Imaging Protocol For Patients Research Articles

Cardiac Magnetic Resonance Relaxometry Parameters, Late Gadolinium Enhancement, and Feature-Tracking Myocardial Longitudinal Strain in Patients Recovered from COVID-19.

COVID-19 infection is associated with myocarditis, and cardiovascular magnetic resonance (CMR) is the reference non-invasive imaging modality for myocardial tissue characterization. Quantitative CMR techniques, such as feature tracking (FT) and left ventricular global longitudinal strain (GLS) analysis, have been introduced as promising diagnostic tools to improve the diagnostic accuracy of suspected myocarditis. The aim of this study was to analyze the left ventricular global longitudinal strain (GLS) and the influence of T1 and T2 relaxation times, ECV, and LGE appearance on GLS parameters in a multiparametric imaging protocol in patients who recovered from COVID-19. The 86 consecutive patients enrolled in the study had all recovered from mild or moderate COVID-19 infections; none required hospitalization. Their persistent symptoms and suspected myocarditis led to cardiac magnetic resonance imaging within 3 months of the diagnosis of the SARS-CoV-2 infection. Results: Patients with GLS less negative than -15% had significantly lower LVEF (53.6% ± 8.9 vs. 61.6% ± 4.8; <0.001) and were significantly more likely to have prolonged T1 (28.6% vs. 7.5%; p = 0.019). Left ventricular GLS correlated significantly with T1 (r = 0.303; p = 0.006) and LVEF (r = -0.732; p < 0.001). Left ventricular GLS less negative than -15% was 7.5 times more likely in patients with prolonged T1 (HR 7.62; 95% CI 1.25-46.64). The reduced basal inferolateral longitudinal strain had a significant impact on the global left ventricular longitudinal strain. ROC results suggested that a GLS of 14.5% predicted prolonged T1 relaxation time with the best sensitivity and specificity. Conclusions: CMR abnormalities, including a myocarditis pattern, are common in patients who have recovered from COVID-19. The CMR feature-tracking left ventricular GLS is related to T1 relaxation time and may serve as a novel parameter to detect global and regional myocardial injury and dysfunction in patients with suspected myocardial involvement after recovery from COVID-19.

“National survey for preliminary evaluation of neuroradiological protocols in patients with infective endocarditis”

ObjectivesThe aim of this study was to identify imaging protocols in patients with infective endocarditis through a nationwide survey. MethodsAn electronic evolutionary survey was sent to interventional Neuroradiologists among neuroradiological centers, under the aegis of the Société Française de Neuroradiologie. Among 33 contacted centers, 25 completed the survey (21 universitary hospitals and 4 peripheric hospitals). ResultsMost of the centers (88%) used systematic imaging screening in IE patients. MRI was the first imaging method used in 56% of cases, while CT was used in 44%. When no IIA was detectable in CT-scan screening, 6 (54%) stopped investigations, while 9 (81%) continued with MRI exploration in case of hemorrhage, ischemia or enhancement. Sulcal hemorrhage on MRI was an indication of complementary DSA in 25 centers (100%). Regarding IIA characterization, 12 centers (48%) used systematic DSA, whereas for 10 centers (40%), DSA was conditioned by hemorrhage or patient status. ConclusionWe highlighted large variations in Neuroimaging exploration and follow-up of IE patients in real-world practices. Expert guidelines able to standardize practices are warranted to improve the management of this serious and often misdiagnosed pathology.

Diagnostic Accuracy of MRI for Detecting Cervical Invasion in Patients with Endometrial Carcinoma: A Meta-Analysis.

Objectives: To evaluate the diagnostic accuracy of magnetic resonance imaging (MRI) in the preoperative assessment of cervical invasion and to analyse the influence of different imaging protocols in patients with endometrial carcinoma.Methods: An extensive search of articles about MRI for assessing cervical invasion in patients with endometrial carcinoma was performed on PubMed, Embase, Web of Science, Cochrane Library, and Clinical Trials from January 2000 to July 2020. Two reviewers independently evaluated the methodological quality of each study by using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). Diagnostic accuracy results and additional useful information were extracted. The pooled estimation data was obtained by statistical analysis.Results: A total of 42 eligible studies were included in the meta-analysis. Significant evidence of heterogeneity was found for detecting cervical invasion (I2 = 74.1%, P = 0.00 for sensitivity and I2 = 56.2%, P = 0.00 for specificity). The pooled sensitivity and specificity of MRI were 0.58 and 0.95 respectively. The use of higher field strength (3.0 T) demonstrated higher pooled sensitivity (0.74). Using diffusion weighted imaging (DWI) alone presented higher pooled sensitivity (0.86) than using other sequences. The studies that used dynamic contrast-enhanced MRI (DCE-MRI) alone showed higher sensitivity (0.80) and specificity (0.96) than those that used T2-weighted imaging (T2WI) alone.Conclusions: MRI shows high specificity for detecting cervical infiltration in endometrial carcinoma. Using DWI or a 3.0-T device may improve the pooled sensitivity. DCE-MRI demonstrates higher pooled sensitivity and specificity than T2WI.

Ultra-High-Field Targeted Imaging of Focal Cortical Dysplasia: The Intracortical Black Line Sign in Type IIb.

Conventional MR imaging has limitations in detecting focal cortical dysplasia. We assessed the added value of 7T in patients with histologically proved focal cortical dysplasia to highlight correlations between neuropathology and ultra-high-field imaging. Between 2013 and 2019, we performed a standardized 7T MR imaging protocol in patients with drug-resistant focal epilepsy. We focused on 12 patients in whom postsurgical histopathology revealed focal cortical dysplasia and explored the diagnostic yield of preoperative 7T versus 1.5/3T MR imaging and the correlations of imaging findings with histopathology. We also assessed the relationship between epilepsy surgery outcome and the completeness of surgical removal of the MR imaging-visible structural abnormality. We observed clear abnormalities in 10/12 patients using 7T versus 9/12 revealed by 1.5/3T MR imaging. In patients with focal cortical dysplasia I, 7T MR imaging did not disclose morphologic abnormalities (n = 0/2). In patients with focal cortical dysplasia II, 7T uncovered morphologic signs that were not visible on clinical imaging in 1 patient with focal cortical dysplasia IIa (n = 1/4) and in all those with focal cortical dysplasia IIb (n = 6/6). T2*WI provided the highest added value, disclosing a peculiar intracortical hypointense band (black line) in 5/6 patients with focal cortical dysplasia IIb. The complete removal of the black line was associated with good postsurgical outcome (n = 4/5), while its incomplete removal yielded unsatisfactory results (n = 1/5). The high sensitivity of 7T T2*-weighted images provides an additional tool in defining potential morphologic markers of high epileptogenicity within the dysplastic tissue of focal cortical dysplasia IIb and will likely help to more precisely plan epilepsy surgery and explain surgical failures.

The use of rotational fluoroscopy and 3-D reconstruction in the diagnosis and surgical planning for complex cloacal malformations

IntroductionCloacal malformations, a confluence of the urinary tract, vagina and rectum into a single common channel, has a broad and complex anatomic spectrum requiring an imaging tool for visualization, measurement, and surgical planning for the reconstruction of these structures. We evaluated the role of 3-D fluoroscopy for this purpose, as it offers a combination of spatial correlation with precise anatomic measurements. MethodsWe examined our imaging protocol for patients with a cloacal malformation and report our experience with rotational fluoroscopy and 3-D reconstruction in 16 consecutive patients referred for cloacal reconstruction. The length of the common channel (CC), the length of the urethra from the bladder neck to the common channel, and the height (and existence or absence) of a vagina or vaginas were determinants of the surgical procedures used for the repair. ResultsWe performed 16 consecutive 3-D cloacagrams (age range 4 months to 9 years) using a new protocol (Figure 1) that provided the following data which helped with surgical planning: Gynecologic: 3 cases with a single vagina, 5 cases with a duplicated Mullerian system (3 of which were asymmetric) and 2 cases with high vaginas requiring vaginal replacement. Colorectal: Four had a high rectum requiring an abdominal approach, and 6 had a rectum reachable via a posterior sagittal approach. Urologic: Two ectopic ureters requiring reimplantation, 3 patients had vesicoureteral reflux (1 bilateral, 2 unilateral), 1 patient had no bladder, and 7 had a normal sized bladder. Common channel length and urethral length were demonstrated in all cases and used to decide between a total urogenital mobilization or a separation of vagina(s) from the common channel, urogenital separation. ConclusionThe 3-D cloacagram can help predict the surgical plan for urologic, gynecologic, and colorectal components of the cloacal repair. It can predict the CC length as well as the length of the urethra. It helps with predicting the need for vaginal replacement and whether an abdominal approach is needed for the rectum. Its effectiveness is based on the ability to adequately distend structures and see their distal most extent, an advantage over other modalities such as MRI. Added benefits (particularly from the 3D view) include a better spatial understanding of the defect and the diagnosis of concomitant urological abnormalities such as vesicoureteral reflux and ectopic ureters. Disadvantages to this procedure include the need for general anesthesia and a higher exposure to radiation. Level of evidence3.

Feasibility and accuracy of single time point imaging for renal dosimetry following 177Lu-DOTATATE (\u2018Lutate\u2019) therapy

BackgroundThis study aims to assess both feasibility and accuracy of renal dosimetry imaging protocols in patients receiving Lutate therapy for neuroendocrine tumours (NETs), when data acquisition over multiple days is not possible on all cycles.MethodPatients who had received a full 4 cycles of Lutate therapy with complete imaging at each cycle were included. Imaging consisted of quantitative SPECT/CT of the kidneys at 4, 24 and 96–120 h post injection. Renal absorbed dose was calculated for each data set, and in addition, five alternative methods were explored for comparison. Method 1: a patient average clearance time (t1/2 average) derived from the first half of contributing patient data was used to estimate absorbed dose for subsequent patients based on 4 h imaging alone; method 2: t1/2 average was applied to subsequent patients on 24 h imaging alone; method 3: a patient-specific clearance rate (t1/2 patient) was determined from complete image data of cycle 1 and applied subsequently to remaining cycles using 4 h image data alone; method 4: t1/2 patient was applied to 24 h imaging alone in subsequent cycles; method 5: the 120 h data was estimated on subsequent cycles based on the cycle 1 fraction of injected activity (%IA) at 24 and 120 h.ResultsTwenty treatments from 18 patients, resulting in 80 cycles of therapy, were analysed. The measured average renal absorbed dose per cycle of treatment was 0.38 ± 0.19 Gy/GBq when derived from full imaging data. The use of t1/2 average applied to a single time point led to large deviations of dose estimates from true values (on average 59% and 30%, when using 4 h data and 24 h data, respectively). The use of complete image data on cycle 1 and the derivation of t1/2 patient led to improved dose estimates, with an average deviation from true values of 13% and 2% when using 4 h data only and 24 h data only, respectively. The use of a 120 h %IA derived from cycle 1 led to an average deviation from true dose estimates of 14%.ConclusionIn instances where demands on both patients and facilities make multiple time point data acquisition impractical, renal dosimetry is best derived through complete imaging at cycle 1 only followed by a single 24 h imaging time point on subsequent cycles, assuming no significant changes in renal function during the time course of therapy.

The Diagnostic Value of MR Imaging in Differentiating T Staging of Bladder Cancer: A Meta-Analysis.

Purpose To assess the diagnostic accuracy of magnetic resonance (MR) imaging for differentiating stage T1 or lower tumors from stage T2 or higher tumors and to analyze the influence of different imaging protocols in patients with bladder cancer. Materials and Methods A systematic literature search for original diagnostic studies was performed in PubMed, Medline, the Cochrane Library, and Web of Science. The methodologic quality of each study was evaluated by two independent reviewers who used the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Data necessary to complete 2 × 2 tables were obtained, and patient, study, and imaging characteristics were extracted. Statistical analysis included data pooling, heterogeneity testing, sensitivity analyses, and forest plot construction. Results Seventeen studies (1449 patients with bladder cancer) could be analyzed. The pooled sensitivity and specificity of MR imaging were 0.90 (95% confidence interval [CI]: 0.83, 0.94) and 0.88 (95% CI: 0.77, 0.94), respectively, for differentiating tumors staged T1 or lower from those staged T2 or higher. Diffusion-weighted imaging and use of higher field strengths (3 T) improved sensitivity (0.92; 95% CI: 0.86, 0.96) and specificity (0.96; 95% CI: 0.93, 0.98). Conclusion This meta-analysis demonstrated high diagnostic performance of MR imaging for differentiating T1 or lower tumors from T2 or higher tumors in patients with bladder cancer. Higher field strength (3 T) and the use of diffusion-weighted imaging can slightly help improve sensitivity and specificity. © RSNA, 2017.

Advances in Imaging and Management Trends of Traumatic Aortic Injuries.

Acute traumatic aortic injury (ATAI) is a life-threatening injury. CT is the imaging tool of choice, and the knowledge of direct and indirect signs of injury, grading system, and current management protocol helps the emergency radiologist to better identify and classify the injury and provide additional details that can impact management options. Newer dual-source CT technology with ultrafast acquisition speed has also influenced the appropriate protocol for imaging in patients with suspected ATAI. This review highlights the imaging protocol in patients with blunt trauma, CT appearance and grading systems of ATAI, management options, and the role of the multidisciplinary team in the management of these patients. We also briefly review the current literature on the definition, treatment, and follow-up protocol in patients with minimal aortic injury.

Sequential SPECT/CT imaging starting with stress SPECT in patients with left bundle branch block suspected for coronary artery disease.

To investigate the impact of left bundle branch block (LBBB) on sequential single photon emission computed tomography (SPECT)/ CT imaging starting with stress-first SPECT. Consecutive symptomatic low- to intermediate-risk patients without a history of coronary artery disease (CAD) referred for SPECT/CT were included from an observational registry. If stress SPECT was abnormal, additional rest SPECT and, if feasible, coronary CT angiography (CCTA) were acquired. Of the 5,018 patients, 218 (4.3 %) demonstrated LBBB. Patients with LBBB were slightly older than patients without LBBB (65±12 vs. 61±11 years, p<0.001). Stress SPECT was more frequently abnormal in patients with LBBB (82 % vs. 46 %, p<0.001). After reviewing stress and rest images, SPECT was normal in 43 % of the patients with LBBB, compared to 77 % of the patients without LBBB (p<0.001). Sixty-four of the 124 patients with LBBB and abnormal stress-rest SPECT underwent CCTA (52 %), which could exclude obstructive CAD in 46 of the patients (72 %). Sequential SPECT/CT imaging starting with stress SPECT is not the optimal imaging protocol in patients with LBBB, as the majority of these patients have potentially false-positive stress SPECT. First-line testing using CCTA may be more appropriate in low- to intermediate-risk patients with LBBB. • Stress-first SPECT imaging is attractive if many patients demonstrate normal stress perfusion. • The majority of left bundle branch block patients have abnormal stress-first SPECT. • Coronary CT excluded obstructive CAD in many LBBB patients with abnormal SPECT. • Stress-first SPECT imaging is not the optimal imaging protocol in LBBB patients. • In LBBB patients imaging with initial coronary CT may be more appropriate.

Correlative imaging of cystic lymphangiomas: ultrasound, CT and MRI comparison.

BackgroundCystic lymphangioma is a rare benign lesion derived from the detachment of the lymph sacs from venous drainage systems; the treatment of choice is a surgical excision and the final diagnosis is of histological type.PurposeTo compare the results of ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) in patients with cystic lymphangioma to clearly evaluate the anatomic as well as the structural lesion features necessary for differential diagnosis and for the patient treatment planning.Material and MethodsWe analyzed the imaging results of six patients admitted in our department to evaluate cyst-like tumor masses clinically palpable or detected by US. All the patients underwent US, CT, and MRI. The pathology reports demonstrated a mesenterial cystic lymphangioma in five cases underwent surgical resection and in the last case a chest cystic lymphangioma underwent a fine needle aspiration biopsy (FNAB).ResultsIn all the cases, the results of US, CT, and MRI were concordant showing cyst-like tumor masses in the abdomen (n = 5) and chest (n = 1) ranging in size from 3.5 to 15 cm.ConclusionAccording to our experience, we suggest that the appropriate diagnostic imaging protocol in patients with cystic lymphangioma should initially include the US study and followed by a MRI scan with contrast administration. CT should be avoided because of radiation exposure. US and MRI may also be useful in the follow-up of patients who refuse surgical resection or in whom surgery is contraindicated or postponed as well as to early detect a possible disease relapse.

Utility of additional CT examinations driven by completion of a standard trauma imaging protocol in patients transferred for minor trauma

Many clinicians order focused computed tomography (CT) examinations for trauma patients based on history and physical examinations. Trauma patients transferred to our level I trauma center undergo an extensive, nonfocused standard trauma CT protocol. We hypothesize that the use of the standard trauma CT protocol does not contribute significant clinical information for patient care when compared with CT examinations based on history and physical examination. We aim to quantify the utility of the additional CT examinations required by our institution's trauma protocol compared with emergent CT examinations dictated by the patient's history and physical examination findings. In this IRB-approved study, we retrospectively evaluated 132 trauma patients transferred to our center who underwent additional CT examinations as determined by fulfillment of our institution's standard trauma CT protocol. The emergency radiologist evaluated the CT examinations acquired after the patient's transfer to determine if there were any additional acute findings that were identified on these additional examinations compared with the initial assessment undertaken at the outside institution. A total of 101 patients transferred to our trauma center met inclusion criteria. The majority of these patients sustained minor trauma. The standard trauma protocol generated 474 negative CT examinations in 101 patients. In seven patients, there were unexpected acute findings. However, these unexpected acute findings did not change clinical management in any of the patients. After initial evaluation, the acquisition of additional nonfocused CT examinations based on the standard trauma CT protocol provides little useful clinical information in patients who are transferred for minor trauma. Rather, CT utilization should be based on clinical findings. Replacement of standard trauma CT protocol with focused CT examinations in trauma patients is a way to curtail overutilization, thereby decreasing health care cost and the amount of patient radiation exposure.

Regrowth of the Psoas Tendon After Arthroscopic Tenotomy: A Magnetic Resonance Imaging Study

The purpose of this study was to evaluate whether the psoas tendon regenerates after arthroscopic tenotomy through the central compartment of the hip in patients with internal snapping hip. Twenty-seven patients with a snapping hip, aged 18 to 54 years (mean, 37.47 years), underwent arthroscopic tenotomy through the central compartment of the hip; all patients had symptomatic femoroacetabular impingement as well. The degree of regeneration was evaluated by preoperative and postoperative measurements of the tendon perimeter with a magnetic resonance imaging protocol in patients with more than 6 months' follow-up. In addition, function was assessed preoperatively and postoperatively with the Western Ontario and McMaster Universities Osteoarthritis Index score. Postoperative active flexion force was graded clinically between 1 and 5 with the Medical Research Council score. Eight patients had less than 6 months' follow-up, and they were excluded. The remaining 19 patients were evaluated after a mean follow-up period of 23.16 months (SD, 12.95 months). Tendon regeneration occurred in all patients. Compared with preoperative measurement, the psoas tendon circumference had recovered by 84.3% on average (55.44 ± 5.68 mm v 46.71 ± 6.05 mm, P < .001). Pain improved in all patients, and the mean Western Ontario and McMaster Universities Osteoarthritis Index score fell from 49 ± 15.9 points to 10.74 ± 11.35 points (P < .001). Muscle force recovered completely in all cases. There is a process of tissular repair after psoas tenotomy, and the findings on magnetic resonance imaging suggest that tendon tissue regrowth occurs. Level IV, therapeutic case series.

Observer reproducibility of results from a low-dose 123I-metaiodobenzylguanidine cardiac imaging protocol in patients with heart failure

Imaging of the cardiac autonomic system with (123)I-metaiodobenzylguanidine (MIBG) is useful in the evaluation of patients with a variety of cardiac conditions, including heart failure (HF), but few data are available about the reproducibility of this technique. We assessed the observer reproducibility of the results from a low-dose (123)I-MIBG cardiac imaging protocol in patients with HF. A total of 74 patients (62 men, age 67 ± 10 years) with HF and left ventricular systolic dysfunction (ejection fraction 31 ± 7 %) underwent low-dose (111 MBq) planar and single-photon emission computed tomography (SPECT) (123)I-MIBG cardiac sympathetic imaging. The intraclass coefficient of correlation (ICC), Lin's concordance correlation coefficient, and Bland-Altman analysis were used to evaluate the intraobserver and interobserver reproducibility of early and late heart-to-mediastinum (H/M) ratios and of defect scores on SPECT images. The κ statistic was used to evaluate the concordance rates for the identification of patients with a low H/M ratio (<1.60) on late planar imaging. The differences between measurements obtained twice by the same examiner and by two examiners were negligible for both early and late H/M ratios and for SPECT defect scores. These findings were confirmed by the results of Bland-Altman analysis, and ICC and Lin's coefficient values were excellent (>0.90) for all measurements. For the identification of patients with a low H/M ratio, the κ values were 0.90 for intraobserver concordance and 0.83 for interobserver concordance. The present study showed a high observer reproducibility of planar H/M ratios and SPECT defect scores using a low-dose (123)I-MIBG cardiac imaging protocol in patients with HF.

Evaluation of MR diffusion-weighted imaging in differentiating endometriosis infiltrating the bowel from colorectal carcinoma

Endometriosis infiltrating the bowel may be difficult to differentiate from colorectal carcinoma in cases that present with non-specific clinical and imaging features. The aim of this study is to assess the value of MR diffusion-weighted imaging (DWI) in differentiating endometriosis infiltrating the bowel from colorectal carcinoma. In 66 patients, MR DWI was added to the standard imaging protocol in patients visiting our outdoor MR clinic for the analysis of suspected or known deep infiltrating endometriosis (DIE). In patients diagnosed with DIE infiltrating the bowel on MR imaging, high b-value diffusion-weighted images were qualitatively assessed by two readers in consensus and compared to high b-value diffusion weighted images in 15 patients evaluated for colorectal carcinoma. In addition, ADC values of lesions were calculated, using b-values of 50, 400 and 800 s/mm(2). A total of 15 patients were diagnosed with DIE infiltrating the bowel on MR imaging. Endometriosis infiltrating the bowel showed low signal intensity on high b-value diffusion-weighted images in all patients, whereas colorectal carcinoma showed high signal intensity on high b-value diffusion-weighted images in all patients. Mean ADC value in endometriosis infiltrating the bowel (0.80 ± 0.06 × 10(-3)mm(2)/s) was significantly lower compared to mean ADC value in colorectal carcinoma (0.86 ± 0.06 × 10(-3 )mm(2)/s), but with considerable overlap between ADC values. Only qualitative assessment of MR DWI may be valuable to facilitate differentiation between endometriosis infiltrating the bowel and colorectal carcinoma.

Evaluation of megavoltage CT imaging protocols in patients with lung cancer

Currently, megavoltage CT studies in most centres with tomotherapy units are performed prior to every treatment for patient set-up verification and position correction. However, daily imaging adds to the total treatment time, which may cause patient discomfort as well as results in increased imaging dose. In this study, four alternative megavoltage CT imaging protocols (images obtained: during the first five fractions, once per week, alternating fractions and daily on alternative weeks) were evaluated retrospectively using the daily position correction data for 42 patients with lung cancer. The additional uncertainty introduced by using a specific protocol with respect to the daily imaging, or residual uncertainty, was analysed on a patient and population bases. The impact of less frequent imaging schedules on treatment margin calculation was also analysed. Systematic deviations were reduced with increased imaging frequency, while random deviations were largely unaffected. Mean population systematic errors were small for all protocols evaluated. In the protocol showing the greatest error, the treatment margins necessary to accommodate residual errors were 1.2, 1.3 and 1.7 mm larger in the left-right, superior-inferior and anterior-posterior directions, respectively, compared with the margins calculated using the daily imaging data. The increased uncertainty because of the use of less frequent imaging protocols may be acceptable when compared with other sources of uncertainty in lung cancer cases, such as target volume delineation and motion because of respiration. Further work needs to be carried out to establish the impact of increased residual errors on dose distribution.

The Added Benefit of a Dedicated Neck F-18 FDG PET-CT Imaging Protocol in Patients With Suspected Recurrent Differentiated Thyroid Carcinoma

To retrospectively analyze whether adding a delayed high-resolution dedicated neck F-18 FDG positron emission tomography-computerized tomographic (PET-CT) imaging protocol in patients with recurrent differentiated thyroid cancer increases the number of abnormal foci within the neck. Seventeen PET-CT studies from a total of 10 patients with suspected recurrent differentiated thyroid cancer between March 2003 and June 2004 were retrospectively reviewed. Each study included a whole body acquisition (WBA), followed by higher resolution dedicated neck acquisition (DNA). Two board-certified nuclear medicine physicians reviewed either the DNA or WBA for each study and recorded the number of abnormal foci, along with presence or absence of a soft tissue abnormality, and maximum standardized uptake value for each foci. Consensus review was used for all discrepancies. Statistical analysis was performed to determine whether there was a statistically significant increase in the number of studies demonstrating new abnormal foci with the addition of a DNA. Five of 17 studies demonstrated an increase in the number of abnormal foci with the addition of the DNA (P < 0.04). A total of 8 abnormal foci were noted on the WBA, 4 of which were within the neck. Eleven additional abnormal foci were seen on the DNA. All abnormal foci within the neck had corresponding soft tissue abnormalities except for one. Adding a higher resolution delayed DNA to the WBA for patients undergoing PET-CT imaging to detect recurrent thyroid cancer increases the number of abnormal sites of FDG accumulation.

Differenzialdiagnose von Läsionen der weißen Hirnsubstanz in der Magnetresonanztomographie

White matter signal changes in magnetic resonance imaging (MRI) are frequent and the correct clinical assessment is very important for the further clinical management of the patient. The first problem in the sequence of dealing with these patients is to determine, if a signal change is truly abnormal or a sign of normal aging. The abundance of unspecific signal changes in the brains of normal persons has lead to the creation of the term unknown bright objects (UBO) for these findings. If a white matter lesion is deemed truly abnormal, it should be categorised into one of the major categories such as microvascular, demyelinating, inflammatory, neoplastic or metabolic. Thereafter, a further classification can be attempted. The mainstay of the MRI diagnostics of white matter lesions are dark fluid T 2-weighted sequences such as fluid attenuated inversion recovery (FLAIR). In contrast to conventional T2, these images maintain a high sensitivity for white matter damage in the vicinity of the CSF spaces. T 1-weighted images prior to contrast administration have been shown to demonstrate the clinical significant lesion load whereas the contrast enhanced scan may aid in differential diagnosis and in the evaluation of lesion activity. T 2*-weighted imaging is useful to identify previous microbleeds, which usually occur in microvascular conditions and portend the risk of further bleeding. Proton spectroscopy, chemical shift imaging and diffusion weighted imaging have been shown to be very useful in some entities of white matter disease, both for differential diagnosis and the assessment of disease activity. They should hence be part of any advanced imaging protocol in patients with white matter disease. © Georg Thieme Verlag KG Stuttgart.

Diffusion-weighted MRI in 300 patients presenting late with subacute transient ischemic attack or minor stroke.

Many patients with transient ischemic attack (TIA) or minor stroke present to medical attention after a delay of several days or weeks, at which time it may be more difficult to obtain a clear history and clinical signs may have resolved. Because ischemic lesions on diffusion-weighted MRI (DWI) often persist for several weeks, we hypothesized that adding DWI to a standard protocol with T2-weighted imaging might be useful in the management of patients presenting late. We studied consecutive patients with TIA or minor stroke presenting > or =3 days after the event. Two independent observers recorded the presence or absence of recent ischemic lesions on 2 different occasions, first with the T2 scan only, and second with T2 and DWI. Each time, with the aid of a written clinical summary, the observers recorded their diagnosis and proposed management. 300 patients (159 men) were scanned at a median of 17 (interquartile range=10 to 23) days after symptom onset. DWI showed a high signal lesion in 114/164 (70%) minor strokes versus 17/136 (13%) TIAs (P<0.0001). The presence of high-signal lesions on DWI decreased nonlinearly with time since symptom onset (P<0.0001) and increased with National Institutes of Health Stroke Score (P=0.038) and with age (P=0.01). In 90/206 (43.7%) patients with 1 or multiple lesions on T2, DWI helped to clarify whether these were related to a recent ischemic event (79 [48%] strokes; 11 [31%] TIAs). Compared with T2 alone, DWI provided additional information in 108 (36%) patients (91 [56%] strokes and 17 [13%] TIAs), such as clarification of clinical diagnosis (18 patients, 6%) or vascular territory (28 patients, 9.3%), which was considered likely to influence management in 42 (14%) patients (32 [19%] strokes; 10 [7.4%] TIAs). The clinically useful information available from DWI provides a further justification for an MRI-based imaging protocol in patients with subacute TIA or minor stroke.

Secondary deformities of the shoulder in infants with an obstetrical brachial plexus lesions considered for neurosurgical treatment.

The authors performed a prospective study in which magnetic resonance (MR) imaging was conducted in 26 consecutive infants (mean age 5.6 months, range 2.7-14.5 months) in whom recovery from an obstetric lesion of the brachial plexus had been inadequate in the first 3 months of life. The purpose was to identify early secondary deformations of the shoulder in obstetrical brachial plexus lesions (OBPLs). Features of the shoulders were analyzed according to a standardized MR imaging protocol in patients with OBPLs. Measurements were made of the appearance of the glenoid, glenoid version, and the position of the humeral head. The appearance of the glenoid on the affected side was normal in only 11 shoulders. In the remainder it was convex in eight and biconcave in seven cases. The degree of humeral head subluxation was significantly greater (p = 0.001) in affected shoulders than in normal shoulders (152 and 170 degrees, respectively). The presence of abnormal glenoid retroversion and humeral head subluxation increased with age: there was a statistical difference (p = 0.001) between infants younger than 5 months of age and those who were older. Magnetic resonance imaging demonstrates shoulder-related anatomical and nerve root lesion, allowing evaluation of neural, osseous, and cartilaginous structures in younger children.

Critical evaluation of a simultaneous aquisition dual Tl-201/sestamibi imaging protocol in patients with known CAD

Critical evaluation of a simultaneous aquisition dual Tl-201/sestamibi imaging protocol in patients with known CAD