT和MRI对鼻咽癌的诊断价值。[方法]收集2003年10月到2005年1月,经病理证实的107例鼻咽癌患者,均行MRI和CT扫描,并根据临床资料和CT或MRI进行’92分期。[结果]MRI对于腔内病变的诊断以及翼腭窝、颞下窝、颈长肌、海绵窦、颅底、颈椎、咽后淋巴结、颈淋巴结等侵犯的检出要高于CT,而对鼻腔、口咽、咽旁间隙等检出与CT差别不大。根据’92分期原则,MRI相对于CT使33.6%(36/107)的病例发生了T分期改变。[结论]MRI对鼻咽癌的诊断、分期相对CT有优势。联合应用更有益。     

颅内表皮样囊肿的影像学诊断

目的:分析颅内表皮样囊肿的CT和MRI表现。方法:对30例经手术及病理确诊的颅内表皮样囊肿的CT和MRI表现作回顾性分析,其中30例作MRI平扫与增强扫描;20例作CT平扫检查。结果:肿瘤位于桥前池及桥小脑角池18例,4例位于鞍上,2例位于鞍旁,5例位于第四脑室,1例位于小脑延髓池。肿瘤大小不等,形态不规则,轮廓光整或呈分叶状。CT平扫17例呈均匀低密度,2例呈稍不均匀低密度,CT值为-15～10Hu,1例呈高密度。MRI平扫28例T1加权像上肿瘤呈不均的低信号,T2加权像上呈不均匀高信号,部分病例在FLAIR图象上表现为不均匀高信号,与周围低信号的脑脊液分界清晰;2例表现为T1加权像上为高信号,T2加权像上为低信号。增强后,2例肿瘤边缘有轻微强化,其余肿瘤均无明显强化。结论:典型的颅内表皮样囊肿,通过CT和MRI检查可做出准确诊断,并可以与颅内其他疾病相鉴别;在鉴别诊断中,MRI优于CT。非典型的颅内高密度囊肿,必须CT和MRI相结合诊断,为准确的术前诊断提供更多的信息。     

邻近腋窝的上皮样血管内皮瘤1例报道

We described a case of a 71-year-old woman with an epithelioid hemangioendothelioma (EHE) in her left axilla,a rare location which hasn't been reported yet. The patient suffered from numbness, pain and decreased muscle strength of her left upper extremity. Sonography revealed a hypoechoic mass surrounded the axillary artery and brachial artery. No obvious capsule was demonstrated. CT showed a soft-tissue mass with some calcifications and peripheral ring-like en-hancement. The MRI indicated a mass with mainly intermediate signal intensity on Tl-weighted imagine and intermediate signal intensity on T2-weighted imagine. The diagnosis was confirmed by histopathologic examination after surgery. There are some correlations of these imaging features with its histopathologic characters.     

10例肝脏淋巴瘤的影像学表现分析

目的：探讨肝脏淋巴瘤的影像学特点。方法回顾性分析10例初诊未治的肝脏淋巴瘤患者的临床表现、病理类型与影像学表现。结果10例均为B细胞型非霍奇金淋巴瘤（4例原发性,6例继发性）,表现为单发肿块型4例,多发结节型4例,浸润型2例。3例CT平扫呈均匀低密度,6例CT增强扫描呈轻度强化,强化程度低于正常肝实质。4例MRI平扫者,T1WI呈低信号,T2WI及脂肪抑制序列呈均匀中高信号,2例DWI扫描呈明显扩散受限,2例行MR增强扫描呈轻度强化。4例有血管穿行肿瘤但无明显受侵征象。7例伴有肝脏区域淋巴结侵犯。原发肝脏淋巴瘤的影像表现与继发性相仿。结论肝脏淋巴瘤的影像表现可多种多样,多数呈密度/信号均匀,增强后呈轻度强化,血管于肿瘤内穿行而无受侵是肝脏淋巴瘤的较为特征性表现。