Incidental findings on MRI of the spine

Incidental findings of cervical magnetic resonance imaging: A retrospective reinterpretation of a large adult population

Background

Magnetic resonance imaging (MRI) of the cervical spine is one of the routine MRI scans of the cervical region in investigating spinal disc pathologies, spinal stenosis, and the detection of spinal lesions, which are the major parameters to be evaluated in this examination.

Purpose

The authors of this study are focused on a different aspect of cervical MRI, revealing the incidences and reporting rates of extraspinal incidental findings.

Methods

A total of 1000 patients (324 males, 676 females, mean age 47 ± 14) who had undergone an MRI of the cervical spine were enrolled in this study. The magnetic resonance (MR) images of these patients were re-interpreted with respect to the incidental extraspinal imaging findings. The incidence and reporting rate of each incidental finding encountered during the evaluation were presented in percentages.

Results

726 patients in this study had at least one incidental lesion. The results of this study revealed that the most common incidental lesions encountered during the reinterpretation of cervical MRI were nasopharyngeal mucosal thickening (n = 442) and thyroid hypertrophy (n = 231). The total reporting rate of incidental findings was 5.29%.

Conclusion

There are many data to be reported and evaluated by MR imaging of the cervical spine, not only the main parameters of MRI scanning in the routine daily practice of radiologists. All our colleagues should be aware and careful of these incidental findings, which may be the initial medical data of the patients' diagnoses, or to avoid undesirable medicolegal problems.

Why Should Radiologists Evaluate MR Localizer Sequences?

AIM

This study aimed to assess the diagnostic accuracy of magnetic resonance (MR) localizer sequences in the detection of spinal incidental findings.

MATERIALS AND METHODS

MR localizer sequence findings from 384 patients were reviewed retrospectively. The images were evaluated by an experienced radiologist. T2-weighted diagnostic sagittal and coronal images included in the abdominal images were taken as references.

RESULTS

Of the 384 patients, 170 were female and 214 were male. Pathology was detected in 63 of the patients. The findings were more common in male groups. These pathologies were spinal discopathy, metastases, hemangioma, angulation in the coccyx, and hemivertebra.

CONCLUSIONS

Although often overlooked, MR localizer images enable diagnosing additional pathologies in the spine. These are unsuspected but can be critical for patient management, reducing patient morbidity and mortality.

Preparing for the Unexpected: A Review of Incidental Extraspinal Findings on Computed Tomography/Magnetic Resonance Imaging of the Spine

Potentially clinically important incidental/unexpected extraspinal findings occur with sufficient frequency in cross-sectional imaging of the spine to warrant the radiologist's careful consideration, regardless of whether the interpreter is a neuroradiologist, a musculoskeletal radiologist, an emergency radiologist, or a generalist. Awareness of the commonly encountered incidentalomas and the anatomy contained within the field of view of cervical, thoracic, and lumbar spine cross-sectional imaging examinations, respectively, assists radiologists in their efficient and accurate analysis. This article familiarizes radiologists with some of the potential relevant extraspinal findings that may be encountered, and recommends an extraspinal search pattern for each spinal segment.

Readability of extraspinal organs on scout images of lumbar spine MRI according to different protocols

Background

Scout images of lumbar spine MRI often include the extraspinal organs, which are barely included in routine MRI and can be a potential cause of lumbar pain.

Purpose

To evaluate the readability of scout images for extraspinal organs in lumbar spine MRI according to different protocols.

Materials and methods

A total of 150 patients who underwent 1.5 T or 3 T lumbar spine MRI from March to September 2015 at three hospitals with different scout image protocols, were selected. Two radiologists independently reviewed the scout images to investigate whether exclusive diagnosis of major diseases involving the femoral head, femoral neck, sacroiliac joint, and kidneys was possible. Readability levels were divided into four categories: definitely, possibly, limited, and non-evaluable. The readability of scout images according to the protocols was compared using Chi-square test. Interobserver agreement for the readability level of scout images was assessed using weighted κ statistics.

Results

Of 150 patients, “definitely evaluable” cases classified by two readers were 50–62 (33.3–41.3%) for femoral head (κ = 0.63–0.71), 37–66 (24.7–44.0%) for femoral neck (κ = 0.41–0.48), 72–93 (48.0–62.0%) for sacroiliac joint (κ = 0.35–0.37), and 63–73 (42.0–48.7%) for kidneys (κ = 0.45–0.47). More than 50% of femoral heads were classified as readable (definitely or possible evaluable) cases by two readers with excellent interobserver agreement. The readability level of scout images was significantly different according to image protocols including the MRI sequence, number of coronal plane slices, and intersection gap of coronal plane slices (p≤0.015).

Conclusion

Scout images of lumbar spine MRI may be readable enough to rule out some major diseases of extraspinal organs. Standardization of the protocol will be needed to validate the potential role of scout images for screening extraspinal organs.

Extraspinal findings prevalence and clinical significance in 4250 lumbar spine MRI exams

To assess extraspinal findings (ESFs) prevalence in lumbar spine MRI, including clinically significant findings using a systematic approach, and to determine their reporting rate. Lumbar spine MRI scans were retrospectively reviewed over 18 months by two radiologists. Reading discrepancies were resolved by consensus. ESFs were classified according to the involved system, clinical diagnosis, and clinical significance. The reporting rate was estimated by referring to the original report. There were 1509 ESFs in 1322/4250 patients with a substantial agreement between the two radiologists (kappa = 0.8). Almost half (621/1322) were in the 45–60 age group. Females represented 56.6% (748/1322). 74.2% (1120/1509) of the ESFs involved the urinary system among which 79.6% (892/1120) were renal cysts. Clinically significant findings represented 8.7% (131/1509) among which hydronephrosis represented 23% (30/131). First time detected malignant lesions represented 4.6% (6/131). ESFs reporting rate was 47.3%. 58.8% of the clinically significant ESFs were not reported. ESFs prevalence was 31.1%. The Urinary system was the most commonly involved. Most ESFs were benign warranting no further workup. However, clinically significant ESF were not infrequently detected. More than half of the clinically significant findings were not reported. A systematic review of MRI images is highly recommended to improve patient’s outcome.

Incidentally Discovered Thyroid Nodules by Routine Magnetic Resonance Imaging of the Cervical Spine: Incidence and Clinical Significance

OBJECTIVE

The aim of our study was to present the prevalence of thyroid nodules we incidentally discovered by routine Magnetic Resonance Imaging (MRI) of the cervical spine, to evaluate their clinical significance, and to discuss the current clinical approach to incidental thyroid nodules.

METHODS

We retrospectively evaluated the cervical spinal MRI studies of 512 patients. Thyroid glands were evaluated for morphologic and signal characteristics and examined for the presence of nodule(s). The nodules with a maximum diameter of 5 mm or more were taken into analysis.

RESULTS

Of 512 MRI studies, 254 revealed incidental thyroid nodule(s) (49.6%). The mean maximum nodule diameter was 7.48±2.92 mm. Thirty-eight of 254 incidental thyroid nodules were radiologically reported, 35 reported nodules were evaluated by US, and 22 were further analyzed by fine needle aspiration cytology. The final diagnosis of 11 aspirated nodules was an adenomatous nodule, whereas 3 were papillary thyroid carcinoma. One of the patients with papillary thyroid carcinoma was a 32-year-old man with a nodule with a maximum diameter of 7 mm.

CONCLUSION

Incidental thyroid nodule is a frequent non-spinal lesion detected by routine cervical spinal MRI. The 3-tiered system which is recommended in the clinical approach to incidental thyroid nodules may miss some clinically significant thyroid nodules. We suggest the criteria of this system to be re-evaluated and modified if necessary. In addition, we would like to emphasize the need for a guideline for radiologists for reporting incidental thyroid nodules on MRI on the basis of a standard clinical approach.

Beyond the Spinal Canal

Cross-sectional spinal imaging is common, and extraspinal findings are often incidentally identified during interpretation. Although some of these findings may cause symptoms that mimic a spinal disorder, the majority are entirely asymptomatic and incidental. It is essential that the radiologist not only identify those abnormalities that may have clinical significance but also recognize those that are clinically irrelevant and thereby prevent patients from being subjected to further unnecessary, expensive and potentially harmful interventions. This article focuses on those abnormalities that are commonly encountered and provides practical guidance for follow-up and management based on current recommendations.

Two Cases with Incidental Finding of Large Asymptomatic Intradural Lumbar Tumors

Benign lumbar intradural tumors are statistically uncommon and usually present with complaints of back pain with or without radicular neurological complaints. This report involves two separate patients that were found incidentally to have large intradural tumors without any neurologic complaints. In both cases the tumors were discovered when having magnetic resonance imaging (MRI) after minor auto accidents. Neither patient had any pre-existing lumbar or neurologic complaints. The report will review the different regions and types of incidental findings commonly seen on lumbar MRI scans and the need for close follow-up in patients with incidental lesions such as tumors.

Incidental extraspinal findings in the lumbar spine during magnetic resonance imaging of intervertebral discs

Purpose

To calculate the frequencies of incidental extraspinal findings and incidentally detected congenital anomalies or anatomical differences in the lumbar spine on magnetic resonance imaging (MRI) scans of intervertebral discs.

Materials and methods

A total of 379 lumbar spine MRI cases were prospectively investigated in the period spanning from August 2016 to January 2018. Both 1.5 and 0.35 Tesla MRI units (Toshiba and Siemens Medical Systems) were used to examine patients with clinically suspected intervertebral disc abnormalities at three MRI diagnostic centers in Khartoum State, Sudan.

Results

Of the 379(100%) patients, 90(23.7%) patients were presented with incidental findings. Among the incidental findings, 39(10.3%) were renal cysts, 10(2.6%) were retroverted uteri, 5(1.3%) were Nabothian cysts, 4(1.1%) were ovarian cysts, 10(2.6%) were uterine fibroids, 3(0.8%) were endometrial thickening, 11(2.9%) were indicative of hydronephrosis, 4(1.1%) were uncovered prostatic enlargement, 2(0.5%) were atrophic kidney, and 1(0.3%) each was of an ectopic kidney and bladder wall thickening, respectively.

Conclusions

A high percentage of extraspinal pathological findings were detected during MRI lumbar spine scans of intervertebral discs. Thus, it is important to be aware of the high percentage of patients who undergo further evaluation given the presence of unexpected findings, but for whom clinical confirmation of these abnormalities is not obtained.

Clinical impact of coronal-STIR sequence in a routine lumbar spine MR imaging protocol to investigate low back pain

Aim of this study is to assess the clinical impact of coronal short tau inversion recovery (STIR)-weighted magnetic resonance (MR) sequence, when acquired in a lumbar spine MR imaging protocol, in detecting significant extraspinal imaging findings in patients with low back pain (LBP).We retrospectively evaluated 931 lumbar spine MR examinations of patients with LBP. Extraspinal MR imaging findings were categorized as: probably related to LBP (Category 1), not related to LBP but with relevant implications on patient's care (Category 2), and not related to LBP without significant implications on patient's care (Category 3). For each MR imaging finding was also assessed if it was detectable or not on the conventional sagittal and axial acquisition planes.Of the 931 evaluated MR examinations, 60 (6.4%) showed additional extraspinal MR imaging findings, categorized as follows: 55% (33/60) probably related to LBP (Category 1), 22% (13/60) not related to LBP but with relevant implications on patient's care (Category 2), and 23% (14/60) not related to LBP and without significant implications on patient's care (Category 3). Among categories 1 and 2 (n = 46), the 72% (33/46) of imaging findings were detected only on coronal plane. Coronal-STIR sequence significantly changed patients' diagnostic work-flow in 3.5% (33/931) of cases.Coronal STIR sequence, acquired in a lumbar spine MR imaging protocol to investigate LBP, may aid radiologists in detecting additional extraspinal MR imaging findings that could be related to LBP, addressing to the most appropriate clinical management.

Abdominal aortic aneurysm screening: concepts and controversies

Abdominal aortic aneurysms (AAAs) are a leading cause mortality and morbidity but often go undiagnosed until late stages unless imaging is performed. In 2005, the United States Preventive Services Task Force (USPSTF) for the first time recommended one-time ultrasound screening for elderly male smokers and selective screening in other populations. These guidelines were reaffirmed and updated in 2014; a proposal for potential further revisions is now in early planning stages. In this article, we review the past and current USPSTF AAA screening recommendations and techniques for performing optimal screening. Evidence supporting screening and alternative guidelines are also discussed. In addition, emerging concepts and controversies in AAA screening are highlighted, including conflicting data on screening benefits, screening underutilization, inconsistent follow-up recommendations, and the potential for duplicative testing, alternative screening modalities, and clinically significant incidental findings.

How reliable is routine lumbar spine MRI for detection of renal cysts? Correlation with abdominal CT

BACKGROUND

Incidental renal cysts are a very common finding in routine lumbar spine magnetic resonance imaging (MRI). However, there is no report of the renal cyst detection rate on routine lumbar spine MRI.

PURPOSE

To determine the renal cyst detection rate in routine lumbar spine MRI based on findings of abdominal computed tomography (CT), and to investigate if the largest renal cyst seen by abdominal CT could be also detected by routine lumbar spine MRI.

MATERIAL AND METHODS

A retrospective study was conducted of 70 patients who underwent both routine lumbar spine MRI and abdominal CT between December 2011 and January 2014. The detection rate of all renal cysts>5 mm as well as the largest renal cyst seen by abdominal CT were assessed in routine lumbar spine MRI.

RESULTS

On routine lumbar spine MRI, the detection rate of renal cysts was 46.5% (73/157) for>5-mm renal cysts and 68.0% (34/50) for>10-mm renal cysts, correlating with abdominal CT. The detection rate of the largest renal cyst seen by abdominal CT was 60.0% (27/45). Non-detection of the largest renal cyst could be caused by upper positioning (n = 7), lateral positioning (n = 6), or relatively small cyst size (n = 5).

CONCLUSION

Approximately half of renal cysts>5 mm and two-thirds of renal cysts>10 mm were detected on routine lumbar spine MRI. However, radiologists should be aware that kidney lesions may not be included in the scan coverage of routine lumbar spine MRI.

Extraspinal Incidental Findings on Routine MRI of Lumbar Spine: Prevalence and Reporting Rates in 1278 Patients

Objective

The aim of the present study was to determine the prevalence and reporting rate of incidental findings (IF) in adult outpatients undergoing lumbar magnetic resonance imaging (MRI).

Materials and Methods

Re-evaluation of a total of 1278 lumbar MRI images (collected from patients with a mean age of 50.5 years, range 16-91 years) captured between August 2010-August 2011 was done by a neuroradiologist and a musculoskeletal radiologist. IFs were classified according to organ or system (liver, gallbladder, kidney, bladder, uterus, ovary, lymph node, intestine and aorta). The rate of reporting of a range of IF was examined. The outcome of each patient's treatment was evaluated based on review of hospital records and by telephone interviews.

Results

A total of 253 IFs were found in 241 patients (18.8% of 1278). Among these, clinically significant IFs (n = 34) included: 2 renal masses (0.15%), 2 aortic aneurysms (0.15%), 2 cases of hydronephrosis (0.15%), 11 adrenal masses (0.86%), 7 lymphadenopathies (0.55%), 6 cases of endometrial or cervical thickening (0.47%), 1 liver hemangioma (0.08%), 1 pelvic fluid (0.08%) and 2 ovarian dermoid cysts (0.15%). Overall, 28% (71/253) of IFs were included in the clinical reports, while clinically significant findings were reported in 41% (14/34) of cases.

Conclusion

Extraspinal IFs are commonly detected during a routine lumbar MRI, and many of these findings are not clinically significant. However, IFs including clinically important findings are occasionally omitted from formal radiological reports.

Magnetic resonance imaging of the cervical, thoracic, and lumbar spine in children: spinal incidental findings in pediatric patients

Study Design Retrospective case series. Objective To determine the rate of spinal incidental findings on magnetic resonance imaging (MRI) of the cervical, thoracic, and lumbar spine in the pediatric population. Methods We reviewed MRI imaging of the neuraxial spine in patients less than 18 years of age and documented abnormal spinal findings. We then reviewed the charts of these patients to determine the reason for ordering the study. Those who presented with pain were considered symptomatic. Those who had no presenting complaint were considered asymptomatic. The data were analyzed to break down the rate of spinal incidental findings in the cervical, thoracic, and lumbar spine, respectively. Results Thirty-one of the 99 MRIs had positive findings, with the most common being disk protrusion (51.6%). Spinal incidental findings were most common in the lumbar spine (9.4%) versus the cervical spine (8%) or thoracic spine (4.7%). In this group, Schmorl nodes and disk protrusion were the two most common findings (37.5% each). Other spinal incidental findings included a vertebral hemangioma and a Tarlov cyst. In the thoracic spine, the only spinal incidental finding was a central disk protrusion without spinal cord or nerve root compression. Conclusion MRI is a useful modality in the pediatric patient with scoliosis or complaints of pain, but the provider should remain cognizant of the potential for spinal incidental findings.

Incidental extraspinal findings on magnetic resonance imaging of intervertebral discs

INTRODUCTION

We aimed to evaluate pathological extraspinal findings and congenital anomalies/anatomical variations that were incidentally detected on the magnetic resonance imaging (MRI) scans of intervertebral discs, to find the frequencies of these incidental findings, and to emphasise the clinical importance of them.

MATERIAL AND METHODS

A retrospective study including 1031 consecutive patients (730 females and 301 males, with a median age of 46 years) was conducted by evaluating a total of 1106 MRI examinations of intervertebral discs. Examinations were performed with a 1.5 T MRI unit. Incidental findings were classified as pathological findings and congenital anomalies/anatomical variations.

RESULTS

The percentages of incidental extraspinal pathological findings and congenital anomalies/anatomical variations were 16.6% (95% confidence interval (CI): 14.4-18.8) and 3.7% (95% CI: 2.6-4.3), respectively. The percentage of incidental extraspinal pathological findings on cervical spinal MRI was 25.7% (95% CI: 20.1-31.7), thyroid nodules being the most common incidental findings. On thoracic spinal MRI (n = 19), inferior pole thyroid nodules were demonstrated as incidental extraspinal pathological findings, with a percentage of 10.5% (95% CI: 9.6-11.5). On lumbar spinal MRI, incidental pathological findings were detected with a percentage of 14.2% (95% CI: 11.9-16.6), while the percentage of congenital anomalies/anatomical variations was 4.8% (95% CI: 3.4-6.3). Eventually, 6.5% (95% CI: 2.6-9.4) of all cases with incidental extraspinal pathological findings underwent surgery.

CONCLUSIONS

On MRI examination of intervertebral discs, paying attention to incidentally detected pathological extraspinal findings and congenital anomalies/anatomical variations is very important due to the fact that they can alter the treatment of the patient or affect the patient's life.

Characteristics and management strategies for the incidental pulmonary nodule

SUMMARY: 

Pulmonary nodules are frequent, unanticipated findings on imaging studies obtained for other purposes across all areas of medical practice. As nodule detection raises concern for malignancy, evaluation and follow-up of an incidental nodule is imperative. Clinicians are charged with counseling patients and directing further evaluation amid uncertainty and anxiety. The goals of follow-up and management are to identify malignant lesions at an early stage, while avoiding unnecessary procedures and potential harm to patients with benign nodules. In this review, we aim to outline the clinical and radiographic characteristics that can aid in likelihood stratification, to identify gaps in our current knowledge, and to present a logical approach to nodule management, based on the available evidence.

Extra-spinal incidental findings at lumbar spine MRI in the general population: a large cohort study

OBJECTIVE

To determine the prevalence of clinically and non-clinically relevant extra-spinal incidental findings (IF) in patients undergoing magnetic resonance imaging (MRI) of the lumbar spine and to evaluate the rate of undetected findings in archived radiological reports.

METHODS

A retrospective search of patients undergoing lumbar spine MRI from January 2006 to December 2010 was conducted. By means of randomisation, we retrospectively reviewed 3,000 lumbar spine MRI examinations. Extra-spinal abnormalities were classified according to a modified CT Colonography Reporting and Data System (C-RADS). We retrospectively compared our structured approach with the archived MRI reports as it regarded the detection of extra-spinal IF to estimate non-detection rates.

RESULTS

By means of the structured approach used, extra-spinal findings were detected in 2,060 (68.6 %) of the 3,000 lumbar spine MRI examinations; 362 (17.6 %) patients had indeterminate or clinically important findings (E3 and E4) requiring clinical correlation or further evaluation. After review of the original archived radiological reports, potentially important C-RADS E3 and E4 extra-spinal IF were respectively reported in 47 of the 265 (17.7 %) and in 8 of 74 (10.8 %) patients.

CONCLUSIONS

Our study shows that incidental extra-spinal findings at conventional lumbar spine MRI are common but underestimated in radiological reports.