Value of the “spine sign” on lateral chest views

Objective:

To determine the performance of the spine sign in detecting lower chest abnormalities in the lateral view.

Methods:

This retrospective study included 200 patients who had undergone lateral view and CT scans of the chest within 1 week. Two radiologists independently read the lateral views, and a third radiologist, blinded to the aim of the study, read the scans. The spine sign was considered as positive if the progressive increase in lucency of the vertebral bodies was altered. Interreader agreement was calculated through k-statistics. Sensitivity, specificity, positive- and negative-predictive values, and accuracy were calculated compared with CT.

Results:

Agreements between readers ranged from 0.12 to 0.68. Positive spine sign could appear in two ways: absent or inversed progressive increase in lucency of the vertebral bodies. Sensitivity, specificity, positive- and negative-predictive values, and accuracy were, respectively, 60% and 70%; 64% and 84%; 91% and 97%; 19% and 29%; and 61% and 72% for each reader (p-value ranging from 0.026 to 0.196). Abnormalities most frequently associated with positive spine sign were plate-like atelectasis, ground-glass opacity, pleural effusion and consolidation.

Conclusion:

The spine sign can present as an absent or inversed progressive increase in lucency of the vertebral bodies. It has a moderate sensitivity but a good positive-predictive value, so it can be useful especially when it appears as inversed progressive increase in lucency of the vertebral bodies to detect various abnormalities usually identifiable on chest radiographs.

Advances in knowledge:

On lateral chest radiographs, the spine sign is useful to detect lower chest abnormalities and is related to various underlying abnormalities and is, per se, non-specific.On lateral chest view obtained in normal subjects, the overall posterior opacity tends to decrease from the level of the upper thoracic spine to that of the diaphragm.^1,2 The “spine sign” is any alteration in this typical pattern and is suggestive of pathology in the lower part of the chest.³ While commonly used, the diagnostic performance of this sign for detecting lower lobe abnormalities remains unknown. The aims of our study were therefore to determine its sensitivity, specificity, positive- and negative-predictive values; to determine the accuracy of the spine sign compared with CT as a method of reference; and to characterize its associated lesions.     

Radiographic clues to the unstable knee: are findings of trochlear dysplasia on lateral knee radiographs reliable and predictive of patellar dislocation?

Emergency Radiology - Trochlear dysplasia (TD) is a key predisposing risk factor for patellar instability (PI) and lateral patellar dislocation (LPD) injuries. It is useful to understand the...     

Bone bruise in acute traumatic patellar dislocation: volumetric magnetic resonance imaging analysis with follow-up mean of 12 months

Objective  

The aim of the study was to assess volumetric analysis of bone bruises in acute primary traumatic patellar dislocation by magnetic resonance imaging (MRI) and resolving resolution of bruises in follow-up MRI.     

First-time patellar dislocation: surgery or conservative treatment?

Primary patellar dislocation injures the medial patellofemoral ligament (MPFL), the major soft-tissue stabilizer of the patella, which may lead to recurrent patellar instability. Recurrent patellar dislocation are common and may require surgical intervention. The variation in location of injury of the MPFL and the presence of an osteochondral fracture produces challenges in clinical decision making between nonoperative and operative treatment, including the surgical modality, to repair or reconstruct the MPFL. Current evidence suggests that not all primary dislocations should undergo the same treatment. MPFL reconstruction may theoretically be more reliable than repair, but the optimal time to perform additional bony corrections is not known. A normal or minor dysplastic patellofemoral joint may be suitable for nonoperative treatment, whereas a higher grade of trochlear dysplasia or other significant abnormalities may benefit from surgical treatment. In this paper, we present a treatment algorithm for primary patellar dislocation.     

The “pool sign” of metastatic adenocarcinoma

The differential of a newly discovered solitary intracranial mass is a primary intracranial neoplasm and metastatic disease. Differentiating between the two entities on imaging is difficult, though there are clues on conventional imaging that suggest one over the other. The purpose of this article is to describe a new imaging finding on T2-weighted imaging, the “pool sign,” that may be specific for metastatic adenocarcinomas and can help differentiate a solitary metastasis from a primary CNS neoplasm. We present a series of four patients with initial magnetic resonance imaging of a solitary intracranial mass demonstrating the “pool sign,” and therefore predicted to be metastatic adenocarcinoma. All of these cases were confirmed to be metastatic adenocarcinoma on pathology.     

The “botryoid sign”: a characteristic feature of rhabdomyosarcomas in the head and neck

We investigated nine patients with rhabomyosarcoma in the head and neck (6–53 years of age), using CT and MRI. The tumours originated in the paranasal sinuses (3), cheek (2), soft palate (1), orbit (1), sternocostoclavicular muscle (1) and parapharyngeal space (1). The histological subtype was embryonal in five, alveolar in three and pleomorphic in one case. The tumours enhanced markedly and heterogeneous on CT and MRI. The masses were isointense or gave slightly higher signal than surrounding muscles on T1- and heterogeneously high signal on T2-weighted images. In four tumours, multiple ring enhancement resembling bunches of grapes. This appears to be characteristic of rhabdomyosarcoma and probably reflects a component of botryoid-type rhabdomyosarcoma in which mucoid-rich stroma is covered with a thin layer of tumour cells. We have named this imaging feature the “botryoid sign”. Received: 9 March 2000 Accepted: 12 July 2000     

“Tenomalacia”: a new sonographic sign of tendinopathy?

The purpose of this study was to assess tendon compressibility with sonography in extensor tendinopathy and in asymptomatic extensor tendons of the elbow. Sonography of both elbows was performed in eight patients with a clinical diagnosis of unilateral lateral epicondylitis. Tendons were assessed for compressibility by measuring their thickness before and after compression with the transducer. The same manoeuvre was performed while tendon vascularity was assessed with colour Doppler. All eight cases showed increased compressibility of the common extensor tendon on the painful side compared to the asymptomatic side, as well as increased vascularity with compressible vessels on colour Doppler. Other signs of tendinopathy were hypoechogenicity (n = 8), loss of fibrillar pattern (n = 8), intratendinous calcifications (n = 1), partial tears (n = 3), and enthesophytes (n = 5). Increased tendon compressibility indicative of tendon softening or “tenomalacia” is a new sonographic sign of common extensor tendinopathy. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

The “gray cortex”: an early sign of stress fracture

The purpose of this report is to describe an early radiographic sign of stress fracture, the gray cortex. The imaging findings in three patients with tibial stress fractures were reviewed. The gray cortex sign was evident on the initial conventional radiographs in all three cases. It was prospectively reported as a sign of stress fracture in two patients and was evident on the initial radiographs (taken elsewhere) of the third patient, who was referred for additional workup of a possible neoplasm. Special imaging studies (technetium-99m bone scan, computed tomography, and magnetic resonance imaging) confirmed the diagnosis in all three cases.     

The double lumen: a pathognomonic angiographic sign of arterial dissection?

A case is reported which questions the absolute significance of the “double-lumen sign” in the diagnosis of arterial dissection. I suggest that when demonstrated in isolation, this sign should be interpreted with caution, giving consideration to the possibility of arterial fenestration, and appropriate diagnostic measures implemented. Received: 1 March 1999/Accepted: 29 June 1999     

The association of infrapatellar fat pad oedema with patellar maltracking: a case–control study

Objective

To look for any association between oedema in the superolateral portion of the infrapatellar fat pad and patellar maltracking.

Materials and methods

We compared two groups of knee MRI with regard to five patellar maltracking parameters. The first group included 100 knees with evidence of oedema in the superolateral aspect of the infrapatellar fat pad (the study group). The second group included another 100 knee MRI that had a normal infrapatellar fat pad (the control group). The five patellar maltracking parameters assessed were the trochlear depth, tibial tuberosity–trochlear groove distance (TTTG), patellar translation, patellofemoral angle (PFA) and the Insall–Salvati index.

Results

There was a statistically significant difference in the Insall–Salvati index, patellar translation and PFA between the two groups (p value of <0.001, <0.001 and 0.004 respectively, Student’s t test). There was a higher prevalence of patella alta, lateral patellar displacement (LPD) and lateral patellar tilt in the study group (p value of <0.001, <0.001 and 0.011 respectively, Fisher’s exact test). Sixty out of 100 knees in the study group had at least one abnormal patellar maltracking parameter in comparison to 16 out of 100 knees in the control group (p?Conclusion Oedema in the superolateral portion of Hoffa’s fat pad, the MRI feature of fat pad impingement, is associated with patellar maltracking.     

The development of a curriculum—a case study of six centres providing courses in radiographic reporting

Aim: To analyse the content of the curricula of radiographic reporting courses in six established sites.Methods: The structures of the six courses were examined by analysis of course materials from the educational institutions. Two sample course documents were scrutinized initially in order to identify major themes. From the information gathered a 27-point questionnaire was developed and distributed to the six educational sites.Results: The data showed the institutions to be placing great importance on meeting the needs of the clinical departments and their patients. Variations were noted in course content, award and measurement of competence.Conclusions: The paper provides an overview of an important paradigm shift in the role of diagnostic radiographers. It is clear that the development of reporting courses should involve close links between academic and clinical sites, with an emphasis on team work.     

“Menigeal sign”: a characteristic finding of meningiomas on contrast-enhanced MR images

Summary In meningiomas, a flat, contrast-enhancing, probably dural structure adjacent to the tumor can occasionally be observed on Gadolinium-DTPA enhanced MR images. This so called meningeal sign was evaluated with respect to the differential diagnosis of meningiomas in MR imaging. The study included 29 patients with intracranial meningiomas and 24 patients with non-meningeal brain tumors. In all meningiomas, MR studies included T2-weighted as well as unenhanced and Gadolinium-DTPA-enhanced T1-weighted images. In all nonmeningeal tumors, Gd-DTPA-enhanced MR images were available. All images were evaluated with respect to the presence of the meningeal sign. In meningiomas, a meningeal sign was seen in 15/29 cases on Gadolinium-DTPA-enhanced images. No abnormalities corresponding to the areas of contrast enhancement were found on unenhanced T2- and T1-weighted MR images. In nonmeningeal tumors only 2/24 cases showed a meningeal sign. In conclusion, with a sensitivity of 52% and a specificity of 92%, the demonstration of the meningeal sign improved the differential diagnosis of intracranial meningiomas in contrast-enhanced MR imaging.     

Magnetic resonance diagnosis of posterior horn tears of the lateral meniscus using a thin axial plane: the zip sign��a preliminary study

Objective  

The “zip” sign is a newly described form of meniscal tear progressing from the distal insertion of menisco-femoral ligaments (MFLs) through the lateral meniscal wall; the tear occurs during anterior cruciate ligament (ACL) rupture. The purpose of this study was to evaluate the zip sign on knee MRI within the context of ACL injuries.     

The “paraglider-wing” sign: an arthroscopic indicator of partial-thickness bursal-surface tears of the supraspinatus tendon

Partial-thickness bursal-surface tears of supraspinatus tendon may be missed on preoperative investigations and can be overlooked at surgery if not specifically sought. The authors describe an arthroscopic sign to detect these tears, when they involve more than half the tendon fibres, from the articular-side of the joint. The "paraglider-wing" sign, visualized during diagnostic glenohumeral arthroscopy, is demonstrated as an upward bulge of the capsulo-tendinous layer through the bursal-surface tear, under pressure of the inflow fluid. A positive sign indicates (1) presence of a partial-thickness bursal-side tear of the supraspinatus tendon, (2) significant depth (stage II or III) of the tear, and (3) the medial extent of the tear along the length of the tendon. A meticulous subacromial bursoscopy and excision of the bursa is then performed to visualize the tear from the subacromial space. Repair of the tear is performed with a double-row suture anchor fixation technique; the medial row of sutures is passed through the intact region of the tendon using the "paraglider-wing" sign as a guide.     

The dynamic range of digital radiographic systems: dose reduction or risk of overexposure?

OBJECTIVES: To investigate the range of diagnostically acceptable digital radiographs and film as a function of exposure time, as well as the relationship to dose reduction and consequences for dental practice. METHODS: Five systems for intraoral radiography were used to take a series of radiographs, with increasing exposure times, of five different dry bone specimens. Seven observers evaluated the 25 series of radiographs. The observers had to determine which radiographs of each series were acceptable for dental diagnostics and which radiograph of each series they preferred. RESULTS: For Ektaspeed Plus film, the exposure time for the preferred radiograph was 0.52 s, with a range of diagnostically acceptable radiographs from 0.23-1.02 s. The preferred radiograph of the solid-state systems required less radiation than film (Sirona, 0.13 s; MPDx 0.35 s). The exposure range of these systems is narrow. In contrast, the exposure range of the phosphor plate systems is very wide. The preferred radiograph of the phosphor plate systems required high exposure (Digora, 1.21 s; Gendex DenOptix, 1.16 s). CONCLUSIONS: All digital systems require less exposure than film for diagnostically acceptable radiographs, but this is less obvious for preferred radiographs. Solid-state systems alert the dentist when a too long exposure time is used by a lack of image quality; phosphor plate systems, however, produce good quality radiographs even at high exposure times, which may result in an unnecessarily high dose.     

Blunt traumatic rupture of a mainstem bronchus: spiral CT demonstration of the “fallen lung” sign

Tracheo-bronchial injuries occur in less than 1 % of blunt chest trauma patients. Indirect signs, such as pneumomediastinum, pneumothorax, and/or subcutaneous emphysema, are revealed on admission plain films and chest CT survey. In most instances, however, tracheo-bronchoscopy is mandatory in assessing the definite diagnosis of tracheo-bronchial lesion. Occasionally, an abnormal course of a mainstem bronchus or a “fallen lung” sign, featuring a collapsed lung in a dependent position, hanging on the hilum only by its vascular attachments, may allow for CT diagnosis of a blunt traumatic bronchial injury. Received: 3 February 2000 Revised: 16 June 2000 Accepted: 22 June 2000     

The “mystery” of the train station: The importance of a forensic approach to a rare case of survival after a train-pedestrian collision

In the early morning a 28-year-old man was found lying on the tracks of a railway station with head injuries and fractures of the cervical spine resulting in permanent quadriplegia. He was in a club about 1 km away until about 2 h earlier and did not have any recollection of what could have happened. Was he the victim of an assault, did he fall down or was he hit by a passing train? The solution to this “mystery” came from a forensic evaluation that included the forensic branches of pathology, chemistry, merceology and genetics as well as the scene evaluation. Through these different steps, the role of a railway collision in determining the injuries was ascertained and a possible dynamic was postulated. The presented case is an expression of the importance of the different forensic disciplines and the difficulties the forensic pathologist encounters when analysing such peculiar and rare cases.     

Renal angiomyolipoma with inferior vena caval extension: MRI demonstration of a “thread-and-streaks” sign

The MR findings in a case of tumor extension into an inferior vena cava from a right renal angiomyolipoma are reported. The flow void demonstrated within the intracaval tumor thrombus on T1-weighted images was consistent with the so-called thread-and-streaks sign. Correspondence to: K. Matsuura