Intrapulmonary lymph nodes: thin-section CT features of 19 nodules

PURPOSE: The purpose of this study was to describe the thin-section CT features of intrapulmonary lymph nodes that accompanied primary or metastatic lung tumors. METHOD: A retrospective analysis of thin-section CT features was performed on 19 nodules in 16 patients with pathologically confirmed intrapulmonary lymph nodes that accompanied primary or metastatic lung tumors. RESULTS: Of the 16 patients, 13 had a solitary nodule and 3 had two nodules. All nodules were distributed in the middle lobe, lingula, or lower lobe. On thin-section CT images, the nodule was located abutting the visceral pleura (n = 10) or within 8 mm of the visceral pleura (n = 9). The thin-section CT findings showed that most of the nodules were well circumscribed (n = 18), homogeneous (n = 19), ovoid (n = 10), or round (n = 9) and smaller than 12 mm in maximal diameter. The surrounding lung field was normal (n = 16). CONCLUSION: Intrapulmonary lymph nodes are subpleural in the lower lung field. On thin-section CT, they are well circumscribed, homogeneous, round or ovoid, and smaller than 12 mm in maximal diameter. In the differential diagnosis of subpleural nodules located in the lower lung field, it should be kept in mind that they may be intrapulmonary lymph nodes even though the patient has malignancy.     

CT features of intrapulmonary lymph nodes confirmed by cytology

We retrospectively assessed the computed tomography features of intrapulmonary lymph nodes confirmed by cytology in 18 patients. The median size of the lymph nodes was 5.8 mm (range=3.3–8.5 mm). All were below the carina, and only one nodule, which was associated with an interlobar fissure, was over 20 mm from the chest wall. The nodules were oval, round, triangular, or trapezoidal; had sharply defined borders; were solid and homogenous; and were without calcification. Six nodules (33.3%) had a discrete thin tag extending to the pleura. Intrapulmonary lymph nodes can reliably be confirmed by fine needle aspiration with cytological diagnosis.     

Thin-section CT features of intrapulmonary lymph nodes

PURPOSE: The objective of this study was to evaluate CT findings of pathologically proven intrapulmonary lymph nodes (IPLNs) and discuss the utility of thin-section CT and contrast-enhanced CT. METHOD: CT findings of 18 nodules in 14 patients with pathologically proven IPLNs were reviewed. CT scanning of the whole lung was performed contiguously with slice thickness of 10 mm. In addition, a helical scan with slice thickness of 2 mm was performed in nine patients, focusing on the nodule. Contrast-enhanced helical CT was performed in four patients, and the utility of thin section CT and contrast-enhanced CT was investigated. RESULTS: One patient had three nodules, 2 patients had two nodules, and the remaining 11 patients had a solitary nodule. All nodules were located below the level of the carina and within 15 mm of the pleura. In one case, conventional CT revealed the nodule 20 mm away from the pleura; however, the nodule attached to the major fissure was clearly revealed on thin-section CT. The size of the nodules was < or =15 mm, and the shape was round (n = 8), oval (n = 9), or lobulated (n = 1) with sharp border. One nodule demonstrated a spiculated border due to a surrounding pulmonary fibrosis on conventional CT; however, thin-section CT showed precisely a sharp border. The lobulated shape of one case histopathologically reflected a hilus of lymph node. On contrast-enhanced helical CT, all four nodules were enhanced and the degree enhancement was 36-85 HU (median 66.6 HU). CONCLUSION: In current times, IPLNs are not uncommon lesions. We should consider IPLN in the differential diagnosis of solitary or multiple pulmonary nodules in the peripheral field and below the level of the carina. Thin-section CT showed precisely the border or relation between IPLNs and the surrounding structure. It was difficult to distinguish between IPLNs and malignant nodules from the degree of enhancement on contrast-enhanced CT. On thin-section and contrast-enhanced CT, the findings of IPLNs are not necessarily specific. Therefore, strict observation on CT is necessary; in certain cases that are increasing in size, video-assisted thoracic surgery should be considered because of their location.     

Tuberculosis of the parotid gland: computed tomographic findings

Background: Tuberculosis (TB) of the parotid gland is rare, even in endemic regions. Approximately 100 cases have been reported in the English literature. The computed tomographic (CT) features, however, have seldom been studied.

Purpose: To determine the diagnostic CT features of tuberculosis of the parotid gland.

Material and Methods: CT studies of four histologically proven cases of tuberculosis of the parotid gland were retrospectively reviewed.

Results: A total of 15 enlarged lymph nodes were found in the superficial lobes of the parotid glands. The nodes were arranged linearly within the gland. Enhancement patterns included homogeneous enhancement (9/15, 60%), homogeneous enhancement with eccentric microcysts (3/15, 20%), and thick-walled rim enhancement with central lucency (3/15, 20%). Thickened adjacent fascial plane and platysma were seen in two patients. Ipsilateral cervical lymphadenopathy was seen in all patients.

Conclusion: In patients presenting with unilateral parotid nodules, TB should be considered when linearly arranged enhancing nodules are demonstrated in the superficial lobes of the glands on CT scan.     

Computed tomography lymphography with intrapulmonary injection of iopamidol for sentinel lymph node localization

PURPOSE: Experimental and clinical evaluation of the potential utility of indirect computed tomographic lymphography (CT-LG) with intrapulmonary injection of iopamidol for preoperative localization of sentinel lymph node station in non-small cell lung cancer. METHODS: CT-LG with intrapulmonary injection of 0.5 mL of undiluted iopamidol was performed in 10 dogs using a multidetector-row CT unit, followed by postmortem examination of enhanced lymph nodes in 5 of these dogs. The CT-LG with peritumoral injection of 1 mL of the contrast agent was also performed in 9 patients with non-small cell lung cancer without lymphadenopathy. At surgery, enhanced lymph nodes were resected under CT-LG guide, followed by standard lymph node dissection with macroscopic and histologic examination. A significant enhancement of lymph nodes was determined when CT attenuation value was increased with 30 Hounsfield units (HU) compared with precontrast images. RESULTS: CT-LG visualized a total of 15 enhanced lymph nodes (on average, 1.5 nodes per animal) within 2 minutes after contrast injection in the 10 dogs, with average size of 6.7+/- 1.9 mm and average maximum CT attenuation of 149 +/- 41 HU. All the 8 enhanced nodes in 5 dogs were found in the appropriate anatomic locations in postmortem examinations. Without noticeable complications, CT-LG visualized 30 ipsilateral intrathoracic lymph nodes including 19 hilar/pulmonary and 11 mediastinal nodes in the 9 patients (on average, 2.2 hilar/pulmonary and 1.1 mediastinal nodes per patient) within 2 minutes after contrast injection, with average size of 4.7+/- 0.4 mm and average maximum CT attenuation of 134 +/- 52 HU. At surgery, all these enhanced nodes could be accurately found and resected under CT-LG guidance. Metastasis was not evident in either of these enhanced lymph nodes or the remaining distant nodes in all patients. CONCLUSION: Quick and accurate localization of sentinel lymph node station on detailed underlying lung anatomy by using indirect CT-LG may be of value to guide selective lymph node dissection for minimally invasive surgery in non-small cell lung cancer.     

Mesenteric lymph nodes: detection and significance on MDCT

OBJECTIVE: Unsuspected mesenteric lymph nodes are frequently found on abdominal CT scans in everyday clinical practice. What to do with these findings has not been well established. The purpose of this study is to document the incidence of mesenteric lymph nodes in a previously healthy population and to provide guidelines for further management. MATERIALS AND METHODS: We examined the CT scans of 132 consecutive patients (84 men and 36 women; age range, 12-90 years; mean age, 43 years) who presented to the emergency department after experiencing blunt abdominal trauma. Twelve patients were excluded because they had disease processes known to be associated with lymphadenopathy. All imaging was performed using 3.2-mm collimation on MDCT scanners with IV contrast material. Two radiologists evaluated the images by consensus and recorded the presence of mesenteric lymph nodes greater than 3 mm in the short axis. Lymph node size, number, and location (central, peripheral, or right lower quadrant) were documented. All studies were reviewed on a PACS workstation. RESULTS: Of the 120 patients with otherwise normal CT scans, 47 had mesenteric lymph nodes greater than 3 mm. Of these 47 patients, 22 (47%) had five or more lymph nodes detected. Twenty-five (53%) of the 47 patients had four or fewer nodes. The mean size of the largest nodes was 4.8 mm (range, 3-9 mm), and the mean size of the nodes found per patient was 3.6 mm (range, 3-6 mm). These nodes were identified only at the mesenteric root in 32 patients (68%), only in the mesenteric periphery in eight patients (17%), and only in the right lower quadrant in five patients (11%). Nodes were identified in more than one location in two patients (4%). CONCLUSION: Incidental finding of mesenteric lymph nodes is common, reflecting more widespread use of thin-collimation MDCT and PACS workstations. In general, these nodes are small, measuring less than 5 mm. Such nodes when found in an otherwise healthy population are clinically insignificant and require no further imaging.     

Intrapulmonary lymph nodes: computed tomography findings with histopathologic correlations

We retrospectively assessed the computed tomography (CT) features of 31 intrapulmonary lymph nodes (IPLNs) with histopathologic correlations. CT scans revealed that the IPLNs are located in the subpleural region, frequently below the level of the carina, and angular in shape. Most of the IPLNs are solid in texture but occasionally present with a ground-glass appearance. For pleura-attached and pleura-separated IPLNs, one or more and 3 or more linear opacities extending from the nodules can be identified, respectively. Histologically, the IPLNs are located either at the junction of the pleura and lung lobules or at the junction of adjacent lung lobules.     

CT-Guided Percutaneous Cryoablation in Patients with Lung Nodules Mainly Composed of Ground-Glass Opacities

PurposeTo assess the safety and efficacy of cryoablation in patients with lung nodules mainly composed of ground-glass opacities (GGOs).Materials and MethodsIn this retrospective study, 50 patients (mean age, 65.0 years ± 12.3; 28 women) with a diagnosis of lung GGO nodules who underwent cryoablation were included (from June 2016 to June 2021). The local recurrence rate, incidence of regional metastases to lymph nodes, incidence of distant metastases, adverse events, and lung function condition were analyzed.ResultsFollow-up computed tomography (CT) was performed at a mean of 33 months (range, 3–60 months) after the cryoablation procedure. Outcomes were only evaluated in 30 patients. A total of 20 patients were excluded. Of these 20 patients, 10 patients had no cancer detected by histopathological analysis and a diagnosis was made using CT or positron emission tomography (PET)-CT, The other 10 patients had nodules with a diameter of <10 mm and a consolidation-to-tumor ratio of >0.25; thus, histopathological analysis was not performed because of the small nodule size, and patients were diagnosed using CT or PET-CT. The local recurrence rate was 0% (0 of 30). Evidence of regional metastases of lymph nodes was not found in any patients (0%; 0 of 30), and the incidence of distant metastases was 0% (0 of 30). No major adverse events were noted. Lung function recovered to normal within 1 month after cryoablation in all patients.ConclusionsCryoablation may serve as a safe and feasible option for the treatment of lung nodules mainly composed of GGOs.     

肺纹移位在肺内小结节CT定性诊断中的意义

目的：探讨肺纹移位在肺结节CT定性诊断中的价值。方法：对43例有随访病理结果或经临床证实直径小于3cm肺内孤立性结节进行回顾性分析，结合病灶边缘光整度研究肺纹移位与病灶性质的关系。结果：用肺窗观察到有肺纹移位现象的病灶共30例，占70．4％，肺纹聚拢23例，推移7例，其中肺纹聚拢且病灶边缘光整的共8例全部为炎性病灶。肺纹推移的7例全部为非炎性病灶。结论：肺纹移位现象可以作为肺结节定性诊断的参考征象之一。     

The role of dual-phase helical CT in assessing resectability of carcinoma of the gallbladder

Our objective was to assess the ability of dual-phase helical CT (DHCT) to predict resectability of carcinoma of gallbladder (CaGB). Thirty-two consecutive patients suspected of having CaGB on clinical examination and sonography presented to our centre over 10-month period. All these 32 patients underwent DHCT. Fifteen patients were considered inoperable and 2 had xanthogranulomatous cholecystitis. The remaining 15 patients (10 women, 5 men; age range 33-72 years) underwent surgery and had histopathological confirmation of CaGB and were included in the study based on the following criteria: presence of mass in gallbladder fossa on sonography and DHCT, and confirmation at surgery and histopathological examination. Axial reconstructions of 2 mm were obtained (collimation 3 mm, table speed 4.5 mm/s) for arterial (scan delay 20 s) and venous (scan delay 60 s) phases on a helical scanner. The criteria used for unresectability were: distant metastasis (liver, peritoneum, lymph nodes), extensive local contiguous organ spread, involvement of secondary biliary confluence of both lobes of liver, tumoral invasion of main portal vein, or proper hepatic artery or simultaneous invasion of one side hepatic artery and the other side portal vein. The CT findings related to unresectability were correlated with surgical findings. On the basis of CT findings, 10 patients were unresectable and 5 were resectable. Of the 10 patients considered unresectable, 9 had tumours that were unresectable at surgery (sensitivity 100%, positive predictive value 90%). Five patients had more than one reason and 4 had one reason alone for being unresectable (lymph nodes, n=2; hepatic metastasis, n=1; and vascular invasion, n=1). All 5 patients considered resectable based on CT findings had resectable tumours at surgery (negative predictive value 100%). The overall accuracy of CT was 93.3%. Dual-phase helical CT comprehensively evaluates CaGB and may be a useful tool in preoperative staging of this tumour in determining resectability.     

MR evaluation of normal retroperitoneal and pelvic lymph nodes

PURPOSE: To establish guidelines for normal retroperitoneal and pelvic lymph node size at magnetic resonance imaging (MRI) by correlation with computed tomographic (CT) and lymphangiographic (LAG) data. MATERIALS AND METHODS: Twelve patients previously studied with pre- and post-LAG CT to determine normal pelvic lymph node size [ 1 ] were examined with MRI. All were on surveillance for stage I testicular tumour (minimum follow-up 10 years). Three observers recorded blind the site, size and number of nodes in the retroperitoneum and pelvis at 11 sites. The results were validated with previous CT imaging. RESULTS: Eight hundred and fifteen nodes in 12 patients were visible on the MRI initially, and a further 44 nodes were identified after comparison with post-LAG CT. More nodes were seen on MRI than on CT. The 95th centile values for maximum short axis diameter (MSAD) of pelvic lymph nodes were common iliac and obturator 4 mm, external and internal iliac 5 mm and hypogastric 6 mm. In the retroperitoneum the 95th centile MSAD values were retrocrural, high left para-aortic, paracaval and interaortocaval 3 mm, post-caval 4 mm and low left para-aortic 5 mm. CONCLUSION: MRI criteria for normal retroperitoneal and pelvic lymph node size are defined. Adoption of these recommendations may improve the sensitivity of MRI for the detection of nodal metastases.     

Evaluation of the "N" factor in nonsmall cell lung cancer. Correlation between computerized tomography and pathologic anatomy

PURPOSE: To evaluate the role of CT in identifying other morphological signs of metastatic lymph node involvement from non small cell bronchogenic carcinoma. This is done to improve N staging, a critical step in this disease. In fact, since diameter is the only criterion used to distinguish normal form abnormal lymph nodes, medistinal CT only has 80% diagnostic accuracy. MATERIAL AND METHODS: 137 patients with known or suspected lung cancer were examined with Helical CT during early and late arterial phases (2 min delay, 3 mm thickness, 5 mm interslice gap) to depict node characteristics. Mediastinal lymph nodes, located according to the American Thoracic Society mapping, were considered normal when they were not visible or, if visible, less than 1 cm in diameter and of homogeneous density; lymph nodes over 1 cm in diameter and homogeneous density were considered reactive. A lymph node was considered metastatic when, independent of size, the following signs were found: central hypodensity; hyperdense thin/thick rim, with nodules within; hyperdense strands or diffuse hyperdensity in perinodal adipose tissue. The tumor site was also considered. RESULTS: Seventy patients were excluded because they were inoperable. Sixty-five of the remaining 67 patients were operated on, 1 underwent mediastinoscopy and another one mediastinoscopy followed by surgery. Based on the above CT signs, 46 patients were staged as N0, 61 as N1 and 15 as N2. In 44/46 N0 patients there was agreement between anatomical and pathologic findings; 3 of the 44 patients had lymph nodes over 1 cm in diameter and with homogeneous density. Micrometastases to mediastinal lymph nodes (N2) were found at histology in 2/46 patients (CT false negatives). In the 6 N1 and the 15 N2 patients there was complete agreement between anatomical and pathologic findings; in particular, 9 N2 patients had lymph nodes less than 1 cm in diameter with signs of metastasis and 4 had lymph nodes over 1 cm in diameter with signs of metastasis and 2 had lymph nodes either over or less than 1 cm. In all N2 patients the tumor histotype and the mediastinal location were also considered relative to the lesion site. DISCUSSION: A closer correlation was found with node morphology and density than with size. Indeed, CT sensitivity, specificity and diagnostic accuracy were 97, 100 and 97%, respectively, for the former versus 52, 93 and 77% for the latter. Adenocarcinoma was the predominant histotype (70.5%) in N2 patients. Metastases to node region 4 were predominant in right upper lobe carcinomas while node region 5 was predominant in left upper lobe lesions. CONCLUSIONS: Other criteria can be associated with size to improve CT diagnostic accuracy in N staging. Technique optimization plays a major role particularly in the late, thin slice, examination phase.     

Imaging of anaplastic carcinoma of the thyroid gland]

Sixteen cases of anaplasic thyroid carcinoma have been reviewed. In 13 cases out of 16, a diffuse invasion of one or both thyroid lobes and of the isthm associated with calcifications (50%) and necrosis (62%) was present. In 6 cases out of 8, CT Scan with contrast media injection has detected an extension into surrounding tissues. Twelve of the 16 patients presented cervical lymph nodes on the ultrasound examination and 4 of 8 patients presented mediastinal lymph nodes on the CT Scan. In 3 cases out of 16, the anaplasic carcinoma of the thyroid presented as a localized, hypoechoic nodule associated with a cervical lymph node in 1 case.     

艾滋病合并非结核分枝杆菌肺病的胸部影像表现

目的 探讨艾滋病合并非结核性分枝杆菌肺病的胸部影像表现.方法 10例艾滋病合并非结核性分枝杆菌肺病患者均行胸部X线检查,其中7例行胸部HRCT检查.结果 10例患者X线胸片显示:9例有明显病变,1例只有轻微病变;6例为双肺受累,4例为单肺受累(其中右肺3例,左肺1例);其中5例为大面积实变并空洞形成(4例伴对侧肺野散发病灶).在病变形态上有斑片状渗出实变(6例)、大片状(叶、段分布)实变(5例)、空洞(5例)、小结节病灶(3例)、粟粒病灶(2例)、纤维索条(1例).7例患者HRCT显示:斑片状渗出实变(7例)、小结节病灶(6例)、大面积(肺叶、段)实变(5例)及随实变吸收消散而出现的空洞、支气管扩张(各5例),纵隔淋巴结肿大(4例),磨玻璃密度影(3例),粟粒病灶及树芽征(各2例),胸腔积液、心包积液、纤维索条(各1例).结论 大面积实变合并空洞、结节病灶、支气管扩张及纵隔和肺门淋巴结肿大是艾滋病合并非结核性分枝杆菌肺病的胸部影像特点.     

Comparison of computed and conventional whole lung tomography in detecting pulmonary nodules: a prospective radiologic-pathologic study.

Whole lung computed tomography (CT) was performed on 25 patients with clinical diagnoses including osteogenic sarcoma. Ewing's sarcoma, rhabdomyosarcoma, fibrosarcoma, and melanoma in whom conventional tomography had revealed from one to four parenchymal nodules in one lung deemed resectable for either staging or treatment purposes. Thoracotomy was performed within 3 weeks after conventional and computed whole lung tomography. All palpable nodules were resected, measured at the time of surgery, mapped by anatomic segment, and submitted for individual histologic evaluation. CT defined more nodules than conventional tomography in 48% of cases. The additional nodules were usually pleural or subpleural and 3--6 mn in diameter. CT identified 78% of all resected nodules greater than 3 mm in diameter, compared to 59% using conventional tomography. CT was also of value in detecting bilateral nodules earlier than conventional tomography and in documenting small nodule growth on successive examination. However, 60% of the additional nodules defined by CT and resected proved to be benign granulomas and pleural-based nodes at thoracotomy.     

周围型小细胞肺癌的CT征象分析

目的 探讨周围型小细胞肺癌(SCLC)的CT征象.方法 回顾分析78例经病理证实的周围型SCLC的CT影像特点.根据有无纵隔淋巴结转移及其大小,将78例周围型SCLC分为2型:Ⅰ型孤立病灶型、Ⅱ型肺内病灶+淋巴结型;又将Ⅱ型分为2个亚型:Ⅱa型,肺门、纵隔淋巴结短径<10 mm;Ⅱb型,肺门、纵隔淋巴结短径≥10 mm.结果 Ⅰ型7例,Ⅱ型71例,其中Ⅱa型8例,Ⅱb型63例.78例SCLC均为实性病变;圆形、类圆形52例,纺锤形、蠕虫状9例,其他形状17例.71例行CT增强扫描,9例呈均匀强化,58例呈不均匀强化,4例病灶内见大面积不强化坏死区.边缘光整65例,毛糙12例,模糊1例.支气管充气征3例,空泡征4例,钙化4例.分叶征46例,毛刺征5例;支气管血管束增粗、结节41例,胸膜凹陷6例,边缘磨玻璃影5例,血管集束征1例;肺气肿42例,阻塞性肺炎4例;支气管与结节边缘截断18例.纵隔淋巴结转移63例,纵隔淋巴结大于肺原发灶42例.少量胸腔积液9例.     

Computed tomographic appearance of three intrapulmonary lymph nodes

Intrapulmonary lymph nodes are rare lesions, usually appearing as small subpleural nodule (coin lesion), at or under the height of the carina. Computed tomography (CT) is very accurate in their detection. Three observations are reported.     

胸内结节病的CT诊断分析

目的：探讨和分析胸内结节病的CT表现及特征。方法：回顾性分析24例经病理证实的结节病的临床资料及CT影像学表现。结果：胸内淋巴结肿大22例,其中肺门和纵隔淋巴结均肿大16例,仅肺门淋巴结肿大3例,仅纵隔淋巴结肿大2例,内乳淋巴结肿大1例;淋巴结钙化2例。17例行增强扫描,其中12例呈中等以上均匀强化,2例囊变,2例呈环行强化,1例无强化。24例中既有胸内淋巴结肿大同时发现肺部浸润改变19例,结节15例,其中小结节12例,大结节3例;结节大小、多种分布形式同时存在的2例;团块5例;毛玻璃影3例;支气管血管束增粗10例;小叶间隔线影11例;支气管狭窄4例;胸膜结节、增厚及胸腔积液各1例。结论：胸内结节病是结节病的局部表现,缺乏特异性,影像学形态多样,CT检查对肺门纵隔淋巴结肿大尤其对肺实质病变的表现具有一定特征性,有助于提高诊断准确率,对临床观察疗效具有指导作用。     

Cross-sectional imaging of Kikuchi disease.

PURPOSE: The purpose of this work was to characterize the cross-sectional imaging features of Kikuchi disease. METHOD: A search of our hospital records yielded three patients with pathologically proven Kikuchi disease. CT, MR, and ultrasound examinations of these patients were reviewed to characterize the imaging features of Kikuchi disease. RESULTS: MRI of the neck in one patient, CT of the chest and abdomen in another, and CT and MRI of the abdomen in the third demonstrated uniformly enhancing small lymph nodes in larger than normal numbers in the submandibular, axillary, gastrohepatic, celiac, periportal, paraaortic, retrocrural, mesenteric, and inguinal regions. Lymph node diameter was usually <10 mm and was always <18 mm. CONCLUSION: Many small clustered lymph nodes may be a characteristic imaging feature of Kikuchi disease. The abdominal extent of disease may be underreported if cross-sectional imaging is not performed.