Accuracy Of Various Imaging Modalities Research Articles

A Systematic Review of Classification Systems for Cervical Ossification of the Posterior Longitudinal Ligament.

Design:Systematic review.Objective:To conduct a systematic review to (1) summarize various classification systems used to describe cervical ossification of the posterior longitudinal ligament (OPLL) and (2) evaluate the diagnostic accuracy of various imaging modalities and the reliability of these classification systems.Methods:A search was performed to identify studies that used a classification system to categorize patients with OPLL. Furthermore, studies were included if they reported the diagnostic accuracy of various imaging modalities or the reliability of a classification system.Results:A total of 167 studies were deemed relevant. Five classification systems were developed based on X-ray: the 9-classification system (0.60%); continuous, segmental, mixed, localized or focal, circumscribed and others (92.81%); hook, staple, bridge, and total types (2.40%); distribution of OPLL (2.40%); and K-line classification (4.19%). Six methods were based on computed tomography scans: free-type, contiguous-type, and broken sign (0.60%); hill-, plateau-, square-, mushroom-, irregular-, or round-shaped (5.99%); rectangular, oval, triangular, or pedunculate (1.20%); centralized or laterally deviated (1.80%); plank-, spindle-, or rod-shaped (0.60%); and rule of nine (0.60%). Classification systems based on 3-dimensional computed tomography were bridging and nonbridging (1.20%) and flat, irregular, and localized (0.60%). A single classification system was based on magnetic resonance imaging: triangular, teardrop, or boomerang. Finally, a variation of methods was used to classify OPLL associated with the dura mater (4.19%).Conclusions:The most common method of classification was that proposed by the Japanese Ministry of Health, Labour and Welfare. Other important methods include K-line (+/−), signs of dural ossification, and patterns of distribution.

Role of imaging in evaluation of intestinal obstruction

Introduction: Small bowel obstruction (SBO) is a common clinical entity that occurs secondary to mechanical or functional obstruction of the small gut, preventing normal passage of its contents. It constitutes 20% of all surgical emergencies for acute abdominal pain and a common cause for hospitalization. Plain abdominal X-ray and ultrasonography were used for initial examination. Now, Computed tomography is the modality of choice for preoperative evaluation of SBO. Aims and Objectives: To evaluate the diagnostic accuracy of various imaging modalities namely plain x-rays of abdomen, ultrasound and computed tomography in the diagnosis of intestinal obstruction with reference to a) The presence or absence of obstruction b) The level of obstructionc) The cause of obstruction. Materials and Methods: It was a hospital based prospective study in which X-Ray and ultrasonography were done as an initial modality for screening and Multi Detector Computed Tomography (MDCT) scan was done later on for detailed evaluation. Relevant history, clinical examination and routine investigations were done. Results: Acute intestinal obstruction: CT scan was found to be superior in predicting a fully correct diagnosis (78%) when compared to ultrasound (29%) which in turn was found to be superior to plain films which provided fully correct diagnosis only in 10% of the cases. Subacute intestinal obstruction- In 62.5 % cases of sub acute intestinal obstruction CT scan provide fully correct diagnosis whereas in none of the cases did ultrasound or plain films provide fully correct diagnosis. Conclusion: CT was found to be superior to ultrasound and plain films in finding out the presence, level as well as cause of obstruction.

Imaging modalities for characterising focal pancreatic lesions.

Imaging modalities for characterising focal pancreatic lesions.

Diagnostic accuracy of sialendoscopy referenced to current imaging modalities

AimThe aim of the present study was to determine the accuracy of diagnostic sialendoscopy in patients with suspected obstructive salivary duct disease referenced to current imaging modalities.Patients and MethodsA retrospective study of patients with symptoms suggestive of obstructive salivary duct disease who underwent one or more imaging modalities, and then sialendoscopy at an academic hospital, were reviewed. The radiological and sialendoscopic findings were compared, and the diagnostic accuracy of various imaging modalities was determined using sialendoscopy as a reference.ResultsSeventy‐five sialendoscopies were performed in 68 patients (39 females, 29 males). Obstructive lesions were identified in 71 of the 75 sialendoscopies; 18 stones and 53 nonstone obstructive lesions were identified. Imaging consisting of plain X‐ray (n = 4), radiosialography (n = 18), ultrasonography (n = 58), computed tomography (n = 13) and magnetic resonance imaging (n = 10) detected disease in 25, 70.6, 69.1, 69.2 and 100 per cent of diseased ducts, respectively.ConclusionSialendoscopy is more sensitive, and thus more useful, in diagnosing obstructive salivary duct disease in symptomatic patients than current imaging modalities. Symptomatic patients with negative imaging should be considered for sialendoscopy when therapy, such as stone retrieval or stricture dilation, can instituted at the time of diagnosis.

Accuracy of estimating Unicondylar Knee Replacement implant varus/valgus angles from antero-posterior radiographs

Unicondylar Knee Replacement (UKR) is an orthopedic surgical procedure to reduce pain and improve function in the knee. Load-bearing long-standing antero-posterior (AP) radiographs are typically used postoperatively to measure the leg alignment and assess the varus/valgus implant orientation. However, implant out-of-plane rotations, user variability, and X-ray acquisition parameters introduce errors in the estimation of the implant varus/valgus estimation. Previous work has explored the accuracy of various imaging modalities in this estimation. In this work, we explored the impact of out-of-plane rotations and X-ray acquisition parameters on the estimation of implant component varus/valgus angles. For our study, we used a single CT scan and positioned femoral and tibial implants under varying orientations within the CT volume. Then, a custom software application was used to obtain digitally reconstructed radiographs from the CT scan with implants under varying orientations. Two users were then asked to manually estimate the varus/valgus angles for the implants. We found that there was significant inter-user variability (p < 0.05) in the varus/valgus estimates for the two users. However, the ‘ideal’ measurements, obtained using actual implant orientations, showed small errors due to variations in implant orientation. We also found that variation in the projection center does not have a statistically significant impact (p < 0.01) on the estimation of implant varus/valgus angles. We conclude that manual estimates of UKR implant varus/valgus orientations are unreliable.

Diagnostic Accuracy of Various Imaging Modalities for Suspected Lower Extremity Stress Fractures

Background: The literature is filled with conflicting findings regarding diagnostic accuracy and protocols for imaging suspected lower extremity stress fractures. The absence of systematic reviews on this topic has limited the development of evidence-based recommendations for appropriate imaging protocols in cases of suspected lower extremity stress fractures. Purpose: To determine the diagnostic accuracy statistics of imaging modalities used to diagnose lower extremity stress fractures and to synthesize evidence-based recommendations for clinical practice. Study Design: Systematic review. Methods: A generic search strategy for published studies was performed using multiple databases. A study was eligible for inclusion if it met all of the following criteria: (1) at least 1 diagnostic imaging modality was studied, (2) at least 1 radiological reference standard was used, (3) the study reported or allowed computation of diagnostic accuracy statistics (sensitivity, specificity, positive likelihood ratio, negative likelihood ratio), (4) a full-text version was available, (5) the article was written in English, and (6) the study included lower extremity stress fractures. Studies that examined asymptomatic individuals or patients with fractures due to disease or pharmacologic intervention were excluded. Results: Reported sensitivity and specificity (95% CI) were as follows: For conventional radiography, sensitivity ranged from 12% (0%-29%) to 56% (39%-72%) and specificity ranged from 88% (55%-100%) to 96% (87%-100%). For nuclear scintigraphy (NS), sensitivity ranged from 50% (23%-77%) to 97% (90%-100%) and specificity from 33% (12%-53%) to 98% (93%-100%). For magnetic resonance imaging (MRI), sensitivity ranged from 68% (45%-90%) to 99% (95%-100%) and specificity from 4% (0%-11%) to 97% (88%-100%). For computed tomography, sensitivity ranged from 32% (8%-57%) to 38% (16%-59%) and specificity from 88% (55%-100%) to 98% (91%-100%). For ultrasound, sensitivity ranged from 43% (26%-61%) to 99% (95%-100%) and specificity from 13% (0%-45%) to 79% (61%-96%). Conclusion: MRI was identified as the most sensitive and specific imaging test for diagnosing stress fractures of the lower extremity. When MRI is available, NS is not recommended because of its low specificity, high dosage of ionizing radiation, and other limitations. Conventional radiographs are likely to result in false negatives upon initial presentation, particularly in the early stages of stress fracture, and in some cases may not reveal an existing stress fracture at any time. A diagnostic imaging algorithm was developed with specific recommendations for cost-efficient imaging of low-risk and high-risk suspected stress fractures.

Primary and minor indications to bedside renal ultrasonography

We appreciated the letter ‘‘Bedside renal ultrasonography: other utilities than hydronephrosis’’ by Chia-Ter Chao [1]. The author described the ultrasonographic (US) findings of acute pyelonephritis (APN), analysed the diagnostic accuracy of various imaging modalities in this disease, and emphasized the role of bedside US in APN. On the basis of these considerations, Chao commented on the fact that in our paper titled ‘‘Clinical applications of bedside ultrasonography in Internal and Emergency Medicine’’ [2] we considered obstructive uropathy and acute urine retention as the primary indications for bedside US in urinary tract diseases and mention, as other indications, hematuria, acute renal failure, suspected abscesses of the kidneys, and gross prostate abnormalities without including APN. We comprehend the enthusiasm of Chao for the application of US in APN that confirms the knowledge and the experience of the author in this field but completely disagree with him when he attributes the same role and similar importance of bedside US to APN versus hydronephrosis, renal stone or other obstructive uropathy. We think that between APN and the latter pathologies, there are very important differences not only for the diagnostic accuracy and the role of US, especially if performed bedside, but also for the epidemiologic occurrence in both Internal Medicine and Emergency Departments. First of all, we have to keep in mind what bedside US is. This is a rapid and simple US method for the diagnostic evaluation of emergency medical conditions in the acutely ill, critically ill or injured patient, performed bedside with small portable instruments often capable of only fundamental imaging [3]. This technique can also be executed by clinicians with a limited experience in US, equipped with only a second level of experience, according to EFSUMB learning guidelines [1]. With respect to the sonographic findings of acute pyelonephritis mentioned by Chao, we have no comment because they are well known and reported in the literature, but they do not have a high specificity, since the disease produces hypoechoic as well as hyperechoic areas. Colour and power Doppler US produces a small increase in the sensitivity of US, but mainly in the case of abscesses. Similarly angiosonography (CEUS) can be usefully employed only in the presence of renal abscesses but not in APN without complications. In fact, EFSUMB guidelines report indications for CEUS only in case of focal renal tumours, trauma, or abscesses, and not in APN [4]. Finally we have to consider that Colour and Power Doppler US, and especially CEUS, are certainly not methods used as bedside US. Moreover, a recent review on the state of the art of imaging of renal infections confirms that US is especially effective in the diagnosis of hydronephrosis or pyonephrosis, is less sensitive than computed tomography (CT) in evaluating for complications, has major limits in operator dependency and in obese patients, and remains a main stay in differentiating cystic versus solid structures [5]. The same conclusions have been reported in another important review on radiologic and pathologic aspects of pyelonephritis: diagnosis is typically based on clinical features and laboratory tests; imaging is reserved for nonresponders or patients with a typical clinical presentation. Computed tomography, over conventional radiography and US, is the preferred method for evaluating APN and emphysematous pyelonephritis. US is useful but CT A. Vincenzo C. Valeria (&) Department of Internal Medicine, Maggiore Hospital, Largo B. Nigrisoli 2, 40133 Bologna, Italy e-mail: v.camaggi@ausl.bologna.it