Computed tomography of the sternum and its articulations

The chest wall presents diagnostic difficulties for both the clinician and the radiologist. Because of normal variations in anatomy and ossification, analysis of the sternal region can be particularly confusing. We reviewed the normal computed tomographic (CT) appearance of the sternum in 354 patients. Important normal sternal variants included cortical unsharpness along the posterior aspect of the manubrium, lateral surfaces of the body, and at the sternal fibrocartilaginous articulations; soft tissue prominence at the junction of the sternum and costochondral cartilage; and bony sclerosis at the transitions from manubrium to body and from body to xiphoid. In seven patients with clinically significant sternal abnormality, key CT features were abnormal soft tissue mass (7/7), destruction or irregularity of the cortical contour (7/7), and abnormal increased attenuation of bone (1/7). CT should be the radiologic study of choice in patients with suspected abnormality of the sternum and its articulations.     

Age-related normal variants of sternal uptake on bone scintigraphy

PURPOSE: The purpose of this study was to describe the variable age-related normal appearance of the sternal area on bone scintigraphy. METHODS: We studied 334 patients (158 males and 176 females) aged 15 days to 85 years, mean age 32.5 +/- 19.9 years, who did not have symptoms associated with the sternum and chest wall or a history of malignancy. All patients underwent whole-body bone scan 3 hours after intravenous injection of Tc-99m MDP. RESULTS: In patients younger than 10 years, sternal uptake was equal to nearby ribs with homogeneous uptake and poorly defined outlines. In older patients, the sternum showed markedly greater uptake than nearby ribs and the borders became well defined. Different patterns of sternal uptake were noted: 1) increased uptake in the manubrium; 2) hot spots in the angle of Louis, body and xiphoid; 3) a photopenic area just above the xiphoid process; 4) heterogeneous sternal body uptake; and 5) hyperactivity along the sternal body borders. Of these variants, the angle of Louis hot spot was the most common finding (63.5%). A linear pattern of hot spots in the sternal body was seen most frequently between 10 and 30 years old and corresponded to 3 transverse ridges of bone, representing the sites of union. Increased tracer uptake only at the medial end of the clavicle in the SC joints was seen in 42.13% of patients younger than 30 years. CONCLUSION: This study showed age-related normal variants of sternal uptake on bone scanning in asymptomatic patients. Understanding these variants may be helpful in differentiating normal and abnormal patterns of uptake in the sternum on radionuclide bone imaging.     

Cross-sectional imaging with CT and/or MRI of pediatric chest tumors

The purpose of this study was to provide an overview of the spectrum of pediatric chest masses, to present the results of cross-sectional imaging with CT and/or MRI, and to define diagnostic criteria to limit differential diagnosis. Seventy-eight children with thoracic mass lesions were retrospectively evaluated using CT (72 patients) and/or MR imaging (12 patients). All masses were evaluated for tissue characteristics (attenuation values or signal intensity, enhancement, and calcification) and were differentiated according to age, gender, location, and etiology. Twenty-eight of 38 (74 %) mediastinal masses were malignant (neuroblastoma, malignant lymphoma). Thirty of 38 (79 %) pulmonary masses were metastatic in origin, all with an already known primary tumor (osteosarcoma, Wilms tumor). With one exception, all remaining pulmonary lesions were benign. Seventeen of 21 (81 %) chest wall lesions were malignant (Ewing sarcoma, primitive neuroectodermal tumor). The majority of mediastinal and chest wall tumors in children is malignant. Lung lesions are usually benign, unless a known extrapulmonary tumor suggests pulmonary metastases. Cross-sectional imaging with CT and/or MRI allows narrowing of the differential diagnosis of pediatric chest masses substantially by defining the origin and tissue characteristics. Magnetic resonance imaging is preferred for posterior mediastinal lesions, whereas CT should be used for pulmonary lesions. For the residual locations both modalities are complementary. Received 7 March 1997; Revision received 9 September 1997; Accepted 14 November 1997     

Tuberculous osteomyelitis/arthritis of the first costo-clavicular joint and sternum

A young Somali immigrant presents with a two-year history of a large, firm, painful right anterolateral chest wall sternal mass. The patient denied any history of trauma or infection at the site and did not have a fever, erythematous lesion at the site, clubbing, or lymphadenopathy. A lateral chest radiograph demonstrated a low density mass isolated to the subcutaneous soft tissue overlying the sternum, ribs and clavicle. Computed tomography (CT) with contrast demonstrated a cystic lesion in the right anterolateral chest wall deep to the pectoralis muscle. Enhanced CT of the chest demonstrated sclerosis and destruction of the rib and costochondral joint and manubrio-sternal joint narrowing. Ultrasound-guided biopsy and aspiration returned 500 cc of purulent, cloudy yellow, foul-smelling fluid. Acid-fact bacilli stain and the nucleic acid amplification test identified and confirmed Mycobacterium tuberculosis. A diagnosis of tuberculous osteomyelitis/septic arthritis was made and antibiotic coverage for tuberculosis was initiated.     

Non-Tumorous Diseases of the Sternum and Its Articulations: At the Front Gate of the Chest

Abnormalities of the sternal and peri-sternal regions are commonly seen in clinical practice and may be one of the important causes of chest pain particularly anterior chest wall pain. While reading computed tomography (CT) of the chest for evaluation of chest pain, the sternal region is either easily overlooked or its abnormality is often detected incidentally. This article will provide an overview of normal sternal anatomy and congenital variants as well as a variety of non-tumorous pathologic conditions of the sternum and adjacent joints, with emphasis on CT, to help radiologists, particularly thoracic radiologists, to make an accurate diagnosis in their daily practice. Non-tumorous abnormalities include trauma (fractures and dislocations), infection (osteomyelitis, septic arthritis), degenerative (osteoarthritis) and inflammatory conditions (rheumatoid arthritis, seronegative arthritides), and metabolic disorders (Paget's disease and renal osteodystrophy) as well as treatment related changes such as poststernotomy and its complications (dehiscence, nonunion) and postradiation changes of the sternum.     

Importance of MRI in the diagnosis of vertebral involvement in generalized cystic lymphangiomatosis

A 9-year-old boy presented with the sudden onset of pleuritic chest pain and on CT was found to have a large pleural effusion, mediastinal fluid, splenic lesions and multiple apparently sclerotic vertebral bodies. Subsequent MRI showed that those vertebral bodies that appeared sclerotic were in fact normal, and the vertebral bodies initially interpreted as normal had an abnormal T1 and T2 hyperintense signal on MRI and were relatively lucent on CT. MRI also demonstrated abnormal heterogeneous T2 hyperintense paraspinal tissue and several multicystic soft tissue masses. Biopsy of two adjacent vertebral bodies, one relatively sclerotic and one lucent, demonstrated findings of bony remodeling without a specific diagnosis. Biopsy of an infiltrative mediastinal mass confirmed the diagnosis of generalized cystic lymphangiomatosis. MRI should be included in the assessment of vertebral involvement in this condition because CT and biopsy findings may be nonspecific.     

椎旁原始神经外胚层瘤CT和MRI诊断

目的:研究椎旁外周性原始神经外胚层瘤(pPNET)的CT及MR表现,提高对该病的认识。方法:报道5例经手术病理证实的pPNET的临床、CT、MRI及组织学所见,并复习相关文献。结果:5例均见单侧椎旁肿块,累及椎管内硬膜外,肋骨骨质侵蚀,胸髓受压变形;CT显示肿块形态不规则、密度均匀;MRI示T1WI肿块信号均匀、略高于邻近骨骼肌信号,T2WI呈不均匀高信号,增强后肿块明显均匀强化。术后MRI显示局部肿块复发和胸腔积液,CT发现肺部、纵隔多发转移结节。结论:pPNET为少见的起源于胸壁、椎旁的恶性肿瘤,其CT、MRI表现无特征性,但可明确肿瘤的范围、进行手术切除可能性评估及治疗后随访。CT易显示肋骨、椎体骨质破坏、肺部小转移灶,MRI则可显示胸壁受累、胸髓受压变形的程度和范围等。     

MRI findings of prolonged post-traumatic sternal pain

Objective The objective of this study was to characterize the different causes of prolonged sternal pain following thoracic trauma with involvement of the sternum and to define criteria for sternal nonunion diagnosis using MRI. Design and patients Five patients with abnormalities of the sternum were evaluated for prolonged sternal pain following thoracic trauma using MRI. MR images were evaluated by two radiologists in consensus. The patients were selected from the radiology database, which included 8 patients with post-traumatic prolonged sternal pain. Results Two patients (n = 2) revealed a sternal nonunion after sternal fracture. One patient had a sternal fracture with delayed union and minor displacement of the sternal halves. Abnormal signal intensity alterations adjacent to and within the manubrio-sternal joint were evident in 2 patients and considered due to trauma-related changes in the manubrio-sternal joint. The 3 patients who were not included in the study had no abnormalities of the sternum: 1 of them proved to have a well-healed sternal fracture and nonunion of a rib fracture, 1 had subtle Tietze’s syndrome, and 1 patient revealed no pathological findings on imaging. Conclusion Various factors may be responsible for prolonged sternal pain following thoracic trauma, and these can be viewed with MRI. In cases of sternal nonunion there was common fluid-like signal in the fracture interspace between the bony edges, and the bone marrow adjacent to the nonunion showed altered signal intensity. MRI identified sternal nonunion and other trauma-related abnormalities of the sternum following chest trauma.     

Limitations of CT in evaluation of neoplasms involving chest wall

We reviewed the CT of 20 patients with peripheral lung malignancies in which CT appearance suggested chest wall invasion on the basis of extension of mass around ribs into fat or muscle of the chest wall, or definite bone destruction. We correlated these findings with other radiographic studies and surgical and autopsy results. All 11 cases in which CT indicated chest wall involvement on the basis of definite bone destruction were confirmed. Tumor extension into the chest wall was disproven in six of the remaining nine cases in which invasion was suggested on the basis of tumor infiltration between ribs or extension of tumor into fat or soft tissue planes. Our findings confirm the lack of reliability of CT findings in determining the extension of malignancy into the chest wall, except when definite bone destruction is present.     

Radiation-induced osteoradionecrosis of the ribs in a patient with breast cancer: A case report

Osteoradionecrosis of the chest wall after radiation therapy for breast cancer is rare; however, it is one of the most severe complications of radiation treatment. Radiologically, osteoradionecrosis can manifest as a focal lucent area in bone, periostitis, sclerosis, and cortical irregularity of bones on X-ray or computed tomography; therefore, differentiation from bone metastasis can be challenging. Associated insufficiency fractures, ulceration, and skin necrosis may also occur. We encountered a patient with osteoradionecrosis in the left anterior ribs after radiation therapy for breast cancer. Chest computed tomography revealed cortical irregularity with severe sclerotic changes of the anterior arc of the left fist to the fourth ribs. The patient''s skin on the left chest wall exhibited ulceration with purulent discharge. Ultrasonography of the left chest wall revealed diffuse skin thickening with hyperechoic changes in the subcutaneous fat layer of the left chest wall with calcifications. The patient underwent rib resection and chest wall reconstruction. Recognizing characteristic imaging features of osteoradionecrosis is important for radiologists to differentiate it from bone metastasis and plan appropriate treatment.     

胸骨肿瘤切除后胸大肌重建胸壁缺损9例临床分析

目的总结分析胸骨肿瘤切除术后胸大肌重建的临床效果。方法对2002—2007年收治的9例胸骨肿瘤病例进行手术治疗,术后形成的胸壁缺损采用胸大肌修复重建。结果9例胸骨肿瘤病例手术均获成功,无手术死亡,术后无胸壁畸形,轻度反常呼吸,无呼吸循环并发症。结论胸骨肿瘤适宜手术切除,但术后一般缺损较大,特别是胸骨全部切除,在修复重建时,采取游离胸大肌对拢缝合,可有效重建胸壁,无明显术后并发症,效果满意。     

Bone imaging of sternocostoclavicular hyperostosis in palmoplantar pustulosis

Sternocostoclavicular hyperostosis is a rare syndrome that is characterized by hyperostosis and soft tissue ossification between the clavicles and the anterior part of the upper ribs. This syndrome frequently is found in the case of palmoplantar pustulosis (PPP), especially in Japan. There have been few published reports, however, of Tc-99m MDP bone imaging findings in PPP. Eleven patients with PPP who were suspected to have sternocostoclavicular hyperostosis were studied with Tc-99m MDP whole body bone imaging. Bone images were abnormal in 11 patients. Abnormal radionuclide concentrations were observed in the sternoclavicular, sternocostal, and manubriosternal joints, in the ribs, and in the sternum. Whole body imaging revealed radionuclide accumulations unexpectedly in other bones such as the vertebrae, femur, tibia, or sacroiliac joints in five of 11 cases. Radiographs were available in nine patients. Three chest radiographs were negative, and six showed various degrees of hyperostosis or sclerotic changes in sternoclavicular, sternocostal, or manubriosternal joints, or in the sternum or anterior upper ribs. These bone lesions usually were more prominent and more easily recognized with bone scintigraphy. Bone scintigraphy should be used as a routine procedure in patients with PPP who are suspected to have sternocostoclavicular hyperostosis.     

MR imaging of the chest: Mediastinum and chest wall

This review presents the options and limitations of MRI in non-vascular diseases of the mediastinum and the chest wall. In numerous thoracic pathologies, MRI is a useful supplement to spiral CT. This imaging procedure also allows a contrast-media-free differentiation of solid tumors and vascular lesions (e. g., aortic aneurysms). The advantages of MRI over CT are particularly useful when multiplanar tumor imaging is required prior to surgery to establish the exact spatial relationship between tumor and the other mediastinal structures. Primary indications for MRI in diseases of the mediastinum and chest wall are therefore: (a) tumors of the posterior mediastinum for determining their position in relation to the neural foramina and the spinal canal; (b) chest wall tumors; (c) preoperative multiplanar imaging of primary mediastinal tumors; and (d) contraindications against CT exams with iodine contrast media.     

High-attenuation mediastinal masses on unenhanced CT

On unenhanced CT scans, a variety of mediastinal masses contain areas with attenuation values higher than the attenuation value of the chest wall musculature. The increased attenuation may be diffuse or focal and may be a result of calcium deposition, high iodine content, or areas of acute hemorrhage. This report illustrates the gamut of high-attenuation mediastinal masses seen on unenhanced CT. Masses that are of high attenuation only on IV contrast-enhanced images (e.g., aberrant vessels) are not included.     

Imaging of primary sternal osteomyelitis in a patient with Crohn's disease

A 41-year-old man with known Crohn's disease presented with chest pain and fever. Plain film and CT of the chest were normal, but bone scan and gallium scans showed intense sternal uptake. Surgery revealed staphylococcal osteomyelitis of the sternum. Following appropriate antibiotic treatment, the patient's symptoms resolved and follow-up gallium scans became normal. This is the first report of the association of sternal osteomyelitis and Crohn's disease, although other sites have been described. Sternal osteomyelitis has a high morbidity and the index of suspicion for this condition must be high even in the face of initially negative imaging.     

胸骨肿瘤的CT诊断

目的:提高胸骨肿瘤的CT鉴别诊断能力。方法:回顾性分析40例经病理证实的胸骨肿瘤患者的CT资料。结果:胸骨肿瘤具有膨胀性生长的倾向;良、恶性膨胀性破坏的区别在于前者有硬化边,后者边缘模糊、血供丰富、生长迅速。瘤软骨、骨样物质、骨质穿凿样破坏分别是软骨类肿瘤、骨肉瘤、多发性骨髓瘤的重要诊断依据。粒细胞肉瘤胸骨浸润CT不具有诊断意义的特征,若无白血病的临床背景,与淋巴瘤、肉芽肿等病变鉴别有困难。骨髓造血源性肿瘤相对好发于胸骨。乳癌胸骨转移骨质破坏以成骨为主伴溶骨,其它转移癌以溶骨为主。发现孤立膨胀性侵袭性胸骨破坏时,应常规检查肾脏、甲状腺、肝脏等部位。结论:MSCT是胸骨肿瘤的首选影像技术能提供胸骨病灶的微细改变,准确显示肿瘤的形态、体积及浸润范围,判断肿瘤的性质。     

Photon-deficient finding in sternum on bone scintigraphy in patients with malignant disease

The sternum is known as a common site of bone metastasis in a variety of neoplasms. Sternal metastasis is usually visualized as hot spot on bone scintigraphy. However, photon deficiency in the sternum on bone scintigraphy is reported in few cases with malignancy. We undertook a retrospective analysis to clarify the clinical significance of photon deficiency in the sternum in 12 patients with malignancy. Twelve patients (five breast cancer, two multiple myeloma, one lung cancer, one renal cell cancer, one hepatocellular carcinoma, one malignant lymphoma, and one thyroid cancer) showing cold sternal metastasis on bone scintigraphy were identified among 9,430 patients in whom bone scintigraphy was performed. Except for two cases with pathologically confirmed sternal metastasis, all patients showed lytic change in the sternum on tomography or CT scan. Six cases of solitary sternal metastasis showed partial effect of systemic therapy (chemotherapy, humoral therapy, and radiation therapy) and surgical treatment. It is necessary to keep in mind that this type of lesion may occur as a manifestation of metastatic disease.     

股骨颈疝窝的影像学表现及诊断价值

目的探讨CT和MR I在股骨颈疝窝的影像学表现及诊断价值。方法回顾性分析总结经临床影像学诊断的10例股骨颈疝窝的影像学表现,所有病例均行X线平片和CT检查,其中2例行MR I检查。结果10例股骨颈疝窝均为单侧单发病灶,10例病灶中X线平片仅显示8例,表现为股骨颈外上侧的类圆形透亮区或硬化环。CT上表现为股骨颈前方皮质下的类圆形骨质缺损区,内为密度均匀的软组织密度,边缘清楚伴有硬化缘。MR I上表现为均匀长T1和长T2液体信号,灶周骨髓信号无异常。结论X线平片对股骨颈疝窝具有初步诊断价值,CT具有确诊价值,MR I具有辅助诊断价值。     

Severe hypoxemia secondary to acute sternal infarction in sickle cell anemia.

This article describes a 28-yr-old black man with sickle cell anemia who presented with severe chest pain secondary to acute infarction of the body of the sternum, hypoventilation, and hypoxemia with no evidence of acute chest syndrome. A bone scan performed 5 days after admission revealed increased uptake in the sternum, suggesting sternal infarction. Repeat bone scan performed 2 mo later demonstrated normal concentration in the sternum.     

Cine-MR in the assessment of the cardiovascular structures in extensive mediastinal pathology]

The authors report their experience with cine-MRI in evaluating the infiltration of the main cardiovascular structures by expansive mediastinal masses. Twenty-four patients with proven lung (12 cases) and mediastinal (12 cases) cancers, previously selected with CT, underwent MRI examination of the chest. A superconductive 1.0 T unit was employed. Cytohistologic confirmation was obtained in all cases (6 thymomas, 6 lymphomas, 12 lung cancers). Ten normal subjects were also studied as a control group. Axial, coronal, and sagittal SE T1 images were obtained as the basis for MRI investigation of the chest. Subsequently, gradient-echo pulse-sequences images were obtained during the whole cardiac cycle, and later displayed on cine-Mode, on the section plane where vessel wall was closest to the tumor. The results prove cine-MRI to allow a correct diagnosis to be made in all cases, especially in those patients where CT and conventional SE MRI yielded questionable results. This preliminary experience suggests that cine-MRI could be used as a complementary method to CT and conventional SE MRI in evaluating mediastinal vessel involvement.