Air trapping in Wegener��s granulomatosis: an additional finding on expiratory chest HRCT

Purpose

This study was undertaken to assess the presence and extent of air trapping (AT) on high-resolution computed tomography (HRCT) in patients with Wegener??s granulomatosis (WG) and to correlate the finding with the inspiratory pattern and bronchial/bronchiolar involvement.

Materials and methods

Twenty-one patients (7 M/14 F) with WG underwent inspiratory and expiratory HRCT. Images were evaluated for the presence and extent of AT and for airway involvement (bronchi/bronchioles); the predominant HRCT pattern was also documented. The attenuation difference was measured between the areas of AT on expiration and the same areas on inspiration in order to verify the finding of AT. The extent of AT was calculated by visual scoring and correlated with the predominant inspiratory patterns and bronchial/bronchiolar involvement.

Results

AT was found in seven patients (33.3%) and its extent ranged between 3% and 70% (mean 15.8±7). Two patients showed no lesions on inspiratory HRCT, and the only finding was AT on expiration. The attenuation difference between areas of AT on expiration and the same areas on inspiration ranged between 32 and 89 HU. Inspiratory HRCT was pathological in 19 patients (90.4%), and the principal lung patterns were nodular, cavitary or noncavitary (n=7, 38.9%); ground-glass opacities (n=5, 26.3%); masses (n=3, 15.8%); fibrotic (n=3, 15.8%); and consolidation with air bronchogram (n=1, 5.3%). Bronchial and bronchiolar involvement was found in 14 and five patients, respectively. No statistically significant correlation was found between AT extent and the findings on inspiration. In addition, there were no specific patterns that caused higher or lower scores of AT. Moreover, when bronchial or bronchiolar involvement was absent, the mean AT score was statistically significantly higher.

Conclusions

Areas of AT represent a new and indirect HRCT finding, ?? and in rare cases the only finding ?? of pulmonary WG. The nonsignificant correlation between AT extent and inspiratory findings may suggest AT as an additional HRCT finding in patients with WG.     

The scab-like sign: A CT finding indicative of haemoptysis in patients with chronic pulmonary aspergillosis?

Objectives

The aim of this study was to assess the CT findings that characterise haemoptysis in patients with chronic pulmonary aspergillosis (CPA).

Methods

We retrospectively identified 120 consecutive patients with CPA (84 men and 36 women, 17–89 years of age, mean age 68.4 years) who had undergone a total of 829 CT examinations between January 2007 and February 2017. In the 11 patients who underwent surgical resection, CT images were compared with the pathological results.

Results

The scab-like sign was seen on 142 of the 829 CT scans, specifically, in 87 of the 90 CT scans for haemoptysis and in 55 of the 739 CT scans obtained during therapy evaluation. In 48 of those 55 patients, haemoptysis occurred within 55 days (mean 12.0 days) after the CT scan. In the 687 CT scans with no scab-like sign, there were only three instances of subsequent haemoptysis in the respective patients over the following 6 months. Patients with and without scab-like sign differed significantly in the frequency of haemoptysis occurring after a CT scan (p<0.0001). Pathologically, the scab-like sign corresponded to a fibrinopurulent mass or blood crust.

Conclusions

The scab-like sign should be considered as a CT finding indicative of haemoptysis.

Key Points

? Haemoptysis is commonly found in patients with CPA. ? A CT finding indicative of haemoptysis in CPA patients is described. ? Scab-like sign may identify CPA patients at higher risk of haemoptysis.

     

Is the “blooming sign” a promising additional tool to determine malignancy in MR mammography?

The aim of this study was to evaluate potential diagnostic relevance of blooming effect for verification of suspicious breast lesions in MR mammography (MRM). The MRM examinations of 1035 patients, all following the same imaging protocol (from 1994 to 2001) were retrospectively evaluated by two experienced radiologists in consensus. A total of 817 lesions showed a focal enhancement; of these, 793 were histologically verified after surgical intervention so that 514 malignant and 279 benign lesions could be evaluated. Using a 1.5-T Gyroscan ACS II-imager (Philips, Hamburg, Germany) and a double breast coil with the patient lying in a prone position, 0.1 mmol/kgbw Magnevist (Schering, Berlin, Germany) were injected into the cubital vein to obtain dynamic axial and coronal T1-weighted fast-field-echo images every minute up to 7 min after bolus injection. Blooming sign describes a progradient unsharpness of lesion borders initially sharply shaped and fast enhancing 7 min after bolus injection; 324 of 514 (63.0%) malignant lesions and 41 of 279 (14.7%) benign lesions revealed a blooming sign (sensitivity 63.0%, specificity 85.3%, accuracy 70.9%, positive predictive value 88.8%, negative predictive value 56.0%). Forty-one of 279 benign lesions showed a blooming sign; of these, there were 4 of 86 (4.7%) fibroadenomas, 2 of 21 (9.5%) phylloides tumours, 11 of 38 (28.9%) papillomas, 3 of 9 (33.3%) radial scars, 2 of 19 (10.5%) mastitis, 1 of 4 (25%) galactophoritis, 1 of 3 (33.3%) ADH and 19 of 99 (17.2%) mastopathic proliferations, respectively. Blooming sign is a phenomenon which should be taken into account when diagnosing MR mammographies because it might increase the ability to discriminate uncertain breast lesions; however, this effect can only be used as an additional item to other well-known effects such as plateau, washout and cancer corner.     

The “whisker sign” as an indicator of ochronosis in skeletal scintigraphy

A patient with alkaptonuria and ochronotic arthrosis was imaged twice with technetium-99m dicarboxypropane diphosphonate (^99mTc-DPD) — once during a bout of arthritic knee pain and once when symptom-free. There was a marked accumulation of radioactivity in the large joints. During the episode of arthritis the knee joints had a higher uptake than when the patient was without symptoms. The intervertebral discs showed a high uptake which extended laterally from the axial vertebral column; the finding gave an impression of whiskers, and this whisker sign may be characteristic of ochronosis.     

Should contrast CT urography replace non-contrast CT as an investigation for ureteric colic in the emergency department in those aged 65 and over?

Purpose

Elderly patients with upper tract urothelial cancer (UTUC) may present with colic and microscopic haematuria, mimicking urolithiasis. Patients presenting to emergency departments with acute ureteric colic are investigated with a CT KUB. CT urography (CTU) identifies UTUC better than a CT KUB. Thus, there is a possibility that a CT KUB may miss UTUC.

Methods

We studied patients aged 65 years or over presenting to the emergency department with ureteric colic and microscopic haematuria who had a CT KUB between January 2014 and October 2016. Patients who had both CT KUB and CTU were then compared to determine if CT KUB had missed a UTUC and if the diagnoses were concordant by the two tests. A radiologist independent from the reporting radiologists reviewed images as well as their reports. According to the Health Research Authority, England regulations, we did not obtain an ethical review on a voluntary basis for this retrospective study.

Results

Four hundred eighty-five patients [228 (47.01%) male and 257 (52.99%) female] had a CT KUB scan over the 34-month period. Their mean age was 74 (SD 6.97) [males 73 (SD 6.42), females 75 (SD 7.42)] years. One hundred eighty-seven scans were normal. Ureteric calculi (167), renal calculi (58) and renal cysts (28) were most frequent diagnoses. The diagnosis was uncertain in 33 patients (6.8%) [16 (48.49%) males and 17 (51.51%) females]. The mean age of this group of patients was 74 (SD 6.64) [males 73 (SD4.43), females 74 (SD7.64)] years. These patients had a CTU for clarity. CTU identified one UTUC not identified by CT KUB (0.2%), corroborated the diagnosis of a ureteric tumour in one patient and excluded UTUC in two others. CTU diagnosed two new bladder tumours and an endometrial tumour. Diagnoses were concordant between CT KUB and CTU in 17 of 33 patients (51.5%).

Conclusions

CT KUB scans for patients 65 years and over presenting with ureteric colic is justified. Only a small proportion of patients will subsequently require the higher radiation dose CTU as the probability of missing UTUC is low.

     

“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.     

”Spinolaminar breach”: an important sign in cervical spinous process fractures

Objective. To report the sign of ”spinolaminar breach” and its likely importance in fractures of the cervical spinous processes. Design. Six cases of spinous process fractures demonstrating disruption of the spinolaminar line or ”spinolaminar breach” were analyzed. Lateral and anteroposterior radiographs (n=6), CT scans (n=3) and MRI scans (n=1) were reviewed together by the authors, with consensus being reached as to the radiographic findings. Clinical records were also reviewed. Results. The levels of injury were C6 (n=5) and C5 (n=2). Injuries were associated with delayed anterior subluxation (n=4) and neurological deficit (n=2). Five patients were male and one was female with a mean age of 31 years (range 8–59 years). Injuries resulted from motor vehicle accidents (n=4), a motor cycle accident (n=1) and a fall (n=1). Conclusion. ”Spinolaminar breach”, or disruption of the spinolaminar line, indicates a complex spinous process fracture with extension into the lamina and spinal canal. Spinous process fractures with spinolaminar breach may have associated posterior ligamentous injury with potential for delayed instability and neurological deficit. It is important that radiologists and physicians caring for the trauma patient be aware of this sign in order to avoid misdiagnosis as a ”clay shoveler’s fracture”, which can lead to adverse outcome. Received: 20 July 1999 Revision requested: 14 September 1999 Revision received: 13 October 1999 Accepted: 26 October 1999     

CT and MR imaging of the “target sign” in metastatic brain disease

The “target sign” is a common finding in granulomatous infection. A case with the target sign in metastatic brain tumor from small cell lung carcinoma is reported. Received: 28 September 1998; Revised: 15 March 1999; Accepted: 15 April 1999     

“Swirl sign” of aggressive angiomyxoma—a lesser known diagnostic sign

Aggressive angiomyxoma is a rare mesenchymal tumor with high rate of local recurrence, found mainly in the pelvis and perineum of women of reproductive-aged group. We present cases of two patients, with emphasis on the magnetic resonance (MR) imaging characteristics. The clinical presentation was nonspecific. MR imaging revealed characteristic “swirl sign” in T2-weighted sequence. Preoperative diagnosis could not be made in the first patient due to a lack of experience about the diagnosis. Preoperative diagnosis was made in the second case and was helpful for the surgeon to excise the mass completely. Aggressive angiomyxoma should be on the top of a differential diagnosis in the appropriate clinical and imaging scenario.     

Does CT have an additional diagnostic value over ultrasound in the evaluation of acute inflammatory neck masses in children?

Objectives  

We assessed the additional value of contrast-enhanced CT versus US for evaluation of acute cervical inflammatory masses and choosing treatment strategy.     

Dynamic nature of the CT angiographic “spot sign”

The “spot sign”, first described in 2007, has shown that a focal area of contrast extravasation within an intracerebral haematoma (ICH) can be correlated with haematoma expansion. We describe a case where time-resolved dynamic CT angiography (dCTA) shows the appearance of the “spot sign” only in later images. This finding highlights the importance of timing of the static CT angiogram which, if performed too early, might result in a false-negative diagnosis.Contrast extravasation into an intracerebral haemorrhage has been associated with haematoma growth and poor clinical outcomes including death [1, 2]. More recently, the “spot sign” has been validated as a marker of intracerebral haematoma (ICH) expansion [3]. However, these imaging studies are static, acquired at a particular point in time. Dynamic CT angiography (dCTA) demonstrates temporal wash-in and wash-out of intravenous contrast material over a chosen temporal resolution. This allows temporal visualisation of contrast flowing through vessels. We present a case capturing distinct areas of “spot sign” within an acute ICH using time-resolved dCTA.The success of future therapies, including haemostatic agents, for the treatment of ICH may depend on accurate determination of haematomas at risk of expansion [4].     

Does the CT whirl sign really predict small bowel volvulus?: Experience in an oncologic population

The objective of this study was to determine the sensitivity of the CT "whirl sign" for the diagnosis of small bowel volvulus in patients who present with a clinical suspicion of intestinal obstruction. Between January 2002 and September 2004, 1,493 CT scans performed in 1,213 patients suspected of having small bowel obstruction were retrospectively reviewed by one attending radiologist with gastrointestinal subspecialization and one senior radiology resident. Multislice helical CT scans were performed after oral and intravenous contrast administration. All CT scans showing a combined vessel and bowel whirl appearance were identified. Other features recorded included the number of degrees of whirl rotation, direction of rotation, presence of bowel obstruction, and signs of ischemia. Diagnoses were determined at either surgery or clinicoradiographic follow-up. Surgical follow-up was available in 174 of the 1,213 patients. There were 460 males and 753 females ranging in age from 1 to 95 years (mean 59 years). A whirl sign was found in 33 of the 1,493 CT scans by reader 1 and in 13 of the 1,493 CT scans by reader 2. In 11 patients, surgery revealed small bowel volvulus (0.9%). Reader 1 detected 7 of the 11 volvuli (sensitivity 64%, specificity 98%, positive predictive value 21%, negative predictive value 99.7%). Reader 2 detected 3 of the 11 volvuli (sensitivity 27%, specificity 99%, positive predictive value 23%, negative predictive value 99.5%). The CT scans of the four remaining patients with volvulus not initially recognized by either reader were re-reviewed and were felt to contain whirl signs. Most patients with small bowel volvulus can be identified on CT through detection of a whirl sign. However, most whirl signs detected on CT will not prove to be indicative of small bowel volvulus.     

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 ultrasonographic “whirlpool sign” in testicular torsion: valuable tool or waste of valuable time? A systematic review and meta-analysis

Purpose

A positive whirlpool sign (WS) is defined as the presence of a spiral-like pattern when the spermatic cord is assessed during ultrasonography (US), using standard, high-resolution ultrasonography (HRUS) and/or color Doppler sonography (CDS), in the presence of testicular torsion. The objective of this review was to assess the validity and accuracy of this sign by performing a comprehensive systematic literature review and meta-analysis.

Methods

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, a comprehensive literature search was performed (August, 2017), using the following databases: BMJ Best Practice, Cochrane Library, Embase, PubMed, Scopus, and Web of Science. Selected studies were further assessed for relevance and quality using the Oxford 2010 Critical Appraisal Skills Program (CASP).

Results

Of the studies assessed, a total of 723 participants were included, with a mean of 72.3 (SD 71.9) participants. Of the participants, 226 (31.3%) were diagnosed with testicular torsion (TT). Meta-analysis of the studies that provided sufficient data resulted in a pooled sensitivity and specificity of the WS of 0.73 (95% CI, 0.65–0.79) and 0.99 (95% CI, 0.92–0.99), respectively. Removal of all neonates increased the pooled sensitivity to 0.92 (95% CI, 0.70–0.98) while the pooled specificity remained almost unchanged at 0.99 (95% CI, 0.95–1.00). The estimated summary effect of all studies with sufficient data was 4.34 (95% CI, 1.01–7.67; n?=?394; p?=?0.001). A large degree of heterogeneity was suggested by an I² statistic of 88.27% (95% CI, 68.60–98.68%). Removal of neonatal subjects increased the estimated summary effect to 5.32 (95% CI, 1.59–9.05; n?=?375; p?=?0.001).

Conclusion

The WS, when correctly diagnosed, may be viewed as a very definitive sign for TT in the pediatric and adult populations. However, its role in neonates is limited.

     

“Dynamic spot sign” on CT perfusion source images predicts haematoma expansion in acute intracerebral haemorrhage

Objectives

To evaluate the association between dynamic progressive enhancing foci (“dynamic spot sign”) in acute haematoma on CT perfusion source images (CTP-SI) and haematoma expansion.

Methods

One hundred twelve consecutive patients with spontaneous intracerebral haemorrhage according to unenhanced CT, CTP and CT angiography within 6 h of symptom onset were prospectively evaluated. Patients were dichotomised according to the presence/absence of the dynamic spot sign on CTP-SI in haematoma. The predictive value of haematoma expansion was analysed.

Results

Haematoma expansion was detected in 28 patients (25.0 %) on follow-up unenhanced CT images. Thirty patients (26.8 %) demonstrated the dynamic spot sign on CTP-SI, about 83.3 % of patients with haematoma expansion (P?<?0.001). Sensitivity, specificity, positive predictive value, negative predictive value and kappa value for expansion were 89.3 %, 94.0 %, 96.3 %, 83.3 % and 0.814, respectively. In multiple regression, the presence of the CTP dynamic spot sign within acute haematomas independently predicted haematoma expansion; the univariate analysis OR value was 131.667 (29.386–590.289), P?<?0.0001. Moreover, the multivariate analysis CTP dynamic spot sign OR value was 203.996 (32.123–1295.488), P?<?0.0001.

Conclusions

The CTP-SI dynamic spot sign is associated with acute haematoma expansion, is more direct in showing active ongoing bleeding and has a higher predictive value than the CTA spot sign.

Key Points

? It is important to identify potential progression of spontaneous intracerebral haemorrhage. ? Dynamic enhancement within CT perfusion source images is associated with haemorrhage expansion. ? The CTP dynamic spot sign may be present throughout arterial to venous phase imaging. ? The CTP dynamic spot sign carries a higher predive value for haematoma expansion than CTA.     

Trapped on the “whirl”: diagnostic sign on emergency CT

The “whirl sign” is an uncommon finding on emergency CT. However, it is easy to overlook if not kept in mind. Its recognition is of capital importance, being most of its causes potentially lethal. Surgical treatment is also mandatory when signs of complication are found. The whirl sign is usually found associated to midgut, cecal and sigmoid volvulus, small-bowel volvulus and closed-loop obstructions, and post-surgical mesenteric windows (including retroanastomotic hernias). CT is an optimal imaging technique to depict the so-called sign and associated CT features suggesting complication (circumferential wall thickening, pneumatosis intestinalis, pneumoperitoneum, mesenteric fat stranding, free intraperitoneal fluid, mesenteric haziness). Radiologists must be able to recognize the whirl sign and seek associated findings that strongly support the diagnosis of a spectrum of entities, some of them lethal if no treatment is established.     

MRI “row of dots sign” in gossypiboma: an enlarging mass 8 months after sarcoma resection

The retention of foreign bodies after surgery is rare, but carries significant morbidity and mortality as well as financial and legal implications. Such retained items cause a foreign-body reaction, which in the case of cotton-based materials are called gossypibomas. We present the case of an 84-year-old woman with a pseudotumor secondary to a retained dressing gauze roll, presenting 5 months after resection of a gluteal sarcoma, which had raised concerns of local recurrence. We also outline the imaging modalities that may assist in diagnosis of a retained foreign body, and suggest the MRI “row of dots” sign as a useful radiological feature associated with gossypiboma. Awareness of the imaging appearances of retained foreign bodies allows the inclusion of this possibility in differential diagnosis of a mass in patients with a surgical history.