Radionuclide Evaluation of the Lower Gastrointestinal Tract

Meckel's diverticulum mimicking acute appendicitis in children: a retrospective cohort study

BACKGROUND

The aims of this study were to summarize the clinical presentation and histological results of 20 cases of complicated Meckel diverticulum (MD) who were presumed to have acute appendicitis before surgery, as well as to improve the diagnosis and treatment of complicated MD in children.

MATERIALS AND METHODS

We retrospectively reviewed the records of 20 complicated MD admitted to our institution who were preoperatively diagnosed with acute appendicitis from January 2012 to January 2019. Patients were divided into the perforated MD group and the Meckel's diverticulitis group. Patient demographics, clinical manifestations, laboratory data, auxiliary examinations, surgical methods, and the result of heterotopic tissue were recorded.

RESULTS

A total of 20 cases of complicated MD (perforated or diverticulitis) were identified. Children were aged from 3 to 13 years, with a mean age of 7.75 years (median 7.75; range, 1-13 years). Perforated Meckel's diverticulum occurred in 5 of 20 (25%) cases. For perforated MD versus diverticulitis, no significant differences were found between age, time to intervention, length of hospital stay, and distance from the ileo-cecal valve. Heterotopic tissue was confirmed on histopathology in 75% of all patients, including 10 cases of gastric mucosa, 3 cases of coexistent gastric mucosa and pancreatic tissue, and 2 cases of pancreatic tissue. All patients underwent diverticulectomy or partial ileal resection under laparoscopy or laparotomy; two cases combined with appendectomy owing to slight inflammation of the appendix.

CONCLUSIONS

The most common presentation of symptomatic MD is painless rectal bleeding; however, it can present symptoms of acute abdomen mimicking acute appendicitis. The key point of diverticulectomy is to remove the ectopic mucosa completely.

Advancing human gut microbiota research by considering gut transit time

Accumulating evidence indicates that gut transit time is a key factor in shaping the gut microbiota composition and activity, which are linked to human health. Both population-wide and small-scale studies have identified transit time as a top covariate contributing to the large interindividual variation in the faecal microbiota composition. Despite this, transit time is still rarely being considered in the field of the human gut microbiome. Here, we review the latest research describing how and why whole gut and segmental transit times vary substantially between and within individuals, and how variations in gut transit time impact the gut microbiota composition, diversity and metabolism. Furthermore, we discuss the mechanisms by which the gut microbiota may causally affect gut motility. We argue that by taking into account the interindividual and intraindividual differences in gut transit time, we can advance our understanding of diet-microbiota interactions and disease-related microbiome signatures, since these may often be confounded by transient or persistent alterations in transit time. Altogether, a better understanding of the complex, bidirectional interactions between the gut microbiota and transit time is required to better understand gut microbiome variations in health and disease.

Torsed gangrenous Meckel's diverticulum causing gangrenous ileal segment: A rare case report of small bowel obstruction in children

INTRODUCTION

Meckel's diverticulum (MD) is the most common congenital anomaly of the gastrointestinal system. It is caused by an incomplete obliteration of the vitelline duct. Rarely, it can present with complications like torsion and gangrene formation.

CASE PRESENTATION

A 13-year previously healthy girl presented with sudden onset periumbilical pain and bilious vomiting who was subsequently diagnosed with Meckel's diverticulum. Intraoperatively, torsed gangrenous diverticulum forming band adhesion was found. Resection of Meckel's diverticulum along with gangrenous ileal segment followed by ileoileal anastomosis was done.

DISCUSSION

Axial torsion of Meckel's diverticulum with gangrene formation is a rare occurrence. Mesodiverticular band adhesion along with herniation of small bowel segments under it endangers viability of herniating segments. Preoperative diagnosis of complicated MD is difficult as it mimics other common acute abdominal conditions. CT scan and enteroclysis are imaging modalities of choice. Surgical resection of MD along with resection and anastomosis of gangrenous bowel segment results in complete cure.

CONCLUSION

Meckel's diverticulum with complications should be kept in the differential of acute abdominal conditions presenting with atypical symptoms. Surgical resection ensures complete cure.

The Predicament of Gastrointestinal Bleeding in Patients With a Continuous-Flow Left Ventricular Assist Device: Pathophysiology, Evaluation, and Management

Heart failure affects over 5 million Americans, with numbers expected to rise. While heart transplantation is the most effective long-term strategy for end-stage heart failure, there is a limited cardiac donor pool, and these organs are often unavailable at the time of need. Left ventricular assist devices, therefore, continue to be used to bridge this gap. Originally implanted as a bridge to transplant, these devices are now additionally utilized as destination therapy for patients ineligible for transplant. With the widespread applicability of these devices for not just temporary measures, but also for prolonged use, the short- and long-term impact on other organ systems has become more evident. For example, gastrointestinal (GI) bleeding, with an incidence approaching 30%, is one such complication post-continuous-flow left ventricular assist device implantation. This high incidence of GI bleeding is thought to stem from a combination of factors, including the need for concomitant anticoagulant and antiplatelet therapy, and intrinsic device-related properties resulting in acquired Von Willebrand disease and arteriovenous malformations. Due to the significant morbidity associated with these GI bleeding events, a standardized protocol optimizing medical and endoscopic management, alongside close coordination between the gastroenterology and cardiology services, should be advocated for and ultimately employed.

[Complications of Meckel's diverticulum in children: about 18 cases]

Meckel's diverticulum (MD) is a remnant of omphalomesenteric channel. It is often asymptomatic but it can be responsible for various clinical complications and variable clinical status especially in children. We conducted a retrospective study on complications of MD among children hospitalized in the division of Paediatric Surgery at the University Hospital Hassan II, Fez, Morocco. The study aimed to describe the clinical, radiological and therapeutic features of MD. The study was conducted over a period of 10 years (January 2009 - December 2018) and involved 18 children (15 boys and 3 girls) aged 1 day - 15 years (with an average age of 5 years) who had undergone surgery for complications of MD. Acute intussusception and intestinal occlusion were the most frequent complications. Other complications included: infection of the MD (1 case) and digestive hemorrhage (2 cases). Two rare types of neonatal Meckel's diverticulum were described (neonatal occlusion and fistula associated with omphalocele). In no case, abdominal X-ray without treatment, ultrasound and CT scan showed MD. Scintigraphy was performed in 2 patients with hematochezia and it helped to make the diagnosis of MD in one case. Three patients underwent laparoscopic surgery with resection of the MD and intestinal anastomosis with laparoscopy. The other patients underwent laparotomy. Ileostomy was performed in one case, followed by secondary recovery. Patient's outcome was good, except for one case of anastomotic leakage. Anatomopathological examination showed two cases of heterotopia.

Multifaceted behavior of Meckel's diverticulum in children

PURPOSE/BACKGROUND

Meckel's diverticulum (MD) is one of the most common congenital malformations of gastrointestinal tract in children. However, the nonspecific clinical manifestations of MD often cause a diagnostic as well as therapeutic challenge to pediatric surgeon. This study aimed to review our experience in managing this disease while evaluating the management strategies.

METHODS

We retrospectively analyzed the clinical data of all patients diagnosed with MD admitted to our center between January 2010 and December 2015. Factors documented including demographic criteria, clinical manifestations, preoperative examinations, surgical methods, histopathological characteristics, postoperative complications, and outcomes.

RESULTS

The patients included 210 males and 76 females, aged from 1day to 15years. In fifty three patients, the MD was an incidental finding at laparotomy or laparoscopy. The remaining 233 patients were symptomatic and presented with various clinical features. Ninety nine patients presented with episodes of bleeding per rectum or melena. Fifty six patients demonstrated symptoms of diverticulitis or perforated MD. Forty patients were diagnosed as intestinal obstruction, and 35 patients with intussusception requiring surgical reduction. Two cases of Littre hernia and one case of foreign body trapped in MD were also observed in this group. Six patients misdiagnosed as appendicitis at another institution were reoperated in our department. Among the 99 patients with bleeding per rectum, 78 underwent a Tc-99m scan that showed a positive tracer in 55 patients and negative in 23. All patients underwent resection of the diverticulum, except for 2 cases of postponed resection. Histology revealed ectopic gastric mucosa or ectopic pancreatic tissue in 154 patients; significant differences were observed between the symptomatic group and the accidentally found group. One patient died of peritonitis and sepsis postoperatively; one case of anastomotic leak and one case of adhesive intestinal obstruction were reoperated.

CONCLUSION

Meckel's diverticulum has various clinical presentations and it is difficult to make a precise diagnosis preoperatively. It is necessary to maintain a high suspicion of MD in the pediatric age group with symptoms of abdominal pain, gastrointestinal hemorrhage or intestinal obstruction. Heterotopic tissue is the main cause of complicated diverticulum, and it is safe and feasible to remove the incidentally found MD. Laparoscopy should become the first choice of methods in diagnosis and treatment of MD.

TYPE OF STUDY

Treatment study.

LEVEL OF EVIDENCE

Level IV.

Hemorrhage and intestinal obstruction secondary to a Meckel's diverticulum: a case report

We present one case of a 17-year-old male with ten-year history of anemia complaining of recurrent bloody stools, abdominal pain and fatigue for 3 months.The gastroscopy, colonoscopy, the-first-time double-balloon enteroscopy (DBE) through the anus and capsule endoscopy were performed with negative results. 99mTc-pertechnetate scan showed a round-like high radioactive concentration at the ileocecum. Double-balloon enteroscopy through the anus was performed again by a more-experienced endoscopic physician, the diverticulum was found at a distance of 50 cm to the ileocecal valve. Then a laparotomy was performed.

Gallbladder Visualization on Tc-99m-labeled Red Cell Scintigraphy: A Rare Finding with an Emphasis on Role of Single-photon Emission Computed Tomography/Computed Tomography

Tc-99m labeled red blood cell (RBC) scintigraphy is one of the most sensitive tests to diagnose occult gastrointestinal (GI) bleed. Visualization of gallbladder is a rare finding in this study. Most of the previously reported cases with similar false-positive finding were associated chronic renal failure, anemia, and received multiple blood transfusions. Thus, while interpreting GI bleed scan, a thorough clinical history is of utmost importance to avoid any false-positive findings. Here, we report a case of gallbladder visualization in ^99mTc-RBC scintigraphy confirmed by single-photon emission computed tomography/computed tomography in a patient with chronic renal failure and anemia with failed renal transplant within 3 months.

Splenic infarction as a pitfall on labeled red blood cell imaging

Patient with a history of overt gastrointestinal bleeding, diabetes mellitus, hypertension, polycythemia vera, and choledocojejunostomy was hospitalized because of hematemesis and melena. An area of Technetium-99m labeled red blood cells accumulation at the splenic flexure similar to an overt bleeding area, was observed on gastrointestinal bleeding scintigraphy (GIBS). In case of underlying malignancy, abdominal computed tomography was performed and demonstrated the infarction area placed laterally in spleen, appearing as a cold region on sctintigraphic image, separating the inferomedial and upper part of splenic uptake. Splenic variants and pathologies can complicate interpretation of GIBS.

Gastrointestinal bleeding after continuous-flow left ventricular device implantation: review of pathophysiology and management

Gastrointestinal bleeding is one of the most common complications in patients with continuous-flow left ventricular assist devices. Though the exact pathophysiology is still unclear, continuous-flow physiology, acquired Von Willebrand disease, and formation of arteriovenous malformations in the gastrointestinal tract are implicated. An individualized plan of endoscopic therapy and anticoagulation management is required when caring for these patients.

Scintigraphic Small Intestinal Transit Time and Defaecography in Patients with J-Pouch

Objective methods for examination of pouch function are warranted for a better understanding of the functional result and treatment of dysfunction. The objective of this study was to evaluate the results of scintigraphic intestinal transit time and defaecography compared to the results of pouch function, mucosal condition and a questionnaire on quality of life (QoL). This cross-sectional study included 21 patients. Scintigraphic transit time and defaecography was determined with the use of Tc-99m. Pouch function was assessed by number of bowel movements, pouch volume, and continence. Pouch mucosal condition was evaluated by endoscopy and histology. Median transit time was 189 min (105-365). Median ejection fraction at defaecography (EF) was 49% (3-77) and 62% (17-98) after first and second defecation. Median pouch volume was 223 mL (100-360). A median daily stool frequency of nine (4-25) was reported and three (14%) patients suffered from daytime incontinence. No patients had symptomatic or endoscopic pouchitis; however, the histology showed unspecific inflammation in 19 (90%) patients. There was no correlation between transit time, evacuation fraction (EF) and pouch function in univariate analysis. However, we found a high body mass index (BMI) and a low bowel movement frequency to be associated with a longer transit time by multivariate analysis. Scintigraphic determination of transit time and defaecography are feasible methods in patients with ileal pouch anal anastomosis, but the clinical relevance is yet doubtful.

Laparoscopic excision of Meckel's diverticulum in children: What is the current evidence?

Complications aroused from Meckel’s diverticulum tend to developed in children. Children presented with abdominal pain, intestinal obstruction, intussusception or gastrointestinal bleeding may actually suffered from complicated Meckel’s diverticulum. With the advancement of minimally invasive surgery (MIS) in children, the use of laparoscopy in the diagnosis and subsequent laparoscopic excision of Meckel’s diverticulum has gained popularity. Recently, single incision laparoscopic surgery (SILS) has emerged as a new technique in minimally invasive surgery. This review offers the overview in the development of MIS in the management of children suffered from Meckel’s diverticulum. The current evidence in different laparoscopic techniques, including conventional laparoscopy, SILS, the use of special laparoscopic instruments, intracorporeal diverticulectomy and extracorporeal diverticulectomy in the management of Meckel’s diverticulum in children were revealed.

Small bowel bleeding: a comprehensive review

The small intestine is an uncommon site of gastro-intestinal (GI) bleeding; however it is the commonest cause of obscure GI bleeding. It may require multiple blood transfusions, diagnostic procedures and repeated hospitalizations. Angiodysplasia is the commonest cause of obscure GI bleeding, particularly in the elderly. Inflammatory lesions and tumours are the usual causes of small intestinal bleeding in younger patients. Capsule endoscopy and deep enteroscopy have improved our ability to investigate small bowel bleeds. Deep enteroscopy has also an added advantage of therapeutic potential. Computed tomography is helpful in identifying extra-intestinal lesions. In cases of difficult diagnosis, surgery and intra-operative enteroscopy can help with diagnosis and management. The treatment is dependent upon the aetiology of the bleed. An overt bleed requires aggressive resuscitation and immediate localisation of the lesion for institution of appropriate therapy. Small bowel bleeding can be managed by conservative, radiological, pharmacological, endoscopic and surgical methods, depending upon indications, expertise and availability. Some patients, especially those with multiple vascular lesions, can re-bleed even after appropriate treatment and pose difficult challenge to the treating physician.

Alterations of global gastrointestinal motility after sleeve gastrectomy: a prospective study

OBJECTIVES

To evaluate the role of sleeve gastrectomy (SG) in gastrointestinal motility.

BACKGROUND

SG is a widely used bariatric operation leading to weight loss and early improvement of patient's metabolic profile. Current data indicate faster postoperative gastric emptying, but detailed studies on alterations in small bowel motility are missing.

DESIGN

We evaluated 21 morbidly obese patients who underwent laparoscopic SG before and 4 months after the procedure. After consumption of a semisolid radiolabeled meal, their gastric and intestinal transit times were studied with a gamma camera. Particularly the times of 10% gastric emptying, 50% gastric emptying, maximal intestinal filling, 10% terminal ileum filling, duodenal to terminal ileum transit, cecal filling initiation, and ileocecal valve transit (T ICVt) were studied pre- and postoperatively.

RESULTS

Ten percent gastric emptying and 50% gastric emptying were decreased postoperatively as well as maximal intestinal filling, indicating faster gastric emptying and intestinal filling. Duodenal to terminal ileum transit and 10% terminal ileum filling also decreased as small bowel transit time accelerated and the meal reached the terminal ileum more rapidly. Contrary opening of the ileocecal valve and food transit through it were delayed, with postoperative increase in cecal filling initiation and T ICVt, respectively.

CONCLUSIONS

SG accelerates gastric emptying and small bowel transit of semisolids. In addition, it delays the initiation of cecal filling and T ICVt. This early and prolonged contact of food with the distal small bowel mucosa may explain the metabolic effects of SG occurring before substantial weight loss.

Colonic manometry and colonic scintigraphy as a diagnostic tool for children with severe constipation

OBJECTIVE

In adults, colonic manometry and colonic scintigraphy are both valuable studies in discriminating normal and abnormal colonic motility. The objective of this study was to compare the diagnostic yield and tolerability of colonic manometry and colonic scintigraphy in children with severe constipation.

METHODS

Twenty-six children (mean age 11.4 years, 77% boys) who had received colonic manometry and colonic scintigraphy as part of a colonic motility evaluation were included. Manometry was performed as per department protocol. After swallowing a methacrylate-coated capsule containing indium-111, images were taken at 4, 24, and 48 hours, and geometric centers were calculated. Results of both tests were categorized in 3 groups: normal, abnormal function in the distal part of the colon, and colonic inertia. Cohen κ was used for the level of agreement. Patients and parents completed a questionnaire regarding their experience.

RESULTS

Colonic scintigraphy showed normal transit time in 20%, delay in the distal colon in 48%, and colonic inertia in 32% of patients. Colonic manometry was normal in 40%, abnormal in the distal colon in 40%, and colonic inertia was diagnosed in 20%. The κ score was 0.34. All 5 patients with colonic inertia during manometry had a similar result by scintigraphy. Eighty-eight percent of patients preferred scintigraphy over manometry and 28% of parents preferred colonic manometry over scintigraphy.

CONCLUSIONS

Colonic manometry and colonic scintigraphy have a fair agreement regarding the categorization of constipation. Scintigraphy is well tolerated in pediatric patients and may be a useful tool in the evaluation of children with severe constipation.

Meckel's scan in children: a review of 183 cases referred to two paediatric surgery specialist centres over 18 years

AIM

To review our practice of Meckel's Tc-99m pertechnetate scans over 18 years with regard to indications for the test, sensitivity and specificity in our particular referral patients' population.

MATERIALS AND METHODS

This is a retrospective review of Meckel's scans performed in two paediatric tertiary care teaching hospitals from April 1993 to March 2011 and followed up till October 2011. The scan was performed according to published international guidelines. 183 patients were included in this study. We classified the patients into two groups: group 1, which included 77 patients (42 %) presenting with painless per rectum bleeding, and group 2, which included 106 patients (58 %) presenting with other non-specific symptoms (e.g. abdominal pain, possibly associated with nausea and/or vomiting, failure to thrive). Data were analysed using Chi square test, considering P value less than 0.05 as significant. The age of the patients ranged from 4 days to 16.5 years (median 3 years).

RESULTS

161 of the total 183 children on the study (88 %) had a negative Meckel's scan, and 22 children (12 %) had a positive scan. In the group with a positive Meckel's scan (22 children), all patients underwent surgical exploration and ectopic gastric mucosa was found in 17 cases (77 %, true positives). In the remaining 5 cases (23 %), there was no evidence of ectopic gastric mucosa (false positives). Within the group with a negative scan, 8 children (5 %) underwent surgery; only 1 child had a ectopic gastric mucosa detected following surgery (false negative). In other 52 children (32 %) of the group with a negative Meckel's scan, an endoscopy was done, which showed a normal result in 21 children and was abnormal in 31 children. Of the remaining 101 (63 %) children with a negative Meckel's scan, 74 children (46 %) improved without any further intervention. In 13 cases (8 %), other pathologies were identified. The sensitivity and specificity of the Meckel's scan for ectopic gastric mucosa were 94 and 97 %, respectively. The Meckel's scan was positive in 26 % of the patients of group 1 and in only 2 % patients of group 2. The difference between the two groups was highly significant [P < 0.0001 (Yates-corrected Chi square); odds ratio 18 (Woolf-logit method 95 % CI)].

CONCLUSION

The Meckel's scan retains a high diagnostic accuracy in children for detecting a Meckel's diverticulum with ectopic gastric mucosa within it, when performed according to the recommended guidelines. The test yields its highest positive result in children presenting with significant per rectum bleeding.

(99m)Tc-pertechnetate scintigraphy and endoscopy in assessment of caustic-induced gastric mucosal injury

Endoscopy is the gold standard for evaluating caustic-induced gastric mucosal injury. Injuries ≥ 2b (confluent ulceration or charring) are associated with perforation and cicatrisation. Grade 1-2a injuries recover without intervention. Grade 2b and 3 injuries require observation and may need intervention. (99m)Tc-pertechnetate imaging can assess gastric viability after caustic injury. We correlated (99m)Tc-pertechnetate SPECT/CT with endoscopic findings in 4 patients with increasing grades of caustic-induced gastric mucosal injury.

Development and evaluation of a novel method for preclinical measurement of tissue vascular volume

Identification of clinically predictive models of disposition kinetics for antibody therapeutics is an ongoing pursuit in drug development. To encourage translation of drug candidates from early research to clinical trials, clinical diagnostic agents may be used to characterize antibody disposition in physiologically relevant preclinical models. TechneScan PYP was employed to measure tissue vascular volumes (V(v)) in healthy mice. Two methods of red blood cell (RBC) labeling were compared: a direct in vivo method that is analogous to a clinical blood pool imaging protocol, and an indirect method in which radiolabeled blood was transfused from donor mice into recipient mice. The indirect method gave higher precision in RBC labeling yields, lower V(v) values in most tissues, and lower (99m)Tc uptake in kidneys and bladder by single photon emission computed tomographic (SPECT) imaging relative to the direct method. Furthermore, the relative influence of each method on the calculated area under the first 7 days of the concentration-time curve (AUC(0-7)) of an IgG in nude mice was assessed using a physiologically based pharmacokinetic model. The model was sensitive to the source of V(v) values, whether obtained from the literature or measured by either method, when used to predict experimental AUC(0-7) values for radiolabeled trastuzumab in healthy murine tissues. In summary, a novel indirect method for preclinical determination of V(v) offered higher precision in RBC labeling efficiency and lower renal uptake of (99m)Tc than the direct method. In addition, these observations emphasize the importance of obtaining accurate physiological parameter values for modeling antibody uptake.

Computed tomography of complicated Meckel's diverticulum in adults: a pictorial review

OBJECTIVE: To show various CT aspects of complicated Meckel's diverticulum in adult patients to facilitate the preoperative diagnosis of this rare pathology in emergency settings. METHODS: A computer search of medical records over a 15 year period identified 23 adult patients who underwent surgery for acute abdomen generated by a complicated Meckel's diverticulum. CT images available for review were analyzed, and some specific patterns leading to the diagnosis of complicated Meckel's diverticulum are presented in this review. RESULTS: Complications were related to inflammation (14 patients), bleeding (5 patients), intestinal obstruction (3 patients), and penetrating foreign body (1 patient). The presence of a Meckel's diverticulum was usually suggested at CT scan by an abnormal outpouching, blind-ending digestive structure connected to the terminal ileum by a neck of variable caliber. Depending on the type of complications, the diverticulum was surrounded by mesenteric inflammatory changes, or presented as a localized fluid or air-fluid collection contiguous with the terminal ileum. The diverticulum was also the source of active bleeding or acted as the lead point to intestinal obstruction or intussusception. CONCLUSION: CT findings of complicated Meckel's diverticulum are polymorphic and should be considered in the evaluation of adult patients with acute abdomen.

Clinical and diagnostic relevance of Meckel's diverticulum in children

Meckel's diverticulum (MD) has varied clinical manifestations and is a diagnostic challenge for pediatricians. This study investigates the clinical and diagnostic characteristics of MD in children with different presentations. We retrospectively reviewed the medical records of pediatric patients diagnosed with MD from 1988 to 2008. The data including the age, sex, clinical features, laboratory data, sensitivity of diagnostic methods, and pathological finding were recorded. These patients were classified into three groups: diverticulitis, intestinal obstruction, and intestinal bleeding. A total of 47 children (35 boys and 12 girls) with a median age of 5.6 years were enrolled and categorized as follows: diverticulitis (n = 12), obstruction (n = 12), bleeding (n = 21), and two diagnosed incidentally. Patients with intestinal obstruction were significantly younger than those with bleeding (3.7, 95% CI, 1.6-5.7 vs. 6.6, 95% CI, 4.5-8.7, P = 0.04). In the obstruction group, intussusception was found in eight of 12 patients, of whom 62.5% were aged older than 3 years. Heterotopic tissues were found in 46.3% of surgical specimens and more frequently existed in patients with bleeding than those with diverticulitis (P = 0.02) and obstruction (P = 0.047). Tc-99m scans yielded a diagnostic sensitivity of about 65% in bleeding patients. Repeated Tc-99m scans and red blood cell (RBC) scans can be good supplementary tools in Tc-99m scan-negative bleeding patients. In conclusion, manifestations of childhood MD are variable and may depend on the presence of heterotopic tissues and the patients' age. Tc-99m scans supplemented with RBC scans are appropriate to diagnose childhood MD with bleeding.