You are a helpful assistant generating synthetic data that captures *System 1* and *System 2* thinking, *creativity*, and *metacognitive reflection*. Follow these steps in sequence, using tags [sys1] and [end sys1] for *System 1* sections and [sys2] and [end sys2] for *System 2* sections.

1. *Identify System 1 and System 2 Thinking Requirements:*
   - Carefully read the text.
   - Identify parts of the text that require quick, straightforward responses (*System 1*). Mark these sections with [sys1] and [end sys1].
   - Identify parts that require in-depth, reflective thinking (*System 2*), marked with [sys2] and [end sys2].

2. *Apply Step-by-Step Problem Solving with Creativity and Metacognitive Reflection for System 2 Sections:*

   *2.1 Understand the Problem:*
   - Objective: Fully comprehend the issue, constraints, and relevant context.
   - Reflection: "What do I understand about this issue? What might I be overlooking?"
   - Creative Perspective: Seek hidden patterns or possibilities that could reveal deeper insights or innovative connections.

   *2.2 Analyze the Information:*
   - Objective: Break down the problem logically.
   - Reflection: "Am I considering all factors? Are there any assumptions that need challenging?"
   - Creative Perspective: Explore unique patterns or overlooked relationships in the data that could add depth to the analysis.

   *2.3 Generate Hypotheses:*
   - Objective: Propose at least 10 hypotheses, each with a Confidence Score (0.0 to 1.0) and Creative Score (0.0 to 1.0), reflecting originality, surprise, and utility.
   - Reflection: "Have I explored all possible explanations or approaches, both conventional and unconventional?"
   - Creative Perspective: Consider novel angles that might provide unexpected insights.

   *2.4 Anticipate Future Steps and Obstacles:*
   - Objective: Make predictions, accounting for potential outcomes and obstacles.
   - Reflection: "What challenges might I face? Is my plan flexible for different scenarios?"
   - Creative Perspective: Visualize unforeseen outcomes and adapt plans to make use of them effectively.

   *2.5 Evaluate Hypotheses:*
   - Objective: Assess hypotheses based on feasibility, risk, and potential impact.
   - Evaluation: Refine Confidence and Creative Scores as needed.
   - Reflection: "Am I unbiased in my assessment? Which options fit best with the overall objectives?"
   - Creative Perspective: Identify hidden opportunities or overlooked details in each hypothesis.

   *2.6 Select the Best Hypothesis:*
   - Objective: Choose the most promising, strategic hypothesis.
   - Reflection: "Why does this hypothesis stand out? How does it uniquely address the issue?"
   - Creative Perspective: Consider any underutilized potential in the selected approach.

   *2.7 Implement the Hypothesis:*
   - Objective: Outline actionable steps for testing the hypothesis.
   - Reflection: "Is this plan practical? What resources or preparation are required?"
   - Creative Perspective: Refine steps to maximize effectiveness and yield unexpected benefits.

   *2.8 Monitor and Review Progress:*
   - Objective: Review progress, noting areas for improvement.
   - Reflection: "What’s working well? What could be improved?"
   - Creative Perspective: Look for emerging patterns that could refine future approaches.

   *2.9 Reflect and Capture Insights:*
   - Objective: Summarize lessons learned and insights gained for future reference.
   - Reflection: "What new understanding has emerged from this process?"
   - Creative Perspective: Identify innovative insights or patterns that could be applied to similar challenges.

3. *Generate Text Output with Interleaved System 1 and System 2 Responses:*
   - Use the tags [sys1] and [sys2] throughout.
   - Aim for a lengthier, detailed response. Combine both direct, straightforward *System 1* insights and reflective, deeply analytical *System 2* segments to capture a blend of quick observations and thoughtful analysis.

---

### *Example Input Text:*

You are tasked with analyzing a sudden shift in customer preferences in a tech market. There has been a noticeable decline in demand for physical devices, with customers increasingly interested in digital-only options. The challenge is to understand this shift, generate hypotheses for why it might be occurring, and explore potential strategies for adapting to this new trend.

---

### *Processed Output with System 1 and System 2 Thinking:*

The tech market is experiencing a shift in customer demand, moving away from physical devices toward digital-only options.

[sys1]
Customer demand has shifted from physical devices to digital-only options.
We need to understand why this change is happening and find strategies to address it.
Key factors may include cost, convenience, and technological trends.
[end sys1]

[sys2]
**2.1 Understand the Problem:**
The goal is to understand the underlying reasons for the shift in demand from physical devices to digital-only options, then develop a strategy to adapt.

*Reflection:* 
"I understand that preferences are changing, but what might be driving this? Is it primarily cost, or are there other factors such as convenience or sustainability?"

*Creative Perspective:* 
"Could there be a larger trend in digital minimalism or a preference for eco-friendly solutions that we’re missing? What unseen motivations might explain this shift?"

**2.2 Analyze the Information:**
There are multiple possible factors driving this shift, from economic influences to cultural shifts. It’s essential to isolate each factor and understand its impact.

*Reflection:* 
"Am I fully considering the various economic and social influences? Could there be a technological factor, like better internet speeds, that makes digital-only products more accessible?"

*Creative Perspective:* 
"Are there patterns or trends in other markets that could shed light on this shift? Could this be part of a larger trend toward virtual experiences?"

**2.3 Generate Hypotheses:**
1. Customers prefer digital options due to lower costs. (Confidence: 0.8, Creative: 0.4)
2. There’s a growing trend toward minimalism and reduced physical clutter. (Confidence: 0.7, Creative: 0.7)
3. Digital products offer greater flexibility and ease of use. (Confidence: 0.6, Creative: 0.6)
4. Environmental concerns are pushing consumers away from physical goods. (Confidence: 0.6, Creative: 0.8)
5. Advances in tech make digital-only options more functional. (Confidence: 0.8, Creative: 0.5)
6. Pandemic-era remote work increased demand for digital solutions. (Confidence: 0.7, Creative: 0.6)
7. Media coverage of the environmental impact of physical devices affects preferences. (Confidence: 0.5, Creative: 0.7)
8. There’s an increase in global digital literacy, expanding market access. (Confidence: 0.6, Creative: 0.6)
9. Customers view digital as more convenient and scalable for future needs. (Confidence: 0.7, Creative: 0.5)
10. Younger consumers prefer the aesthetics and convenience of digital products. (Confidence: 0.6, Creative: 0.6)

*Reflection:* 
"Have I considered all possible influences? Are there any surprising factors that could explain this shift?"

*Creative Perspective:* 
"Could specific social trends, like the rise of influencer culture or digital-first lifestyles, be influencing customer choices?"

**2.4 Anticipate Future Steps and Obstacles:**
*Objective:* Anticipate possible challenges, such as resistance from segments still preferring physical products.

*Reflection:* 
"What market obstacles might we face if we shift our focus to digital-only? Are there sub-segments that still prioritize physical products?"

*Creative Perspective:* 
"Could expanding digital options help us reach a more global audience? Are there emerging trends that we could leverage in our strategy?"

[end sys2]

[sys1]
To address this shift, consider a strategy that incorporates both digital-only offerings and educational campaigns about the benefits of digital solutions.
Use insights from customer feedback and current trends to guide product development.
Focus on flexibility and adaptation to cater to different customer segments.
[end sys1]


Subacute granulomatous thyroiditis is one of the inflammatory thyroid diseases known as de Quervain\'s disease. This is an uncommon disease that most often occurs in middle-aged women. The disease affects women three to five times more often than men, and viral infection is the most common cause of the disease ([@B1], [@B2]). Subacute granulomatous thyroiditis can be diagnosed clinically, and the features of the disease include acute thyroid pain, hypermetabolism, a low grade fever, occasional dysphagia, suppressed levels of thyroid stimulating hormone (TSH), and an elevated erythrocyte sedimentation rate ([@B3]). A painful thyroid following an upper respiratory tract infection is often a sign of subacute granulomatous thyroiditis. This self-limited disease often resolves spontaneously, usually without subsequent thyroid function abnormalities ([@B4]), or it may improve with anti-inflammatory medications and corticosteroids, and often within 24 hours ([@B5]).

Thyroiditis is generally clinically diagnosed after evaluating both the clinical and laboratory data. This is because the characteristic ultrasonographic features that suggest thyroiditis have not been clearly defined ([@B6]). However, several recent reports have shown that ultrasonography (US) is a useful tool for diagnosing and monitoring thyroid pathology, including thyroiditis ([@B7]-[@B9]).

In some cases, the thyroid gland has been reported to be enlarges to approximately twice its normal size ([@B9]). Some of the other ultrasonographic findings are hypoechoic areas and a lack of flow on color Doppler US ([@B1]). In this study, we tried to determine the characteristic ultrasonographic and clinical features of subacute granulomatous thyroiditis.

MATERIALS AND METHODS
=====================

Between January 2000 and May 2003, we reviewed the medical records at our institute and we found 4,672 thyroidal cytological reports that were based on US-guided fine needle aspiration biopsy (FNAB). A total of 31 lesions from 27 patients were found to exhibit subacute granulomatous thyroiditis. Four patients had two lesions that were biopsied at the same time. Most of the aspiration biopsies were recommended by radiologists because of the difficulty in differentiating subacute granulomatous thyroiditis from thyroid malignancy. Some of the biopsies were requested asked by other physicians or by the patients because of concern about the lesions. All the aspiration biopsies were performed with 23 G needles; this was done twice for each lesion at the same session. Twenty-five patients were female and two were male. The patients were between 29 and 70 years of age (mean age: 48.2 years).

Ultrasonography was performed using an HDI 3000/5000 ultrasound scanner (Advanced Technology Laboratories, Bothell, WA) equipped with a 12-MHz linear-array transducer. The US findings were analyzed radiologists working in consensus. The clinical findings such as acute neck pain or fever were reviewed from the medical records. Follow-up evaluations of the ultrasonographic and clinical features were available for 15 patients.

RESULTS
=======

Mild to severe painful neck swelling was present in 18 patients, and an accompanying fever was documented in nine of these 18 patients. Even after reading the medical records, it was not always certain whether or not an upper respiratory tract infection occurred before the onset of the subacute granulomatous thyroiditis. The initial laboratory data at the time of diagnosis showed an elevated ESR (15-55 mm/hr, mean: 37 mm/hr \[normal, 0-20.0\]) in 12 of the 16 examined patients.

On gray-scale US, unilateral thyroid involvement was demonstrated in 23 patients, and bilateral involvement was demonstrated in four patients. The thyroid gland was enlarged more than 1.8 cm at the anterior-posterior diameter in five patients, it was normal sized in 20 patients and it was decreased in size in two patients. Of the five patients with enlarged glands, four had unilateral enlargement and one had bilateral enlargement. Focally ill-defined heterogeneously hypoechoic areas (the largest diameter: 8-26 mm, mean: 17 mm) were found in all lesions ([Figs. 1](#F1){ref-type="fig"}, [2](#F2){ref-type="fig"}). Nine of these patients had an irregular or microlobulated margin, and nodular space-occupying hypoechogenicity that mimicked thyroid carcinoma ([Fig. 3](#F3){ref-type="fig"}). The lesions had a tendency to be long (i.e. not round or ovoid shape) on the longitudinal scan, unlike the transverse scan on which they appeared as focally ill-defined masses. The ratio between the length and the breadth of the lesions was 0.8-2.2 (mean: about 1.4). No hypervascularity was noted in any of the lesions on color Doppler US.

Fourteen patients received steroid therapy. Follow-up US was available after therapy for 10 patients. Two patients had no remaining lesions. The lesions were decreased in six patients, and no change in lesion size was seen in two patients. Four of five patients with enlarged glands had a reduced lesion volume. Among the 13 patients who had not been treated, the follow-up data were available for five patients. Of these patients, the lesion had completely resolved in one patient, and the lesions had decreased in size in three patients.

DISCUSSION
==========

Subacute granulomatous thyroiditis is a self-limited thyroid disorder that presents with localized neck pain and/or low-grade fever. The basic clinical and laboratory data are needed for making the diagnosis, and a biopsy is rarely required ([@B6]). The number of diagnoses made by using biopsies is not high. However, with the broad application of thyroid ultrasonography, the frequency of performing cytopathological diagnosis is increasing. In addition to the clinical feature, the physicians\' knowledge of the US features of this disease will be helpful to confirm the diagnosis of subacute granulomatous thyroiditis.

Although an enlarged thyroid volume was seen in 100% of the patients in a previous report ([@B8]), only six of the 31 lesions (19.4%) in the present study were found to have an enlarged thyroid. The reason for this seems to be that we did not perform aspiration biopsies for the diffuse lesions that were compatible with a general form of thyroiditis.

Several studies have mentioned hypoechogenicity as a finding suggestive of malignancy ([@B10]). However, most nonpalpable thyroid nodules are hypoechoic and benign. In our study, all the patients had ill-defined hypoechoic lesions with a nonhomogeneous pattern. Some of the lesions had marked hypoechogenicity that mimicked that of thyroid carcinoma. In addition to the margin and echogenicity, any of the other features of malignancy such as a taller-than-wide shape or the presence of microcalcification were either equivocal or absent. Despite some malignancy-mimicking features, the lesions could be easily differentiated in most cases because their morphologies were geographically changed on many imaging planes, which is unlike true focal mass lesions.

It has generally been accepted that a hypoechoic, heterogeneous thyroid gland may be related to thyroiditis. Besides being present in subacute thyroiditis, this nonspecific finding may be seen in lymphocytic thyroiditis, a multinodular goiter and Graves\' disease ([@B7]). The radiologist usually considers generalized parenchymal abnormality as underlying diffuse non-neoplastic thyroid disease, but performing follow-up US or even FNAB should be considered due to the risk of an infiltrative malignancy such as lymphoma. A cytopathological examination for subacute granulomatous thyroiditis reveals a severe inflammatory area, with non-caseating granulomas. As mentioned above, it was difficult differentiating subacute granulomatous thyroiditis from thyroid cancer in 11 of the cases. The radiological-cytopathological correlation was an important tool in these cases. Aydin et al. ([@B11]) showed that the true diagnosis rate of thyroiditis was increased up to 81.8% when US-guided FNAB was performed, while it was 4.5% with using only the clinical and laboratory findings.

Color Doppler US has been useful for assessing thyroid nodules in addition to the ultrasonographic features on the gray scale, and this methodology has provided information that is highly predictive of malignancy ([@B12]). Zacharia et al. ([@B1]) reported the utility of color Doppler US in a case of subacute granulomatous thyroiditis mimicking a thyroid carcinoma. They reported that color Doppler US showed no hypervascularity in the acute stage, and slightly increased vascularity was seen in the recovery stage.

This study was limited because there was an undetermined number of patients who had subacute granulomatous thyroiditis, but they did not undergo FNAB because their US exam raised no suspicion of focal lesion or because they did not undergo US. Therefore, our study included a relatively large number of cases of malignant-looking lesions on US. However, we also performed FNAB for some diffuse lesions that were not suspected to be malignant, but either the physicians or patients had requested it. Additional studies that are without a selection bias are needed to assess the representative US features of subacute granulomatous thyroiditis. A second limitation of the study was the small sample size owing to the rarity of subacute granulomatous thyroiditis.

In summary, thyroid US is useful for the initial diagnosis and follow-up of patients with subacute granulomatous thyroiditis. The characteristic US findings for this disease are an ill-defined hypoechoic area, without round or ovoid mass formation on the multiple planes of US, and no vascular flow on color Doppler US. Even in the absence of clinical symptoms, subacute granulomatous thyroiditis should be included in the differential diagnosis for a lesion having these findings. In such circumstances, a follow-up US exam is recommended rather than immediately performing FNAB. However, FNAB is indispensable in cases of lesions that are seen as a focal mass mimicking thyroid malignancy. The follow-up US findings of subacute granulomatous thyroiditis were a reduction of an enlarged thyroid volume and a decreased or absent hypoechoic area.

![A 62-year-old woman with diffuse neck swelling and malaise. The laboratory tests suggested normal thyroid function. The transverse right (**A**) and left (**B**), and longitudinal right (**C**) and left (**D**) thyroid sonograms show ill-defined hypoechoic lesions involving nearly the entire area of both thyroid glands. Both thyroids are diffusely enlarged, but no cervical lymphadenopathy was detected. Subacute granulomatous thyroiditis was confirmed by fine needle aspiration biopsy. The patient\'s condition improved dramatically following steroid treatment.](kjr-7-229-g001){#F1}

![A 45-year-old woman with severe neck pain and low-grade fever. The transverse (**A**) and longitudinal (**B**) sonograms of the right thyroid reveal an ill-defined elongated hypoechoic lesion, which is a typical finding of subacute thyroiditis. Color Doppler ultrasonography (**C**) shows no vascular flow in the hypoechoic lesion. Cytology suggests subacute granulomatous thyroiditis (**D**). On the day after steroid therapy, the patient felt free of neck pain. On sonogram after two months (**E, F**), the size of the hypoechoic area was markedly decreased.](kjr-7-229-g002){#F2}

![A 50-year-old woman with neck swelling. Transverse (**A**) and longitudinal (**B**) sonograms of the left thyroid show an ill-defined, markedly hypoechoic lesion mimicking a malignant nodule. Subacute granulomatous thyroiditis was confirmed by performing fine needle aspiration biopsy. On the follow-up longitudinal sonogram after one month of medication (**C**), the lesion is not clearly visualized.](kjr-7-229-g003){#F3}