Pitfalls in computed tomography of the cervical and lumbar spine

In 10 patients, evaluated by computed tomography studies of the spine, radiological findings alone may have led to misinterpretation of the clinical condition. Five patients demonstrated CT findings of cervical disc herniation or protrusion, while clinical examination resulted in the diagnosis of neuralgic amyotrophy. In contrast, 3 patients with clinical signs of compression of lumbar nerve roots had negative findings in CT studies of the lumbar discs. Additional slices at the level of the vertebral body, however, demonstrated free sequestration of disc substance. Two patients with signs of compression of cervical roots had normal CT findings, but extensive disc herniation was present at surgery.     

Sinus venosus atrial septal defect with partial anomalous pulmonary venous return: diagnosis with 64-slice spiral computed tomography at low radiation dose

The use of computed tomography is often debatable for pediatric patients because of the associated radiation exposure. Using a state-of-the-art 64-slice spiral computed tomography unit, we demonstrate the feasibility of lowering the radiation dose without losing essential diagnostic information in a case of a 2-year-old boy with a rare congenital heart defect.     

Patient selection essential for computed tomography coronary angiography

Objective: Computed tomography coronary angiography (CTCA) has become a commonly used imaging modality in patients with suspected anginal symptoms but also in asymptomatic populations. This practice has raised concerns due to potential high radiation exposure in terms of adequate benefit to risk profile.

Design: Demographics and CTCA scan details were collected from a consecutive series of 586 patients referred to a single community radiology practice for a CTCA.

Results: Of the 586 patients, 271 (46.2%) were women. Mean age was 58.3 standard deviation (SD) 12.2, range 15–90 years, body mass index (BMI) 28.6 SD 5.9?kg/m², and heart rate 60 SD 10 beats per minute. Mean total radiation was 4.79 SD 3.45 mSv (range 0.64–31.34). The mean radiation exposure in the lowest quartile of BMI and heart rate were 3.01 SD 1.84 mSv and 3.95 SD 2.72 mSv, compared to the highest 7.32 SD 3.51 mSv and 6.20 SD 4.38 mSv (p for trend <0.0001 in both).

Conclusion: The radiation exposure in this consecutive series of patients is low in general but patient selection for CTCA imaging appears to be paramount. Patients with a high BMI and especially with high heart rate receive a higher dose of radiation.     

Body computed tomography in critically ill patients

The aim of the study was to assess the effectiveness of computed tomography in the management of critically ill patients. We performed a prospective study over a 4-month period. The requesting clinician was asked to document their clinical diagnosis and confidence thereof on a visual analogue scale. They were also asked about their management plan if computed tomography had not been available. After imaging, any change in the management plan was assessed. During the study period, 16 computed tomograms were performed on 14 patients. There were 21 possible clinical diagnoses: of these eight were confirmed, and 13 were refuted. Seven new diagnoses were established. Computed tomography did not help in the management of two patients and it led to more confusion in the management of one patient. The management of seven patients was altered after computed tomography and in six the management depended solely on computed tomography findings.     

Quantification of the visceral and subcutaneous fat by computed tomography: Interobserver correlation of a single slice technique

PurposeTo assess the interobserver reproducibility of the quantification of the visceral and subcutaneous fat by computed tomography from an umbilical slice and study the effect of the level of the slice (slice going through the navel versus a slice going through disc L3–L4).Materials and methodsForty-four breast cancer patients who had a CT-scan were included in this study. This is a double blind (junior versus senior) retrospective study to determine the interobserver reproducibility. A junior observer studied the variation between two levels of slice by selecting an image going through L3–L4 and the navel.ResultsThe measurement of the fat obtained from an umbilical slice seemed to be well correlated and consistent with that obtained from a slice with a disc reference (L3–L4). The interobserver reproducibility is good for the quantification of the umbilical fat (Spearman and Lin at 0.9921 and 0.985 [P < 0.001] for the visceral fat).ConclusionThe interobserver reproducibility of the single slice CT-scan measurement going through the navel (easily detected) is excellent and may therefore be used in oncology as a predictive tool to measure a characteristic of the host and not the tumor.     

肝门部胆管癌的CT诊断

CT技术的进步使胆管癌的诊断和病变范围的判断具有较大的进展。多排螺旋CT的空间分辨力有明显提高,辅助以三维重建技术,可将不规则的解剖关系简化,从而清楚显示病变征象,特别有助于观察胆管壁的全长,有利于观察包块与肝门部胆管分叉部的关系。     

Anatomic analysis of computed tomography images obtained during fluoroscopic computed tomography-guided percutaneous lumbar sympathectomy

Purpose  The fluoroscopic computed tomography (CT)-guidance technique increases the accuracy and safety of needle placement for percutaneous lumbar sympathectomy. The aim of the present study was to provide anatomic data from CT images and to discuss the safest route for needle insertion. Methods  We retrospectively analyzed CT images that were obtained from 25 patients (14 men, 11 women; 37—89 years of age [mean, 68.4 years]) during fluoroscopic CT-guided percutaneous lumbar sympathectomy. The anatomy around the inserted needle was measured and the correlations between patient characteristics and the procedure-related distances were assessed. Results  The distance from the midline (spinous process) to the entry point and the depth to the target site correlated with body size, especially height and weight. The maximal distance from midline to the insertion point in the range of safe needle insertion at L2 was less than 7.0 cm in approximately 20% of the patients. Conclusion  The present study was performed to determine the anatomic details required to guide safe percutaneous lumbar sympathectomy based on CT images. The use of CT guidance is recommended for lumbar sympathectomy, especially at the L2 spinal level.     

Pitfalls in the computed tomographic diagnosis of toruloma

A case of multiple intracerebral mass lesions is presented in which significant "improvement" in the computed tomographic appearance was noted following steroid and radiation therapies. Nonetheless, the patient's clinical course was one of rapid deterioration, and an autopsy revealed multiple torulomas. It seems that the computed tomographic appearance of torulomas can mimic those of other intracranial mass lesions and can be greatly altered by steroid and radiation therapies, either singly or in combination.     

Chiari malformation presenting as loss of cerebellar substance on computed tomography

Cerebral computed tomography (CT) is the primary imaging modality in the investigation of suspected cerebellar degeneration. A case is presented in which an inaccurate clinical and radiologic diagnosis of olivopontocerebellar degeneration resulted from CT imaging demonstrating loss of cerebellar substance. Subsequent clinical recognition of downbeat nystagmus led to a diagnosis of Chiari malformation. This malformation was classified as a “severe” Chiari type I via clivomyelography and angiography. Surgical decompression resulted in marked clinical improvement. Visualization of the loss of cerebellar substance should not be considered to exclude Chiari malformation.     

Accuracy of computed tomography in predicting appendiceal perforation

Background

Some surgeons use nonoperative management with or without interval appendectomy for patients who present with perforated appendicitis. These strategies depend on accurately delineating perforation by computed tomography (CT). Since 2005, our institution has used an evidence-based definition for perforation as a hole in the appendix or fecalith in the abdomen. This has been shown to clearly separate those with a high risk of abscess from those without. To quantify the ability of CT to identify which patients would meet these criteria for perforation, we tested 6 surgeons and 2 radiologists who evaluated blinded CT scans.

Methods

A junior and senior surgical residents, 2 staff interventional radiologists, and 4 attending pediatric surgeons with 3 to 30 years of experience reviewed 200 CT scans of pediatric patients who had undergone a laparoscopic appendectomy. All CT scans were reviewed electronically, and the reviewers were blinded to the results, outcome, and intraoperative findings. None of the patients had a well-formed abscess on CT. The reviewers were asked to decide only on perforated or nonperforated appendicitis according to our intraoperative definition. Clinical admission data were reviewed and compared between groups.

Results

In total, the reviewers were correct 72% of the time with an overall sensitivity of 62% and a specificity of 81%. The overall positive predictive value was 67%, and the negative predictive value was 77%.

Conclusions

This study shows that in the absence of a well-formed abscess, the triage of patient care based on a preoperative diagnosis of perforation from CT may be imprudent and subject a portion of the population to an unnecessarily prolonged course of care.     

Role of fluorine-flurodeoxyglucose positron emission tomography/computed tomography in preoperative assessment of anterior mediastinal masses

Objective: The purpose of the study was to explore the usefulness of fluorine-fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG PET-CT) in the preoperative assessment of isolated anterior mediastinal lesions, especially in the planning of operative strategy (biopsy or upfront resection). Methods: During the last 36 months, 19 consecutive patients (10 males, mean age 54 ± 16 years) underwent PET-CT in the preoperative work-up of isolated anterior mediastinal diseases. Maximal transverse diameter at CT and the postoperative histology and Masaoka staging for thymomas were collected and related to the maximum standardised uptake values (SUVs). Thymomas were divided into low-risk thymoma (LRT = A, AB and B1) and high-risk thymoma (HRT = B2, B3 and C). Results: There were 13 thymomas (six LRT and seven HRT), three lymphomas and three other primitive thymic tumours (one paraganglioma, two non-seminomatous germ cell tumours). In LRT, the mean SUV was 3.3 ± 0.5 resulting significantly lower than HRT, 13.5 ± 7 (p = 0.009). The SUV in LRT was also significantly lower with respect to lymphoma, 12.4 ± 4 (p = 0.001), and the other primitive anterior mediastinal tumours, 8 ± 0.8 (p = 0.001). Between thymomas we found a significant correlation between Masaoka stage and SUV, r = 0.718, p = 0.006. No correlation was found between transverse diameters and SUV, r = 0.141, p = 0.6. Conclusions: In our experience, low SUV (<5) is associated with LRT and minimal invasive thymoma (Masaoka stages I–II) and, therefore, susceptible to upfront surgery. For lesions with an infiltrative aspect on CT scan associated with a higher SUV (>5), an open biopsy is mandatory to exclude mediastinal lymphomas or, in case of HRT, to address a neoadjuvant treatment.     

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目的探讨螺旋CT判断胰头癌可切除性的方法和标准。方法上海华东医院2002年1月至2003年9月使用螺旋CT对18例胰头癌病人进行术前薄层多期扫描，将胰周血管受侵犯程度分为4级，结合周围组织脏器的受累情况判断胰头癌的可切除性，并与手术结果相对照。结果18例胰头癌病人，术前9例判断可切除，实际8例得到了根治性切除。准确率达87．5％，不可切除的判断准确率达90％。结论利用血管受侵犯程度分级，螺旋CT可以较准确的判断胰头癌的可切除性，具有重要的临床意义。     

Early experiences with computed axial tomography colonography

BACKGROUND: Computed axial tomography (CT) colonography is the latest radiologic technique to be used to image the large bowel. We studied its role as a diagnostic tool in colorectal practice. METHODS: One hundred and three patients suspected of having colorectal pathology underwent CT colonography. RESULTS: CT colonography suggested a diagnosis of colonic carcinoma in 18 patients, and 17 of these underwent surgery. A colorectal neoplasm was not found in only 1 patient who had extrinsic colonic compression by an ovarian cyst. Twenty-one patients had suspected colonic polyps on scanning. Subsequent endoscopy in 19 of these patients confirmed the presence of polyps in only 10. CT colonography also revealed valuable extracolonic pathology: 8 occult noncolonic neoplasms and 163 other incidental findings. CONCLUSIONS: CT colonography has good patient compliance and is a useful diagnostic modality in detecting colorectal neoplasms. Its main advantage over other such investigative tools is its ability to detect extracolonic pathology.     

Fluorodeoxyglucose positron emission tomography integrated with computed tomography to determine resectability of primary lung cancer

PURPOSE: Fluorodeoxyglucose positron emission tomography integrated with computed tomography (FDGPET/CT) was evaluated as a routine staging technique for primary lung cancer. MATERIALS AND METHODS: We prospectively compared FDG-PET/CT in determining clinical stage and surgical indication with conventional staging not including positron emission tomography (PET). A total of 50 consecutive patients diagnosed with primary lung cancer by cytological or histological examination were studied; 20 of them underwent surgery. RESULTS: Discrepancies between the two staging methods were observed in 14 patients (28%). The stage assigned by PET increased in 12 cases (24%) and decreased in 2 (4%). PET staging was accurate in eight cases with otherwise undetected distant metastases (M1) but was incorrect in six cases, including five where it overdiagnosed nodal metastases (N). Two clinical N3 patients (4%) would have missed a chance of surgery if the surgical indication had been determined by PET staging alone. According to our criteria for surgery, other patients were assigned correctly to surgery by PET staging. The maximum standard uptake value (maxSUV) of all primary lesions ranged from 0 to 23.0 (mean +/- SD, 8.0 +/- 4.4). The mean maxSUV among surgical cases (5.8 +/- 3.6) was significantly smaller than among nonsurgical cases (9.5 +/- 4.2) (P < 0.05). CONCLUSION: Staging examination including FDG-PET/CT and brain magnetic resonance imaging ordinarily can determine the clinical stage and resectability of primary lung cancer. False-positive findings in regional lymph nodes, possibly reflecting past infectious disease, are the most important remaining problem.     

Stereotactic exploration of the brain in the era of computed tomography

Surgical exploration was undertaken in 102 patients with various brain lesions using a stereotactic system coupled with computed tomography (CT) scanning. All patients were referred for stereotactic surgery because of the critical size or location of the lesions and the need to select appropriate postoperative therapy. Histologic diagnoses were obtained in 98 patients (96.1%). Direct therapeutic intervention using the stereotactic technique alone was possible in 26 patients (25.5%). No mortality and no permanent morbidity occurred in this series. Twenty-six patients had brain lesions that were unsuspected by either clinical or neurodiagnostic tests conducted before surgery. Since January 1983, 48 procedures were performed in an operating room equipped with a high-resolution CT scanner that allowed multiplanar imaging before, during, and immediately after surgery. Stereotactic surgery with CT scanning has proved safe and accurate. It is believed that histologic diagnoses must be sought in all patients with symptomatic brain lesions regardless of size or location. "Empiric" forms of therapy are no longer justified in the age of CT scanning.     

胰腺肉瘤样癌的多层螺旋CT检查特征

胰腺肉瘤样癌是非常罕见的胰腺恶性肿瘤.本研究回顾性分析2001年3月至2013年1月江苏省苏北人民医院收治的8例胰腺肉瘤样癌患者的临床资料,并总结其CT影像学特征.CT检查结果显示:8例胰腺肿瘤均为囊实性,呈外生性生长,其中位于胰头部2例、胰颈部1例、胰体部3例、胰尾部2例.肿瘤以类圆形和椭圆形为主,直径(短径)为(7.2±1.8)cm(6.3～9.6 cm).CT平扫结果示瘤体呈稍高密度或等密度影,边界清晰;瘤体内均发生囊变,瘤内无出血表现,1例瘤体内出现结节小钙灶.CT增强扫描结果示:瘤体实性成分呈中等强化;门静脉期及延迟期瘤体强化高于正常胰腺实质,但动脉期低于正常胰腺实质;瘤体三期增强扫描强化程度均低于主动脉.8例胰腺肉瘤样癌均有完整包膜,包膜未见异常强化.肿瘤与周围淋巴结和脏器关系:胰周淋巴结肿大3例、侵犯脾动脉2例、侵犯结肠脾曲2例、侵犯十二指肠浆膜或肌层1例.总结胰腺肉瘤样癌的CT检查特征,可为该病的诊断、鉴别诊断及治疗提供帮助.     

How to interpret computed tomography of the lumbar spine

Computed tomography (CT) of the spine has remained an important tool in the investigation of spinal pathology. This article helps to explain the basics of CT of the lumbar spine to allow the clinician better use of this diagnostic tool.     

胸椎椎弓根螺钉置入位置的CT评价

目的:探讨胸椎椎弓根螺钉置入的准确性和安全性。方法:对37例胸椎椎弓根螺钉内固定患者术后行CT断层扫描,观察螺钉在椎弓根内的位置,记录螺钉穿透骨壁的位置、数目和距离。结果:37例患者共置入405枚胸椎椎弓根螺钉,124枚螺钉(30.61%)穿透骨壁,其中76枚(18.77%)穿透椎弓根外侧壁,32枚(7.90%)穿透椎弓根内侧壁,16枚(3.95%)穿透椎体前壁。66枚(16.30%)穿透距离<2mm,37枚(9.14%)穿透距离在2mm~4mm之间,21枚(5.9%)穿透距离>4mm。结论:胸椎椎弓根螺钉骨壁穿透率较高,应严格按照胸椎椎弓根螺钉置入方法,仔细操作,避免出现因螺钉置入不当造成神经、血管或内脏损伤等并发症。     

Pneumatosis intestinalis and pneumoperitoneum on computed tomography: Beware of non-therapeutic laparotomy

Pneumatosis intestinalis(PI) is defined as gas within the gastrointestinal wall and is associated with a variety of disorders.As a concurrent occurrence with pneumoperitoneum,it can easily to be mistaken for bowel ischemia with perforated peritonitis.In fact,air dissection or rupture from subserosal cysts may be the cause of intraperitoneal and intraluminal free air,with clinical symptoms such as abdominal pain and fullness occurring as a result.We hereby report a case of an 82-year-old male with a history of chronic obstructive pulmonary disease who was diagnosed with bowel ischemia and received emergency laparotomy because of the appearance of PI and pneumoperitoneum on abdominal computed tomography scan.However,no perforated hollow organ or necrotic bowel segment was found,only diffusely distributed massive intraperitoneal air and PI of gastrointestinal tract.The laparotomy seemed non-therapeutic for this patient.This is significant warning for clinicians to differentiate the associated conditions of PI,and to evaluate whether or not emergency surgery is necessary.