Diagnosis of pneumothorax on F-18 FDG PET after transbronchial biopsy

Transbronchial lung biopsy (TBLB) is associated with pneumothorax, 12% occurring 1 to 4 hours postprocedure (delayed pneumothorax). We report a case of a delayed pneumothorax first diagnosed on a positron emission tomography (PET) scan performed 5 days after TBLB. An early post-TBLB chest radiograph (after 1 hour) had not demonstrated any pneumothorax. The delayed pneumothorax was later confirmed with a repeat radiograph after the PET scan. Often, PET is performed to diagnose or stage pulmonary lesions after TBLB rather than before. Therefore, nuclear physicians must remain vigilant to recognize subtle pneumothoraces on PET scans.     

Enlarged accessory spleens: CT appearance in postsplenectomy patients

An unexplained abdominal mass discovered on CT examinations of a postsplenectomy patient may represent a hypertrophied residual accessory spleen. Six such patients were found to have left upper quadrant masses on CT examinations that were subsequently proved to be enlarged accessory spleens. The CT appearance is that of discrete, solitary, rounded masses of uniform soft-tissue density in the left upper quadrant. Diameters of the masses were 3.5-5.0 cm. The splenic nature of such a mass can be confirmed by appropriate radionuclide imaging.     

Influence of "optical illusion" on the detectability of pneumothorax in diagnosis for chest CT images: substantiation by visual psychological simulation images

Some cases have been reported in which an optical illusion of lightness perception influences the detectability in diagnosis of low-density hematoma in head CT images in addition to the visual impression of the photographic density of the brain. Therefore, in this study, the author attempted to compare the detectability in diagnosis for chest images with pneumothorax using visual subjective evaluation, and investigated the influence of optical illusion on that detectability in diagnosis. Results indicated that in the window setting of lung, on such an occasion when the low-absorption free space with pneumothorax forms a crescent or the reduced lung borders on the chest-wall, an optical illusion in which the visual impression on the difference of the film contrast between the lung and the low-absorption free space with pneumothorax was psychologically emphasized when contrast was observed. In all cases the detectability in diagnosis for original images with the white thorax and mediastinum was superior to virtual images. Further, in case of the virtual double window setting of lung, thorax, and mediastinum, under the influence of the difference in the radiological anatomy of thorax and mediastinum as a result of the grouping theories of lightness computation, an optical illusion different from the original images was observed.     

Do bullae indicate a predisposition to recurrent pneumothorax?

A relationship between idiopathic spontaneous pneumothorax (ISP) and visible parenchymal bullae and blebs has been reported. The causal relationship between blebs and bullae and ISP is questionable. Consequently, resection of the involved area is only indicated if it predisposes to recurrence of the pneumothorax. CT studies on 101 cases of ISP were analysed. The presence of bullae and their distribution was then related to the first and recurrent pneumothorax. CT demonstrated bullae in 56% of first ISP and in 64% of recurrent ISP, mostly among older patients. Only eight patients had bullae larger than 2 cm on the side of the pneumothorax. The location of the bullae was not a factor in predicting recurrent pneumothorax.     

Cross-sectional imaging of idiopathic solitary renal vein varix: report of two cases

Two cases of solitary renal vein varices are reported which presented as incidental findings on abdominal computed tomography (CT) and were initially thought to represent retroperitoneal lymph nodes. Contrast-enhanced CT, magnetic resonance imaging (MRI), and Doppler ultrasound (US), all demonstrated the vascular nature of these masses suggesting the correct diagnosis. When a rounded soft tissue density mass is seen on noncontrast-enhanced CT either in or contiguous to the renal hilum, a renal vein varix must be excluded. Doppler US, MRI, or dynamic contrast-enhanced CT should be done to exclude a renal varix as the cause.     

Pneumothorax post CT-guided lung biopsy: a comparison between detection on chest radiographs and CT

Pneumothorax is reported to be a more common complication of lung biopsy performed under computed tomography (CT) than under fluoroscopic guidance. This may simply reflect the greater sensitivity of CT over chest radiographs (CXRs) in the detection of small pneumothoraces. This study aimed to determine the incidence of pneumothorax detected by CXR and by CT after CT-guided biopsy of non-pleurally based pulmonary masses, and to compare these incidences with previous reports in the literature of pneumothorax incidence post fluoroscopic biopsy. 88 consecutive CT-guided lung biopsies of masses not abutting the pleural surface were included. Immediate post-biopsy CT images, and 1 and 4 h CXRs were assessed independently by two observers for the presence and size of pneumothorax. 72 biopsies were fine needle aspirations (FNAs) performed with 22 G spinal needles only, seven were cutting needle biopsies (CNBs) performed with 18 G cutting needles only, and nine were both. 37 patients (42%) developed a pneumothorax. 35 were detected on CT (40%) and 22 on CXR (25%). None required tube drainage. Of the patients in whom CT demonstrated a pneumothorax, the average depth of this was significantly greater for those in whom CXR also detected a pneumothorax compared with those in whom CXR was negative (7.3 mm versus 3.4 mm, p < 0.05). The incidence of pneumothorax detected on CXR post CT-guided biopsy is similar to the reported incidence post fluoroscopic biopsy.     

Scintigraphic pattern of pneumothorax complicating Pneumocystis carinii pneumonia in patients with AIDS

Spontaneous pneumothorax is a serious though infrequently reported pulmonary complication of AIDS. An unsuspected lung collapse was discovered via gallium scintigraphy for the study of Pneumocystis carinii pneumonia. Neither the pneumonia nor the pneumothorax were apparent on the most recent chest roentgenogram. In evaluating gallium images during the work-up of AIDS patients with associated pulmonary pathology, the possible complication of lung collapse should be considered. If pneumothorax is suspected on gallium imaging, a chest roentgenogram in expiration must be obtained for prompt delineation of this serious, yet correctable, condition.     

Efficacy of manual aspiration immediately after complicated pneumothorax in CT-guided lung biopsy

PURPOSE: The goal of this study was to evaluate the efficacy of simple aspiration of air from the pleural space to prevent increased pneumothorax and avoid chest tube placement in cases of pneumothorax after computed tomography (CT)-guided lung biopsy. MATERIALS AND METHODS: This retrospective study was based on experience with 283 consecutive percutaneous needle lung biopsies with real-time CT fluoroscopic guidance. While patients were on the CT scanner table, percutaneous manual aspiration was performed in all those with moderate or large pneumothorax demonstrated on postbiopsy chest CT images regardless of symptoms. The authors evaluated the frequency of biopsy-induced pneumothorax, management of each such case, and factors that influenced the incidence of worsening pneumothorax that required chest tube placement despite manual aspiration. RESULTS: Of the 104 (36.7%) pneumothoraces occurring after 283 biopsy procedures, 52 were treated with manual aspiration immediately after biopsy. In 95 of the 104 pneumothoraces (91.3%), the pneumothorax had resolved completely on follow-up chest radiographs without chest tube placement. Only nine patients (3.2% of the entire series; 8.7% of those who developed pneumothorax) required chest tube placement. Requirement of chest tube insertion significantly increased parallel to the increased volume of aspirated air. The optimal cutoff level of aspirated air on which to base a decision to abandon manual aspiration alone and resort to chest tube placement was 543 mL. CONCLUSION: Percutaneous manual aspiration of biopsy-induced pneumothorax performed immediately after biopsy may prevent progressive pneumothorax and eliminate the need for chest tube placement. However, in cases in which the amount of aspirated air is large (such as more than 543 mL in this study), the possibility of required chest tube placement increases.     

CT diagnosis of unsuspected pneumothorax after blunt abdominal trauma

Review of abdominal CT scans for evaluation of blunt abdominal trauma yielded 35 cases of pneumothorax, 10 of which had not been diagnosed before CT by clinical examination or plain radiographs. Of the 10 cases initially diagnosed on CT, seven required tube thoracostomy for treatment of the pneumothorax. CT detection of pneumothorax is especially important if mechanical assisted ventilation or general anesthesia is used. Demonstration of pneumothorax requires viewing CT scans of the upper abdomen (lower thorax) at lung windows in addition to the usual soft-tissue windows.     

Renal vein leiomyosarcoma: A case report and literature review

A case of leiomyosarcoma of the renal vein occurring in a 48-year-old woman is reported, and the literature is reviewed. Ultrasonography (US) revealed a rounded uniform echogenic mass in the renal hilus. Computed tomography (CT) showed a well-demarcated, uniform, soft tissue density mass. Both US and CT were useful to detect the renal mass in the present case, and may be useful for staging of renal vein leiomyosarcoma. However, these imaging procedures did not reveal diagnostic features of leiomyosarcoma.     

Tumor invasion of the chest wall and mediastinum in lung cancer: evaluation with pneumothorax CT

For preoperative evaluation of chest wall and mediastinal invasion by lung cancer, computed tomography (CT), combined with artificial pneumothorax (pneumothorax CT), was performed in 43 patients with lung cancer in whom conventional CT scans showed that the mass was contiguous to the chest wall (n = 30) and/or mediastinum (n = 25) but without evidence of definite tumor invasion. Invasion was diagnosed on the basis of whether an air space existed between the mass and the adjacent structures. In three patients pneumothorax was not produced. After the procedure, four patients developed symptomatic pneumothorax, and one, subcutaneous emphysema. Comparison of diagnoses based on findings at pneumothorax CT, surgery, and pathologic examination showed that pneumothorax CT is 100% accurate for chest wall invasion and 76% accurate for mediastinal invasion. The authors conclude that this procedure is helpful in accurate evaluation of the T criterion in lung cancer, especially for patients in whom findings at conventional CT suggest tumor invasion of the chest wall and mediastinum.     

Diagnóstico ecográfico del neumotórax

The ultrasonographic diagnosis of pneumothorax is based on the analysis of artifacts. It is possible to confirm or rule out pneumothorax by combining the following signs: lung sliding, the A and B lines, and the lung point. One fundamental advantage of lung ultrasonography is its easy access in any critical situation, especially in patients in the intensive care unit. For this reason, chest ultrasonography can be used as an alternative to plain-film X-rays and computed tomography in critical patients and in patients with normal plain films in whom pneumothorax is strongly suspected, as well as to evaluate the extent of the pneumothorax and monitor its evolution.     

Duration of pneumothorax as a complication of CT-guided lung biopsy

The purpose of this study was to determine management guidelines for biopsy-induced pneumothorax with the assistance of manual aspiration, mainly based on the duration of complicated pneumothorax. Data from 388 consecutive percutaneous needle lung biopsies were examined. Patients with pneumothorax on postbiopsy chest CT images underwent percutaneous manual aspiration with an 18-G i.v. catheter. Frequency and management of biopsy-induced pneumothorax and period to its disappearance were reviewed. Postbiopsy pneumothorax occurred in 133 of 388 (34.3%) procedures. Manual aspiration in 72 of these 133 patients was carried out immediately after biopsy. The pneumothorax had resolved completely on follow-up chest radiographs without chest tube placement in 121 of the 133 pneumothoraces (91.0%). In cases requiring chest tube, the mean period from biopsy until resolution of the pneumothorax was 6.0 +/- 5.3 days, but was only 2.4 +/- 2.9 days when chest tube placement was not needed. Specifically, time until recovery was short both in those not requiring manual aspiration (2.1 +/- 3.4 days) and in those with a pneumothorax that disappeared completely or almost completely after manual aspiration (1.9 +/- 2.0 days). The almost equally short recovery periods in patients not requiring manual aspiration and those requiring immediate manual aspiration indicates the value of rapid management.     

CT引导下肺实性结节切割活检术后出血与气胸的多因素分析

目的 探讨CT引导下经皮穿刺肺实性结节切割活检术后并发出血、气胸的危险因素.方法 回顾性分析肺实性结节(≤3 cm)320例经16 G半自动切割活检的临床及影像学资料,行单因素和多因素Logistic回归分析.结果 活检术后针道出血发生率33.1％,气胸发生率18.1％,良恶性诊断准确率约99.6％.针道长度是出血的独立危险因素,针道每增加3 cm,风险增加3.881倍,且风险也随穿刺时间(P=0.061)和穿胸膜次数(P=0.062)呈正相关.年龄、位置和针-胸膜夹角是气胸独立风险因素,年龄每增加10岁,风险增加2.102倍;上肺叶病灶显著低于下肺叶;针-胸膜夹角每增加20°,风险增加2.413倍,肺气肿以微弱差距(P=0.086)被排除方程之外.以出血、气胸概率值绘制ROC曲线,AUC值分别为0.753和0.725.结论 CT引导下肺实性结节切割活检术后出血、气胸的发生受多种因素影响,术前仔细评估,术中操作熟练度可以有效预判和降低出血、气胸的发生.     

新生儿气胸并纵隔积气的X线诊断

目的 分析新生儿气胸并纵隔积气的X线表现及特点,提高其诊断水平.方法 47例患者均摄有仰卧前后位胸腹联合片,20例同时摄有仰卧水平侧位片,1例行胸部CT检查,45例有一次或多次随访.结果 47例新生儿气胸中,胸腔前缘积气20例,肋膈角区积气1 5例,纵隔旁积气12例,同时伴有纵隔内积气11例.新生儿多采用仰卧位及卧水平侧位摄片,其气胸和纵隔积气的X线表现与年长儿、成人立位摄片时表现不同,气体多聚集在胸腔前部、肋膈角区及前纵隔旁,X线多表现为一侧胸腔密度降低,中内带明显,同时可见压缩肺边缘,肋膈角异常锐利变深,纵隔心影旁或膈顶部异常清晰锐利;纵隔积气表现胸腺上抬,远离心底部,称为“胸腺帆征”,胸腺边缘清晰,见“八”字征.结论 根据新生儿气胸的X线表现特点,X线可明确新生儿气胸、纵隔积气的诊断.     

Pneumothorax as a complication of percutaneous radiofrequency ablation for lung neoplasms

PURPOSE: The present study was performed to determine the frequency of the complication of pneumothorax after radiofrequency (RF) ablation for lung neoplasms and risk factors affecting such pneumothoraces. MATERIALS AND METHODS: The study was based on 129 consecutive sessions of percutaneous RF ablation of lung neoplasms under real-time computed tomographic fluoroscopic guidance performed in a single institution between May 2003 and November 2005 in 41 patients (17 women, 24 men; mean age, 63 years; age range, 29-82 y). Correlation was determined between the incidence of pneumothorax after RF ablation and multiple factors: sex, age, presence of emphysema, lesion size, lesion depth, contact of tumor with pleura, number of punctures, maximum power of RF generator, period of ablation, tissue temperature at the end of the RF ablation session, and patient position during the procedure. Management of each case of iatrogenic pneumothorax was reviewed. RESULTS: Pneumothorax after RF ablation occurred in 38 of 129 RF ablation sessions (29.5%). Fourteen of the 38 cases were treated by manual aspiration, and 24 were simply observed. In five cases (3.9%), chest tube placement was required as therapy for pneumothorax. The risk of pneumothorax was significantly increased in patients with pulmonary emphysema. CONCLUSIONS: The frequency of pneumothorax after RF ablation in our experience is similar to the frequency of pneumothorax after lung biopsy reported in the literature. Various conditions for RF ablation did not influence the incidence of pneumothorax. Emphysema was the only individual factor that correlated significantly with the development of iatrogenic pneumothorax.     

Factors affecting the development of pneumothorax associated with thoracentesis

This study is a retrospective survey of the variables that may influence the development of pneumothorax after thoracentesis. In a 30-month period, a computer search of hospital records identified 342 thoracenteses, of which 154 were done with conventional techniques by the clinical services, and 188 were done with sonographic guidance. Other factors surveyed included the patients' age, sex, underlying pulmonary disease, and overall clinical condition; the size of the effusion; the type of tap (diagnostic or therapeutic); the amount and type (exudate or transudate) of fluid acquired; and the size of the needles used. The technique used was the most significant single risk factor affecting the development of pneumothorax (18% for clinical vs 3% for sonography-guided thoracenteses). The incidence of pneumothorax decreased when a smaller amount of pleural fluid was aspirated (mean, 246 ml aspirated from patients who did not vs 472 ml from those who did develop pneumothorax) and when thin needles were used (4% pneumothorax with 20-gauge or smaller and 18% with larger than 20-gauge needles). The other factors surveyed did not influence the development of pneumothorax. Our results show that sonography-guided thoracentesis is complicated by pneumothorax significantly less often than is thoracentesis done with conventional techniques. Use of the smallest possible needle and aspiration of the smallest possible amount of fluid will also result in fewer cases of pneumothorax.     

新生儿气胸的X线诊断

目的 分析新生儿气胸的X线表现特点，以提高其诊断能力。资料与方法 39例新生儿气胸均摄有仰卧前后位胸片，30例同时摄有仰卧水平侧位片，19例有1次或多次随访X线片，3例作胸部螺旋CT扫描。结果 39例新生儿气胸表现为内侧气胸16例，前部气胸22例，外侧气胸1例，其中伴有纵隔积气9例。结论 由于新生儿多采用卧位摄片，因此其气胸与年长儿、成人的X线表现不同，气体多聚集在胸腔前部和内侧，并常伴有纵隔积气。CT能提供更多的病变信息。     

Baker cyst as seen on a PET/CT scan

We present the case of a 48-year-old woman who had been diagnosed with multiple myeloma a year ago. She had persistent pain in her right knee that she tended to ignore. As part of her follow-up she underwent a PET/CT scan that did not show any metastatic lesions. However, a focal rounded area of FDG uptake behind her right knee showed a fluid density on the CT scan. A presumptive diagnosis of Baker cyst was suggested. Review of her previous MRI report performed at another hospital corroborated this finding.     

Pneumomediastinum complicating bleomycin related lung damage.

We describe two patients who developed spontaneous pneumomediastinum without pneumothorax against a background of bleomycin-induced pulmonary interstitial disease whilst on treatment for metastatic germ cell tumours of the testis. Pneumomediastinum is a rare but recognized complication of bleomycin-induced lung toxicity, which has previously only been described in association with pneumothorax.